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How to understand Floating Ball Valves and Trunnion Ball Valves

A ball valve features a spherical disc to open and close the flow of the fluid. Ball valves represent the industry standard for pipeline shut-off applications, as their design guarantees very tight and leak-free sealing even after years of operation. The two key types of ball valves are the floating and the trunnion designs (side or top entry). The body can be cast or forged and monolithic or split (in 2 or 3 pieces). The API 6D and ASME B16.34 are key specifications.

BALL VALVES

WHAT IS A BALL VALVE

A ball valve is a type of quarter-turn valve that controls the flow of a fluid through it with a spherical disc known as a ball. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed by turning the handle 90 degrees, the ball is rotated so that the hole is perpendicular to the flow paths of the valve body, effectively blocking the flow.

Ball valve floating and trunnion

Key Features

  • Quarter-Turn: The valve operates with a simple 90-degree turn of a handle or lever, making it quick and easy to open or close.
  • Full Port Design: Many ball valves are full port, meaning the hole in the ball is the same size as the pipeline, resulting in minimal friction loss.
  • Durability: Ball valves are known for their durability and long service life, even in high-pressure applications.
  • Versatility: Suitable for a wide range of applications, from water and gas to chemicals and corrosives, depending on the materials used in construction.
  • Sealing Mechanism: Provides excellent sealing capabilities, with many ball valves designed to be leak-proof.

Types

  • Floating Ball Valve: The ball is held in place by the compression of two elastomeric seats against it. The ball moves slightly within the valve body to maintain contact with the downstream seat, ensuring a tight seal.
  • Trunnion Mounted Ball Valve: The ball is anchored at the top and bottom, reducing the operating torque and allowing for the control of larger sizes and higher pressure services.
  • Top Entry & Side Entry: Refers to how the ball valve is assembled, which impacts maintenance and repair ease.

Each type of ball valve is explained in greater detail below.

Applications

Ball valves are used in a variety of applications across many industries, including water supply, gas supply, oil and petrochemical processes, manufacturing, and more. Their ability to quickly shut off flow makes them particularly useful for emergency and shut-off applications. Material selection for the valve body, ball, and seals (often made from metal, plastic, or ceramic) can vary based on the fluid’s nature, ensuring compatibility and performance across a wide range of temperatures and pressures.

BALL VALVE PARTS

A ball valve consists of several key components, each playing a crucial role in its functionality. Understanding these parts can help in selecting the right valve for a specific application, as well as in maintenance and troubleshooting. Here’s an overview of the main parts of a ball valve:

1. Body

The outer casing of the valve that holds all other components together. It can be made from a variety of materials, including stainless steel, brass, plastic, and others, depending on the application requirements.

2. Ball

The core component that controls flow through the valve. It is a spherical disc with a hole (or bore) through its center. The material of the ball usually matches or complements the body material for compatibility with the fluid being handled.

Special Treatments For The Ball Of A Ball Valve

The ball of a ball valve can undergo various special treatments to enhance its performance, durability, and suitability for specific applications. These treatments can improve the ball’s resistance to wear, corrosion, and galling, as well as its sealing capabilities. Here are some commonly applied special treatments for the ball of a ball valve:

1. Hard Coatings
  • Chrome Plating: A thin layer of chromium is electroplated onto the ball surface, enhancing its wear and corrosion resistance. This treatment is suitable for applications involving abrasive materials or corrosive fluids.
  • Nickel Plating: Similar to chrome plating, nickel plating provides corrosion resistance and increased durability, especially in environments where the valve is exposed to harsh chemicals.
  • Tungsten Carbide Coating: Applied using High-Velocity Oxygen Fuel (HVOF) spraying, this coating offers exceptional hardness and resistance to extreme wear and erosion.
2. Soft Coatings
  • PTFE (Polytetrafluoroethylene): A soft coating that provides excellent chemical resistance and reduces friction between the ball and seats. This is particularly beneficial in applications requiring tight sealing and low operating torque.
  • Enamel Coating: Offers good corrosion resistance and is used in applications where chemical compatibility is a concern.
3. Electroless Nickel Coating

This process deposits a uniform nickel-phosphorus or nickel-boron alloy coating on the ball, offering excellent corrosion and wear resistance. It’s particularly useful in offshore and marine applications, as well as in the processing of corrosive fluids.

4. Nitriding

Nitriding enhances the surface hardness of the ball through a heat-treating process that diffuses nitrogen into the surface. This treatment improves wear resistance and fatigue strength, making it suitable for high-pressure and high-velocity applications.

5. Cryogenic Treatment

This treatment involves cooling the ball to cryogenic temperatures and then gradually warming it up. The process stabilizes the structure of the material, improving its toughness and wear resistance. It’s especially beneficial for valves used in cryogenic services.

6. Molybdenum Disulfide Coating

A dry lubricant coating that reduces friction and improves wear resistance. It’s useful in applications where lubrication is difficult or where the valve must operate under high loads or extreme temperatures.

7. Fusion Bonded Epoxy Coating

A thick, protective coating that offers excellent corrosion protection. It’s widely used in water and wastewater applications, as well as in pipelines transporting corrosive gases and liquids.

The choice of treatment depends on the specific operational conditions, including the type of fluid handled, pressure, temperature, and the presence of abrasive or corrosive elements. These specialized treatments can significantly extend the life of a ball valve and enhance its performance in demanding industrial applications.

3. Seats

Rings that provide a seal between the ball and the valve body. When the valve is closed, the ball presses against these seats to create a tight seal, preventing fluid from leaking past. Seats can be made from soft materials (like PTFE) for better sealing or hard materials for high-temperature applications.

Special Treatments For The Seats Of A Ball Valve

The seats of ball valves play a crucial role in ensuring tight sealing and smooth operation across a wide range of applications, from low-pressure residential systems to high-pressure industrial processes. To enhance their performance, durability, and resistance to harsh conditions, several special treatments and material enhancements can be applied to ball valve seats. Here are some of the notable treatments and materials used:

1. Soft Seating Materials
  • PTFE (Polytetrafluoroethylene): Offers excellent chemical resistance and a low friction coefficient, suitable for a broad temperature range. Variants like reinforced PTFE (RPTFE) have added fillers to improve strength and wear resistance.
  • PEEK (Polyether Ether Ketone): A high-performance thermoplastic with excellent mechanical and chemical resistance properties, suitable for high-pressure and high-temperature applications.
  • Nylon: Provides good wear resistance and strength, suitable for certain types of oils and hydrocarbons.
2. Metal Seating

Hard Facing: Metal seats can be coated or overlaid with harder materials such as Stellite, tungsten carbide, or chromium carbide through processes like welding or thermal spraying. These treatments improve wear resistance, thermal stability, and longevity in severe service conditions, including abrasive and corrosive environments.

3. Elastomeric And Composite Materials
  • Viton, Buna-N (Nitrile): Elastomers offer good sealing capabilities and resistance to a variety of chemicals and temperatures. They are used in applications where softer sealing materials are needed for improved sealing at lower pressures.
  • Composite Materials: Seats made from a combination of materials, such as fibrous reinforcements in a resin matrix, offer enhanced performance characteristics, including resistance to wear and chemical attack.
4. Surface Treatments
  • Electroless Nickel Plating (ENP): A chemical process that deposits a nickel-phosphorus coating on the surface of the seat. ENP improves corrosion resistance and hardness, enhancing the seat’s durability in corrosive environments.
  • Surface Coatings: Various coatings can be applied to improve resistance to chemicals, temperature, and wear. Examples include PFA (Perfluoroalkoxy) and FEP (Fluorinated Ethylene Propylene) coatings, which are types of fluoropolymers with excellent chemical resistance.
5. Seat Design Enhancements
  • Live-Loaded Seats: Some ball valve seats are designed with live-loading mechanisms, such as spring energizers, to maintain consistent sealing force against the ball. This compensates for wear and thermal expansion, ensuring a reliable seal over the valve’s lifespan.

Selecting the appropriate seat material and treatment depends on several factors, including the type of fluid being handled, operating pressures and temperatures, and specific application requirements. By choosing the right seat treatment, users can significantly enhance the performance, reliability, and service life of ball valves in their systems.

4. Stem

Connects the ball to the control mechanism (like a handle or actuator) outside the valve. The stem allows for the rotation of the ball, typically a quarter turn (90 degrees) from the open to the closed position. It’s designed to prevent leakage from the valve body to the atmosphere.

5. Handle Or Actuator

Used to manually or automatically control the valve’s position. A manual handle is turned to rotate the stem and the attached ball. Actuators, which can be pneumatic, electric, or hydraulic, allow for remote operation and can be used for more precise control in automated processes.

6. Packing

A sealant material around the stem to prevent leaks. Packing is often made from PTFE or graphite and is compressed by a packing nut or gland follower to ensure a tight seal.

7. O-Rings/Gaskets

Provide additional sealing at various points, such as between the valve body and the bonnet (if the valve design includes a bonnet) and around the stem. The material depends on the application’s temperature and pressure conditions.

8. Bonnet

Some ball valve designs include a bonnet, which is a section of the valve body covering the opening where the internal parts are inserted. It can be bolted, screwed, or welded to the valve body.

9. End Connections

The interface points where the valve connects to the piping system. Common types include threaded, flanged, and socket weld connections, chosen based on the piping system’s design and requirements.

Understanding these components and their materials is essential for selecting a ball valve that meets the operational requirements of temperature, pressure, flow control, and compatibility with the processed fluids. Proper selection ensures reliable performance and longevity of the valve in the system.

BALL VALVE ADVANTAGES AND DISADVANTAGES

Ball valves have the following advantages advantages:

  • can be quickly opened and closed with a quarter-turn movement
  • ensure a very tight seal without the need for high torque forces
  • have a compact design (this is the main difference between a ball valve and a gate valve – which are both on/off devices)

The disadvantages of ball valves are:

  • valve has poor regulating and throttling capabilities, as it is designed for pipeline shut-off instead of flow modulation (this is an ideal function for globe valves): throttling causes the partially exposed seat to erode because of the high-velocity flow and pressure experienced by the valve. The wear may lead to a leakage of the valve progressively.
  • valve can’t be used for slurries, as the accumulation of suspended particles and debris would make the valve leak. These particles may solidify in the cavities in the proximity of the ball and seats.  Ball valves are way more very efficient with gases and other liquid fluids (even challenging chemicals such as dry chlorine, hydrofluoric acid or hydrochloric acid, and oxygen).
  • may be difficult to clean (except for top entry design)

The open, close,d or partially open position of the valve can be detected by looking at the position of the lever:

  • when the lever is aligned to the pipe, the valve is open; when it is perpendicular to the pipe, the valve is closed;
  • when it is in any other position, the valve is partly open (or partly closed) and is modulating the flow.

These valves belong to the family of “quarter turn” valves or “1/4 turn valves” (together with butterfly and plug valves), as the opening and closing operations are executed by turning a lever connected to the disc by 90 degrees.

The key ball valve specifications are the API 6D, BS 5351 (forged) and ASME B16.34 (pressure and temperature ratings), ASME B16.5/B16.47 (flanged ends) and ASME B16.25 (butt welding ends).

HOW DOES A BALL VALVE WORK?

A ball valve operates using a simple but effective mechanism that involves a quarter-turn rotational motion to open or close the flow of fluid. The core component of a ball valve is a spherical disc, known as the ball, which has a hole or port through its center. Here’s a breakdown of how a ball valve works:

In The Open Position

  • The handle or lever of the ball valve is aligned with the pipe, indicating that the valve is open.
  • The hole in the ball is positioned in line with the flow direction of the pipe, allowing fluid to pass through the valve with minimal resistance.
  • As the ball rotates to this position, the fluid can flow freely through the hole, enabling full flow through the valve.

In The Closed Position

  • To close the valve, the handle or lever is turned 90 degrees from the open position. This quarter-turn movement rotates the ball so that the hole is perpendicular to the flow direction of the pipe.
  • When the hole or port in the ball is perpendicular to the flow path, it blocks the flow of fluid, effectively stopping the flow through the valve.
  • The sealing mechanism around the ball (typically elastomeric seats) ensures a tight seal when the valve is closed, preventing leaks.

Key Functional Aspects

  • Quarter-Turn Operation: The ball valve’s design allows for quick and easy operation, making it an efficient choice for controlling fluid flow. The 90-degree turn offers a clear visual indication of the valve’s position.
  • Sealing: The effectiveness of a ball valve’s seal, when in the closed position, is aided by the pressure of the fluid which pushes the ball against the downstream seat. This pressure enhances the sealing effectiveness, making ball valves suitable for high-pressure applications.
  • Versatility: Ball valves can handle various fluids, including gases, liquids, and slurries. Their design minimizes pressure drop and allows for bidirectional flow control in the fully open position.
  • Durability: The simplicity of the ball valve’s design contributes to its durability and reliability, with many ball valves capable of maintaining their sealing ability over thousands of cycles.

Ball valves are favored for applications requiring reliable and rapid shut-off, offering a practical solution for flow control across a broad range of industrial and residential settings.

BALL VALVE TYPES

Ball valves can be classified according to multiple criteria:

  • Ball valve design: floating, trunnion mounted, and double bleed and block
  • Number of valve’s ports: the standard type is with 2 ports design (1 inlet, 1 outlet), but 3-way design is also available (1 inlet and 2 outlets or vice-versa)
  • Bore size: full bore or reduced bore (FB vs. RB), and V-notch
  • Body assembly: unibody (the ball body is made out of one single piece of cast or forged steel), 2 pieces or 3 pieces (the body results from the assembly of two or three different parts)
  • Ball access: side entry or top entry (depending on the fact that the ball can be accessed, for maintenance, from the side of the valve or from its top)
  • Seat Type: metal or soft (Teflon)

Let’s now delve into the characteristics of each different type of ball valve.

