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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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ASTM Materials for Valves: ASTM A216, A351, A352, A105, and A182 (Cast & Forged Grades)

Discover the essential AsTM material standards for valves., Valves larger than 2 inches typically have cast valve bodies, created by casting molten metals into molds, Forged valve bodies, suitable for smaller or high-pressure valves, are made by shaping and machining solid steel. The principal material specifications for cast steel valve bodies include ASTM A216 (WCA, WCB, WCC forstandard conditions, ASTM A352 LCB/LCC for low temperatures, and ASTM A351 CF8/CF8M for stainless steel valves. For forged valve bodies, the relevant ASTM standards are A105, A350, and A182.

CAST STEEL VALVES(ASTM GRADES)

DEFINITION OF CAST VALVE

Cast valves are valves whose bodies have been formed by pouring molten metal into a mold where it solidifies into the desired shape. This casting process allows for the creation of complex shapes and sizes, making it possible to produce valve bodies with intricate internal geometries that would be challenging or impossible to achieve through forging or machining alone. Cast valves are widely used across various industries due to their versatility in design, the ability to work with a wide range of materials, and their cost-effectiveness for producing large or complex valves, They are suitable for numerous applications, handling everything from water and steam to chemicals and gas, depending on the material used in the casting process Therefore, cast valves are characterized by a body made through casting, whereas forged valves possess a body created by forging. Essentially, the difference between cast and forged valves lies in the method used to construct the valve body material.specifically whether it involves steel forging or casting.
Let’s now delve into the most common cast valve body materials according to ASTM

ASTM A216 WCA, WCB, WCC (CARBON STEEL FOR HIGH-TEMPERATURE)

ASTM A216 is a specification established by the American Society for Testing and Materials (AsTM) that covers carbon steel castings for valves, flanges, fittings, and other pressure-containing parts for high-temperature service. The standard is divided into three grades: WCA, WCB, and WCC, with WCB being the most commonly used grade.
These 3 grades covered by the AsTM A216 specification differ mainly in their mechanical properties and temperature capabilities:

 

WCA is the grade with the lowest strength and temperature tolerance.
WCB is the intermediate grade, offering a good balance of strength and ductility across a wide range of temperatures.
WCC has higher strength and impact properties at low temperatures compared to WCB.
ASTM A216 specifies the chemical composition, mechanical properties, heat treatment, and testing requirements to ensure the material’s quality and durability under high-temperature condition This standard is commonly applied in the manufacturing of components for industrial boilers, pressure vessels, and other equipment where robust performance at elevated temperatures is required.
The ASTM A216 specification applies to cast valves that match carbon steel pipes in grades A53, A106, and API 5L.
ASTM A216 steel castings shall be heat treated and can be manufactured in annealed, normalized, or normalized tempered conditions.The surface of steel castings shall be free of adhering elements such as sand, cracks, hot tears, and other defects.

Notes:
1., for each reduction of 0.019% below the specified maximum Carbon content, an increase of 0.04% of manganese above the specified maximum is allowed up to a maximum of 1.10%.
2. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.0496 Mn above the specified maximum is allowed up to a maximum of 1.28%.
3. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% of manganese above the specified maximum is allowed to a maximum of 1.40%.

ASTM A352 LCB/LCC (CARBON STEEL FOR LOW-TEMPERATURE)
ASTM A352 is an ASTM (American Society for Testing and Materials standard specification that covers steel castings for valves,flanges, fittings, and other pressure-containing parts intended primarily for low-temperature service. The standard includes several grades of carbon and alloy steel castings that vary in their mechanical properties and chemical compositions to suit different environmental conditions and temperature ranges.
The grades under ASTM A352 are designed to perform reliably in environments where temperatures may fall below freezing, making them suitable for applications in cold climates or in processes requiring cryogenic temperatures.

 

Key grades within this specification include:
LCB: A grade of carbon steel castings suitable for low-temperature applications where temperatures can go as low as-46°C (-50°F).
LCC: Similar to LcB but with improved impact strength at lower temperatures, making it suitable for even more demanding
low-temperature environments.
LCl, LC2, LC3, LC4: These are alloy steel grades within AsTM A352, each designed for specific low-temperature ranges and applications, with Lc3, for example, being nickel steel castings intended for service down to -01’C -150°F).

Each grade specified in ASTM A352 has defined requirements for chemical composition, mechanical properties such as tensile strength, yield strength, and elongation), and toughness to ensure the castings perform adequately under the specified service conditions, The standard also outlines requirements for heat treatment, quality, and test methods to verify the properties of the castings.
ASTM A352 is widely used in the oil and gas industry, petrochemical plants, and other applications where materials are exposed to low temperatures and require a high level of toughness to prevent brittle fracture.
The ASTM A352 specification applies to cast valves that match carbon steel pipes for low-temperature applications in grades A333.
Chemical composition of A352 cast valves Gr, LCA/LCB/Lcc (valve material chart)

valve material chart

ASTM A351 CF8/CF8M (STAINLESS STEEL FOR HIGH-TEMP. & CORROSIVE SERVICE)

ASTM A351 is a standard specification established by the American Society for Testing and Materials (ASTM) that covers castings of austenitic steel for valves, flanges, fittings, and other pressure-containing parts. This specification is particularly focused on stainless steel castings that are intended for high-temperature service. The ASTM A351 standard includes several grades, each with specific chemical compositions and mechanical properties to suit different environments and applications.

Key grades under ASTM A351 include:

  • CF8: Equivalent to 304 stainless steel, this grade is known for its good corrosion resistance and is widely used in general applications.
  • CF8M: Equivalent to 316 stainless steel, CF8M offers enhanced corrosion resistance due to its molybdenum content, making it suitable for more corrosive environments such as those encountered in chemical processing.
  • CF3 and CF3M: These are the low-carbon versions of CF8 and CF8M, respectively, offering similar corrosion resistance but with improved weldability and reduced susceptibility to intergranular corrosion after welding or heating.

The standard specifies requirements for chemical composition, mechanical properties, heat treatment, and testing procedures to ensure the quality and performance of the castings. ASTM A351 stainless steel castings are commonly used in applications requiring good corrosion resistance at both ambient and elevated temperatures, including the chemical industry, food processing, and petrochemical operations, among others.

Any ASTM A351 cast part shall receive heat treatment followed by a quench in water or rapid cooling. The steel shall conform to the chemical and mechanical requirements set by the specification. The steel shall be made by the electric furnace process with or without separate refining such as argon-oxygen decarburization.

The ASTM A351 specification applies to cast valves that match stainless steel pipes for high-temperature and corrosive applications applications in ASTM A312.

 

ASTM A351 stainless steel valves, chemical composition

 

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Valve Material ASTM, DIN, JIS Convertion Chart

Valve Material ASTM, DIN, JIS Convertion Chart

Valve Material ASTM, DIN, JIS Convertion Chart

The following material is commonly used for valves.

