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What is a wafer butterfly valve?

China butterfly valve Manufacture

This is a butterfly valve that is sandwiched between two pipe ends. The pipe ends are in terms of flanges with holes. Long bolts are used to surround the valve body to hold it firmly in its position. The bolts cross the whole valve body. Wafer butterfly valve manufacturers design this valve with or without flange holes on the valve body. Tightly fitted seals such as gasket and O-rings are used between the valves and pipe to enhance leakage-proof connection. Wafer butterfly valve manufacturers produce these valves to operate manually or automatically. The automatic types use actuators to start or stop while the manual types use a handwheel or hand lever. These valves occupy a small space since they are short in length. This property makes the valve light in weight and less expensive. Depending on the material used to make the valve and more so internal components, this valve can be used for low to high temperatures as well as corrosive media.

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Figure: Wafer butterfly valve.

 

Components of a wafer butterfly valve 

Body 

The body is the component of a wafer butterfly valve that is used to cover internal parts. The body is usually made of strong metallic materials like brass, nickel alloy, stainless steel, and carbon steel among other strong materials. However, other valves are made of plastic bodies and are meant for use in low-temperature and low-pressure applications.

Handwheel/ actuator

Handwheel is the component where the operator applies force to start and stop the valve by making a quarter turn angle. Handwheel is used in manual wafer butterfly valves while the actuator is used in automatic valves. The actuator is designed provide torque to start and stop the valve.

Stem 

The stem is the component connecting the handwheel/ hand lever or actuator to the valve disc. The use of the stem is to transmit torque applied on the handwheel or actuator to the disc.

Disc 

This is the main component of a wafer butterfly valve as it is used to start and stop fluid flow. It gets the power to open and close from the handle/actuator through the stem.

Seat 

A seat is a component used to prevent fluid leakage when the valve is closed. It forms the component on which the disc rests when the valve closes.

Gasket 

This component is placed between the valve and pipe mating surfaces to prevent fluid leakage.

Components of a wafer butterfly valve

Figure: Components of a wafer butterfly valve.

 

How does a wafer butterfly valve work? 

A wafer butterfly valve is classified as a quarter-turn valve. This means that the valve turns the disc for 90o degrees to open or close. Both the actuated and the manual valves have the same working principle. To start the fluid flow, the handwheel is rotated in the counterclockwise direction for a 90o degree angle. This rotation of the handle causes the stem and thus the disc to make the same rotation. As such, the disc becomes oriented collinear to the fluid flow. This leaves the valve open for the fluid to keep flowing. To close the valve, the handwheel is rotated again but in the clockwise direction. This rotation forces the disc to turn and become perpendicular to the pipe where it completely blocks flow through the valve. Wafer butterfly valve manufacturers have designed these valves for both shut-off and throttling use. To use these valves for throttling, the handle and thus the disc is rotated for an angle of less than a quarter turn to allow some level of fluid flow through the valve.

Working of a wafer butterfly valve

Figure: Working of a wafer butterfly valve.

 

Types of wafer butterfly valves 

Manual wafer butterfly valves 

This is a wafer butterfly valve that is operated manually. The manual control mechanism is the handwheel or hand lever and the valve operator applies force to open/close the valve. Compared to the automatic wafer butterfly valve, this valve is cheaper. This valve is suitable for use where electricity or another source of power is not available or would be expensive. Manual butterfly valve manufacturer design some of these valves with a gear system. This design is meant to help change the torque along the horizontal axis to the vertical axis. The torque along the horizontal axis comes from the handwheel and it has to change direction to move vertically downwards to the disc hence the use of the gear system in the gearbox. The gearbox is placed on top of the valve stem. Despite manual wafer butterfly valves being cheaper and convenient to use, they are risky to the operator in case of leakage and hazardous fluids. Also, it may be so tiresome for the operator if a lot of torque is needed where the valve has to start and stop frequently.

Stainless steel wafer butterfly valve

Figure: Manual wafer butterfly valve.

Electric actuated wafer butterfly valve 

This is a wafer butterfly valve that is operated using an electric actuator. Wafer butterfly valve manufacturers design the actuator with an automated system to help in determining when the disc closes and opens fluid flow. These valves operate using mechanical energy. As such, the valve is designed with an electric motor that converts electrical energy to mechanical energy in terms of torque. The actuator is connected to the valve stem so that it can get the torque needed by the valve. Electric actuated wafer butterfly valves can be installed in all industries because electricity is readily available. However, an electric actuated butterfly valve is expensive compared to the manual one. Repair of the valve is also expensive because of the electrical components like a motor which is expensive to replace. However, the advantages of this valve greatly outweigh the disadvantages since the valve relieves the user of fatigue unlike manual types.

Electric actuated wafer butterfly valve

Figure: Electric actuated wafer butterfly valve.

Pneumatic wafer butterfly valve 

This is a wafer butterfly valve that operates using a pneumatic actuator. A pneumatic actuator is one that converts energy of compressed air into mechanical energy needed to run the valve. A pneumatic actuator has other names such as air cylinders, pneumatic cylinders, and air actuators. Wafer butterfly valve manufacturers design this valve to rely on compressed air which enters a chamber to build up pressure. Once the pressure exceeds a certain pressure level exceeding the atmospheric pressure outside the chamber, it creates controlled mechanical energy in terms of torque. This pneumatic butterfly valve is versatile as it can be used in different industrial applications involving corrosive and food products. The compressed air can be cleaned before being used to run the valve and thus enhance high levels of hygiene.

Pneumatic wafer butterfly valve

Figure: Pneumatic wafer butterfly valve.

Hydraulic wafer butterfly valve 

This is a wafer butterfly valve that operates using a hydraulic actuator. The hydraulic actuator operates by using hydraulic liquid. This actuator helps to change hydraulic liquid’s pressure energy into kinetic energy in terms of torque needed to start and stop the valve. This valve is suitable for use where high torque is required since it is more efficient in producing torque because of the incompressible properties of the hydraulic liquid. However, wafer butterfly valve manufacturers recommend use of this valve where there is low temperature since the hydraulic fluid can be affected if the temperature is high. Also, in case the hydraulic fluid leaks, it causes a lot of contamination which is undesirable in industries like foods and beverages and pharmaceuticals processing.

Hydraulic wafer butterfly valve

Figure: Hydraulic wafer butterfly valve.

Plastic wafer butterfly valve 

This is a wafer butterfly valve that is made of plastic material. There are various plastic materials used by wafer butterfly valve manufacturers to make this valve among them polyvinyl chloride and propylene. This valve is made for use in very corrosive media and which is at low temperatures. Plastic wafer butterfly valve manufacturers recommend this valve in such applications because they are much more resistant to corrosion compared to metallic types like stainless steel. Plastic materials are also cheaper compared the metallic ones. As such, this valve ends up being cheaper compared to the metallic wafer butterfly valves. The design employed to make this valve renders it strong to make it withstand fluid pressure as well as the impact of falling objects.