FLOATING BALL VALVE

A floating ball valve is a type of ball valve where the ball is not rigidly fixed but is allowed to float between the valve seats. In this design, the ball is held in place by the compression of two elastomeric seats, one on each side of the ball.

The ball has some freedom to move (float) within the valve body. The term “floating” refers to the ball’s ability to move slightly along the axis of the valve.

How It Works

When the valve handle (or actuator) is turned to open the valve, the ball rotates to a position where the hole through the ball is aligned with the valve’s inlet and outlet, allowing fluid to flow through. When the valve is closed, the handle rotates the ball so that it blocks the flow path.

Upon closing the valve, the pressure of the fluid acts on the ball, pushing it against the downstream seat. This action enhances the seal and prevents fluid from leaking past the ball. The floating design means that the sealing pressure against the ball increases with increased fluid pressure, thereby improving the sealing efficiency as the system pressure rises.

Advantages Of Floating Ball Valves

  • Tight Sealing: The pressure-assisted sealing mechanism ensures a reliable seal between the ball and the seats, making floating ball valves suitable for a wide range of applications.
  • Simplicity and Durability: With fewer moving parts and a simple design, floating ball valves are durable and require minimal maintenance.
  • Versatility: They can be used in various applications, handling a wide range of fluids and operating conditions.

Applications

Floating ball valves are commonly used in industries such as water and wastewater treatment, chemical and petrochemical processing, oil and gas, and manufacturing. They are suitable for applications requiring reliable shut-off capabilities, such as in pipelines, storage facilities, and distribution systems. Floating ball valves are typically used in low to medium-pressure and temperature applications.

Considerations

While floating ball valves are suitable for a wide range of applications, the floating design may not be as effective in very high-pressure systems where the ball could be pushed too hard against the seat, potentially leading to seat deformation and increased operational torque. For such high-pressure applications, trunnion-mounted ball valves, where the ball is supported by bearings and the pressure load is not entirely on the seats, might be more appropriate.

Floating and trunnion ball valves design

When the shaft of the floating ball valve is moved, a load is applied to the ball which gets pressed against its seats.

This design, which is lightweight and economical, suits bore sizes up to 10 inches: above this bore size, the seats of the valve would not be able to withstand heavier and heavier balls and the valve would not operate safely and efficiently.

Floating valves allow a bi-directional shut-off of the flow (as the trunnion type).

Floating ball valve

TRUNNION BALL VALVE

A trunnion ball valve is a type of ball valve that utilizes a fixed ball design to control the flow of fluid. Unlike floating ball valves, where the ball is allowed to float between the valve seats, in trunnion ball valves, the ball is anchored at the top and bottom by trunnions. These trunnions, essentially extensions of the ball or additional support mechanisms, hold the ball in a fixed position while allowing it to rotate.

Trunnion ball valve

How It Works

The ball in a trunnion ball valve has a hole through its center. When the valve is open, this hole is aligned with the flow path, allowing fluid to pass through. Turning the valve’s handle or actuator rotates the ball to block the flow path, stopping the flow. The trunnions absorb the line pressure, reducing the load on the valve seats and ensuring a tight seal regardless of pressure fluctuations.

Key Features And Advantages

  • Low Operational Torque: Because the ball is supported by trunnions, there’s less friction between the ball and the seats during operation, which translates to lower torque requirements. This makes it easier to operate, especially for larger valve sizes or in high-pressure applications.
  • High Pressure and Temperature Capabilities: Trunnion ball valves are well-suited for high-pressure and high-temperature applications. The trunnion design effectively manages the thrust from line pressure, preventing excess stress on the valve components.
  • Durability and Reliability: The fixed ball design minimizes wear on the seats and ensures consistent performance over time, contributing to the valve’s longevity and reliability.
  • Double Block and Bleed (DBB) Capability: Many trunnion ball valves offer DBB functionality, allowing for maintenance and pressure verification without shutting down the entire system.

Applications

Trunnion ball valves are used in a wide range of industrial applications, especially where high pressure and large diameters are involved, such as:

  • Oil and Gas: For controlling flow in pipelines, processing facilities, and offshore platforms.
  • Petrochemical and Chemical Manufacturing: In systems requiring robust valves that can handle high pressures and corrosive fluids.
  • Power Generation: For steam, water, and feedwater systems within power plants.
  • Water and Wastewater Treatment: In high-pressure lines and for applications requiring durable and reliable shut-off.

Considerations

While trunnion ball valves offer several advantages, they are typically more expensive than floating ball valves due to their more complex design and manufacturing process. They are also generally larger and heavier, which may be a consideration for installation and support structures. Despite these factors, their reliability and performance in demanding conditions make them a preferred choice for many high-pressure and large-scale applications.

TOP ENTRY BALL VALVE

A top entry ball valve is a type of ball valve where the main components, including the ball and seats, can be accessed and serviced from the top of the valve without removing the entire valve body from the pipeline. This design provides a significant advantage in terms of maintenance and repair.

Top entry ball valve

Design And Operation

  • Ball Mechanism: Similar to other ball valves, a top entry ball valve uses a spherical ball with a hole through its center to control fluid flow. The valve opens when the ball’s hole is aligned with the flow path and closes when rotated 90 degrees.
  • Access: The distinguishing feature of a top entry ball valve is the single-piece body design that allows access to the valve internals through a removable bonnet or cover on the top. This design means that the valve internals can be inspected, repaired, or replaced without detaching the valve body from the pipeline.
  • Sealing and Support: Top entry ball valves can be designed with floating or trunnion-supported balls, depending on the application requirements. They also feature robust sealing mechanisms to prevent leaks, which can be easily replaced or serviced due to the top entry design.

Advantages

  • Ease of Maintenance: The primary advantage is the ease of maintenance and repair. Valve components can be serviced directly on the line, reducing downtime and operational costs.
  • Versatility: Top entry ball valves are suitable for a wide range of applications, pressures, and temperatures. They can be used in critical and high-performance settings, including the oil and gas industry, power generation, and process industries.
  • Durability and Reliability: These valves are built for durability and reliability, with designs that can handle high pressure and adverse conditions effectively.

Applications

Top entry ball valves are used in various industrial applications where valve accessibility and ease of maintenance are crucial, especially in high-pressure and high-temperature environments. Common applications include:

  • Oil and Gas: For onshore and offshore pipelines, production facilities, and refining processes where rapid maintenance may be required.
  • Chemical Processing: In systems handling corrosive or hazardous materials that may require frequent maintenance.
  • Power Generation: In feedwater, steam, and other critical power plant systems.

Differences Top-Entry And Side-Entry Ball Valves

Top entry and side entry ball valves are two distinct designs within the ball valve family, each offering specific advantages for different applications. The primary difference lies in how the ball and internal components are accessed and maintained. Here’s a breakdown of each type:

Top Entry Ball Valve

Design: In a top entry ball valve, the ball and seats can be accessed from the top of the valve. The valve body is a single piece, with a removable bonnet or cover on top that provides direct access to the valve internals without removing the valve from the pipeline.

Advantages:

  • Maintenance: Allows for easier maintenance, inspection, and replacement of the internals (ball, seats, seals) without detaching the valve from the pipeline, saving time and reducing downtime.
  • Application: Suitable for high-pressure and high-temperature applications, as well as in situations where inline maintenance is necessary or where system downtime needs to be minimized.

Considerations:

  • Typically more expensive due to the precision engineering required for the top entry design.
  • Often used in critical or hard-to-reach areas where valve removal would be challenging.
Side Entry Ball Valve (Split Body Ball Valve)

Design: The side entry ball valve, often referred to as a split body ball valve, features a body that is divided into two or three pieces, bolted together. The ball is inserted from the side when assembling the valve. The body joint is typically along the horizontal axis for a two-piece design and may include a third piece (center piece) for three-piece designs.

Advantages

  • Cost-Effectiveness: Generally more cost-effective than top entry valves, making them suitable for a wide range of applications.
  • Versatility: Available in a wide variety of sizes and pressure ratings, suitable for many industrial applications.

Considerations

  • Maintenance or repair requires the valve to be removed from the pipeline, which can increase system downtime.
  • The seal at the body joint may have specific pressure limitations, influencing the valve’s suitability for high-pressure applications.
Key Differences (Top Vs. Side Entry)
  • Maintenance Accessibility: Top entry valves allow for inline maintenance without removing the valve from the pipeline, while side entry valves need to be fully removed for servicing.
  • Construction and Cost: Top entry valves have a one-piece body design that can be more expensive to manufacture, whereas side entry valves have a split body design that is generally more cost-effective.
  • Application Suitability: The choice between top entry and side entry may depend on the application’s maintenance requirements, cost considerations, and pressure/temperature demands.

In summary, the decision between a top entry and side entry ball valve often comes down to the specific needs of the application, including maintenance practices, budget constraints, and operational conditions. Each type offers unique benefits that make it suitable for different industrial environments.

Trunnion-mounted ball valves, as well as floating ball valves, are available with a “side entry” and “top entry” design.

The top entry design is specified when frequent inline maintenance activities are expected on the valve.

This is because top-entry ball valves allow easier and faster access to the ball and the valve trim compared to side-entry valves (which require more maintenance time and space for the same operations).

Final Considerations About Top-Etntry Ball Valves

While top-entry ball valves offer significant maintenance advantages, they may come with a higher initial cost compared to other ball valve types due to their design complexity and manufacturing requirements. Additionally, their selection should consider the specific application’s pressure, temperature, and fluid compatibility to ensure optimal performance and longevity.

3-WAYS BALL VALVE (OR “MULTIPORT”)

A 3-way ball valve is a type of ball valve designed to control the flow of fluids in three different directions. It is characterized by having three ports (inlet and two outlets, or one inlet and two outlets), making it versatile for various applications where flow diversion, mixing, or directional control is needed. The internal ball typically has either an L-shaped or T-shaped port, allowing for different flow patterns depending on its position.

Multiport Ball Valve (3 ways)

How It Works

  • L-Port Configuration: The L-shaped port connects the center port to one of the side ports at a time, making it suitable for diverting flow from one line to another. By rotating the ball, the valve can alternate between connecting the inlet to either of the two outlets.
  • T-Port Configuration: The T-shaped port can connect all three ports simultaneously or block one port while connecting the other two. This configuration is useful for mixing two inlet flows or dividing one inlet flow into two outlets.

3 Way Ball Valve L and T

Key Features

  • Versatility: 3-way ball valves can serve multiple functions, such as stopping and starting flow, changing the flow direction, mixing, or splitting the flow within a single valve body.
  • Easy Operation: Like other ball valves, 3-way ball valves offer quick and efficient operation, typically with a quarter-turn mechanism to change flow paths.
  • Compact Design: These valves can replace multiple two-way valves and fittings in a system, saving space and reducing potential leak points.

Applications

3-way ball valves are widely used across various industries for different purposes, including:

  • Chemical Processing: For directing chemical flows between different processing stages or mixing chemicals.
  • HVAC Systems: To control the direction of heating or cooling media.
  • Food and Beverage: In systems requiring the diversion of fluids or mixing of ingredients.
  • Water Treatment: For directing water flow through different treatment paths.

Selection Considerations

When selecting a 3-way ball valve, consider:

  • Flow Requirements: Determine the required flow pattern (L-port or T-port) based on the application’s needs.
  • Material Compatibility: Ensure the valve materials are compatible with the fluids being handled, considering factors like corrosion resistance and food safety.
  • Pressure and Temperature: Select a valve that can withstand the operating pressure and temperature conditions of the system.
  • Actuation: Decide between manual operation or automated actuation (electric, pneumatic, hydraulic) based on system requirements.

In summary, 3-way ball valves offer a flexible and efficient solution for controlling flow directions in a piping system, accommodating a variety of operational needs with simple adjustments.

FULL PORT VS REDUCED PORT BALL VALVES

These concepts refer to the relation between the bore diameter of the valve and the connected piping system. The term “port” can be also referred to as “bore” (full bore/small bore).

Full bore vs Reduced Bore Ball Valve

Full port and reduced port ball valves are two common design variations found in ball valves, each serving specific operational purposes based on flow requirements and pressure drop considerations. Understanding the differences between them is crucial for selecting the appropriate valve type for a particular application.

Full Port Ball Valve (Full Bore)

  • Design: In a full port ball valve, the diameter of the ball’s hole (bore) matches the inner diameter of the connecting pipeline. This design ensures that there is no restriction in the flow path when the valve is fully open.
  • Advantages: Minimal pressure drop across the valve, which is especially beneficial in applications requiring the preservation of flow rate and pressure. It also allows for pigging operations in pipelines, where a cleaning pig is sent through the pipe to remove debris and buildup.
  • Applications: Full port valves are ideal for applications where flow efficiency is critical and for systems that require regular pigging for maintenance.

Reduced Port Ball Valve (Reduced Bore)

  • Design: The bore diameter of a reduced port ball valve is smaller than the pipeline’s diameter. This results in a flow path that is somewhat restricted compared to the full port design.
  • Advantages: Reduced port valves are generally smaller and less expensive than full port valves of the same nominal size. The smaller bore also requires less torque to operate, which can reduce the size and cost of the actuation mechanism.
  • Applications: Suitable for applications where flow rate and pressure drop are less critical. They are commonly used in applications where space and cost savings are desired without significantly compromising the system’s performance.