ASTM DIN EN10213 DIN EN No. UNS JIS Trademark
A216 WCB GP240GH 1.0619 J03002 SCPH2  
A352 LCB G20Mn5 1.0622 J03003 SCPL1  
A352 LC3 G9Ni14 1.5638 J31550 SCPL31  
A217 WC1 G20Mo5 1.5419 J12524 SCPH11  
A217 C5 GX15CrMo5 1.7365 (1.7363) J42045 SCPH61  
A217 C12 GX12CrMo10-1 1.7389 J82090    
A351 CF3 X2CrNi19-11 1.4306 J92500 SCS19  
A351 CF3M X2CrNiMo17-12-2 1.4404 J92800 SCS16  
A351 CF8 GX5CrNiMo19-10 1.4308 J92600 SCS13  
A351 CF8C GX5CrNiNb19-11 1.4552 J92710    
A351 CF8M GX5CrNiMo19-11-12 1.4408 J92900 SCS14  
A351 CF8MC GX5CrNiMoNb19-11-2 1.4581      
A351 CG8M          
  GX2CrNiMoN22-5-3 1.447      
           
A351 CK3MCuN          
A351 CN7M     N08007 SCS23  
A494 N-12MV     N10001   HASTELLOY B
A494 CW-12MW     N10002   HASTELLOY C
A494 M35-1     N04400   MONEL 400
A494 CW-6MC     N06625   INCONEL 625
      N08825   INCOLOY 825
      S31803   SAF 2205
      S31254   254 SMO
      S32550   FERRALIUM 255
Material Comparison
Casting Forging
ASTM EN 10213 EN No. ASTM EN 10213 EN No.
A216 WCB GP240GH (GS-C 25N) 1.0619 A105 C22.8 1.046
A352 LCB G20Mn5 1.622 A352 LF2   1.0437
A352 LC3 G9Ni14 1.5638 A352 LF3   1.5637
A217 WC1 G20Mo5 1.5419 A182 F1   1.5415
A217 WC6 G17CrMo5-5 1.7357 A182 F11 14CrMo405 1.7335
A217 WC9 GS12CrMo9-10 1.738 A182 F22   1.738
A217 C5 GX15CrMo5 1.7365 A182 F5   1.7362
-1.7363
A217 CA15     A182 F6 X20Cr13 1.4021
A217 C12 GX12CrMo10-1 1.7389 A182 F9 15CrMo12.1 1.492
A351 CF3 X2CrNiMo17-12-2 1.4406 A182 F304L X2CrNi19-11 1.4306
A351 CF3M X2CrNiMo17-12-2 1.4404 A182 F316L X2cRNImO17-12-2 1.4404
A351 CF8 GX5CrNiMo19-10 1.4308 A182 F304 X5CrNi18-10 1.4301
A351 CF8C GX5CrNiNb 19-11 1.4552 A182 F321 X6CrNiTi18-10 1.4541
A351 CF8C GX5CrNiNb 19-11 1.4552 A182 F347 X6CrNiNb18-10 1.455
A351 CF8M GX5CrNiMo19-11-2 1.4408 A182 F316 X5CrNiMo17-12-2 1.4401
A351 CF8MC GX5CrNiMoNb19-11-2 1.4581 A182 F348 X6CrNiMoNb17-12-2 1.458
A351 CG8M GX2CrNiMoN22-5-3 1.447 A182 F317    
A351 CK3MCuN     A182 F44    
A351 CN7M     A182 F20  

 

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What is the difference between a foot valve and a check valve?

In short, a foot valve and a check valve are very similar in that they automatically open or close depending on system pressure, allowing flow in only one direction and preventing backflow. Figure 1 shows a check valve on the right and a foot valve on the left, with the main visual difference being that the foot valve has a strainer on it. Given the similarities between the two valves, there are important differences. Foot and check valves have different installation locations in a system, different material requirements, and different designs. This article will focus on these key differences. Read our comprehensive articles about check valves and foot valves to learn more about each type of valve.

Operation principle

Understanding how check and foot valves work is helpful before discussing their differences. Both valve types open when the inlet pressure is above the valve’s cracking pressure. The cracking pressure is the minimum amount of pressure required to open the valve and overcome the force keeping the valve closed (spring or gravity). When the inlet pressure reduces below this limit, or there is backpressure, the valve closes shut.

Differences between check valves and foot valves

Design

Foot and check valves have a variety of design types, for example, ball check valves and ball foot valves. This section, though, focuses on the design differences that exist between all check and foot valves.

  • Screen: The first visual difference is the screen attached to the foot valve’s inlet end, which is often called a strainer or filter. Foot valves typically sit submerged in water in a well. The screen prevents larger debris from entering the foot valve and sticking the valve’s disc open and damaging other components within the system. A check valve does not have this protection and therefore is not applicable for media that has large solids in the flow.
  • Threading: A check valve has threading on both sides. So, a check valve fits into any part of the piping deemed appropriate. Removing a section of the pipe and installing a check valve is a straightforward process. Foot valves, however, have threading only on one side. Therefore, foot valves are only suitable for the end of a pipe, which is the end of a pump’s suction line.

Material

The key material difference between foot and check valves is that foot valves are in water for the duration of their use. Therefore, whichever material selected must be corrosion resistant. Materials often chosen are PVC, heavy-duty cast iron, bronze, and stainless steel.

Check valves have a wider range of material options because they operate in a wider range of environments. When selecting a check valve material, first understand the system’s pressure, temperature, and operating environment. Read our chemical resistance guide to learn more.

Installation

Because foot valves work on pump systems, this section will only cover the installation locations of check and foot valves on these systems. Both valves stop media from flowing back into the well when the pump turns off, thus keeping the pump primed.

A jet pump uses a foot valve at the very end of its suction line. In contrast, a submersible pump has a foot valve directly installed on its inlet. Both pump systems can use check valves in the same locations. However, this is not suitable for any wells that may contain solids large enough to get stuck in the valve and hinder its operation.

Deep well systems use one or more extra check valves along the suction line to protect the submersible pump and foot valve from the water column’s pressure. Shallow well systems may have a check valve on the suction line. Also, check valves can install directly at the jet pump’s inlet or between the jet pump and pressure tank. Beyond stopping backflow into the well, check valves are applicable anywhere where backflow may damage an upstream component or contaminate upstream media.

Foot valve and check valve P&ID symbols

Figure 2 depicts a check valve symbol (left) and a foot valve symbol (right).

Check valve symbol (left) and foot valve symbol (right).Figure 2: Check valve symbol (left) and foot valve symbol (right).