Plastic wafer butterfly valve

Figure: Plastic wafer butterfly valve.

 

Applications of wafer butterfly valves 

  • Wafer butterfly valves are used in fire protection systems.
  • They are used in the manufacturing of chemicals.
  • They are used in municipal wastewater treatment and water purification.
  • Wafer butterfly valves are used in heating ventilation and air-conditioning (HVAC) systems.
  • They are used in the processing of foods and beverages.
  • These valves are used in petroleum refineries.
  • Wafer butterfly valves are used in mining applications.
  • They are used in the pharmaceutical industries as they can easily maintain high levels of hygiene.

 

Advantages of wafer butterfly valves 

  • These valves can be automatic or manual.
  • Wafer butterfly valves are cheaper compared to other butterfly valves.
  • The use of quarter turn to open and close fluid flow makes these valves fast operating.
  • Wafer butterfly valves are made of simple and compact design.
  • They are of small size and thus light in weight.
  • Their small sizes leads to small installation space in the piping system.
  • Wafer butterfly valves are easy to clean, install and repair.
  • Their design makes them versatile and hence applicable in various industries.
  • These valves can allow bi-directional or uni-directional fluid flow.
  • They are resistant to corrosion and abrasion wear.
  • Wafer butterfly valves can be used in slurries and sludge applications.

 

Disadvantages of wafer butterfly valves 

  • Wafer butterfly valve seals are weak compared to other valves which may cause leakage in case of high pressure.
  • They contribute to pressure drop because the disc remains in the fluid flow path when the valve is open.
  • Their design makes them prone to choking and cavitation.
  • The closing and opening of the valve disc is influenced by fluid turbulence.

 

Troubleshooting wafer butterfly valves 

The wafer butterfly valve does not close completely 

  • Foreign materials in the valve. Open the valve and remove the materials. Clean the internal parts of the valve.

Valve is hard to operate 

  • Presence of foreign materials in the valve. Open the valve and remove any foreign materials.
  • Corrosion in the valve. Open the valve and clean off the corrosion. Ensure the valve is used on the correct type of fluid as recommended by the wafer butterfly valve manufacturer.

External fluid leakage 

  • Worn out packing. Replace the packing.
  • Worn out O-rings. Replace the O-rings.
  • High fluid pressure. Reduce the fluid pressure to the range indicated by the wafer butterfly valve manufacturer.
  • Loose bolts. Tighten the bolts.
  • Worn out gaskets between the valve and the pipe. Replace the gaskets.

Internal fluid leakage 

  • Worn out seats. Replace the seat.
  • O-rings worn out. Replace the O-rings.
  • Clogged dirt in the valve. Clean the dirt.

 

Summary 

A wafer butterfly valve is a valve that is installed in a piping system by clamping it between two flanges of the pipe. The pipe flanges are connected using bolts. These bolts cross the valve body to the pipe flanges. Wafer butterfly valve manufacturers design this valve with short lengths which makes it possible for the bolts over the valve. This valve is classified as a quarter-turn valve. This means that the valve operates by turning the disc for a quarter turn angle to start or stop fluid flow. The available designs of these valves operate using handwheel/hand lever or actuator. These valves are applicable in different industries. However, for the best service and economical application, the valve has to be used according to the instruction given by the wafer butterfly valve manufacturer.

Wafer butterfly valves are of various types which include manual wafer butterfly valves, plastic wafer butterfly valves, hydraulic wafer butterfly valves, pneumatic wafer butterfly valves, and electric actuated wafer butterfly valves among others. Applications of wafer butterfly valves include HVAC, wastewater treatment, mining operations, food processing, and chemical manufacturing among others. Advantages of using wafer butterfly valves include lightweight, small size, easy installation, cleaning and repair, fast operation, simple and compact design, and versatility.

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C95800 Wafer Check Valves

We finished manufacturing some C95800 Wafer Check Valves for one of our European clients, the details are as follows:

Product descriptions

Type Check Valve
Size 16”
DesignPressure JIS5K
Construction Dual Plate Type, With Retainer
Connection Wafer Type
Design & Manufacture API 594
End to End ASME B16.10
Connection JIS2216
Pressure & Temp ASME B16.34
Test & Inspection API 598
Body Material Aluminum Bronze C95800
Trim Material Aluminum Bronze C95800
Media W.O.G.

Medium: air
Working pressure: 5K

Body, bonnet: C95800
Spring: ASTM A182 F316

STV Valve Technology Group Co., Ltd
DATED April 19, 2022

dual Plate Check Valve WAFER Check Valve

dual Plate Check Valve Wafer Check Valve AL Bronze

 

What is a non-slam check valve?

To answer this question we must first consider the basic structure of a check valve. A check valve consists of two ports; an inlet for liquid or gas to enter the valve and an outlet for it to exit the valve. Within the chamber of the check valve is contained an opening and closing mechanism (valve disc). Therefore, liquid or gas can only pass through the valve in one direction, hence it is sometimes referred to as a non-return valve, one-way valve etc. When the liquid or gas attempts to flow backwards through the valve the disc will close or slam shut. The surge of the backflow hitting the closed disc can create a hydraulic shock or water hammer. Water hammering can cause problems such as pipe rupture, collapse or damage to pumping systems. To get around these problems, the non-slam check valve utilises an internal coiled spring downstream from the disc. So instead of relying on backward flow to close the valve, as the forward flow starts to slow, the valve is closed off with the spring mechanism, eliminating any backflow and the cause of the water hammer.

What-is-a-non-slam-check-valve

Applications of Non-Slam Check Valves

Typical applications of Non-Slam Check Valves would include:

  • Centrifugal Compressor Discharge
  • Reciprocation Compressor Discharge (Sizing is critical for this application)
  • Rapid Closure requirements
  • Low Pressure Drop Requirements
  • Salt Water Fire Safety Systems Critical Service
  • Desalination Reverse Osmosis Process
  • Critical Applications
  • Non Serviceable Locations *
  • High system deceleration applications
  • Elevate Valve Slamming applications
  • High Temperature critical applications
  • Cryogenic Application
  • Pulsating Flow Applications
  • Renewable Energy Hydrogen Service
  • Lethal Service **

Top 10 Valve manufacturers in India

Asian valve manufacturers are on the rise in rankings. In recent years, several new Valve manufacturers in India have entered the market. They satisfy the rapidly rising demand for industrial valves in the booming economy of that region. Some of the top players are:

  • L&T Valves, Chennai, TN, India.
  • Amtech Valves, Ahmedabad, GJ, India.
  • Kirloskar Brothers Limited, Pune, MH, India.
  • Hawa Valves, Mumbai, MH, India.
  • Nirmal Industrial Controls Pvt Ltd, Mumbai, MH, India.
  • Citizen Metals Pvt Ltd, Mumbai, MH, India.
  • JEKON Controls, Ahmedabad, GJ, India.
  • GM Engineering Pvt. Ltd., Rajkot, GJ, India.
  • VIP Valves, Mumbai, MH, India.
  • Amco Valves, Chennai, TN, India.