Key Differences

  • Flow Path and Pressure Drop: Full port valves offer an unrestricted flow path, resulting in lower pressure drops, while reduced port valves introduce some restriction and higher pressure drops.
  • Size and Cost: Reduced port valves are typically more compact and cost-effective than full port valves, making them attractive for applications where space is limited, and the full flow capacity is not required.
  • Operational Efficiency: The choice between full and reduced port often depends on the system’s requirements for flow efficiency and pressure maintenance. Full port valves are preferred in systems that cannot tolerate significant pressure drops or where pipeline pigging is necessary.

In summary, the choice between full port and reduced port ball valves depends on the specific requirements of the application, including considerations of flow rate, pressure drop, operational efficiency, and cost. Understanding these differences ensures the selection of the most appropriate valve type to meet the system’s needs effectively.

V-PORT BALL VALVE

A V-Port ball valve, also known as a V-Ball or V-Notch ball valve, is a specialized type of ball valve designed for more precise flow control and regulation compared to standard ball valves. This valve features a ball with a V-shaped cutout on its surface, giving it the name “V-Port.” The unique shape of the V-Port allows for better throttling control and rangeability, making it particularly suited for applications requiring precise flow modulation.

v port ball valves
v port ball valves

Design And Operation

  • V-Port Design: The angle of the V-notch cut into the ball can vary, typically ranging from 15 to 90 degrees. The shape and angle of the V-Port directly affect the flow characteristics, allowing for linear or equal percentage flow control. As the valve is opened or closed, the V-shaped portion provides a gradual change in flow area, enabling fine adjustment of flow rate.
  • Operation: Like other ball valves, V-Port ball valves operate with a quarter-turn mechanism. Rotating the valve handle 90 degrees opens or closes the valve, but the precise shape of the V-Port allows for more nuanced control over the flow as the valve moves between open and closed positions.

Advantages

  • Enhanced Flow Control: The V-Port design offers superior control over fluid flow, especially in partially open positions, making it ideal for throttling applications.
  • High Rangeability: V-Port ball valves can effectively manage a wide range of flow rates, providing flexibility across various operational conditions.
  • Reduced Cavitation and Flashing: The gradual change in flow area helps minimize the risks of cavitation and flashing, common challenges in fluid control applications.
  • Durability: V-Port ball valves maintain the inherent durability and reliability of traditional ball valves, suitable for high-pressure and high-temperature applications.

Applications

V-Port ball valves are used in diverse industries where precise flow regulation is required, including:

  • Chemical Processing: For controlling the flow of aggressive or corrosive fluids.
  • Water and Wastewater Treatment: In applications requiring fine adjustment of water flow.
  • Food and Beverage Production: Where precise flow control is necessary for process accuracy.
  • Pulp and Paper Manufacturing: For controlling the flow of slurry and other process fluids.

Selection Considerations

When selecting a V-Port ball valve, consider factors such as the specific flow control requirements, the fluid properties (including viscosity and potential for particulate matter), operating pressures and temperatures, and the valve materials’ compatibility with the process fluid.

In summary, V-Port ball valves offer enhanced flow control capabilities, making them a valuable option for applications requiring precise flow regulation. Their design combines the robustness and reliability of standard ball valves with improved performance for throttling and modulation tasks.

SEGMENTED BALL VALVE

A segmented ball valve, also known as a V-notch ball valve, is a specialized type of ball valve designed to provide precise flow control, especially in applications involving liquids with varying viscosities or slurries. It combines the robust sealing characteristics of a traditional ball valve with enhanced control capabilities, thanks to its unique ball design.

segmented ball valve
segmented ball valve

Design

The key feature of a segmented ball valve is its ball segment or V-notch design. The ball has a V-shaped cutout on one side, which gradually opens or closes as the valve is turned, allowing for more precise modulation of flow than a standard ball valve. The “segment” refers to the part of the ball that is cut out, and it can rotate within the valve body to regulate the flow.

How It Works

As the valve handle or actuator is turned, the V-notch segment of the ball rotates, aligning more or less with the flow path. This design allows for a range of flow control, from fully open to nearly closed, with the V-notch providing a shearing action that is effective at controlling the flow of slurry or viscous fluids.

Key Features

  • Precise Flow Control: The V-notch design enables finer control over the flow rate, making it suitable for throttling applications.
  • Shearing Action: The V-notch can cut through solids and slurries in the fluid, reducing clogging and ensuring smoother operation in challenging conditions.
  • High Rangeability: The valve offers a wide range of flow capacities, from fully open to minimal flow, allowing for versatile use across different applications.
  • Durability: Segmented ball valves are designed to withstand harsh operating conditions, including high pressures and temperatures.

Applications

Segmented ball valves are used in various industrial applications where precise flow control and durability are required, including:

  • Chemical Processing: For handling corrosive fluids, viscous products, or slurry mixtures where precise flow modulation is necessary.
  • Pulp and Paper Manufacturing: In processes involving fibrous slurries, where the valve’s shearing action can prevent clogging.
  • Water and Wastewater Treatment: For controlling the flow of water with varying levels of particulate matter.
  • Food and Beverage: In applications involving viscous liquids or products with solids.

Considerations

When selecting a segmented ball valve, it’s important to consider the specific requirements of your application, including the fluid’s nature, pressure and temperature conditions, and the degree of flow control needed. The material of the valve and its components should be compatible with the process fluid to ensure longevity and reliability.

In summary, segmented ball valves offer an efficient solution for applications requiring precise flow control and the ability to handle difficult fluids, combining the benefits of ball valve sealing with the adjustability of a control valve.

BALL CONTROL VALVE

A ball control valve is a type of control valve that uses a ball with a hole through it to regulate the flow of a fluid. It combines the spherical closure element of a traditional ball valve with the ability to modulate flow, making it suitable for precision control applications. Ball control valves are designed to offer variable control of fluid flow, allowing for adjustment from full flow to minimal flow based on the position of the ball.

control ball valve
control ball valve

Design Features

  • Rotary Ball: The core component is a rotary ball with a bore through the center. The position of the ball (and thus the alignment of the bore with the flow path) is adjusted to control the flow rate.
  • V-Port: Many ball control valves feature a V-shaped cut or notch on the ball or in the bore, enhancing their ability to provide finer control over a wide range of flow rates. The “V” shape allows for more precise control as the valve moves from the closed to the open position.
  • Actuation: Ball control valves are often operated by pneumatic, electric, or hydraulic actuators, allowing for remote control and automation of the valve’s position in response to system demands.

  • Operational Advantages

    • Precise Flow Control: Offers excellent control over flow rates, making it ideal for applications where the flow needs to be adjusted or regulated accurately.
    • High Rangeability: The design allows for a wide range of flow capacities, enabling precise control from fully open to nearly closed positions.
    • Good Shut-Off Capabilities: When fully closed, ball control valves provide a tight seal, similar to standard ball valves, making them suitable for on/off control in addition to flow modulation.
    • Durability: The robust design of ball control valves, especially those with hard-sealed components, can handle high-pressure applications and aggressive media.

    Applications

    Ball control valves are used in a variety of industries and applications, including:

    • Process Industries: For controlling the flow of gases, liquids, and even slurries in chemical, petrochemical, and pharmaceutical processes.
    • Water Treatment: In systems requiring precise control of water flow, such as in filtration, distribution, and wastewater treatment.
    • Oil and Gas: For regulating the flow in pipelines, production processes, and refining operations.
    • Food and Beverage: In applications involving the control of liquids and semi-liquids during processing and manufacturing.

    Selection Considerations

    When selecting a ball control valve, consider factors such as:

    • Fluid Compatibility: Ensure the materials of the valve are compatible with the process fluid to prevent corrosion and wear.
    • Pressure and Temperature Ratings: The valve must be capable of operating within the system’s pressure and temperature ranges.
    • Flow Characteristics: Consider the required flow pattern (e.g., linear or equal percentage) and rangeability to ensure the valve meets the application’s control needs.

    In summary, ball control valves are an effective solution for applications requiring both precise flow modulation and reliable shut-off capabilities. Their versatility and durability make them a popular choice in various industrial processes where control accuracy is paramount.

    BALL VALVE VS. OTHER TYPES OF VALVES

    Ball Valve Vs Gate Valve

    Ball valves and gate valves are two commonly used types of valves in piping systems, each serving specific purposes with distinct advantages and operational differences. Here’s a comparison to highlight the key aspects of ball valves versus gate valves:

    Ball Valve

    • Operation: Utilizes a rotating ball with a hole through its center to control flow. Turning the valve’s handle 90 degrees opens or closes the flow path.
    • Sealing: Offers a tight seal with low torque, making it suitable for applications requiring a leak-proof operation.
    • Flow Control: Provides excellent on/off control but is not typically used for flow modulation, as partial opening can create turbulent flow and potentially damage the valve.
    • Pressure Drop: Generally experiences a lower pressure drop when fully open compared to gate valves, due to the straight flow path.
    • Applications: Widely used for gas and liquid applications where quick and full shutoff is required, including residential, industrial, and commercial plumbing and water systems.

    Gate Valve

    • Operation: Operates by lifting a gate out of the path of the fluid. Turning the handle or wheel opens or closes the valve by moving the gate vertically.
    • Sealing: When fully open or fully closed, gate valves provide a good seal. However, they are prone to wear and leakage over time, especially in the partially open position.
    • Flow Control: Primarily designed for on/off control and not recommended for throttling as the partially open gate can be damaged by the fluid flow.
    • Pressure Drop: When fully open, gate valves offer very little resistance to flow, resulting in a minimal pressure drop.
    • Applications: Ideal for applications where a straight flow path and minimal restriction are desired, such as in water and wastewater treatment, oil and gas industries, and other situations requiring minimal valve operation.

    Key Differences

    • Functionality: Ball valves are better for applications requiring fast, frequent operation and tight shutoff. Gate valves are preferred for applications where the valve remains either fully open or fully closed for extended periods.
    • Flow Regulation: Ball valves are not suited for precise flow control, while gate valves, although not designed for throttling, can provide finer control when opening and closing.
    • Maintenance: Ball valves generally require less maintenance than gate valves, as their design is simpler and more resistant to wear from the turbulent flow.
    • Cost: The cost can vary depending on the size, material, and specific application requirements. However, ball valves tend to be more cost-effective for smaller sizes, while gate valves can be more economical for larger diameters.

    In summary, the choice between a ball valve and a gate valve depends on the specific requirements of the application, including the need for flow control, frequency of operation, and budget considerations. Each valve type offers distinct advantages that make it suitable for different operational contexts.

  • Ball Valve Vs Globe Valve

    Ball valves and globe valves are both critical components used in piping systems for controlling flow, but they have distinct design features, operational mechanics, and applications that make them suited to different tasks.

    Trunnion forged ball valve

    Here’s a breakdown of the key differences between ball valves and globe valves:

    Ball Valve

    • Design: Features a spherical disc (the ball) with a hole through its center. The ball rotates within the valve body to open or close the flow path.
    • Operation: Operates with a quarter-turn (90-degree) movement, offering quick and easy shutoff. The handle’s position (parallel or perpendicular to the pipe) indicates the valve’s status (open or closed).
    • Flow Control: Primarily used for on/off control due to its design. While it can be used for throttling, it’s not as precise as a globe valve for this purpose.
    • Sealing: Provides a tight seal with minimal wear over time, making it suitable for applications requiring leak-proof operation.
    • Pressure Drop: Generally has a lower pressure drop when fully open, as the flow path is straight through the ball.
    • Applications: Widely used in applications requiring fast and frequent operation, including gas, liquid, and even slurry services, due to its robust design and effective sealing.

    Globe Valve

    • Design: Characterized by a body with a Z-shaped partition and a moveable disc or plug that seats against an opening in the partition to regulate flow.
    • Operation: Utilizes a multi-turn stem operation, requiring several turns to open or close, which allows for precise control of the flow rate.
    • Flow Control: Excellently suited for throttling and regulating flow due to its design, which allows for fine adjustments of the disc position.
    • Sealing: Effective sealing capabilities, but the design can lead to more wear on the seating surface due to the disc’s sliding motion against the seat.
    • Pressure Drop: Typically experiences a higher pressure drop compared to ball valves because of the tortuous flow path.
    • Applications: Commonly used in applications requiring precise flow control, such as in heating and cooling systems, and in processes where flow needs to be adjusted regularly.

    Key Differences

    • Functionality and Control: Ball valves are best for quick, on/off control but can offer some throttling capabilities. Globe valves excel in applications requiring precise flow regulation.
    • Pressure Drop: Ball valves have a lower pressure drop in the open position due to the straight-through flow path, making them more efficient for certain applications. Globe valves, with their Z-shaped flow path, incur a higher pressure drop but provide better flow control.
    • Operational Speed: Ball valves can be operated quickly with a quarter-turn, making them suitable for emergency and safety-related applications. Globe valves require multiple turns, offering slower but more precise control.

    Choosing between a ball valve and a globe valve depends on the specific needs of the application, including the type of control required (on/off vs. throttling), operational efficiency (pressure drop concerns), and the fluid service conditions (temperature, pressure, and corrosiveness).

    Ball Valve Vs. Butterfly Valve

    Ball valves and butterfly valves are both popular choices for controlling the flow of fluids in piping systems, but they have distinct features, operating mechanisms, and suitability for different applications. Understanding their differences is key to selecting the most appropriate valve for a specific use case.