Summary

Table 1: Comparison between foot valve and check valve

Foot valve Check valve
Design A foot valve has a strainer on the inlet side. A check valve does not have a strainer.
Material Foot valves have a limited selection of materials: stainless steel, heavy-duty cast iron, PVC, and bronze. Check valves have more material options because they do not rest in water.
Application Foot valves are used for suction lift applications, like a well pump. Check valves are applicable for pump systems and any system that requires backflow prevention.
Installation Foot valves only go at the end of a pump’s suction line. Check valves can go at the end of a suction line, in the middle of the suction line, and anywhere else in the system where necessary.
Threading Foot valves have threading on the outlet side only. Check valves have threading on both sides.

FAQs

What is the difference between a foot valve and a check valve?

A foot valve has a screen on its inlet side to prevent large solids from entering the valve. Also, it fits at the end of a suction line in a pump system. A check valve is suitable for any system, including pump systems, that require media to flow in only one direction.

Can a check valve be used in place of a foot valve?

Yes, a check valve can be used in place of a foot valve. However, check valves do not have a protective screen and any large solids in the media can stick them in the open position.

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How to Select the material for Gate Valve

Selecting the right gate valve material is crucial in the gate valve selection process. Various materials are used for the gate valve’s body and seal. The material selection depends primarily on the media type and design temperature. This article discusses the common materials used in gate valves and how to find the right one for each application.

Gate valve material selection

Gate valves are used in a wide range of applications, and they come in contact with diverse media. It is critical to consider the material used for valve construction to prevent premature valve failure and system delays during valve operation. Consider the following criteria to select the proper materials for a gate valve:

  1. Media composition (whether clear or filled with particles)
  2. Material compatibility with the media used
  3. How long the valve gets exposed to the media
  4. Operating pressure
  5. Service temperatures
  6. Effectiveness of coating on materials
  7. Material availability and cost

Gate valves are available in various materials, as discussed in the next section. Various organizations are committed to developing and maintaining standards for valves and materials in specific environments. For example, gate valves are specified by the American Petroleum Institute (API) and the National Association For Corrosion Engineers (NACE) for their suitability to work with heavy corrosive media.

Gate valve body materials

The various materials used to construct gate valve body are discussed below.

PVC gate valve

PVC gate valve gate-valve-pvc.jpegFigure 2: PVC gate valve

In a PVC gate valve, the valve’s three main components, namely, the handle, housing, and gate, are made of PVC.

PVC gate valve features

  • PVC gate valves are not damaged by freezing temperatures, and these valves can also withstand temperatures up to 60°C.
  • Resistant to corrosion, making these valves ideal for chemical processing applications involving highly corrosive substances.
  • PVC valves are affordable compared to metal valves.
  • Excellent durability offering many years of reliable use.
  • Available in a wide range of sizes.

PVC gate valve applications

PVC gate valves are a good low-cost solution for most flow control needs at home. These valves are durable and corrosion-resistant, hence widely used in aquatic environments. A few common applications are:

  • Aquatics and aquaculture
  • Landscaping and irrigation
  • Tank drain valves and septic systems
  • Indoor plumbing
  • Spas

Brass gate valve

In applications where PVC gate valves would burst, it is a viable option to use gate valves made of metals or their alloys.

Brass gate valve features

  • Brass gate valves work on 0-16 bar pressure range with media temperatures from -20°C to 120°C. Hence, they can withstand higher temperatures and pressure than PVC gate valves.
  • Brass is stronger than PVC, but stainless steel is the strongest.
  • Brass gate valves are costly compared to PVC gate valves, but less costly than stainless steel gate valves.

Brass gate valve applications

Brass can withstand more heat than PVC, making them an ideal choice for residential plumbing applications. Brass is extremely corrosion resistant, and the gate valves made of brass are ideal for manufacturing industries involving natural gas or potable water.

Stainless steel gate valve

Stainless steel gate valveFigure 3: Stainless steel gate valve

Stainless steel gate valve features

  • Stainless steel is the most durable, heat-resistant, and corrosion-resistant material when compared to brass and PVC.
  • Withstands very high temperature (up to 800°C) and pressure. Stainless steel can withstand a wide range of temperatures (low to high) and pressure compared to brass and PVC.
  • Used to manufacture gate valve body and internal parts
  • Stainless steel gate valves have a simple body design enabling ease of repair, cleaning, and maintenance
  • Used in applications involving liquid, gas, and steam
  • Expensive compared to PVC, brass, and bronze gate valves
  • Needs a large area for installation compared to brass or PVC

Stainless steel gate valve applications

Stainless steel is extremely durable and corrosion-resistant, hence used in marine and industrial applications. Some common applications are:

  • Industrial applications like transporting natural gas and crude oil
  • Slurry applications
  • Drinking water applications at home as the material doesn’t leach into the water

Bronze gate valve

Bronze gate valveFigure 4: Bronze gate valve

Bronze gate valve features

  • Excellent machinability, strength, and corrosion resistance
  • Used to manufacture relatively small gate valves in low-pressure applications
  • Bronze gate valves are typically used for water pipes and equipment pipelines of about 300 psi (20 bar) or less, and temperatures in the range -20° C -150° C.
  • Higher cost compared to PVC, but less than brass and stainless steel
  • Bronze has higher corrosion resistance than cast iron, but less than PVC or brass.
  • Costlier than PVC but the cost is lower than brass or stainless steel.

Bronze gate valve applications

Bronze has high lead content; hence the material is not used frequently for drinking water applications. Bronze is commonly used for fluid control in low-pressure manufacturing industries and works well with steam, air, and gas. The material is also used in HVAC and marine applications.

Cast iron gate valve

Cast iron gate valveFigure 5: Cast iron gate valve

Cast iron gate valve features

  • Cast iron has strength lying in between bronze and stainless steel
  • Used to manufacture gate valve body
  • Very low tensile strength and elongation properties, but good casting qualities
  • Cast iron gets corroded over time.
  • Less costly compared to all other valve materials.

Cast iron gate valve applications

Cast iron is used for constructing gate valves in low-pressure and low-temperature applications. The material is a popular choice for gate valves in water, wastewater, heating, ventilation, and air-conditioning (HVAC) units. Cast iron gate valves are extremely cheap, yet sturdy; hence these valves are more suitable for underground applications than steel valves.

Cast steel gate valve

Cast steel gate valve feature

  • Casted carbon steel is a tough material, and the material is hard with excellent tensile strength and impact value.

Cast steel gate valve application

  • Gate valves made of cast steel are commonly used in industrial plants for high temperature and pressure applications.
Cast steel gate valves used in industrial plantsFigure 5: Cast steel gate valves used in industrial plants

Gate valve seal materials

Gate valve seats are available in two forms:

  • Integrated-type: The gate valve seal is made of the same material as the valve body and it is integrated into the valve body.
  • Ring type: In this type, the gate valve seal is in the form of a ring that can be either pressed in or threaded which favors more variation. The seat can be coated with polytetrafluoroethylene (PTFE) to aid high-integrity shutoff. The ring-type seal is again classified into resilient-seated and metal-seated gate valves:
    • Resilient seated gate valves: The gate is mostly composed of ductile iron and enclosed in a resilient elastomer material like ethylene propylene diene monomer (EPDM) forming a tight seal. These valves are preferred in water distribution systems because of the tight shut-off.
    • Metal-seated gate valves: Ductile iron is commonly used as the gate material, and rings are made of bronze to ensure a watertight seal.
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What is the difference between standard port and full port ball valves?