 

Top ball valve manufacturers in India

The ball valve is either an on-off or a shut-off valve. The ball valve is a quarter-turn valve and is used where a simple and regular operation is necessary. Ball valves are usually soft seated, making them unsuitable for abrasive operation. Although soft seat designs are suitable for bubble-tight sealing when used for the clean fluid operation. Two main designs are Floating Ball and Trunnion Ball design.

L&T Valves, Chennai, India.

Established: 1961

Website: https://www.lntvalves.com

Valve Types: Floating Ball & Trunnion Mounted Ball Valve.

Certification: ISO 15848-1, API 622, EU Declaration of Conformity, SIL Certification.

L&T Valve is a pioneer in flow control systems. The company is a part of Larsen & Toubro, an engineering and technology group. L&T Valves reflects on its fifty-year experience of excellence in the manufacture of valves for key sectors of the economy, such as oil & gas, power, petrochemicals, chemicals, water, defense, and aerospace.

 

Top Gate valve manufacturers in India

The gate valve is used to shut off fluid flow or to provide optimum pipeline flow in a fully open position. Thus, it can be used either in fully closed or fully open positions. The gate valve comprises the body of the valve, seat and disc, spindle, gland, and a valve wheel. The seat and the gate together play a part in shutting down the flow of fluid.

Kirloskar Brothers Limited, Pune, India

Established: 1888

Website: http://www.kirloskarpumps.com/index.aspx

Valve Types: FM Approved Gate, Cast steel Gate, Forged Steel Gate Valves.

Certification: ISO 9001:2015, ISO 14001:2015.

KBL is the first and only valve manufacturer in India to receive the Factory Mutual Compliance Certificate for its fire service water control valves covering Outside Screw & Yoke and Non-Rising Stem Gate Valves (Metal Seated) from Factory Mutual.

 

Top Solenoid valve manufacturers in India

Solenoid valves are used in fluid power systems to monitor the flow or direction of air or fluid, solenoid valves are electrically operated valves. Used in both pneumatic and hydraulic fluid control systems, the spool or poppet configuration of most solenoid valves makes them suitable for various functions and applications.

Jekon Controls, Ahmedabad, GJ, India

Established: 2000

Website: https://jekonvalves.com/

Valve Types: Diaphragm Type, Single/ Double Acting, Dust Collector, Direct Acting.

Certification: ISO 9001:2015, UK Cert Limited (UK)

JEKON CONTROLS is one of the best manufacturers of Pneumatic Control & Solenoid Valves, company is committed to providing the consumer with a full range of solutions worldwide. Their valves are specifically built for fluids such as water, air, gas, oil, chemicals, steam, and pharmaceutical Goods, etc.

Jekon valves have the best facilities for production and testing to review the design and performance specifications of the component. The company’s R&D team is day by day improving the production and efficiency of product design according to consumer demand. They have the best manufacturers and suppliers’ chain for outsourcing superior quality jobs.

 

Top Butterfly valve manufacturers in India

The Butterfly valve is a rotary motion valve, a quarter-turn is used to close, regulate, and start the flow. Butterfly valves are easy to open and quick to operate. The 90 ° movement of the handle provides a complete closure or opening of the valve. Large butterfly valves are usually fitted with a gearbox, where the handwheel is connected by gears to the stem. This makes the operation of the valve easier, but the operation slows down a bit.

Amtech Valves, Ahmedabad, GJ, India

Established: 1985

Website: http://www.amtechvalves.com/index.html

Valve Types: Double Flange, Wafer Lug Type, Offset Type.

AMTECH Butterfly valves are ideal for both basic and extremely complicated uses. The range comprises rubber-coated, PTFE lined, metal sealing, and high-performance butterfly valves. Butterfly valves are ideal as either open/closed or control valves. They are available in a wide range of sizes, materials, and designs. Butterfly valves can be fitted with a range of control and actuator options. Amtech Butterfly valves are commonly used in the water, process, and marine industries for chemical and corrosive applications. They sell a variety of valves designed exclusively for pharmaceuticals, food & beverages.

 

Top Globe valve manufacturers in India

The Globe valve is a linear motion valve designed specifically to stop, start, and control the flow. The disc of the Globe valve can be entirely separated from the flow path or the flow path can be completely closed.

Globe valves are commonly used to regulate the flow. In the configuration of the valve, the range of flow control, pressure drop, and the task must be considered to avoid premature loss and ensure adequate operation. Valves subjected to a high-differentiated pressure-throttle operation need specially designed valve trim.

Hawa Valves, Mumbai, MH, India

Established: 2001

Website: https://www.hawavalves.com/

Valve Types: HPHT Globe Valve as per API 6A.

Certification: ISO 9001:2008, ISO 14001:2004, OHSAS 18001:2007, SIL3, CE/PED, etc.

HAWA VALVES are producers and exporters of valve applications in the essential hydrocarbon/oil and gas industries Upstream, Midstream, Downstream, Chemical, Power, Marine, Mining, and General Industry. With a fully-fledged engineering staff caring for large and technically challenging orders and with an in-house mega specialty ERP online infrastructure.

 

Top Control valve manufacturers in India

The control valve is a power-operated mechanism used to control or regulate the flow of fluids, such as gas, oil, water, and steam. It is a vital part of the control loop and an example of a final control feature. The Control Valve is by far the most common final control feature used by industry today.

The control valve may be operated either electrically, pneumatically, or hydraulically. The control valve gets a signal from the controller, such as the PLC, so that it can shift, resulting in a change inflow.

Nirmal Industrial Controls Pvt Ltd, Mumbai, MH, India

Established: 1973

Website: https://www.nirmal.co.in/index.html

Valve Types: Pressure Regulators, Safety Relief Valve, Safety Shut-off valve, Creep Relief Valve, etc.

Certification: ISO 9001:2015, ISO 45001:2018, etc.

Nirmal has become the pioneer of self-actuated pressure control valves and Allied process control devices and solutions. Nirmal provides its expertise internationally to all major sectors, such as Oil & Gas, Petrochemical & Refineries, Pharmaceutical, Steel & Power, Food & Dairy, Plastic, and Nuclear Power Industries. Today, Nirmal has been successfully developed as an “Expertise that delivers”

 

Top Check valve manufacturers in India

The check valve is also known as a clack valve, a one-way valve, or a non-return valve as it allows fluid to move in one direction only. These industrial valves are automatically triggered by the force produced by the movement of the medium itself through the pipeline and can be labeled as an automatic valve. Check valves are often used in pipeline networks, their main roles are to prevent the fluid from reversing back to prevent the pump and its compressor from reversing, and to prevent the medium from flowing back from the container.