    Ball Valve

    • Design: Features a spherical disc (the ball) with a hole through its center. The ball rotates within the valve body to open or close the flow path.
    • Operation: Utilizes a quarter-turn mechanism for operation, allowing for quick and easy shutoff. The handle’s position directly indicates the valve’s open or closed status.
    • Sealing: Typically offers excellent sealing capabilities due to the tight fit between the ball and the valve seats, making it suitable for gas and high-pressure applications.
    • Flow Control: While primarily used for on/off control, some ball valves are designed for flow regulation. However, they are not as precise in controlling flow as butterfly valves.
    • Pressure Drop: When fully open, ball valves usually present a minimal pressure drop because the hole in the ball allows for nearly unrestricted flow.

    Butterfly Valve

    • Design: Consists of a flat disc that rotates around a central axis within the valve body. The disc’s position relative to the flow direction controls the fluid passage.
    • Operation: Also operates with a quarter-turn mechanism, allowing for rapid opening and closing. The lever or gear operator indicates the valve’s position.
    • Sealing: Offers good sealing with the use of elastomeric seat materials but may not be as tight as a ball valve, especially under high-pressure conditions.
    • Flow Control: Excellently suited for throttling applications due to the ease with which the disc can be positioned to regulate flow. Provides more precise flow control compared to ball valves.
    • Pressure Drop: Even when fully open, the presence of the disc within the flow path means butterfly valves typically have a higher pressure drop than ball valves.

    Key Differences

    • Application Suitability: Ball valves are preferred for applications requiring tight shutoffs, such as in gas transmission and high-pressure scenarios. Butterfly valves are favored in applications where precise flow control and regulation are necessary, especially in larger diameter pipes where ball valves would be impractical or too expensive.
    • Operational Efficiency: Ball valves provide a more secure seal and are generally more effective for on/off control, while butterfly valves offer superior capabilities for flow modulation and adjustment.
    • Cost and Space Considerations: Butterfly valves tend to be more cost-effective for larger sizes and require less space for installation due to their compact design compared to ball valves.

    The choice between a ball valve and a butterfly valve ultimately depends on specific factors like the fluid’s nature, pressure, and temperature conditions, required flow control precision, space availability, and budget constraints. Each valve type has its advantages and ideal use cases, ensuring optimal performance for various applications.

  • MATERIALS FOR BALL VALVES

    Cast Vs. Forged Ball Valves Body Materials

    Ball valves are manufactured either with cast or forged body materials (which can be monoblock, or split, body types).

    When Forged Bodies?

    Generally, ball valves below 2 inches in diameter are manufactured in 2 pieces or 3 pieces body configurations (the most common materials used for forged ball valves are ASTM A105 for high-temperature service, ASTM A350 LF2/LF3 for low-temperature service, and ASTM A182 F304/F316 for stainless steel valve or higher grades, such as duplex valves ASTM A182 F51 and super duplex ASTM A182 F53/F55).

    Forged bodies are also used for high-pressure valves of higher bore sizes (with 2 or 3-piece split body construction).

    Examples of forged ball valves (small size and stainless steel valve with a forged body, trunnion mounted).

    ball valve sphere

    When Cast Bodies?

    Valves in sizes above 2 inches are generally manufactured with cast body materials (the most common grades are ASTM A216 WCB for high temp. service, ASTM A352 for low-temperature service and ASTM A351 CF8, CF8M for cast stainless steel valves).

    ASTM Materials For Ball Valves

    • Carbon Steel: ASTM A216 WCB is a common grade used for the valve body in moderate temperature applications. It offers good strength and toughness.
    • Stainless Steel: ASTM A351 CF8M (equivalent to SS316) and ASTM A351 CF8 (equivalent to SS304) are widely used for corrosion resistance in harsh environments.
    • Alloy Steel: ASTM A494 CW-6MC (Inconel 625), ASTM A494 CW-12MW (Hastelloy C), and other alloys are used for high-temperature and high-corrosion applications.
    • Bronze and Brass: ASTM B62 (Bronze) and ASTM B16 (Brass) are used for general low-pressure applications and are particularly common in plumbing and water systems.

    API Materials For Ball Valves

    • API 608: Specifies the requirements for ball valves used in the petroleum and natural gas industries. This standard covers material requirements for different classes of service, including carbon steel, stainless steel, and alloy materials.
    • API 6D: While primarily a specification for pipeline valves (including gate, plug, and ball valves), API 6D also outlines material specifications for ball valves used in pipeline applications. Materials are chosen based on the pressure and temperature class of the valve.

    Material Selection Considerations

    • Corrosion Resistance: Stainless steel and alloy materials are selected for services involving corrosive fluids, while carbon steel may be sufficient for water, steam, and oil where corrosion is not a significant concern.
    • Temperature and Pressure: High-temperature and high-pressure applications may require alloy steels or special alloys to maintain integrity under extreme conditions.
    • Compatibility: The material must be compatible with the fluid to prevent contamination or degradation of the valve components.
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Understand Check Valves (BS 1868, API 6D, API 602)

A check valve prevents potentially damaging backflows to protect equipment like pumps and compressors. Non-return valves allow the flow of the fluid in one direction only and block reverse flows. This type of valves is available with cast and forged bodies (BS 1868, API 6D, API 602) and in several designs as swing, ball, lift, stop and piston designs.

CHECK VALVE

WHAT IS A CHECK VALVE?

Briefly, a check valve is a protection device that prevents the fluid from flowing in an unwanted direction within the piping system or the pipeline (as backflows may damage upstream equipment).

A check valve, also known as a non-return valve or one-way valve, is a type of valve that allows fluid (liquid or gas) to flow through it in only one direction. Check valves are used to prevent the backflow of fluid, automatically preventing reversed flow when the fluid in the line reverses direction. They are crucial components in various piping systems to ensure the safety and efficiency of operations.

Swing check valve

Design And Operation

Check valves operate automatically and most do not have any valve handle or stem. The design of a check valve incorporates a mechanism that opens with forward flow and closes against reverse flow. This mechanism can vary depending on the type of check valve, but common types include ball check valves, swing check valves, and lift check valves:

  • Ball Check Valve: Utilizes a ball that rests on a seat within the valve body. Forward flow lifts the ball off the seat, allowing flow, while reverse flow presses the ball back onto the seat, blocking the flow.
  • Swing Check Valve: Features a disc or a door that swings on a hinge or a shaft. The disc swings off the seat to permit forward flow and swings back to the seat to block reverse flow.
  • Lift Check Valve: Contains a disc or cone that lifts vertically off the seat by the pressure of the forward flow. When the flow stops or reverses, gravity or reverse flow pushes the disc back onto the seat to stop backflow.

Applications

Check valves are used in a wide range of applications to protect equipment, maintain process conditions, and ensure directional flow, including:

  • Pump Protection: To prevent backflow that could damage pumps and drive systems.
  • Preventing Contamination: To stop backflow in systems where contamination could be a significant issue, such as in potable water supply.
  • Pressure Maintenance: In systems where pressure needs to be maintained in one part of the system, preventing fluid from flowing back and reducing pressure.
  • Safety Applications: In systems where reverse flow could lead to hazardous conditions or equipment failure, such as in gas supply systems.

Advantages And Limitations

Advantages:

  • Automatic operation, requiring no external controls or power.
  • Simple design, leading to reliability and ease of maintenance.
  • Available in a wide range of sizes and materials, suitable for various applications and fluids.

Limitations:

  • Potential for water hammer or surge pressures due to the rapid closing of the valve, especially in fast-flowing systems.
  • Limited flow control capabilities since they are designed primarily for preventing backflow rather than regulating flow.
  • Possibility of leakage if debris prevents the valve from fully closing.

In summary, check valves play a vital role in ensuring the unidirectional flow of fluids in piping systems, offering protection against reverse flow and its associated problems. Selecting the appropriate type of check valve depends on specific system requirements, including flow rate, pressure, and the nature of the fluid.

Cast steel valves are available with flanged and butt weld ends.
Forged, small-size, valves are available with threaded and socket weld connections.

These valves are represented by the following symbol in piping P&ID diagrams: Symbol for check valve in P&ID diagram

HOW TO SELECT A CHECK VALVE?

Selecting the right check valve for a particular application requires careful consideration of various factors to ensure optimal performance, reliability, and safety of the piping system. Here’s a step-by-step guide on how to select a check valve:

1. Understand The Application

  • Fluid Type: Determine the type of fluid (water, oil, gas, etc.), as this will influence the material selection for the check valve to ensure compatibility and prevent corrosion.
  • Flow Conditions: Consider the flow rate, pressure, and temperature of the system. The check valve must be capable of operating effectively under these conditions.

2. Determine The Correct Size

  • Pipe Size: The check valve should match the size of the connecting pipe to ensure proper fit and minimize installation issues.
  • Flow Requirements: Calculate the required flow rate (Cv) to ensure the valve can handle the system’s flow without causing excessive pressure drop or flow restriction.

3. Select The Valve Type

Based on the application requirements, decide on the type of check valve needed. Common types include:

Each type of check valve is discussed later in greater detail.

4. Choose The Material

  • Body and Trim Material: Select materials that are compatible with the fluid type and the operating conditions (temperature and pressure). Common materials include stainless steel for corrosive fluids, cast iron for water applications, and PVC for chemical services.
  • Sealing Material: Ensure the sealing material (e.g., NBR, EPDM, Viton) is suitable for the fluid type and temperature.

5. Consider End Connections

  • Connection Type: Choose the appropriate end connection (flanged, threaded, wafer, socket weld, etc.) based on the piping system design and ease of maintenance.

6. Evaluate Special Requirements

  • Leakage: Determine the acceptable level of leakage, if any. Some systems may require a zero-leakage valve.
  • Orientation: Consider the installation orientation (horizontal, vertical flow up, vertical flow down) as it may affect the valve’s operation.
  • Pressure Drop: Minimize pressure drop by selecting a valve with an appropriate flow design.
  • Back Pressure: Ensure the system provides sufficient back pressure to close the valve properly.

7. Regulatory And Standards Compliance

  • Verify that the check valve meets any applicable industry standards (e.g., API, ASME, ANSI) and regulatory requirements for safety and performance.

8. Manufacturer And Warranty

  • Select a reputable manufacturer with proven experience in check valves for similar applications. Review warranty terms and post-sale support.

By systematically addressing these selection criteria, you can ensure that the chosen check valve will perform efficiently and reliably within your specific application, contributing to the overall safety and effectiveness of the piping system.

APPLICABLE SPECIFICATIONS (BS, API, ASME)

The key specifications that cover this type of valve are:

Check valves, critical components in various piping systems, are governed by numerous standards to ensure their reliability, safety, and performance. These standards, set by recognized bodies like the British Standards (BS), the American Petroleum Institute (API), and the American Society of Mechanical Engineers (ASME), specify design criteria, material specifications, testing requirements, and performance characteristics for check valves. Here’s a brief overview of some key BS, API, and ASME specifications applicable to check valves:

British Standards (BS)

  • BS 1868: Steel Check Valves for the Petroleum, Petrochemical, and Allied Industries
    • Specifies requirements for steel check valves with flanged and butt-welding ends, designed for the petroleum, petrochemical, and allied industries. It covers valves of nominal sizes DN 50 to DN 600 and specifies body materials, pressure-temperature ratings, and testing.
  • BS EN 12334: Industrial Valves – Check Valves of Metallic Materials
    • This European Standard specifies requirements for check valves made from metallic materials excluding steel and applies to check valves used for all industrial applications. It includes provisions for nominal sizes, pressure designations, and aspects of design, testing, and marking.

    • American Petroleum Institute (API)

      • API 6D: Specification for Pipeline and Piping Valves
        • While API 6D covers a broad range of pipeline valves, it includes specific requirements for check valves used in pipeline applications. It addresses aspects like design, materials, testing, and documentation for valves intended for use in the petroleum and natural gas industries.
      • API 594: Check Valves: Flanged, Lug, Wafer, and Butt-Welding
        • API 594 is dedicated to check valves and covers design, materials, face-to-face dimensions, pressure-temperature ratings, and testing for check valves with flanged, lug, wafer, and butt-welding ends. It applies to types A (single plate) and B (double plate).
      • API 598: Valve Inspection and Testing
        • While not specific to check valves, API 598 covers the inspection and testing of all types of valves, including check valves. It outlines the testing methods and acceptance criteria for pressure testing to ensure valve integrity and leak tightness.
      • API 620: Forged check valves

      American Society Of Mechanical Engineers (ASME)

      • ASME B16.34: Valves – Flanged, Threaded, and Welding End
        • This standard establishes requirements for materials, pressure-temperature ratings, dimensions, tolerances, and markings for gate, globe, check, ball, and butterfly valves. It includes criteria that check valves must meet for design and construction.
      • ASME B16.10: Face-to-Face and End-to-End Dimensions of Valves
        • ASME B16.10 specifies the face-to-face and end-to-end dimensions of valves, including check valves. This standard ensures compatibility and interchangeability in valve replacements and installations.
      • ASME B16.25: Buttweld ends

      Adherence to these BS, API, and ASME specifications is essential for the proper selection, installation, and maintenance of check valves in various industrial applications. Compliance with these standards guarantees that check valves meet the necessary quality, safety, and performance requirements for their intended use.

      CHECK VALVE TYPES

      Check valves, essential components in preventing backflow in piping systems, come in various designs to accommodate different flow dynamics, pressure conditions, and installation requirements. Here’s a detailed explanation of the different types of check valves:

      Swing, Ball, Lift, Piston valves

      SWING CHECK VALVE

      Swing check valves are a type of non-return valve used in piping systems to prevent backflow. They operate automatically, allowing fluid to flow through in one direction and preventing reverse flow. The design and operation of swing check valves make them suitable for a wide range of applications, particularly where low-pressure drop and self-acting backflow prevention are required.