A ball valve is a type of valve that controls the flow of fluids through piping systems. Depending on the intended application, ball valves have a variety of designs. Based on the port size, a ball valve can be classified as either a full port, standard port, or reduced bore ball valve. This article compares the various advantages and disadvantages of each ball valve type. Read our ball valve overview article for more details on the working and design of ball valves.

Ball valves based on port size

Full port ball valve

A full port or full bore ball valve is a type of ball valve where the inlet and outlet pipes have the same diameter as the bore in the valve. In simple terms, the valve port is the same size as the pipe resulting in a full flow ball valve. For a full port ball valve, there is little or no resistance to the flow of fluids, and the flow path is straight.

Standard port ball valve

In a standard port ball valve, the size of the bore in the ball is smaller than the size of the inlet and outlet pipes. The diameter of the flow path through the ball valve is narrower on the interior. The standard port ball valve creates resistance to flow, increasing its fluid pressure. The flow path is usually straight.

Reduced port ball valve

In reduced bore ball valves, the port in the ball valve is one pipe size narrower than the inlet and outlet pipes. In other words, the diameter of the bore is one specification smaller than the pipes’ diameter specification. The fluid flowing through a reduced port valve has a higher velocity.

Full port (left) and reduced port (right) ball valvesFigure 2: Full port (left) and reduced port (right) ball valves

Comparison between full port, standard port, and reduced port ball valves

As the features of reduced port and standard port ball valves are identical in all aspects both valve types are grouped into one throughout the comparison process as seen below.

Port size

  • Reduced/standard port ball valves: The valve port is smaller than the pipe diameter.
  • Full port ball valves: The size of the valve port is the same as that of the pipe diameter.

Media

Media is the fluid flowing through the pipes and the ball valve. The media can be solids, liquids, or gases.

  • Reduced/standard port ball valves: Reduced or standard port ball valves are helpful to convey plain fluids like gasses or water. These valves transport light media in general.
  • Full port ball valves: The full-bore ball valves are suitable forviscous fluids because it offers little or no flow resistance. Examples of viscous fluid include paraffin, glycerin, etc.

Pipeline and flow control

  • Reduced/standard port ball valvesReduced and standard port ball valves offer a flow resistance, thus producing a pressure drop. The flow path through the valve becomes narrower on the valve’s inside. Reduced or standard port ball valves are ideal for relaxed working conditions where pressure drop does not affect pipe performance. This is because these valves reduce the velocity of the medium and hence suitable for applications where flow resistance is acceptable.
  • Full port ball valves: A full port ball valve has a straight flow path and offers little or no resistance to the media flow. The flow path through a full port ball valve does not become narrower on the inside. Full-bore ball valves are the only option for piping systems under strict working conditions. Underground pipes, regardless of the medium, must only use full port ball valves. When it comes to pipeline control, full port valves are ideal.

Pigging applications

Pigging is the process of cleaning a gas pipeline where a device known as a pig travels through the pipeline. This process is not supported by certain valve types that do not allow the free travel of pig through the connected valve.

  • Reduced/standard port ball valves: Reduced port ball valves have different diameters for the bore and connecting pipe; hence the pigging device cannot travel freely through a reduced bore ball valve for cleaning purposes.
  • Full port ball valves: In an open state, the bore of a full-port ball valve is parallel to the inlet and outlet ports; hence, there is no visual difference between the valve and pipe bores. In this way, a pig can have an unrestricted flow through the valve, thereby cleaning the bore of the valve along with the entire pipeline.

Cost

  • Reduced/standard port ball valves: A reduced or standard port ball valve has a compact body and thus lower costs.
  • Full port ball valves: Purchasing a full port ball valve requires a larger initial investment than purchasing a reduced port ball valve. The full port is more expensive because many materials are used in its construction. Because of its effective performance, a full-port ball valve is cost-effective in the long run.

Fitting space

Fitting space is the amount of space the ball valve will occupy when installed.

  • Reduced/standard port ball valves: A reduced/standard port ball valve has a small volume and thus requires little space.
  • Full port ball valves: A full-port ball valve has a large volume necessitating more space.

Transportation

  • Reduced/standard port ball valves: The small volume and lightweight properties of a reduced port ball valve make it easy to transport.
  • Full port ball valves: The full-port ball valve is heavy and has a large volume. This makes its transportation difficult and costly.

Full port ball valve with a drain

A full port ball valve with a drain is essential for preventing fluid or condensation buildup inside the valve. Failure to drain the valve can damage the valve. Draining is done to replace contaminated and stale fluids within the valve. Draining relieves any pressure that has built up within the valve. To drain a ball valve, first, allow fluid to flow into the drain by opening the valve. Then, close the valve to prevent fluid from flowing through it. Finally, open the valve and allow the fluid to drain. Read our article on condensate drain valve for more information.

3-way full port ball valve

A 3-way full port ball valve has three ports. These valves are available with either an L or T-port design. The L and T designation refers to the internal bore design, determining the media’s flow direction. A 3-way ball valve with a T or L port allows for mixing, distribution, or diverting the flow direction for different applications. To open a 3-way, rotate the ball until the ports are aligned with the corresponding ports, allowing fluids to flow through. To close, rotate the ball back to the closed position. When the ports are closed, they are out of place and not aligned with one another.

Comparison chart

Table 1: Comparison between standard/reduced and full port ball valve port designs

Standard/reduced port ball valve Full port ball valve
Pipeline control Not ideal Ideal
Cost Low initial cost High initial most
Fitting space Less More
Transportation Easy Difficult
Pigging applications Not ideal Ideal

FAQs

What is the difference between standard port and full port ball valves?

In a full port ball valve, the ports of the valve have the same diameter as the connecting pipes. The valve port size is smaller than the pipe diameter in a standard port ball valve.

Why is the standard port more common than the other types of ball valves?

The design of a standard port ball valve is convenient for most applications. It is compact, relatively light, and less expensive.

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Which valve is better between globe valves and ball valves?

Globe valves and ball valves are both shut-off valves typically used in piping systems. However, it is usually not immediately obvious which valve is most suitable for an application. System design should be finished before valve selection in order to select the best valve for the job in terms of cost, installation space, flow control, and more. Keep reading to learn more about how a globe valve may be more suitable than a ball valve and vice versa.