GM Engineering Pvt. Ltd., Rajkot, GJ, India

Established: 1996

Website: http://www.gmengg.com/

Valve Types: Dual Plate, Wafer Check, Swing Check Valve, etc.

Certification: ISO 9001:2008, API 6D, etc.

The check valve is the most widely used in residential and industrial complexes. GM Engineering provides a world-class range of check valves that are suitable for various environments. GM is a multinational player whose name is synonymous with consistency in the production of the check valve.

GM Tech presents itself as innovators of conventional origins who build check valves that execute traditional functions more smartly. Their designers and engineers are constantly searching for technology and inventions that can support and create the highest performing valves.

 

Top Safety valve manufacturers in India

The safety valve is a protection mechanism intended to regulate the system pressure. If the pressure is not regulated, it may build up in the device that causes equipment failure, explosions, or fire hazards. This valve is intended to be opened at a fixed pressure to prevent equipment failure as a result of being exposed to a pressure that exceeds its specification limits. Once the valve is opened due to excess pressure, the media is discharged until the pressure decreases to its appropriate level and the valve is closed automatically.

Hyper Valve, Ahmedabad, GJ, India

Established: 2003

Website: https://www.hypervalves.com/

Valve Types: Safety Relief Valve, Pressure Relief Valve, etc.

Certification: ISO 9001:2008.

Hyper Valve is one of India’s leading manufacturers of industrial valves. Hyper Valve is engaged in the manufacture, design, supply, and export of industrial valves. The company has established a predefined framework and has outlined all the tools needed to satisfy the increasing demands of the market and technological enforcement. Hyper Valve has an ISO 9001:2015 quality control certificate which meets numerous standards such as ASME B 16.11, API 598/BS 5146, API 602/BS 5352, ASME B 16.34, API 598, ASME B 1.20.1, ASME B 16.25, and several other engineering standards.

 

Top Plug valve manufacturers in India

Plug valves are valves with cylindrical or conical “plugs” that can be turned within the valve body to regulate the flow through the valve. The connectors in the plug valves have one or two hollow passageways flowing horizontally through the plug so that the fluid can pass through the plug while the valve is open.

Citizen Metals Pvt Ltd, Mumbai, MH, India

 Established: 1981

Website: https://www.citizenvalves.com/

Valve Types: Sleeved, Lubricated, Steam Jacket Plug Valves, etc.

Certification: ISO 9001:2008, 14001:2004, 18001:2007, etc.

The Citizen Plug Valve available in sizes ranging from 1/2″ to 72″ is designed especially for wastewater applications. The round port shape available in sizes 1/2″ – 12″ provides the least opposition to the slurry, sludge, and fluid flow resulting in less corrosion, longer service life, and lower pumping costs. A wide round port configuration can flow through larger solids to avoid plugging issues. Round port valves give the best flow characteristics relative to alternate port openings, resulting in a lower pressure drop through the pipe. Pressure classes on 12″ and below are 175 psi, pressure classes on 14″ and above are 150 psi, higher pressure on request.

 

Summary

Many new players are investing in the production business of valves. We have provided you with ten high-quality Valve Manufacturers in India, at affordable prices.

Top Valve Manufacturer in China

The industrial valves market in china is projected to report substantial growth in the coming years due to new industrial infrastructure construction ventures, reconstruction and restoration of existing businesses, and extension of the gas pipeline network.

Few factors that market growth depends on are.

  • The oil and gas sector has dominated the market and is expected to witness growth over the next few years due to growing oil and gas operations across the world.
  • Increased demand for automatic valves is expected to be an advantage in the future.
  • Asia-Pacific was the dominant market in the world, with the highest intake from countries such as China and India.
  • Reports suggest that the industrial valve market globally is expected to grow up to US$ 85.19 billion by 2025.

Market these days have a large number of manufacturers and it is quite a task for consumers to select a valve as per their requirements and budget by maintaining proper quality.

If you have the same questions, you’re in the right place. This article provides you with top valve manufacturers in China. We’ve got suppliers of about any sort of valve you need. Read on and pick the best valves for your application.

We are providing a list of suppliers which are best in a selected application by:

  1. Structure i.e., types of the valve by design.
  2. Power i.e., types of the valve by an operation.
  3. Condition i.e., types of the valve by system parameters.
  4. Function i.e., types of the valve as per their use.

 

Classified By Valve Structure.

 

Top Ball Valve manufacturers in China.

Lanzhou High-Pressure Valve Co. Ltd

Established: 1938

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Floating & Trunnion Mounted Ball Valve.

Certification: TS licensing A1, A2, B1, B2, API-6D, CE, ISO9001, ISO14001, OHSAS18001, TUV issued by the API 6FA gate valve, API607 ball valve fireproof test.

Lanzhou High-Pressure Valve Co., Ltd (formerly Lanzhou High-Pressure Valve Factory, short for LZHPV) associated with the Langao Group of companies, was a state-owned company founded in 1938, established as non-public enterprises in 2003 with strong support from the provinces, municipalities, and departments of districts at all levels, LZHPV was only one high-tech company in northwest China combining ‘high & low temp., high pressure, high alloy, large diameter’ valves with teams dedicated for R&D, design, manufacturing, and sales.

LZHPV currently has 178 sets of machinery for the processing center, CNC machine tools and cutting processing, 98 sets of physical and chemical machinery, NDE and PMI machinery, with superb technology, modern management principles and enhanced quality assurance method, LZHPV has established a leading role in the domestic valve industry in technology.

LZHPV invested heavily in the development of high high-pressure high-alloy valve patent industrialization ventures, and the project obtained funding from the National Development and Reform Commission, Ministry of Industry and Information Technology, for key industries and technological transformation.

  
NTGD Valve Co. Ltd

Established: 2005

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Floating & Trunnion Mounted Ball Valve.

Certification: ISO9001/ ISO14001/ ISO18001 certified.

NTGD valve is an ISO 9001 certified company who was founded by a team of people with more than 30 years of experience in the supply of industrial valve. During these years NTGD valve has been adapting the media to new technologies. All this has allowed NTGD to provide the finest quality products and services to match the need of their clients.

NTGD Valve considers product quality and customer satisfaction as their highest priority. NTGD valve looks forward to a new client relationship by providing top-quality valves and close cooperation.

Affordable pricing and efficient distribution options make NTGD the top choice among valve manufacturers. NTGD valve specialized in valve supplies, including ball valve, gate valve, globe valve, check valves, strainer, plug valves, and butterfly valves in carbon steel, stainless steel, duplex stainless, and alloy materials. Their products conform to the latest industry standards in accordance with ANSI, ASME, API, and DIN.

 

Sanhua Valve-Zhejiang Sanhua Co. Ltd

Established: 1984

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Floating & Trunnion Mounted Ball Valve.

Certification: CQC, CE, TUV, UL, VDE, ISO9001, ISO14001, QC080000, ISO10012.