      Swing Check Valve Design

      The primary components of a swing check valve include:

      • Body: The outer casing of the valve, which contains the internal components. It can be made from various materials, including cast iron, steel, stainless steel, and PVC, depending on the application requirements.
      • Disc: A movable door-like element that swings on a hinge or a shaft. The disc opens with forward flow and swings back to its closed position when the flow stops or reverses, blocking the flow.
      • Seat: The surface against which the disc seals when the valve is closed. The seat can be integral to the valve body or replaceable, and it is often designed to ensure a tight seal to prevent backflow.
      • Hinge or Shaft: Enables the swinging motion of the disc. In some designs, a lever and weight or spring mechanism may be added to assist in closing the valve more rapidly or controlling the swing to reduce the water hammer.

      Operation

      In operation, the pressure of the forward flow pushes the disc open, allowing fluid to pass through the valve. When the flow stops or reverses, the disc swings back to its closed position, either due to gravity or assisted by a lever and weight mechanism, preventing backflow. The simplicity of this mechanism ensures reliability and minimal maintenance.

      Advantages

      • Low-Pressure Drop: When fully open, swing check valves provide a relatively straight flow path, resulting in a low-pressure drop across the valve.
      • Simple and Reliable: The design is straightforward, with few moving parts, contributing to the valve’s reliability and ease of maintenance.
      • Versatility: Suitable for a wide range of fluids, including water, oil, and gas, and can be used in various applications, from low to high-pressure systems.

      Applications

      Swing check valves are commonly used in:

      • Water Supply Systems: To prevent backflow and protect equipment like pumps.
      • Wastewater Treatment: Where preventing reverse flow is crucial for process integrity.
      • Industrial Processes: In chemical, petrochemical, and other industrial plants where backflow prevention is necessary.

      Considerations

      While swing check valves are suitable for many applications, proper selection involves considering factors like the risk of water hammer (sudden closing can lead to pressure surges), the need for rapid closure, and the compatibility of valve materials with the fluid. Additionally, they are not recommended for pulsating flows as the constant opening and closing may lead to premature wear or failure.

      In summary, swing check valves offer a simple, efficient solution for preventing backflow in piping systems, combining low-pressure drop with reliable operation across a broad range of applications.

      swing check type

      STOP CHECK VALVE

      Stop check valves are specialized valves that combine the features of a check valve and a globe valve, offering both backflow prevention and the ability to manually stop the flow of fluid in a piping system. They provide a unique functionality that allows operators to control the valve’s position, acting as a check valve when left to operate automatically or as an isolation valve when manually adjusted.

      stop-check design

      Design Of Stop Check Valves

      The key components of a stop check valve include:

      • Body: The outer casing that houses the valve’s internal mechanisms. It can be made of various materials suited to the application’s needs, such as cast iron, stainless steel, or other alloys.
      • Disc: A movable element that lifts away from the valve seat to allow flow in one direction and seats back to block flow in the opposite direction. Unlike standard check valves, the disc in a stop check valve can also be manually positioned to fully close, regardless of flow direction.
      • Stem: Connected to the disc, the stem can be moved manually (e.g., via a handwheel or actuator) to lift the disc from the seat or to firmly press it against the seat, effectively stopping flow.
      • Seat: The area against which the disc seals to prevent backflow or to stop flow entirely when the valve is manually closed.
      • Bonnet: The top part of the valve that contains the stem and, in some designs, may house packing material to prevent leaks along the stem.

      Operation

      In its default mode, a stop check valve functions as a check valve, allowing flow in one direction and automatically preventing backflow by seating the disc against the valve seat under reverse flow conditions. However, the key feature of a stop check valve is its ability to be manually closed by an operator, overriding the automatic function. This is accomplished by turning the handwheel or actuator, which moves the stem and disc into a closed position against the seat, regardless of flow direction or pressure.

      Advantages

      • Dual Functionality: Provides the benefits of a check valve and a globe valve in a single unit, offering flexibility in applications that require both backflow prevention and flow isolation.
      • Manual Override: The ability to manually stop flow, irrespective of system pressure or flow direction, enhances control over the system.
      • Safety and Protection: Helps protect against reverse flow that could damage equipment, while also allowing for system maintenance by isolating parts of the system.

      Applications

      Stop check valves are commonly used in high-pressure and high-temperature applications, such as:

      • Boilers: To prevent the backflow of water or steam that could damage the boiler or other equipment in steam systems.
      • Power Generation: In feedwater lines, to control flow to steam generators and allow for system isolation for maintenance.
      • Process Industries: Where process safety requires both the prevention of backflow and the ability to isolate sections of the system for maintenance or emergency shutdowns.

      Considerations

      When selecting a stop check valve, it’s essential to consider the fluid characteristics, pressure and temperature conditions, and the specific requirements for flow control and isolation. Additionally, like all valves, regular maintenance is necessary to ensure reliability, especially given the critical safety functions these valves often serve.

      In summary, stop check valves offer a versatile solution for systems requiring both backflow prevention and the capability to manually stop flow, making them invaluable in various industrial applications where safety, control, and maintenance are paramount.

      BALL CHECK VALVE

      A ball check valve is a type of check valve that uses a ball to prevent backflow in a piping system. It operates automatically, allowing fluid to flow through it in one direction and preventing reverse flow by utilizing a ball that moves within the valve body. Ball check valves are simple, reliable, and effective for a wide range of applications, particularly where viscous fluids or fluids with suspended solids are present.

    • Design

      The key components of a ball check valve include:

      • Body: The outer casing of the valve, which can be made from various materials such as cast iron, stainless steel, PVC, or other corrosion-resistant alloys, depending on the fluid characteristics and application requirements.
      • Ball: The movable element inside the valve that seals against reverse flow. The ball is typically made of metal, rubber, or plastic. Its material and density are chosen based on the fluid type and the required sealing capability.
      • Seat: The surface inside the valve body against which the ball seals when the valve is closed. The seat is often designed to match the contour of the ball for a tight seal and can be made from materials similar to or compatible with the ball.
      • Cover or Bonnet: A removable part that provides access to the interior of the valve for maintenance, inspection, or replacement of the ball and seat.

      Operation

      In operation, forward fluid pressure pushes the ball away from the seat, allowing fluid to flow through the valve. When the fluid flow stops or reverses direction, the ball rolls or is pushed back against the seat by the reverse flow, effectively sealing the valve and preventing backflow. In some designs, a spring or external weight may assist in closing the valve, especially in horizontal installations where gravity alone may not be sufficient to seal the valve.

      Advantages

      • Versatility: Effective for a broad range of fluids, including liquids and gases, and particularly suitable for viscous fluids and slurries.
      • Low Maintenance: The simple design has few moving parts, reducing the risk of malfunction and the need for maintenance.
      • Durability: When made with appropriate materials, ball check valves can be highly durable and resistant to wear and corrosion.
      • Self-Cleaning: The rolling action of the ball can help dislodge small particles, preventing clogging and ensuring reliable operation.

      Applications

      Ball check valves are used in various applications, including:

      • Wastewater and Sewage Systems: For preventing backflow in sewage lines and treatment facilities.
      • Chemical Processing: In systems handling viscous chemicals or fluids with suspended solids.
      • Pumping Systems: To prevent reverse flow and protect pumps in water, oil, and other liquid transfer systems.
      • Agricultural Irrigation: In irrigation systems to maintain water flow direction and prevent contamination.

      Selection Considerations

      When selecting a ball check valve, consider:

      • Fluid Characteristics: Ensure compatibility with the valve materials to prevent corrosion or degradation.
      • Pressure and Temperature: Choose a valve rated for the system’s maximum pressure and temperature conditions.
      • Installation Orientation: While ball check valves are versatile, confirm the valve’s suitability for the intended orientation, especially in horizontal lines.
      • Valve Sizing: Proper sizing is crucial to minimize pressure drop while ensuring effective backflow prevention.

      Ball check valves offer a practical solution for preventing backflow in a wide range of applications. Their simplicity, reliability, and effectiveness make them a preferred choice in systems where maintenance should be minimal, and fluid characteristics are challenging.

      Ball check valves belong to the family of “lift valves”, and have a seat design similar to globe valves.

    • A variant of the ball design is the so-called piston type. This type of valve is used for high-pressure services where the fluid can change direction suddenly and with good force (this because the disc is precisely guided and fits perfectly into the seat).

      Ball and piston check valves can be installed both horizontally and vertically.

      DUAL PLATE CHECK VALVE

      A dual plate check valve, also known as a double door check valve or a butterfly check valve, is an advanced design of the traditional check valve. It operates automatically to prevent the backflow of fluid in a piping system, ensuring flow in only one direction. The valve features two spring-loaded plates (or discs) that open with forward flow and close rapidly to prevent reverse flow, making it an efficient and reliable choice for a wide range of applications.

      dual plate check valve

      Design

      The key components and design features of a dual plate check valve include:

      • Body: The outer shell of the valve that houses the internal components. It can be made from various materials, including cast iron, stainless steel, carbon steel, and other alloys, depending on the application’s specific requirements for pressure, temperature, and corrosion resistance.
      • Plates (Discs): Two semi-circular plates are hinged on either side of the valve body, allowing them to swing open or close. The plates are typically lightweight, enhancing their ability to respond quickly to changes in flow direction.
      • Springs: Each plate is equipped with a spring that facilitates quick closing of the plates when the forward flow stops or when there is a reversal in flow direction. The springs help in minimizing the risk of water hammer and valve slam.
      • Seat: A sealing surface inside the valve body against which the plates close. The seat can be integral to the valve body or replaceable and is designed to ensure a tight seal when the valve is closed.
      • Hinge Pins: Pins around which the plates pivot. They are designed to ensure smooth and reliable operation of the plates.

      Operation

      In operation, forward flow exerts pressure on the plates, causing them to swing open and allow fluid to pass through the valve. The design of the plates and the presence of springs ensure that they open with minimal pressure drop. When the flow decreases or reverses, the springs assist in quickly closing the plates, preventing backflow. The rapid response of the plates helps to significantly reduce the potential for water hammer.

      Advantages

      • Compact and Lightweight: Dual plate check valves are more compact and lighter than traditional swing check valves, making them easier to install and requiring less support structure.
      • Low-Pressure Drop: The design allows for a smoother flow path when open, resulting in a lower pressure drop compared to other types of check valves.
      • Quick Closure: The spring-loaded plates close rapidly, reducing the risk of water hammer and backflow.
      • Versatility: Suitable for a wide range of applications and can be installed in both horizontal and vertical orientations with upward flow.

      Applications

      Dual plate check valves are used in various industrial applications, including:

      • Water and Wastewater Treatment: To prevent backflow in treatment plants and distribution systems.
      • Oil and Gas: In pipelines and processing facilities for protecting equipment and ensuring unidirectional flow.
      • HVAC Systems: To prevent reverse flow in heating and cooling systems.
      • Process Industries: In chemical, petrochemical, and food and beverage processing plants to protect sensitive equipment and maintain process integrity.

      Selection Considerations

      When selecting a dual plate check valve, it’s important to consider:

      • Fluid Characteristics: Compatibility with the valve materials to prevent corrosion and ensure durability.
      • Operating Conditions: The valve’s rating must match the system’s maximum pressure and temperature.
      • Installation Space: The compact design is advantageous in tight spaces, but the orientation and location should still be considered for optimal performance.
      • Maintenance Requirements: Though generally low maintenance, access for inspection or replacement of components should be considered.

      In summary, dual plate check valves offer an efficient and reliable solution for preventing backflow in piping systems, combining compact design with quick operation and low-pressure drop. Their versatility and performance advantages make them suitable for a broad range of applications across various industries.

      TITLING DISC CHECK VALVE

      A tilting disc check valve is a type of check valve designed to allow fluid to flow in one direction and prevent backflow. It features a disc that tilts on a hinge or pivot point, opening in response to forward flow and closing when the flow stops or reverses. This design offers improved dynamics over traditional swing check valves, making it particularly effective in applications where rapid closure is needed to prevent reverse flow and minimize the risk of water hammering.

      titling disc check valve
      titling disc check valve

      Design Features

      • Disc Mechanism: The disc in a tilting disc check valve is mounted such that it tilts around a point or axis that is offset from the center of the disc. This allows the disc to open with a smaller amount of fluid pressure compared to swing check valves and to close more quickly as the flow diminishes.
      • Seat: The valve seat is designed to provide a tight seal when the disc closes. The seating arrangement can be configured to reduce wear and enhance the sealing capability.
      • Body: The valve body can vary in design but is typically streamlined to facilitate smooth fluid flow and minimize pressure drop across the valve.

      Operational Advantages

      • Quick Response: The tilting mechanism allows for rapid opening and closing of the valve, which helps in preventing the backflow more effectively and reduces the potential for water hammer, a pressure surge caused when a fluid in motion is forced to stop or change direction suddenly.
      • Low-Pressure Drop: When open, the valve offers minimal obstruction to the flow, resulting in a lower pressure drop compared to some other check valve designs.
      • Long Service Life: The design of the tilting disc check valve, including the way the disc interacts with the flow, can contribute to reduced wear on the valve components, leading to a longer service life.