Working principles

Globe valve working principle

A globe valve in the open position (left) and the closed position (right) with the valve stem (A), stem (B), plug (C), and body (D).Figure 2: A globe valve in the open position (left) and the closed position (right) with the valve stem (A), bonnet (B), plug (C), and body (D).

A globe valve is a multi-turn valve, meaning that the handwheel needs to be turned more than 360° to fully open or close the valve. The main components of a globe valve are the valve body, bonnet, handwheel, stem, and plug. Media flows into the valve body (Figure 2 labeled D) through an inlet and exits the valve body through an outlet. The bonnet (Figure 2 labeled B) protects the threaded components of the valve and attaches to the valve body. As the user turns the handwheel, it turns the threaded stem (Figure 2 labeled A), which raises or lowers the plug (Figure 2 labeled C). Raising the plug opens the orifice, thereby allowing media flow. Lowering the plug into the valve seat seals the orifice, preventing the flow. Raising the disc, on the other hand, increases the flow rate. The flow rate is maximum when the disc is raised to its maximum position. The fluid flow rate is controlled by moving the disc proportionally through the stem.

Ball valve working principle

Ball valve parts; Stem (A), o-rings (B), body (C), ball (D), and seat (E)Figure 3: Ball valve parts; Stem (A), o-rings (B), body (C), ball (D), and seat (E)

A ball valve is a quarter-turn valve, meaning that the handle only needs a 90° turn to fully open or close the valve. The main components of a ball valve are shown in Figure 3. The stem (Figure 3 labeled A) connects to the ball (Figure 3 labeled D). The ball sits on the ball valve seat (Figure 3 labeled E), creating the seal. O-ring stem seals (Figure 3 labeled B) are used to prevent leakage. All of these components are within the valve housing (Figure 3 labeled C). As seen in Figure 3, the ball has a bore running through it. Under normal operation, the bore is either aligned with the valve ports to allow flow, or perpendicular to the ports to block flow. Read our article on ball valves for more details on how they work.

Flow control

Globe and ball valves are both used to turn on or off the flow. Globe valves, though, can also function in a partially open or closed state to modulate the flow. This flow regulation is achievable due to the globe valve’s disc sitting parallel to the flow. The linear flow rate achieved by globe valves is higher than that achieved by ball valves, and reduces the effects of water hammer.

Head loss

Globe valves have significantly higher pressure loss (head loss) in the fully open position than ball valves. This is because the fluid has to change direction multiple times as it passes through a globe valve.

Valve design

Globe valve design

Globe valves are available in three basic configurations: T- or Z globe valve, Y-globe valve, and angle globe valve. Read our article on globe valves for more information on each type.

Ball valve design

The ball valve can be classified into different categories depending on its housing structure, ball design, and port size. Depending on the housing structure, we can have 1, 2, or 3-piece ball valves. Depending on the port size, ball valves are categorized as full port ball valves, standard port ball valves, or reduced port ball valves. And depending on the number of ports, ball valves are classified into 2-way and multiport valves.

Symbols

  • Figure 4 shows the symbols for various globe valve configurations.
Globe valve symbols: globe (A), hand operated (B), pneumatic (C), motor operated (D), hydraulic operated (E).Figure 4: Globe valve symbols: globe (A), hand operated (B), pneumatic (C), motor operated (D), hydraulic operated (E).

The symbols for a ball valve are shown in Figure 5. For more details on the symbols of various ball valve configurations, read our article on ball valve symbols.

Actuated ball valve symbols; manually operated ball valve (A), pneumatically actuated ball valve (diaphragm type) symbol (B), pneumatically actuated ball valve (rotary piston type) symbol (C), electrically actuated ball valve symbol, and a hydraulic actuator ball valve symbol (D).Figure 5: Actuated ball valve symbols; manually operated ball valve (A), pneumatically actuated ball valve (diaphragm type) symbol (B), pneumatically actuated ball valve (rotary piston type) symbol (C), electrically actuated ball valve symbol (D), and a hydraulic actuator ball valve symbol (E).

Applications

Globe valves are used to control fluid flow. Furthermore, globe valves are advantageous in applications requiring precise throttling. Ball valves, on the other hand, are commonly used for plumbing system shut-off and isolation. Industrial applications for globe valves include fuel oil systems and cooling water systems, while those of ball valves include chemical storage and natural gas industries.

Globe valve and ball valve similarities

Globe valves and ball valves share some similarities. Both valves are used in piping systems to control the flow of liquids and gasses. Both are shut-off valves designed to allow or block the fluid flow within a pipe. Globe valves and ball valves can be operated manually or automatically.

Pros and cons of ball valves and globe valves

  1. Operation: Ball valves are simple and easier to operate than globe valves.
  2. Throttling: Globe valves are suitable for throttling operations, whereas ball valves should be either fully shut or fully open.
  3. Handle: Ball valves are quarter-turn valves which means the ball valve handle must be turned by 90° to go from fully open to a fully closed state or vice versa. The handwheel of globe valves must be turned multiple times from entirely closed to fully opened.
  4. Cost: Due to their simple structure, ball valves are cheaper than globe valves.
  5. Space: Globe valves occupy more space compared to ball valves.
  6. Pressure rating: Ball valves can handle higher pressure than globe valves.
  7. Durability: Ball valves are longer-lasting than globe valves.
  8. Leakages: Globe valves are more prone to leakages than ball valves.
  9. Media flow resistance: A globe valve offers more resistance to media flow compared to ball valves.
  10. Head loss: Globe valves have a higher head loss than ball valves.

Globe valve and ball valve selection

The selection between a ball valve and a globe valve depends on the intended purpose. The main factors to consider during the selection process are discussed below:

  1. Flow rate: Ball valves are desirable in applications where a high flow rate is necessary due to their full-bore design.
  2. Pressure drops: Ball valves have lower pressure drops because flow moves straight through them.
  3. Maintenance: Ball valves are simple to maintain because the valve only needs a little lubrication to stay clean. Further maintenance is necessary upon debris buildup.
  4. Temperature: Ball valves function better under high-temperature conditions due to their durable construction.

FAQs

What are the typical applications of a globe valve?

Globe valves are used commonly to control water flow in irrigation systems, regulate airflow in AC systems, and control oil flow in pipelines.

What is the main difference between a ball valve and a globe valve?

The ball valve has a hollow ball that rotates inside the valve, whereas the globe valve has a disc that moves vertically through the valve stem.

Which valve is better between globe valves and ball valves?

This depends on the intended application. Globe valves are better for throttling applications, while ball valves offer better performance as shutoff valves.

View our online selection of globe and ball valves!

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What is the advantage of gate valves over globe valves?

Despite their similarities at first inspection, globe and gate valves have significant differences that make each suitable for their applications. When choosing between these two valves for an application, understanding the application’s pressure, sealing, and flow requirements can ensure the correct valve is selected. This article discusses the differences between globe and gate valves to allow an educated decision before choosing between the two valves.