In China, Sanhua is one of the leading producers of reliable and robust ball valves. With more than 30 years of experience in creating control components for automobile, appliance, and HVAC&R industries for major companies.

Sanhua has worked with giant air conditioning and refrigeration firms over the years. These include Mitsubishi, Samsung, Panasonic, Fujitsu, Hitachi, Carrier, York, Daikin, LG, Haier, Midea, and Gree, etc.

The company provides a range of SBV ball valves for industrial air conditioning, freezing or deep-freezing devices, cooling circuits, vacuum pumping, injection of refrigerants, and more.

 

Top Gate Valve Manufacturers in China. 

Sufa Technology Industry Co., Ltd

Established: 1997

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Cast Steel, forged steel, Cryogenic, Slab & Pressure Gate Valve.

Certification: API 6D, API 600, API 602, ISO 9001, ISO 14001 Certifications.

Sufa is one of the leading industrial steel valve manufacturers in China. Their valves are supplied for a wide variety of power generation, chemical and petrochemical, oil and gas, pulp and paper, mining, and shipbuilding applications. They focus on one business, developing, manufacturing, and marketing advanced steel valve technology in a wide variety of styles and sizes. Their products are made according to certain globally agreed specifications such as API, ANSI, DIN BS, AND JIS, and contain different types of valves in various materials.

 

 

STV Valve Technology Group Company

Established: 2003

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Cast Steel, forged steel, Stainless steel, Bellow seal & Pressure Gate Valve.

Certification: ANSI, API 602, API 600, ISO 9001, etc.

STV Valve Technology Group Co., Ltd is a China Valve Company which was founded in 2003 and now their production line extends to a ball valve like a stainless-steel ball valve, a gate valve like a forged steel gate valve, a globe valve, a control valve, a plug valve and a butterfly valve made of carbon steel, stainless steel, duplex stainless steel, and alloy materials. Their goods comply with the current industry standards in compliance with ANSI, ASME, and API.

The products are of guaranteed high quality and fair price, these products have been under the brand name “STV” for the last 10 years. The exposure, popularity, and recognition of the STV brand worldwide have made it possible to rapidly become a well-known trade name that is acknowledged to be one of the leading industrial valve lines sold worldwide.

STV Valve is committed to meeting your needs and providing you with the right valve at the right price. They’ll have a valve that suits your needs and matches your budget. When you buy from STV, you purchase from dedicated professionals who are committed to customer satisfaction.

 

Top Check Valve Manufacturers in China

China Yuanda Valve Group Co. Ltd.

Established: 1994

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Swing Check, Lift Check, Cast Steel, forged steel, Stainless steel Valve.

Certification: API 6D, API 600, API 602, ISO 9001, ISO 14001, WRS, EAC Certifications.

Yuanda Valve Group Co., LTD. Used the short 30 years to raise and grow at a pace of 100 times. They are going forward with time, upgrading facilities, elaborately sculpting the brand, concentrating on creating high-end goods, and aggressively reacting to consumer demands with imagination. Every move they make is a breakthrough in the valve industry in China.

Yuanda Valve has also invested in specialized equipment to avoid significant product defects, such as sand inclusion, air hole, fire frying, fire drawing, mis-boxing, and so on. Yuanda Valve makes some of the best industrial valves, including check valves.

They sell many types, such as the DIN swing control valve, the DIN lift control valve, the screw attachment control valve, and much more. As Yuanda Valve observes advanced methods of international resource management, the organization has earned the confidence and loyalty of many of its clients.

In recent years, Yuanda has witnessed an increasing recognition in the engineering and international fields, developed a long-term and stable partnership of cooperation with renowned companies and several transnational groups in areas such as oil, petrochemicals, water conservation, and steel, and has made this vision a reality. Yuanda attaches importance to after-sales services, continues to develop the after-sales service mechanism: Yuanda’s philosophy of service is to remain customer-oriented and provide prompt response and quality services.

 

WELCO Valve Co. Ltd.

Established: 2009

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Swing Check, Lift Check, Dual Plate, Single Check Valve.

Certification: ISO 9001:2008 EN, ISO 9001:2008 CN, EC Certification Etc.

WELCO valve is among the leading manufacturers in China specializing in the design, production, selling and after-sales of industrial valves, such as check valve, butterfly valve, gate valve, globe valve, ball valve, bellow seal valve, pressure seal valve, API 602 forged steel valve, API 603 corrosion-resistant valve, strainer. It comprises two machinery workshops, one assembly workshop, one synthetic finished warehouse, and one semi-finished warehouse.

It has a modernized research and development team for its valve devices. In every move, they strictly comply with ISO9001 procedures. Now the Welco valve co. has the capability to produce high temperature and high-pressure valve series for all forms of the valve.

The organization has complete precision casting molds for internal components, integrated physical and chemical inspection instruments, experimental devices, and research techniques, as well as CAD production skills that ensure our output is always at the highest standard.

 

Top Plug Valve Manufacturers in China

Chaoda Valves Group Co. Ltd.

Established: 1984

Business Type: Exporter, OEM Supplier, Manufacturer.

Valve Types: Lift Plug, American Standard Plug, National Standard Plug Valve, etc.

Certification: ISO9001, ISO14001, OHSAS18001, API6D, CE/PED, API607, API6FA, ISO 15848-1, TS, API 600.

Chaoda is one of the best manufacturers of plug valves in China. It requires a professional R&D staff, sophisticated machinery, and facilities, completely functioning physical & chemical analysis and inspection systems, and a high-tech knowledge processing system to satisfy the needs of its customers. Chaoda’s stainless steel plug valve provides superior sealing efficiency and durability. The valve can be quickly opened and closed by raising, which eliminates any pressure between the body and the seal. The valve is made of carbon steel, stainless steel, alloy steel, duplex stainless steel and can be powered by hand, gear, electrical or pneumatic actuation. It can be used for mediums such as water, tar, acetic acid, carbamide, steam, nitric acid, oxidizing agent, and more.

 

Xiamen Dervos Valves Industry Co. Ltd

Established: 2008

Business Type: Exporter, Supplier, Manufacturer.

Valve Types: RF Plug, Sleeve, Three-way Jacket Plug Valve, etc.

Certification: Certificates of ISO9001, API607, etc.

Dervos Valves are leading the way for high-quality industrial valves in China. As a multinational retailer, Dervos Valves is dedicated to designing and providing valves that satisfy the exact needs of its customers. The plug valve contains an upright pressure plug valve, a jacket plug valve, a 3-and 4-way plug valve, a soft sealing valve style sleeve, an orbit plug valve, and more. The plug valves are simple to control, economical and effective. Dervos’ butt welded plug valve can be made of carbon steel, stainless steel, and alloy steel. It can accommodate a PN16~PN100 pressure range and a working temperature of-29 °C~180 °C. It may be handwheel, magnetic, electrohydraulic, gearbox, pneumatic, and oil-powered actuated.