      Applications

      Tilting disc check valves are suitable for a wide range of applications, particularly in systems where rapid valve closure is necessary to protect equipment and ensure system integrity. Common applications include:

      • Water Supply Systems: Used in high-rise buildings and municipal water distribution networks to prevent backflow.
      • Power Generation: Installed in cooling water systems, feedwater systems, and condensate pump discharge lines to prevent reverse flow.
      • Process Industries: Utilized in chemical and petrochemical plants, where the prevention of backflow is critical to process safety and efficiency.
      • HVAC Systems: Implemented heating and cooling systems to maintain directional flow and system balance.

      Selection Considerations

      When selecting a tilting disc check valve, consider the following:

      • Fluid Characteristics: Ensure the valve materials are compatible with the fluid, including considerations for temperature, pressure, and potential corrosiveness.
      • Installation Orientation: While versatile, the specific design of the tilting disc check valve may make it more suitable for certain orientations. Consult manufacturer recommendations.
      • Maintenance Requirements: Consider the ease of maintenance and access to internal components, as regular inspection may be necessary to ensure optimal performance.

      Tilting disc check valves offer an efficient solution for preventing backflow in fluid systems, combining quick response, durability, and effective operation across a variety of applications.

    • FOOT CHECK VALVE

      A foot check valve is a specific type of check valve designed to be installed at the bottom of a pump suction line, primarily used to maintain the pump’s prime by preventing the backflow of fluid. These valves are typically submerged in the source fluid, such as a well or a tank. Foot check valves are essential components in pumping systems where the pump is located above the fluid level, ensuring a steady and reliable supply of fluid to the pump and preventing the system from running dry.

      foot check valve
      foot check valve

      Design Features

      • Body: Foot check valves are commonly made from durable materials such as cast iron, stainless steel, PVC, or bronze, depending on the application and the type of fluid being handled.
      • Screen or Strainer: A key feature of foot check valves is the integrated screen or strainer at the inlet. This screen prevents debris, sediment, and other particulates from entering the pump suction line, protecting the pump and the system from damage.
      • Valve Mechanism: The valve mechanism can vary but often includes a ball, disc, or flap that opens under the pressure of incoming fluid when the pump operates. When the pump stops, the mechanism seals against a seat to prevent fluid from flowing backward.

      Operational Advantages

      • Maintains Prime: By preventing the backflow of fluid, foot check valves help maintain the pump’s prime, which is crucial for efficient pump operation and to avoid pump damage due to dry running.
      • Filtration: The built-in screen or strainer filters out debris, ensuring that the fluid entering the pump is free from particulates that could cause wear or clogs.
      • Versatility: Suitable for a wide range of applications, including water, chemicals, and other fluids, depending on the construction materials.

      Applications

      Foot check valves are used in various applications where pumps need to draw fluid from a source below the pump, such as:

      • Water Supply Systems: In wells, cisterns, or tanks where pumps supply water to residential, agricultural, or industrial systems.
      • Irrigation Systems: To ensure a constant supply of water and prevent contamination of the water source by soil or debris.
      • Flood Control and Drainage: In pumping stations that remove water from low-lying areas.
      • Industrial Processes: Where liquid ingredients or products are transferred from storage tanks into processing systems.

      Selection Considerations

      When choosing a foot check valve, it’s essential to consider:

      • Fluid Compatibility: Select materials that are compatible with the fluid to prevent corrosion or chemical degradation.
      • Screen Mesh Size: The mesh size of the screen should be suitable for filtering out debris while allowing sufficient flow to meet the system’s demands.
      • Pressure and Flow Requirements: Ensure the valve can handle the system’s pressure and flow rate without causing excessive pressure drop or hindering pump performance.
      • Maintenance Accessibility: Consider how easily the valve can be accessed for cleaning or maintenance, especially since foot check valves are often submerged.

      In summary, foot check valves play a critical role in pumping systems, providing both a non-return function to maintain the pump prime and a filtration role to protect the pump and the system. Their selection and maintenance are vital for the reliability and efficiency of fluid transfer operations.

      PRESSURE SEAL CHECK VALVE

      Pressure seal check valves are a type of check valve designed for high-pressure and high-temperature applications, commonly found in power generation, oil and gas, and industrial process systems. Unlike traditional bolted bonnet check valves, pressure seal check valves use a pressure seal bonnet design that ensures a tighter seal as system pressure increases. This design is particularly effective in environments where safety and efficiency are paramount, and where operating conditions can exceed pressures of 600 psi and temperatures above 1000°F (538°C).

    • Pressure seal check valve

      Design

      The key components of a pressure seal check valve include:

      • Body: The main structure that contains the internal components. It can be made of materials suited for high pressure and temperature, such as carbon steel, alloy steel, or stainless steel.
      • Bonnet: Instead of being bolted to the body, the bonnet in a pressure seal valve is sealed using a pressure seal gasket. As system pressure rises, the gasket is further compressed, enhancing the seal between the bonnet and the valve body.
      • Pressure Seal Gasket: A unique component of pressure seal valves, this gasket is usually made of flexible graphite for high-temperature applications or metal for extremely high pressures. It is designed to ensure a tight seal that improves with increased pressure.
      • Disc: The movable part that opens to allow flow in the forward direction and seats against the valve seat to prevent backflow. The design of the disc can vary but typically mirrors that of swing or lift check valves.
      • Seat: The surface against which the disc seals when the valve is closed. It can be integral to the valve body or replaceable, depending on the design.

      Operation

      In operation, forward flow pressure pushes the disc away from the seat, allowing fluid to pass through the valve. When flow stops or reverses, the disc moves back to the seat, preventing backflow. The unique pressure seal design ensures that as system pressure increases, the seal between the bonnet and the body becomes tighter, which is particularly advantageous in high-pressure applications where ensuring a reliable seal is challenging.

      Advantages

      • High-Pressure and Temperature Capability: Designed to operate reliably in conditions where standard check valves might fail, making them ideal for critical applications.
      • Improved Seal Integrity: The pressure seal design ensures that the valve’s sealing capability improves under higher pressures, providing a robust solution for high-pressure systems.
      • Compact Design: Pressure seal valves tend to be more compact than their bolted bonnet counterparts, beneficial in systems where space is limited.

      Applications

      Pressure seal check valves are used in applications that demand reliable operation under high pressure and temperature, such as:

      • Power Generation: In steam, feedwater, and other high-pressure systems within power plants.
      • Oil and Gas Production: For high-pressure drilling and production systems.
      • Chemical Processing: In processes involving high-pressure reactions or transfers.

      Selection Considerations

      When selecting a pressure seal check valve, consider:

      • System Pressure and Temperature: Ensure the valve material and design are rated for the system’s maximum operating pressure and temperature.
      • Fluid Compatibility: Choose materials that are compatible with the fluid to prevent corrosion or degradation of the valve components.
      • Maintenance Requirements: While durable, pressure seal valves can be more challenging to maintain due to their design. Consider ease of maintenance and access when selecting a valve.

      Pressure seal check valves offer a reliable solution for controlling flow in high-pressure and high-temperature systems, ensuring safety and efficiency in demanding industrial environments.

      DUCKBILL CHECK VALVE

      A duckbill check valve is a unique type of check valve that gets its name from the duckbill-shaped flexible rubber or elastomer flap that acts as the valve mechanism. This design allows the valve to permit fluid flow in one direction while preventing backflow in the opposite direction. Duckbill check valves are known for their simplicity, reliability, and low maintenance, making them an excellent choice for various fluid control applications, especially where backflow prevention is critical.

      Duckbill Valve
      Duckbill Valve

      IN-LINE CHECK VALVE

      An inline check valve, also known as an in-line check valve, is a type of check valve designed for simple, direct installation within the pipeline. Its primary function is to allow fluid (liquid or gas) to flow in one direction only, preventing backflow which could potentially cause damage or disrupt the operation of a system. Inline check valves are known for their compact design, which makes them particularly suitable for applications with limited space.

      Inline Check Valve
      Inline Check Valve

      Design Features

      • Compact and Simple: Inline check valves have a straightforward and compact design, allowing for easy installation directly into a piping system without the need for special fittings or extensive modifications.
      • Body Construction: The valve body is typically cylindrical and can be made from a variety of materials, including metals like brass, stainless steel, and PVC, to suit different application needs and fluid compatibility.
      • Closure Mechanism: The closure component inside an inline check valve varies by design but commonly includes a ball, disc, or piston that moves away from the valve seat to allow flow and seals against the seat to prevent backflow. Some designs use a spring to ensure the closure mechanism responds quickly to changes in flow direction.
      • Connection Types: Inline check valves are available with various types of end connections, such as threaded, socket weld, or flanged, to match the piping system requirements.

      Operational Advantages

      • Low Pressure Drop: Many inline check valve designs are optimized to minimize pressure drop across the valve when it is in the open position, maintaining system efficiency.
      • Fast Response to Flow Changes: The simplicity of the design often allows for a quick response to stopping backflow, protecting the system from potential damage.
      • Versatility: Inline check valves can be used in a wide range of applications and are compatible with many types of fluids and gases.

      Applications

      Inline check valves are used across various industries and applications, including:

      • Water and Wastewater Systems: To prevent backflow and protect pumps and other equipment.
      • Chemical Processing: For ensuring unidirectional flow of chemicals in processing lines.
      • HVAC Systems: In heating and cooling lines to maintain proper flow direction.
      • Hydraulic and Pneumatic Systems: To prevent reverse flow in systems that rely on pressurized fluids or air.

      Selection Considerations

      When selecting an inline check valve, consider the following:

      • Material Compatibility: Choose a valve material that is compatible with the fluid or gas to prevent corrosion or chemical degradation.
      • Operating Conditions: Ensure the valve can withstand the system’s pressure and temperature conditions.
      • Flow Requirements: Select a valve size and design that meets the flow rate requirements without causing excessive pressure drop.
      • Maintenance and Accessibility: Consider how the valve design will impact maintenance needs and whether it can be easily accessed for service if necessary.

      Inline check valves offer a convenient and efficient solution for ensuring unidirectional flow in piping systems. Their compact design, ease of installation, and reliability make them a popular choice for many applications where backflow prevention is critical.

      SUMP PUMP CHECK VALVE

      A sump pump check valve is a critical component in a sump pump system, designed to prevent the backflow of water from the discharge pipe back into the sump pit after the pump has turned off. Sump pumps are commonly used in basements and crawl spaces to remove accumulated water, preventing flooding and water damage. The check valve ensures that once water is pumped out of the pit and through the discharge line, it does not return, thereby enhancing the efficiency of the pump and reducing the risk of flooding.

      Design

      The design of a sump pump check valve is relatively simple, comprising a few key components:

      • Body: Usually made of durable plastic, PVC, or sometimes metal, designed to withstand the water pressure and any debris that might be present in the water.
      • Flapper or Ball: The mechanism inside the valve that allows water to flow in one direction and blocks it from flowing backward. In sump pump check valves, a flapper or a ball is common, which moves or tilts to open when water is pumped through and seals shut when the flow stops.
      • Connectors: Ends that attach to the discharge pipe of the sump pump and the discharge line leading away from the house. These can be designed for various types of connections, including threaded, slip-on, or barbed, depending on the installation requirements.

      Operation

      When the sump pump activates, water pressure opens the flapper or moves the ball, allowing water to pass through the valve and into the discharge line. When the pump shuts off, the decrease in pressure allows the flapper or ball to return to its closed position, creating a seal that prevents water from flowing back into the sump pit. This one-way operation is crucial for maintaining the effectiveness of the sump pump system and preventing cycling (where the pump turns on and off frequently), which can lead to premature pump failure.

      Advantages

      • Prevents Backflow: Keeps pumped water from returning to the sump pit, reducing the workload on the sump pump and minimizing wear.
      • Reduces Cycling: By preventing backflow, it reduces the frequency of pump activation, thereby extending the life of the pump.
      • Simple Installation: Most sump pump check valves are designed for easy installation and can be added to existing systems without significant modifications.

      Applications

      Sump pump check valves are used in residential, commercial, and industrial settings where sump pumps are installed to control water accumulation. These include:

      • Basements and Cellars: To prevent flooding from groundwater or stormwater intrusion.
      • Crawl Spaces: To manage moisture and prevent water damage.
      • Outdoor Drainage Systems: Where pumps are used to move water away from buildings or sensitive areas.

      Selection Considerations

      When choosing a sump pump check valve, consider:

      • Compatibility: Ensure the valve fits the discharge pipe diameter of your sump pump system.
      • Material: Select a material compatible with the type of water being pumped, especially if debris or chemicals may be present.
      • Valve Type: Consider the mechanism (flapper vs. ball) based on the pump’s flow rate and the head pressure.
      • Ease of Maintenance: Some designs allow for easier cleaning and maintenance, which can be beneficial in systems that handle debris-laden water.

      In summary, a sump pump check valve is an essential component that enhances the efficiency and longevity of a sump pump system by preventing backflow of water into the sump pit, ensuring that once water is removed, it stays out.

      CHECK VALVE MATERIALS (ASME, API)

      Materials used for check valves in various industries, particularly those handling critical processes, need to meet specific standards to ensure reliability, safety, and longevity. The American Society of Mechanical Engineers (ASME) and the American Petroleum Institute (API) provide guidelines and standards for materials used in the manufacturing of check valves. These standards help in selecting materials that are suitable for the intended application, especially considering the operational pressures, temperatures, and fluid characteristics. Below are some key materials standards from ASME and API relevant to check valves:

      ASME Material Standards

      • ASME B16.34 – Valves – Flanged, Threaded, and Welding End
        • This standard covers material requirements for ferrous and non-ferrous valve construction, including temperature and pressure ratings for various materials. It is widely referenced for valve materials in piping systems.