Globe valve vs gate valve comparison

Globe valves and gate valves are multi-turn, linear motion valves, meaning both valves require multiple turns to open or close. The closing mechanism moves up and down in a straight line to turn open or close the valve. At this point, similarities between the valves begin to diminish.

The globe valve differs from most valves because its name derives from its body shape (rounded) rather than its disc, which is the gate valve’s convention. Its disc moves up and down to allow or block the flow, similar to a gate. Read more on globe valves and gate valves to get a comprehensive understanding of both.

Flow properties

As seen in Figure 2, a gate valve is a straight-through, bi-directional valve, meaning its design permits flow directly through it in both directions. The only change to the flow occurs when the gate valve is closed, and the flow stops.

A gate valve flow properties when it is closed (left) and open (right).Figure 2: A gate valve flow properties when it is closed (left) and open (right).

A globe valve, on the other hand, has more turns for the flow path. As seen in Figure 3, the flow can take a z-shaped path (T- or Z-valve), an oblique path (Y-valve), or a 90° turn path (angle valve).

Because a globe valve diverts flow in a specific way, it has an inlet and an outlet port. Typically, an arrow on the outside of the valve’s body will indicate the valve’s flow direction. Also, the flow diversion causes a significant pressure drop through the globe valve. In contrast, a gate valve’s pressure drop is nearly non-existent.

Globe valves' flow paths: T- or Z-valve (left), angle valve (center), and Y-valve (right)Figure 3: Globe valves’ flow paths: T- or Z-valve (left), angle valve (center), and Y-valve (right)

Valve functions

Both gate valves and globe valves can operate as on/off valves. A gate valve is not meant to bused to throttle flow, but a globe valve can. Flow diverts within the globe valve and becomes parallel to the valve seat. This design makes globe valves efficient flow throttlers. Globe valves become unsuitable for throttling flow at larger diameters (above DN 150). Gate and globe valves can be operated mechanically, pneumatically, or electrically.

Note: With other factors equal, Y-valves are the least efficient at throttling flow because the valve seat is not parallel to the flow direction. However, this also means that Y-valves have the smallest pressure drop.

Visual differences

At a quick glance, gate valves and globe valves are not easy to tell apart. The following traits are what to look for to tell the difference:

  • Body: Gate valves usually have a rectangular or wedge-shaped body. Whereas the body of a globe valve is rounder, especially at its bottom.
  • Maximum height: Gate valves usually are higher when opened than globe valves.
  • Flow direction indicator: Gate valves are bi-directional, whereas globe valves are unidirectional. A marker on the valve, such as an arrow, indicates the flow direction and that it’s a globe valve.

Advantages and disadvantages chart

Globe and gate valves may have similar or different materials for their housing and seals. Read our chemical resistance guide to learn more about the advantages and disadvantages of the various materials. See the following chart to learn about more advantages and disadvantages.

Table 1: Globe valve and gate valve advantages and disadvantages chart

Globe valve Gate valve
Application Used for flow regulation (e.g., cooling water systems and fuel oil systems) More suitable for slurry due to less space in the valve’s body for sediment to get stuck and build up
Flow control Can be used or on/off control and can throttle flow Can be used for on/off control and cannot regulate the flow
Flow capacity Lower Higher
Flow direction Unidirectional Bi-directional
Flow restriction/pressure drop Flow diversion within the valve’s body creates significant pressure drop Full-bore valve, meaning there is no reduction to flow and pressure drop is insignificant
Power requirement Needs a large amount of force or an actuator to close under high pressure Needs less power to close under high pressure
Operating conditions Can operate at higher temperatures Can operate at higher pressures
Cost More expensive than a gate valve due to its complicated structure Cheaper
Leakage More effective sealing because force is applied to the disc when closed Good sealing properties
Installation space Takes up less vertical space, but requires more horizontal space If a rising-stem style, needs more vertical space, but less horizontal space
Weight Heavier Lighter
Ports Can have a 3-port configuration for straight-through flow Two ports

Selecting between globe valves and gate valves

Gate valves and globe valves are both excellent shut-off valves. However, when choosing between them, neither valve will outperform the other in every single application. Consider the following factors:

  • Flow control: Select a globe valve if an application requires flow modulation.
  • Flow capacity: Choose a gate valve if an application demands high flow.
  • Flow direction: Choose a gate valve if an application requires bi-directional flow.
  • Pressure drop: Select a gate valve if a minimal pressure drop is necessary.
  • Sealing: If an application demands excellent sealing, select a globe valve.
  • Contaminated media: Choose a gate valve if an application has slurry or other contaminated media.

The above variables are typically the most important when selecting a shut-off valve. Refer to Table 1 for further information.

Example applications

Globe valves

  • Cooling water systems: Globe valves operate in cooling water systems by controlling the water flow to maintain a desired temperature.
  • Chemical injection systems: Globe valves work well in industrial systems that need control over chemicals into reaction vessels or process streams.

Gate valves

  • Bulk material handling systems: Heavy-duty processes (e.g., mining, agriculture, and construction) use gate valves to control the flow of bulk materials such as grains, coal, and aggregate.
  • Water distribution systems: Many components of a water distribution system do not require precise flow control. Therefore, gate valves are suitable because they either block or allow flow.

FAQs

Which is better? A gate valve or a globe valve?

Globe valves have better sealing than gate valves and last longer. However, gate valves have significantly lower pressure drop.

What is the advantage of gate valves over globe valves?

One significant advantage of gate valves over globe valves is that they require significantly less power to close since they close perpendicular to flow rather than parallel as globe valves do.

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What is the difference between a gate valve and a plug valve

Plug and gate valves are both stop-valves suitable for a wide array of applications and media types. For example, they can both be used for clean media and media containing solids or stringy material. Therefore, it may be difficult to determine which is more suitable for a specific application. This article looks closer at the similarities and differences between gate valves and plug valves to help ensure the correct valve is chosen and used for varying applications.

Before deciding between the two valves, it is important to consider the following:

  • The number of ports needed
  • How fast the valve needs to operate
  • The pressure and temperature of the planned system
  • Installation space available

  • Plug vs gate valve comparison

    Plug and gate valves are named after the method that each uses to allow or block flow. A plug valve uses a plug with an opening running through it. When a gate valve is closed, its disc sits perpendicular to and blocks the flow, operating much like a gate.

    Operating principles

    Plug valves are quarter-turn valves, meaning the valve stem needs to turn only 90° for the valve to fully open or close. With mechanical lever actuation (pneumatic and electrical actuation are also possible), the valve’s lever is turned 90° to accomplish this. When turned on, the opening in the plug is in line with the ports, and media can flow through the valve. Closing the valve rotates the plug, so the opening is no longer aligned with the ports, and the plug’s body blocks the flow.