 

China Valves Technology (Changsha) Co. Ltd

Established: 1958

Business Type: Exporter, Supplier, Manufacturer.

Valve Types: Lift Plug, Sleeve, Three-way Jacket Plug Valve, etc.

Certification: API 6D, API 6D SS, API 6F, ANSI API 607, ISO 9001, ISO 14001, OHSAS18001.

China Valves Technology Co., Ltd is a subsidiary of CVVT. It has a predecessor, the Changsha Valve Factory, which was established in 1958 and was the leading manufacturer of the Chinese valve. It has a declared capital of $10,000,000 and a gross valuation of $25,000,000,000. CSV has more than 5 years of experience working in automotive valve development. They house top-of-the-line production, refining, and research equipment to help them manufacture high-quality automotive valves.

The CSV plug valve is constructed with ductile cast iron and can withstand pressure from 0.6Mpa to 1.6Mpa and a temperature range from-10°C to 80°C. The sealing surface is built of stainless-steel welding technology with strong corrosion resistance. The double eccentric structure provides good sealing quality, low flow resistance, and energy savings. The plug valve is used for flow control in the petrochemical, electrical, steel, municipal, and other industries.

 

Top Strainer & Filter Manufacturer in China

Shanghai KS Flow Control Equipment Co. Ltd

Established: 1984

Business Type: Exporter, OEM Supplier, Manufacturer.

Certification: ISO 9001, API 6D, CE, ISO14001, OHSAS18001, API 607, 6FA, API 600, etc.

Shanghai KS Flow features modern packaging and engineering facilities with more than 70 CNC machine tools and machining centers and three spray lines. Their Y-type strainer is invaluable for any transmission pipeline system. It is located at the inlet of pressure-reducing valves, pressure relief valve, water valve, and other items to limit the impurity of the valve inlet. KS Flow strainers are available in sizes 1/2′′–18′′ and can be produced from cast iron, stainless steel, and WCB. They have a ductile body that preserves their form and structure. The architecture induces low-pressure decreases and the epoxy coating avoids corrosion and rust. The mesh area is 3 to 4 times greater than the nominal diameter area, resulting in poor flow resistance.

 

Xiamen Landee Industries Co., Ltd

Established: 1994

Business Type: Exporter, OEM Supplier, Manufacturer.

Strainer Types: Y-type strainers, T-type strainers, basket strainers, conical strainers, etc.

Certification: ISO9001, ANSI, API certified.

Xiamen Landee Industries Co., Ltd has been in business since 1994. It provides a wide variety of valves, tubing, flanges, fasteners, pipe fittings, gaskets, and other automotive fittings. The company produces more than 50 different types of goods available in 20 different fabrics and 400 different sizes. Xiamen Landee is the maker of some of the finest industrial machinery in China. Their industrial valves are primarily used in oil rigs, but they also manufacture valves for the refined chemical, pharmaceutical, gas, and paper industries.

They include a range of strainers, including Y-type strainers, T-type strainers, basket strainers, conical strainers in cast iron, ductile iron, and more. Landee carbon steel Y strainer is 16 inches long and made of high-grade carbon steel. It can withstand a pressure of 150 lb and has a painted top. The dual strainer comes with flanged ends and is 6 inches long.

What is stainless steel gate valve?

A stainless steel gate valve is a type of gate valve which is made entirely of stainless steel material. A stainless steel gate valve is known for its high strength. With that high strength, these valves are suitable for high pressure and high-temperature applications. Stainless steel gate valves are also known to be made of tough bodies, more durable relative to other valves like ductile iron and cast iron valves. Stainless steel gate valves are also known for their corrosion resistance. A combination of corrosion resistance, high strength, and high toughness makes stainless steel gate valves very useful in all high-pressure applications. However, stainless steel gate valves are expensive because the machining of stainless steel is difficult to shape and takes a lot of energy. 

As the name suggests, stainless steel gate valves have a gate to control fluid flow. Stainless steel gate valves are used to control fluid flow by either closing or opening a gate. The process of opening or closing the gate is linear and the gate travels vertically upwards or downwards to open or close the valve respectively. Stainless steel gate valves are not used to regulate fluid flow because this causes its gate to get damaged easily. They are only used to close or open fluid flow. Stainless steel gate valve manufacturers design the valve such that the gate is perpendicular to the fluid flow. This design helps to reduce pressure loss. Stainless steel gate valves are bi-directional which makes them be installed in almost any direction. 

Components of a stainless steel gate valve

Handwheel/actuator 

The handwheel is a component used in manual stainless steel gate valves so that the valve operator can apply torque to open/close the valve. If the stainless steel gate valve is not manual, then it is operated by an actuator. An actuator is a device used in stainless steel gate valve to provide torque to open/close the valve. When the handwheel/actuator rotates, it helps to rotate the stem which is connected to the gate. Thus handwheel works with a stem to open/close the stainless steel gate valve. 

Valve body 

The valve body in a stainless steel gate valve is the main component used to house internal parts of the valve. This component of a stainless steel gate valve is made of stainless steel material. Stainless steel is known to be strong and tough and thus it helps to protect the valve against damage in times of very high pressure and high temperature since these valves are mostly used in high pressure and high-temperature applications. 

Bonnet 

This is a component used to cover the top of the stainless steel gate valve. The bonnet is placed on the top of the valve body and the two are connected using screws or bolts. The screws and bolts help to enhance a tight seal free from fluid leakage. Between screw and bolted connection, the bolted connection is mostly used since it can provide a tighter seal at very high pressure. Another method of connecting the bonnet and the valve body is by welding. The welded bonnet is superb as it provides zero leakage seal. The bonnet is also made of stainless steel material like the valve body which enhances valve strength.

Stem 

This is the component of a stainless steel gate valve which is connected to the handwheel and the gate/disc. The stem is meant to transmit torque from the handwheel through its threads to the gate. This torque is then converted to linear force which is used to raise or lower the gate to open or shut off fluid flow. The stem needs to be strong to enhance its ability to transmit torque to the gate. As such, the stem in a stainless steel gate valve is made of stainless steel to enhance its strength. 

Gate 

A gate in a stainless steel gate valve is an internal component that is tasked with blocking or opening fluid flow. The gate used in stainless steel gate valves can be either wedge or parallel-shaped. 

Seat 

The seat is an interior component of a stainless steel gate valve. Stainless steel gate valves are designed with two seats to ensure a tight seal with the gate. Seats used in stainless steel gate valves are integrated with the body or they are in terms of a seat ring. For seat rings in stainless steel gate valves, they are pressed or threaded into position and seal welded to the body. Integrated seats are valves made of the same material (stainless steel) as the body. Threaded in or pressed in seats allow for variations such as the seat can be made of different materials like PTFE instead of stainless steel. 

Backseat 

The backseat in a stainless steel gate valve is mounted in the bonnet. The backseat helps when the valve is opened fully so that the valve stem can “back seat” against the bonnet to help close off fluid pressure to the stuffing box. This helps to support the main seal on a stainless steel gate valve which is often a stuffing box. 