      API Material Standards

      • API 600 – Steel Gate Valves – Flanged and Butt-Welding Ends, Bolted Bonnets
        • Though primarily focused on gate valves, API 600 includes material specifications applicable to check valves, especially regarding carbon steel, alloy steel, stainless steel, and other materials for high-pressure and high-temperature service.
      • API 602 – Compact Steel Gate Valves – Flanged, Threaded, Welding, and Extended-Body Ends
        • This standard, while focusing on gate valves, also touches on material specifications for smaller size valves that can be relevant to compact check valves in similar service conditions.

      Common Materials For Check Valves

      • Carbon Steel: Widely used due to its strength and durability, suitable for a broad range of temperatures and pressures. ASME and API standards specify different grades, such as ASTM A216 WCB, for various service conditions.
      • Stainless Steel: Offers excellent corrosion resistance and is used in applications involving corrosive fluids or stringent cleanliness requirements. Common grades include ASTM A351 CF8M (316 stainless steel).
      • Alloy Steel: Used for applications requiring higher strength and resistance to high temperatures or pressures. Alloys like ASTM A217 WC6 are commonly specified for services with elevated temperatures.
      • Bronze and Brass: Offer good corrosion resistance and are commonly used in low to moderate temperature and pressure applications, such as water, gas, and some chemical services.
      • Ductile Iron: Provides good strength, durability, and some corrosion resistance, making it suitable for water and other non-corrosive services at lower costs than steel.

      Considerations For Material Selection

      1. Fluid Service: The material must be compatible with the fluid to prevent corrosion or degradation that could lead to valve failure.
      2. Pressure and Temperature: The material should withstand the maximum expected pressure and temperature in the system.
      3. Environment: External environmental conditions, such as exposure to corrosive atmospheres, should also be considered.

      By adhering to ASME and API material standards, engineers and specifiers can ensure that check valves will perform reliably and safely in their intended applications, maintaining system integrity and protecting against failure.

      CHECK VALVE TRIM

      Check valve trim refers to the internal components of a check valve that come into direct contact with the process fluid and are critical to the valve’s operation and performance. The trim typically includes parts such as the disc (or ball), seat, stem (if applicable), and any springs or other mechanisms that contribute to the opening and closing of the valve. The material selection and design of the check valve trim are crucial for ensuring proper function, durability, and compatibility with the fluid being handled.

      Components Of Check Valve Trim

      • Disc or Ball: The movable part that seals against the seat to prevent backflow. In ball check valves, a ball acts as the movable element, whereas other types of check valves may use a disc or other shapes.
      • Seat: The surface against which the disc or ball seals when the valve is closed. It can be integrated into the valve body or designed as a replaceable component. The seat must provide a tight seal to effectively prevent backflow.
      • Stem: In some types of check valves, such as lift check valves, a stem connects the disc to an actuator or mechanism outside the valve body. The stem facilitates the movement of the disc within the valve.
      • Spring: Many check valves incorporate a spring to assist in closing the valve, ensuring quick response to flow changes and helping to prevent flow reversal and water hammer.

      Material Considerations

      The choice of materials for check valve trim is determined by factors such as:

      • Fluid Compatibility: The trim materials must be chemically compatible with the process fluid to avoid corrosion, degradation, or contamination.
      • Operating Conditions: The materials must withstand the temperature and pressure conditions of the application without losing structural integrity or performance.
      • Wear Resistance: Components like the disc and seat are subject to wear due to repeated opening and closing; thus, materials should be selected for their durability and wear resistance.

      Common materials used for check valve trim include:

      • Stainless Steel: Offers excellent corrosion resistance and strength, suitable for a wide range of applications.
      • Brass: Commonly used in low-pressure applications and compatible with many types of fluids.
      • Bronze: Provides good corrosion resistance and is often used in water and steam applications.
      • Alloy Steels: Selected for high-pressure, high-temperature applications where additional strength and durability are required.
      • Plastics and Composites: Used in applications where corrosion resistance is paramount, such as in aggressive chemical environments.

      Selection Guidelines

      When selecting check valve trim materials, consider the following:

      • Review Fluid Service: Analyze the chemical properties of the fluid, including any potential for corrosion or chemical reaction.
      • Assess Operating Conditions: Ensure the materials can handle the maximum expected temperature and pressure.
      • Consider Flow Characteristics: For applications involving abrasive or viscous fluids, select materials that resist wear and erosion.
      • Compliance with Standards: Ensure that the materials meet relevant industry standards and regulations, such as those set by ASME, API, or NACE for specific applications.

      Choosing the appropriate trim materials is essential for the reliability and longevity of check valves, ensuring they function correctly under the intended service conditions and minimize maintenance requirements.

      CHECK VALVE GA DIAGRAM

      he body of non-return valves below 2 inches is generally made of forged steel (common grades are ASTM A105 for high-temperature service, ASTM A350 for low-temperature service, and, ASTM A182 F304/F316 for corrosive service), whereas the bodies for larger bore sizes check valves are made of cast steel (ASTM A216 WCB for high-temperature service, ASTM A351 for low-temperature conditions and ASTM A351 CF8 and CF8M – i.e. SS304 and SS316).

      Check valve assembly drawingStandard check valves materials

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HOW TO ORDER A VALVE

Learn about the different types of valves used in the oil and gas industry: API and ASME gate, globe, check, ball, and butterfly designs (manual or actuated, with forged and cast bodies). Valves are mechanical devices used in piping applications to control, regulate and open/close the fluid’ s flow and pressure. Forged valves are used for small bore or high-pressure piping applications, cast valves for piping systems above 2 inches. 

WHAT ARE VALVES?

INTRODUCTION TO OIL & GAS VALVES

Valves play a crucial role in the oil and gas industry, serving as the gatekeepers for controlling the flow of fluids through pipelines and equipment. These mechanical devices can open, close, or partially obstruct pathways to manage the movement of oil, gas, and sometimes water or other fluids, ensuring safe and efficient operation of extraction, processing, transportation, and storage systems.

Petrochemical valves
Petrochemical Valves

Let’s delve into the importance, types, and applications of valves in the oil and gas sector, offering a comprehensive overview for readers interested in the pivotal role these components play in our energy infrastructure.

Functions Of Valves In Oil And Gas

Valves are indispensable for the oil and gas industry due to their ability to:

  • Control the Flow: Regulate the rate of flow of oil and gas in pipelines, ensuring optimal operation conditions (start/stop/modulate/change the direction of the flow)
  • Maintain the Pressure: Keep the pressure within pipelines and systems at safe levels to prevent accidents and ensure the integrity of the system.
  • Ensure Safety: Act as safety devices that can shut off flow in emergency situations, preventing leaks, spills, and catastrophic failures.
  • Allow operational Flexibility: Allow for the maintenance of parts of the system without shutting down the entire operation, providing operational flexibility and minimizing downtime.

Petrochemical valves

(Source: Spirax Sarco)

ypes Of Valves In Oil And Gas

The oil and gas industry uses a wide variety of valves, each designed for specific functions, pressure ranges, and fluid types. Some of the most common include:

  • Gate Valves: Used for on/off control of fluid flow, offering minimal restriction when fully open.
  • Globe Valves: Ideal for regulating flow or pressures as well as starting or stopping flow due to their precise throttling capabilities.
  • Ball Valves: Known for their quick shut-off capabilities, providing a tight seal with a quarter-turn motion, suitable for both on/off and throttling services.
  • Butterfly Valves: Feature a disc that rotates to open or close the flow path. They are compact and suitable for large-diameter pipes, offering quick operation and low-pressure drop.
  • Check Valves: Allow fluid to flow in one direction only, preventing backflow that could damage equipment or disrupt the process.
  • Safety Valves: Automatically release pressure when it exceeds set limits to protect equipment and ensure safe operations.
  • To explore these valve types in greater detail, our site hosts specialized articles for each category. Follow the links mentioned above to gain a more comprehensive understanding of each specific valve type, if you wish to broaden your expertise.

    Applications Of Valves In Oil And Gas

    Valves are used throughout the oil and gas supply chain, from upstream exploration and production to downstream refining, distribution, and storage:

    • Upstream Operations: In drilling rigs, production wells, and offshore platforms, valves control the flow of oil and gas from reservoirs to the surface and manage injection processes for enhanced recovery.
    • Midstream Infrastructure: Valves are used in pipelines, pumping stations, and compressor stations to transport oil and gas across long distances, ensuring that flow and pressure levels are maintained.
    • Downstream Processing: In refineries and petrochemical plants, valves manage the flow of crude oil into various processes for separation, conversion, and treatment to produce fuels and chemicals.
    • Storage and Distribution: Valves are essential in tank farms and terminals for controlling the storage and loading of oil, gas, and finished products for distribution.

    A valve is manufactured by assembling multiple mechanical parts, the key ones being the body (the outer shell), the trim (the combination of the replaceable wetted parts), the stem, the bonnet, and an actioning mechanism (manual lever, gear, or actuator).

    Valves with small bore sizes (generally 2 inches) or that require high resistance to pressure and temperature are manufactured with forged steel bodies; commercial valves above 2 inches in diameter feature cast body materials.

    The valve market is rather huge in terms of revenues and number of dedicated workers: it was worth approximately 40 billion USD per year in 2018. The major manufacturers of oil & gas valves are located in the US, Europe (Italy, Germany, France, and Spain), Japan, South Korea, and China.

    In conclusion, valves are fundamental to the safe, efficient, and effective operation of the oil and gas industry, ensuring that energy resources are extracted, processed, transported, and stored with precision and care. Their variety and adaptability make them indispensable tools in the complex systems that fuel the modern world.

  • VALVE TYPES

    Valves used in the oil and gas industry and for piping applications can be classified in multiple ways:

    BY DISC TYPE (LINEAR, ROTARY, QUARTER TURN)

    In the diverse world of valves, categorizing them by their operational mechanics—specifically, how they move to regulate flow via the disc —provides insight into their suitability for different applications in industries like oil and gas, water treatment, and chemical processing.

    Let’s explore the distinctions between linear motion valves, rotary motion valves, and quarter-turn valves to understand their functionalities, advantages, and typical uses.

    Linear Motion Valves

    Linear motion valves operate by moving a closure element in a straight line to control the flow of fluid. This category includes:

    • Gate Valves: Utilize a flat gate that moves vertically to the flow, providing a straight-through pathway when open and a secure seal when closed.
    • Globe Valves: Feature a plug that moves up and down against the flow, offering precise flow regulation and the capability to stop flow entirely.
    • Diaphragm Valves: Employ a flexible diaphragm that moves up and down to permit or restrict flow.

    Advantages:

    • Precise control of flow and pressure.
    • Suitable for on/off and throttling applications, particularly where flow rate control is essential.

    Typical Uses:
    Situations requiring tight shut-offs and flow regulation, such as in water treatment plants and in the control of gas or steam.

    Rotary Motion Valves

    Rotary motion valves rotate a disc or ellipse about an axis to control fluid flow. This group encompasses:

    • Ball Valves: Contain a ball with a hole through it, which rotates 90 degrees to open or close the flow path.
    • Butterfly Valves: Have a disc mounted on a rod, which rotates to allow or block flow.

    Advantages:

    • Compact and lightweight design.
    • Quick operation with low torque requirements.
    • Generally lower in cost than linear motion valves for the same size and rating.

    Typical Uses:
    Broadly used in applications requiring rapid operation and space-saving solutions, such as in the chemical industry and for water distribution systems.

    Quarter-Turn Valves

    Quarter-turn valves are a subset of rotary motion valves that operate with a simple 90-degree turn of the handle or actuator to go from fully open to fully closed positions, or vice versa. This category includes Ball Valves and Butterfly Valves, as mentioned above, due to their quarter-turn operation.

    Advantages:

    • Speed and ease of operation.
    • Effective shut-off capabilities, making them ideal for both isolating and control applications.
    • Versatility in handling a wide range of media, pressures, and temperatures.

    Typical Uses:
    Extensively used across various sectors, including oil and gas for pipeline flow control, in manufacturing processes, and in HVAC systems for controlling water flow and temperature.

    In summary, the choice between linear motion, rotary motion, and quarter-turn valves depends on specific application requirements such as the need for precise flow control, space constraints, and operational efficiency. Linear motion valves excel in providing precise control and tight shut-off, rotary motion valves offer compact and quick solutions, and quarter-turn valves bring the best of rotary action in terms of speed and simplicity, making them versatile for a wide array of applications.

  • Oil & Gas Valve Types Linear motion valves Rotary  motion valves Quarter turn valves
    Gate valve X
    Globe valve X
    Check valve X
    Lift check valve X
    Tilting-disc check valve X
    Stop check valve X X
    Ball valve X X
    Pinch valve X
    Butterfly valve X X
    Plug valve X X
    Diaphragm valve X
    Safety Valve / Pressure Relief Valve X

  • VALVES BY BODY MATERIAL (CAST, FORGED)

    The distinction between cast and forged valves lies in their manufacturing processes, which fundamentally affect their physical characteristics, performance, and applications.

    As a general rule, cast bodies are used for valves above 2 inches in bore size, whereas forged bodies are used for valves below 2 inches (or preferred to cast valves, regardless of the pipeline bore size, in mission-critical applications). 

    Both types of valves play critical roles in controlling the flow of liquids and gases in various industries, including oil and gas, power generation, and water treatment.

    Understanding the differences between cast and forged valves is essential for selecting the right valve for a specific application, ensuring optimal performance, durability, and safety.

    Cast Valves

    Manufacturing Process

    Cast valves are made by pouring molten metal into pre-shaped molds where it solidifies into the desired valve shape. The casting process can be done through various methods, including sand casting, investment casting, and die casting, each with its own set of characteristics regarding surface finish, dimensional accuracy, and intricacies of design.