    Gate valves are multi-turn valves, meaning the valve stem needs to turn more than 360° for the valve to fully open or close. Therefore, a gate valve closes significantly slower than a plug valve. Turning the valve’s handwheel (mechanical actuation) can raise or lower the disc within the valve’s body. Fully raising the disc allows media to flow unobstructed, and fully lowering the disc blocks the media. Discover more by reading our gate valve and plug valve articles!

    Plug valve design

    Plug valveFigure 2: Plug valve

    The four distinguishing design characteristics of a plug valve are the plug shape, plug opening, whether the valve is lubricated or non-lubricated, and the number of ports.

    Plug shape

    • Cylindrical: This shape allows for a larger opening but has a shorter life span.
    • Tapered: This shape has a restricted opening but typically lasts longer.

    Plug opening

    • Rectangular: This opening is the most common; the size of the opening is at least 70% of the connecting pipe’s inner diameter.
    • Round: This opening can be full-bore or reduced-bore design.
    • Diamond: This opening has a venturi restricted flow type and is designed for throttling flow.

    Lubricated vs non-lubricated

    • Lubricated: The valve’s parts are entirely metal. Lubrication reduces friction between the plug and valve body, acts as a seal, and prevents corrosion.
      • Before lubricating a plug valve, consult the plug valve’s manufacturer to determine the correct lubricant to use.
    • Non-lubricated: A Teflon or plastic sleeve fits around a tapered plug, which presses the sleeve against the valve body for better sealing. Non-lubricated plug valves require minimal maintenance and are unsuitable for high-temperature applications.

    Ports

    • Double-port: A standard, bidirectional design used as a full-bore or reduced-bore valve.
    • Multiport: 3-way plug valves are common, but 4-way and 5-way are also possible. Multiport plug valves are used in transfer lines and diverting services. A single multiport plug valve can take the place of multiple gate valves.

    Gate valve design

    Beyond how to actuate a gate valve (mechanically, pneumatically, or electrically), the primary distinguishing design characteristics are the valve’s disc, how the bonnet connects to the valve body, and whether the stem is rising or non-rising.

    Disc types

    • Wedge: This type has a high wedging force which assists with sealing due to its wedge shape that sits on two inclined seats.
    • Knife: This type can cut through thick fluids and dry solids that build up using its beveled edge.
    • Double-disc: This type uses two discs that expand from one another to give a tight seal.
    • Slab: This type is one piece with a hole bored through it. The hole aligns with the ports, allowing flow, when the gate is fully open and the disc body blocks flow through the ports when the gate is fully closed.

    Bonnet types

    • Welded: This type is less likely to leak because it is threaded into the valve body and the body-bonnet joint is welded.
    • Bolted: This type is suitable for high-pressure and large valve size applications.
    • Screwed: Normally used in small size valves, this is the simplest type of bonnet construction.
    • Pressure sealed: As pressure within the valve increases, the body-bonnet joint seal increases. This type is used typically for high-pressure applications above 100 bar.

    Rising vs non-rising stem

    • Rising stem: The stem moves up or down as the valve opens or closes.
    • Non-rising stem: The stem remains within the valve as the valve opens or closes.

    Advantages vs disadvantages chart

    There are many materials available for plug and gate valves, so finding the right material for an application is possible. Learn more by reading our chemical resistance guide!

    Tbale 1: Plug valve vs gate valve

    Plug valve Gate valve
    Installation space Requires less space but has a long handle relative to valve size that must be considered Requires more space, particularly space above for rising stem valves
    Response time Quarter-turn valve, faster Multi-turn valve, slower
    Operation frequency Designed for more cycles Designed for infrequent cycles
    Leakage Can provide a bubble-tight shutoff Strong sealing capabilities except for low-pressure systems
    Corrosion/Wear Less corrosion and wear on the stem because it doesn’t sit in the flow path. May cause water hammer if incorrectly operated. The stem sits in the flow path and will experience more corrosion and wear
    Pressure Excellent design for low-pressure systems More suitable for high-pressure systems and may leak if used in low-pressure systems
    Temperature Lubricated plug valves are more suitable for high-temperature applications than non-lubricated plug valves Suitable for higher temperature systems but check with the manufacturer as too high of temperatures may warp the valve body, which will cause the disc and seats to become unaligned
    Flow control Provides on/off functionality and diamond opening plug valves can throttle flow Can only provide on/off functionality. Throttling flow will damage the valve.
    Flow restriction/Pressure drop Plug valves with restricted openings cause some pressure drop, full-bore plug valves are available Full-bore valve, pressure drop is insignificant
    Flow capacity Lower Higher
    Flow direction Bidirectional and multiport Bidirectional
    Power requirement Higher under high pressure Lower under high pressure
    Torque High, especially under high pressure Low

    FAQs

    Is a plug valve full bore?

    A plug valve’s plug opening can be full bore but is also available in reduced flow for applications where pressure drop is not a large concern.

    What is the difference between a gate valve and a plug valve?

    A big difference between a gate and plug valve is that a gate valve is multiturn, and a plug valve is quarter-turn. So a plug valve can be opened or closed faster than a gate valve.

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Gate Valve vs Butterfly Valve

Gate and butterfly valves are both used to turn on and off the flow, but butterfly valves can also regulate flow via partial disc closure. Butterfly valves are part of the quarter-turn family of valves and can be shut off much faster than gate valves, which are multi-turn valves. Gate valves are preferable for high-pressure systems whereas butterfly valves are preferable for larger port sizes.

Gate valves

How does a gate valve work?

A gate valve is named after its disc, which behaves like a gate by either stopping or allowing media flow. It has a simple operation compared to other control valves, which makes it one of the most commonly used valves. Because a gate valve is a full-port valve, which means that the valve’s ports are the same size as the inner diameter of the connecting pipes, there is very little resistance to liquid or gas media that flows directly through it. Therefore, the pressure drop through the valve is quite low. For a more extensive understanding, read our article on gate valves.

Operating a gate valve

Gate valves are multi-turn valves, meaning the handwheel must turn more than 360° to fully open or close the valve. Turning the handwheel in one direction or the other moves the gate up or down via the stem. When the gate is completely up, the passageway is unobstructed, and media can flow. When the gate is down, media is blocked and cannot flow. Gate valves cannot modulate or throttle flow because there is a nonlinear relationship between the gate’s travel and flow rate. If the gate is partially open, the flow will crash into it while traveling through the valve, causing the flow to move at a higher velocity and create turbulence, both of which lead to increased wear on the disc and seats.

The three common means for actuating a gate valve are manually, pneumatically, or electrically. The manual method requires an on-site user to spin the handwheel to open or close the valve. This method is the most cost-effective since gate valves are not typically opened or closed often. The pneumatic and electric solutions allow for remote operation of a gate valve. Pneumatic actuation requires a pneumatic system on-site and electrical actuation requires electrical power on-site.