Trim 

Trim is a name given to the internal components of a stainless steel gate valve. The components under trim include gaskets, seat, seating surface, gate, gate surfaces, seals, stuffing box, and bushing. 

How does a stainless steel gate valve work? 

Stainless steel gate valves work by turning a handwheel to either open or close fully. When the handwheel is rotated, it rotates the stem. The stem is connected to the gate/disc. As the stem rotates through its threads it helps in raising or lowering the gate/disc. When this gate raises upwards it opens the valve allowing fluid to flow. When the gate is lowered it closes the fluid flow. Opening of stainless steel gate valve occurs when the handwheel is rotated anti-clockwise while closing occurs when you rotate the handwheel in a clockwise direction. 

Working of a stainless steel gate valve

Types of stainless steel gate valves 

Rising stem stainless steel gate valve 

This is a stainless steel gate valve in which the stem can move upwards when the valve is opening. Using this type of stainless steel valve, the valve operator can monitor the closing of the valve and thus easily know when the valve is fully closed/opened. This is because when the stainless steel gate valve is fully opened the stem will be exposed above the handwheel. 

Non-rising stem stainless steel gate valve 

This is a stainless steel gate valve that has a blind stem. The stem in this type of gate valve turns to close and open the valve but it does not move down or up as it turns. When the stem in a stainless steel gate valve rotates, it moves in or out of the valve. As such, the gate moves proportionately to close or open the valve. This type of stainless steel gate valve is used in several applications such as water supply, HVAC, gas, steam, and other utility applications. Non-rising stem stainless steel gate valves operate in small spaces relative to rising stem counterparts. 

Stainless steel knife gate valve 

This is a stainless steel gate valve design that reduces contact between various valve components. As such, this stainless steel knife gate valve helps to reduce the wear and tear of its parts in contact. Stainless steel knife gate valves are used for closing/opening services in applications with high levels of suspended solids. These valves are suitable for handling corrosive, slurry, viscous, and abrasive fluids. Stainless steel knife gate valve is easy to operate and it has low weight.

Stainless steel flexible wedge gate valve 

This is a stainless steel gate valve with a solid gate and a cut around the perimeter. The cut is of different sizes, shapes, and depths. When the cut is narrow and shallow it offers high strength but low flexibility. When the cut is wide and deep it reduces strength but enhances flexibility. Stainless steel flexible wedge gate valve design has enhanced seat alignment and better leakage tightness. These valves are used in different applications such as steam systems. Stainless steel flexible wedge gate valves allow the gate to bend when the seat is compressed during the thermal expansion in steam application. This helps to prevent thermal blindness. 

Stainless steel wedge gate valve 

This is a stainless steel gate valve that uses a wedge-shaped gate/disc. When a stainless steel wedge gate valve closes, it does so by pushing the gate to a taper machined on the valve body. The seal becomes better by combining the gate wedge shape of the body with a seat ring. When a stainless steel wedge gate valve opens fully, the back seat enters into a bonnet bush. For actuated valves, the stem does not keep wholly on the back seat to prevent damage. 

Stainless steel slab gate valve

This is a stainless steel gate valve that is unitary with a bore-size hole. When a stainless steel slab gate valve is opened, the holes are coincident with two seat rings. Such orientation in a stainless steel gate valve helps to produce even media flow with minimal turbulence which helps to reduce system pressure loss. Stainless steel slab gate valves need their seats clean. However, the gate cavity can at times be clogged with debris. As such, stainless steel slab gate valves are designed with a plug used for expelling the debris during maintenance. Stainless steel slab gate valves are suitable for transporting crude oil and natural gas liquids. 

Stainless steel parallel slide gate valve 

This is stainless steel gate valve that does not require a wedging action for proper seating. The stainless steel parallel slide gate valve closes using two individual gates connected via a disc holder. Springs in parallel move down to close the valve. When the port seals, the stem plug prevents additional movement. When the valve is open, the gate moves upwards, and the stem sits back. Stainless steel parallel slide gate valve close and open fully with limited movement. 

 

Applications of stainless steel gate valves 

  • Stainless steel gate valves are is used in chemical plants. 
  • Stainless steel gate valves are used in transporting crude oil and natural gas liquids. 
  • These valves are used in pipeline industries. 
  • Stainless steel gate valves are used in slurry applications. 
  • They are used in liquids, gas, and steam applications. 
  • Stainless steel gate valves are used in the control of hydrocarbons, feedwater, air, and fuel gas applications. 
  • Stainless steel gate valves are used in high pressure and high-temperature applications. 
  • Stainless steel gate valves are used in food processing and beverages applications. 
  • These valves are used in the heating, ventilation, and air conditioning (HVAC) systems of buildings.

 

Advantages of stainless steel gate valves 

  • Stainless steel gate valves have low small fluid resistance. 
  • It requires a small force to open and close the valve. 
  • Stainless steel gate valves are bi-directional. 
  • Stainless steel gate valves are very strong for high-temperature and high-pressure applications. 
  • Stainless steel gate valves can be manual or operated by an actuator. 
  • Stainless steel gate valves get less erosion on the sealing surfaces by the flowing fluid when they are fully open relative to stop valves. 
  • Stainless steel gate valves have a relatively simple body design for ease of repair, cleaning, and maintenance. 
  • Stainless steel gate valves are of different varieties which makes them serve in many applications. 

 

Disadvantages of stainless steel gate valves 

  • Stainless steel gate valves open and close slowly. 
  • Stainless steel gate valves need a large area for operation, maintenance, and installation. This is because the stainless steel gate valve’s overall height and dimensions are large.  
  • Stainless steel gate valves tend to make a lot of vibrations and noise while in use. 
  • Stainless steel gate valves use two sealing surfaces which makes it difficult to process, grind, and do maintenance. 

 

Troubleshooting stainless steel gate valves 

Stainless steel gate valve leakage 

  • Leakage past packing after installation. This could be due to the stainless steel gate valve having been subjected to high temperatures during shipment. It could also be due to normal packing wear. Tighten the packing or replaced it as necessary. 
  • The stainless steel gate valve is leaking past its seat. Gate or seat is damaged. Replace the gate or seat as necessary. 
  • Leakage past the seat. Worn out the seat or worn out O-ring seal. Replace the seat or the O-ring seal as necessary. 
  •  Leakage in the seat. Foreign materials stuck in the gate. Remove the materials by flushing dirt through the valve. 
  • Leakage through bolted connections. Check loose body to bonnet connections. Tighten the connections (bolts, nuts, screws) as necessary. 

The excess force needed to open/close the stainless steel gate valve 

  • The valve needs lubrication. Check recommended lubrication by the stainless steel gate valve manufacturer. 
  • Misalignment between gate and stem. Loosen the valve yoke and handwheel/actuator and check the stem and gate alignment. Correct any misalignment and then tighten again. 
  • Stainless steel gate valve packing is very tight. Loosen the packing. Follow stainless steel gate valve manufacturer’s instructions in regards to tightening the packing. 