    Characteristics

    • Versatility in Design: Casting allows for complex shapes and sizes, making it possible to produce valves with intricate internal geometries that would be difficult or impossible to achieve through forging.
    • Material Variety: A wide range of materials can be cast, including various types of steel, iron, and non-ferrous alloys, offering flexibility in material selection based on the application requirements.
    • Cost-Effectiveness for Complex Shapes: For complex shapes and larger sizes, casting can be more cost-effective than forging, especially for low to medium-volume production.

    Limitations

    • Potential for Defects: The casting process can introduce internal defects such as porosity, shrinkage cavities, and inclusions, which can affect the mechanical properties and integrity of the valve.
    • Variability in Quality: Cast valves can exhibit variability in quality and material properties across different batches due to the nature of the casting process.
    Forged Valves

    Manufacturing Process:
    Forged valves are created through the process of forging, where a piece of metal is heated and then deformed and shaped into the desired form using high pressure. Forging can be performed using various techniques, including open-die forging, closed-die forging, and ring rolling, depending on the desired final shape and characteristics.

    Characteristics

    • Strength and Durability: Forging produces valves with superior strength, ductility, and resistance to impact and fatigue compared to casting. The forging process aligns the grain structure of the metal with the shape of the valve, enhancing its mechanical properties.
    • Consistency in Quality: Forged valves generally offer more uniformity and consistency in material properties, with fewer internal defects than cast valves.
    • High Performance in Critical Applications: Due to their strength and reliability, forged valves are preferred in high-pressure, high-temperature, and other critical applications where safety and performance are paramount.

    Limitations

    • Design Limitations: Forging cannot achieve the same level of complexity and intricate internal features that casting can, especially for large or very complex valve designs.
    • Cost Considerations: For high-volume production of simple shapes, forging can be cost-effective. However, for complex shapes or lower volumes, the cost may be higher than casting, particularly for large-sized valves.

    In summary, the choice between cast and forged valves depends on the specific requirements of the application, including mechanical strength, pressure and temperature conditions, desired material properties, design complexity, and cost considerations. Forged valves are typically favored in high-stress, high-performance applications due to their superior strength and reliability, while cast valves offer greater design flexibility and cost-effectiveness for complex shapes and large sizes.

  • To learn more about the difference between steel casting and forging please refer to the linked article.

    VALVES BY TYPE OF ACTUATION (MANUAL, ACTUATED)

    Valves can also be categorized based on their method of operation into manually operated valves and actuated valves. Understanding the differences between these two types is crucial for selecting the appropriate valve for a specific application, considering factors like ease of operation, control precision, and the necessity for automation.

    Manually Operated Valves

    Characteristics

    • Operation: Manually operated valves require physical effort by an operator to change their position, using handwheels, levers, or gears. The manual input directly controls the opening, closing, or throttling of the valve.
    • Design Simplicity: These valves are simpler in design as they do not require additional equipment for operation, making them straightforward to install and maintain.
    • Cost-effectiveness: Without the need for external power sources or automation equipment, manually operated valves are generally more cost-effective than their actuated counterparts.
    • Reliability: With fewer components that could fail, manually operated valves are highly reliable and suitable for applications where valve adjustments are infrequent or where direct manual control is preferred.

    Limitations

    • Labor Intensive: For systems requiring frequent adjustments or in situations where valves are not easily accessible, manual operation can be labor-intensive and time-consuming.
    • Lack of Remote Control: Manual valves cannot be operated remotely, limiting their use in large, complex systems or in hazardous environments where remote operation is necessary for safety.
    Actuated Valves

    Characteristics

    • Operation: Actuated valves are equipped with an actuator that allows valve operation (open, close, or modulate) through electrical, pneumatic, or hydraulic power. Actuators can be controlled remotely, allowing for automation and integration into control systems.
    • Automation and Precision: With the ability to be controlled by various signals (electric, pneumatic, or hydraulic), actuated valves offer precise control over flow and pressure, enabling more efficient operation of the system.
    • Flexibility and Safety: Remote operation capabilities allow actuated valves to be used in inaccessible, hazardous, or harsh environments, improving safety and operational flexibility.
    • Adaptability: They can be integrated into automated control loops, responding to sensor inputs to adjust flow conditions automatically, which is essential for optimizing processes and ensuring safety in dynamic conditions.

    Limitations

    • Complexity and Cost: Actuated valves require additional components (actuators, power sources, control systems) making them more complex and expensive to install and maintain compared to manually operated valves.
    • Power Requirement: Dependence on an external power source (electrical, pneumatic, or hydraulic) for operation can be a limitation in environments where such resources are limited or unavailable.

    In summary, the choice between manually operated and actuated valves depends on several factors, including the need for automation, the operational environment, safety considerations, and cost. Manually operated valves are suitable for simpler, cost-sensitive applications where direct control and infrequent adjustments are sufficient. In contrast, actuated valves are ideal for complex systems requiring precise, remote, or automated control to enhance efficiency, safety, and operational flexibility.

    VALVE BY DESIGN

    Regarding their design, valves can be categorized in the following manner (it’s worth noting that our site features detailed articles on each type, so the descriptions provided here are intended to be broadly overviewed):

    GATE VALVE

    Gate valves are the most used type in piping and pipeline applications. Gate valves are linear motion devices used to open and close the flow of the fluid (shutoff valve). Gate valves cannot be used for throttling applications, i.e. to regulate the flow of the fluid (globe or ball valves should be used in this case). A gate valve is, therefore, either fully opened or closed (by manual wheels, gears, or electric, pneumatic and hydraulic actuators)

    GLOBE VALVE

    Globe valves are used to throttle (regulate) the fluid flow. Globe valves can also shut off the flow, but for this function, gate valves are preferred. A globe valve creates a pressure drop in the pipeline, as the fluid has to pass through a non-linear passageway.

    CHECK VALVE

    Check valves are used to avoid backflow in the piping system or the pipeline that could damage downstream apparatus such as pumps, compressors, etc. When the fluid has enough pressure, it opens the valve; when it comes back (reverse flow) at a design pressure, it closes the valve – preventing unwanted flows.

    BALL VALVE

    A Ball valve is a quarter-turn valve used for shut-off application. The valve opens and closes the flow of the fluid via a built-in ball, that rotates inside the valve body. Ball valves are industry standard for on-off applications and are lighter and more compact than gate valves, which serve similar purposes. The two main designs are floating and trunnion (side or top entry)

    BUTTERFLY VALVE

    Butterfly valves are versatile, cost-effective, valves to modulate or open/close the flow of the fluid. Butterfly valves are available in concentric or eccentric designs (double/triple), have a compact shape, and are becoming more and more competitive vs. ball valves, due to their simpler construction and cost.

    PINCH VALVE

    This is a type of linear motion valve that can be used for throttling and shut-off applications in piping applications that handle solid materials, slurries, and dense fluids.  A pinch valve features a pinch tube to regulate the flow.

    PLUG VALVE

    Plug valves are classified as quarter-turn valves for shut-off applications. The first plug valves were introduced by the Romans to control water pipelines.

    SAFETY VALVE

    A safety valve is used to protect a piping arrangement from dangerous overpressures that may threaten human life or other assets. Essentially, a safety valve releases the pressure as a set value is exceeded.

    CONTROL VALVE

    Control valves are automated devices that are used to control and regulate the flow in complex systems and plants. More details about this type of valves are given below.

    Y-STRAINERS

    while not properly a valve, Y-strainers have the important function of filtering debris and protecting downstream equipment that may be otherwise damaged

    VALVE SIZES (ASME B16.10)

    To make sure that valves of different manufacturers are interchangeable, the face-to-face dimensions (i.e. the distance in mm or inches between the inlet and the outlet of the valve) of the key types of valves have been standardized by the ASME B16.10 specification.

    ASME B16.34: VALVE COMPLIANCE

    The ASME B16.34 standard, issued by the American Society of Mechanical Engineers (ASME), is a pivotal guideline that specifies the requirements for the design, material selection, manufacturing, inspection, testing, and marking of flanged, threaded, and welding end steel valves for application in pressure systems.

    ASME B16.34 is also mentioned in the more general ASME spec ASME B31.1, “Power Piping Design”.

    This standard is critical for ensuring the safety, reliability, and efficiency of valves used in various industrial sectors, including oil and gas, chemical, power generation, and water treatment, among others.

    Understanding the ASME B16.34 standard is essential for engineers, manufacturers, and end-users involved in the selection and application of valves.

    Key Aspects Of ASME B16.34

    1. Valve Design and Construction:
      ASME B16.34 sets forth the criteria for the design of valves, including dimensions, pressure-temperature ratings, and other factors essential for ensuring that valves can operate safely under specified conditions. It covers a range of valve types, such as gate, globe, check, ball, and butterfly valves.
    2. Pressure-Temperature Ratings:
      One of the most critical aspects covered by ASME B16.34 is the pressure-temperature rating of valves, which defines the maximum allowable working pressure for a valve at a given temperature. These ratings ensure that valves are selected and used within their safe operating limits.
    3. Material Specifications:
      The standard provides detailed specifications for the materials used in valve construction, including requirements for body, bonnet, trim, and gasket materials. These specifications ensure compatibility with the fluid being handled and the operating environment, contributing to the valve’s integrity and longevity.
    4. Testing and Inspection:
      ASME B16.34 outlines the requirements for testing and inspecting valves to verify their integrity and performance. This includes tests for shell strength, seat tightness, and backseat effectiveness, among others, which are crucial for ensuring that valves meet stringent safety and reliability standards.
    5. Marking and Documentation:
      The standard specifies the marking requirements for valves, which include the manufacturer’s identification, pressure-temperature rating, material designation, and other relevant information. These markings provide essential information for the identification, traceability, and selection of valves.

    Importance Of ASME B16.34 In Valve Selection

    Adherence to the ASME B16.34 standard is crucial for ensuring that valves perform safely and effectively in their intended applications. Engineers and procurement specialists rely on this standard to select valves that meet the necessary performance criteria, including compatibility with the process medium, operating pressures and temperatures, and durability requirements.

    Compliance with ASME B16.34 is also often a regulatory requirement in many industries, making it a key consideration in the procurement and installation of valves in critical applications.

    Valve Compliance To ASME B16.34

    A valve complies with ASME B16.34 when the following conditions are met:

    • The valve body & shell materials comply with ASME and ASTM material standards for chemistry and strength
    • Body & shell materials are heat-treated to ensure proper grain structure, corrosion resistance, and hardness.
    • Wall thicknesses of the body and other pressure-containing components meet ASME B16.34 specified minimum values for each pressure class.
    • NPT and SW end connections comply with ASME B1.20.1 or ASME B16.11.
    • Stems are internally loaded and blowout-proof.
    • All bolting will be ASTM grade with maximum applied stress controlled by B16.34.
    • Each valve is shell tested at 1,5x rated pressure for a specific test time duration.
    • Each valve is tested for seat leakage in both directions for a specific test time duration.
    • Each valve is permanently tagged with materials of construction, operating limits, and the name of the manufacturer.

    In conclusion, ASME B16.34 plays a fundamental role in the design, selection, and application of valves in pressure systems. It provides a comprehensive framework for ensuring that valves are safe, reliable, and suitable for their intended use, supporting the operational integrity of industrial processes across various sectors.

  • HOW TO ORDER A VALVE

    Manufacturers of valves used in the oil and gas industry need to know the following information to supply the right device:

    • Valve type
    • Bore size in NPS or DN
    • Valve pressure rating (class range from 150# to 4500#)
    • Specification (example API 6D, API 600, API 602, etc)
    • Body and trim materials (at least)
    • Required end connection (flanged, threaded, butt weld, lug and others)
    • Fluid in the pipeline (>oil, gas, water, steam, solids)
    • Working temperature and pressure
    • Quantity
    • Delivery time
    • Origin restrictions (Chinese and Indian origins allowed or not)

    EXAMPLE HOW TO ORDER OIL & GAS GATE, GLOBE, CHECK VALVES

    Each manufacturer has own valves ordering sheets that map the valve configuration parameters that user has to consider:

    GS – F – 6″ / 150 – 316 – B

      1    2        3           4      5

    1. Valve type 2. End type 3. Size / Class 4. Body Material 5. Options
    C: Check Valve
    CL: Lift Check Valve
    CS: Check pressure Sealed Valve
    CW: Swing Check Valve
    G: Gate Valve
    GG: Forged Gate Valve
    GL: Light Type Gate Valve (API 603)
    GS: Gate Pressure Sealed Valve
    O: Globe Valve
    OB: Globe Bellowed Sealed Valve
    OS: Globe Pressure Sealed Valve
    Y: Y-strainer    		 F: Flanged End
    T: Threaded End
    W: Butt Weld End
    S: Socket Weld End    		 Size: NPS 1/2 – 80″

    ANSI Standard:
    150: 150 LB Class
    300: 300 LB Class
    600: 600 LB Class
    1500: 1500 LB Class

    DIN Standard：

    PN16
    PN25
    PN40

    JIS Standard：

    10K: JIS 10K
    20K: JIS 20K

    		 GG: Forged Gate Valve
    316: Casting S.S CF8M
    304: Casting S.S CF8
    F316: Forgings S.S F316
    F304: Forgings S.S F304
    WCB: Steel WCB
    LCB: Steel LCB
    HB: Hastelloy B
    IN: Inconel    		 B: By-Pass
    G: Gear Operator
    D: Drains
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