Gate valve types

As mentioned above, there exist different styles of gate valves. Three factors typically determine a gate valve’s style: the gate type, the bonnet type, and the stem type.

Gate type refers to the disc that blocks the flow when the valve is closed, for example:

  • Wedge disc: The gate is shaped like a wedge and it sits on two inclined seats. This provides a high wedging force which assists with sealing.
  • Knife disc: The gate is a piece of metal with a beveled edge like a knife. It can be used to cut through thick fluids and dry solids.
  • Double disc: The gate is two discs which sit on two seats. The discs expand away from each other to provide a tight seal.

Bonnet type refers to how the bonnet is attached to the valve body. It can be:

  • Screwed: This is the simplest type of bonnet construction and is normally used in small size valves.
  • Bolted: These bonnets are used in larger valves and high-pressure applications.
  • Welded: The bonnet is threaded in and the body-bonnet joint is welded. This offers extra protection against leaking.
  • Pressure sealed: The body-bonnet joint seal enhances as pressure within the valve increases. Used typically for high-pressure applications above 100 bar.

Stem type refers to the position and action of the stem

  • Rising vs non-rising: Rising stem gate valves require more space above the valve than non-rising.
  • Remains within the valve vs rises out of the valve upon opening: Rising out of the valve makes the stem easier to lubricate.

Materials

The correct material depends on the application’s fluid service and temperature. Common materials used for a gate valve are:

  • Body and bonnet: cast steel, stainless stell, cast iron, gunmetal, bronze, brass, and PVC
  • Disc: stainless steel, polypropylene, Teflon, rubber lined (e.g., wedge disc)
  • Seal: EPDM, NBR, Teflon

These materials allow for a range of applications, so gate valves apply to relatively mild applications like household plumbing to more corrosive applications such as use in saltwater environments. For more information, read our chemical resistance guide.

Butterfly valves

How does a butterfly valve work?

The essential operation of a butterfly valve is achieved by turning its handle 90° or using a pneumatic or electric actuator. This turns the valve’s stem, which rotates the disc. In the fully closed position, the disc is perpendicular to the flow, and in the fully open position, the disc is parallel to the flow. Partial opening or closing of the disc can achieve proportional or throttled flow rates. In cases of a large butterfly valve or a valve used in a liquid application for which fast closure could produce water hammer, a butterfly valve can be gear operated via a gearbox (Figure 2, right). The gearbox’s handwheel must be turned more than 90°, though, which eliminates the butterfly valve’s relatively fast closing speed. For a more comprehensive understanding, read our article on butterfly valves.

A zero offset butterfly valve with a lever handle on the left and an eccentric butterfly valve with a hand wheel on the rightFigure 2: A zero offset butterfly valve with a lever handle on the left and an eccentric butterfly valve with a hand wheel on the right

Butterfly valve types

There are two key topics when discussing types of butterfly valves: body and stem offset. Body refers to how the valve’s body connects with piping, and stem offset refers to whether the stem passes through the center of the disc or is offset.

The butterfly valve body types are:

  • Double-flanged: This design is typically used for larger butterfly valves.
  • Wafer: Most cost-effective design; sandwiched between two pipe flanges.
  • Single flange: This design uses bolts and nuts passed through the valve’s holes to connect to both sides of the piping.
  • Lug type: This design has threaded inserts, and bolts are used to connect pipe flanges to each side. Suitable for removing piping from one side without affecting the other.
  • Flangeless: Like the wafer style, this design is sandwiched between two pipe flanges.
  • Butt-welding ends: Prepared for welding directly to piping.
  • U-section: Also clamped between pipe flanges and suitable for end-of-line service.

The stem can pass through the centerline of the disc (concentric) or be offset behind the centerline (eccentric). Offset, which can be single-, double-, or triple-offset, is used to reduce how much the disc rubs against the seating while closing. The higher the offset, the more the disc moves towards fully closed before contacting the seal. Any rubbing against the seal can reduce the service life of the valve. High-performance butterfly valves are specifically designed to withstand more demanding applications in terms of pressure and temperature.

The following compares a high-performance butterfly valve with a standard butterfly valve:

  • Maximum shutoff pressure: Approximately 50 bar (725 psi) vs approximately 14 bar (203 psi)
  • Tight shutoff: Below 260°C (500°F ) vs below 120°C (248°F)
  • Shutoff with allowable seat leakage: Below 538°C (1000°F) vs below 425°C (797°F)

Read our article on butterfly valve design differences article for more details on the features of each design type.

Materials

The valve’s body and seat materials should be chosen carefully based on the needs of the application. Common body materials are iron, stainless steel, carbon steel, nickel alloy, titanium alloy, and nickel aluminum bronze. These materials vary in weight and resistance to corrosion and extreme temperatures.

Common seat materials are EPDM, EPDM white, FKM, XNBR, and NBR. Depending on the seat material, a butterfly valve can be used in temperatures ranging from -10°C to 180°C. Resilient and metal seated butterfly valves are also available, using the same materials listed here, and are designed to operate under more extreme temperatures and pressures.

Gate valves vs butterfly valves

There are many factors to consider when deciding whether a gate or butterfly valve is correct for a given application. Below are some of the most important:

  • Cost: A butterfly valve is typically less expensive than a gate valve, especially at larger port diameters.
  • Installation space: A butterfly valve takes up less installation space than a gate valve.
  • Weight: A butterfly valve weighs less than a gate valve; the latter may need support structures at larger port diameters.
  • Maintenance: While a butterfly valve is relatively easy to maintain, repair, or install due to its small size and low weight, its center disc makes it not suitable for systems that use pigging and swabbing for cleaning purposes. On the other hand, a gate valve is ideal for such maintenance.
  • Operation: A butterfly valve can close faster than a similar port diameter gate valve. However, this fact means that butterfly valves are more susceptible to water hammer.
  • Flow regulation: A butterfly valve can modulate or throttle flow, whereas a gate valve can only be on/off.
  • Flow resistance: A gate valve offers less flow resistance and, therefore, less pressure drop than a butterfly valve.
  • Pressure: Gate valves can handle higher pressures than butterfly valves.

Applications

  • Gate valves have a higher sealing tightness, and therefore are more suitable for applications that require zero leakage.
  • Butterfly valves are more suitable for applications that require flow modulation or throttling.
  • If a slurry flow does not need to be modulated, gate valves are preferable to butterfly valves.
  • Gate valves are more suitable for systems that require bi-directional, uninterrupted flow.

FAQs

Which is better, a gate valve or a butterfly valve?

A gate valve has a stronger seal and is more suitable for high-pressure applications. A butterfly valve is less expensive and available in very large sizes.

Can a butterfly valve be used instead of a gate valve?

A butterfly valve can be used instead of a gate valve in low-pressure systems for which some leakage is not a major concern.

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