 

Summary 

A stainless steel gate valve is a gate valve that has most of its components made of stainless steel. Stainless steel is a metallic material known for its high strength and toughness. As such, gate valves made using stainless steel are of high strength and more durable. Stainless steel gate valves use a gate that is tasked to block or open fluid flow. These valves work by using a handwheel/actuator which transmits torque to the gate through a component known as a stem. When the actuator/handwheel is rotated anticlockwise it raises the gate and thus opens fluid flow. When the stainless steel gate valve is rotated clockwise, it lowers the gate and thus blocks fluid flow. Stainless steel gate valve manufacturers design the valves in a way that makes the gate and fluid flow perpendicular to each other in a straight flow path. This helps to reduce pressure drop in the valve since fluid flow in a straight line has a low-pressure drop. 

Stainless steel gate valves are used in different industries such as chemical industries, petroleum, water supply, food and beverage processing, HVAC systems, among others. Stainless steel gate valves are mostly preferred due to their superb features and advantages which are very strong, simple design, bi-directional capability, suitable for different actuators, small pressure drop, low fluid resistance, and ability to work at high temperature and high pressure. 

 

What-is-a-Gate-Valve-and-How-does-they-work

Gate Valve – How They Work


Figure 1: Gate valve

A gate valve controls the medias flow by lifting the gate (open) and lowering the gate (closed). A gate valves distinct feature is the straight-through unobstructed passageway, which induces minimal pressure loss over the valve. The unobstructed bore of a gate valve also allows for a pigs passage in cleaning pipe procedures, unlike butterfly valves. Gate valves are available in many options, including various sizes, materials, temperature and pressure ratings, and gate and bonnet designs.

Gate valves tend to be slightly cheaper than ball valves of the same size and quality. They are slower in actuation than quarter-turn valves and are for applications where valve operation is infrequent, such as isolating valves. Gate valves should be used either fully open or fully closed, not to regulate flow. Automated gate valves exist with either an electric or pneumatic actuator, but a manual gate valve is cost-effective since they have infrequent usage.

Table of Contents

Functioning principle

Gate Valve ComponentsFigure 2: Gate valve components

A gate valves main components as seen in figure 2 are the handwheel (A), spindle (B), gasket (C), bonnet (D), valve body (E), flange (F), and gate (G). The primary operation mechanism is straightforward. Turning the handwheel rotates the stem, which moves the gate up or down via the threads. They require more than one 360° turn to fully open/close the valve. Lifting the gate from the path of the flow, the valve opens. Lowering the gate to its closed position seals the bore resulting in a full closure of the valve.

For a gate valve, the relationship between the gates vertical travel and the flow rate is nonlinear, with the highest changes occurring near shutoff. When used to regulate flow, the relatively high velocity of the flow at partial opening results in gate and seat wear, which along with possible vibrations of the gate, shortens the valves service life.

Gate valve design & types

Gate valves come in a wide variety of designs, each of which uses different technologies to meet various application requirements.

Bonnets

Bolted bonnet gate valveFigure 3: Bolted bonnet gate valve

A bonnet protects the internal parts of a gate valve (Figure 2). It is screwed in or bolted to the valve body, creating a leak-proof seal. Therefore, it is removable for repair or maintenance purposes. Depending on applications, gate valves can have screw-in, union, bolted, or pressure seal bonnets.

Screw-in Bonnets

Screw-in bonnets are the simplest in construction. They are common in small size valves and provide a durable leak-proof seal.

Union Bonnets

Union bonnets are held in place by a union nut. The union nut sits on the lower edge of the bonnet and screws into the valve bodys threads. This type of design ensures that the leak-proof seal created by the nut does not deteriorate by frequent removal of the bonnet. Therefore, union bonnets are common for applications that require regular inspection or maintenance.

Bolted Bonnets

Bolted bonnets provide sealing in larger valves and higher pressure applications. In this type, the bonnet and valve body are flanged and bolted together. Figure 3 shows a gate valve with a bolted bonnet.

Pressure Seal Bonnets

Pressure seal gate valves are ideal for high-pressure applications (more than 15 MPa). This type of construction uses internal pressure to create a better seal. Pressure seal bonnets have a downward-facing cup inserted into the valve body. When internal fluid pressure increases, the cups forced outward, improving the seal.

Gates

The gate comes in a variety of designs and technologies to produce effective sealing for differing applications.

Wedge Gates

In most gate valves, the gate has a wedge form and sits on two inclined seats (Figure 4). In addition to the primary force created by fluid pressure, a high wedging force on the seats created by the stems tightening assists with the sealing. The wedge-shaped gate does not stick to the seat in case of high fluid differential pressure and has an increased service life due to less “rubbing” on the seats.

Wedge gate valve vs parallel gate valveFigure 4: Wedge gate valve vs parallel gate valve

Parallel Slide Gates

Gate valves can also come in a parallel form where the gate is flat, and the seats are parallel. Parallel gate valves use line pressure and positioning to make a tight seal. Flat gates consist of two pieces and have a spring in the middle. The spring pushes the pieces towards the seats for enhanced sealing. Due to their inherent design, parallel gate valves have a safety advantage in higher temperature applications. In wedge-shaped gate valves, an additional compression load on the seats may result in thermal binding and restricted opening of the valve due to expansion. Furthermore, since there is no wedging action in parallel gates, closing torques are comparatively smaller, resulting in smaller, less expensive actuators or less manual effort. Due to their sliding into position, parallel gates keep dirt away from the seating surfaces.

Slab Gates

Slab Gate ValveFigure 5: Slab gate valve

Slab gates, also called through-conduit gate valves, are one-unit gates that include a bore size hole (Figure 5). In the open state, the bore is in line with the two seat rings. This alignment creates a smooth flow with minimal turbulence. This unique design allows for minimal pressure loss on the system and is perfect for the transportation of crude oil and natural gas liquids (NGLs). The valve seats remain clean. However, the disc cavity can capture foreign material. Therefore, the cavity typically has a built-in plug for maintenance purposes of draining the accumulated foreign material.

Parallel Expanding Gates

Expanding gate valves have two slab gates matched together that provide sealing through the mechanical expansion of the gate (Figure 6). When lifted, both of the slab gates cavity allows the media to flow. The upward force on one slab and the stoppage of the second slab, by a step in the valve body, allows for outward mechanical expansion for a proper seal. When closed, the slab gates block the media flow, and the downward force (stem) on one slab and upward force (step in valve body) allows for outward mechanical expansion for a proper seal.

These valves provide an effective seal simultaneously for both upstream and downstream seats. This seal makes them ideal for applications like isolation valves in power plants, block valves in process systems, and high-temperature valves in refineries.

Expanding gate functioningFigure 6: Expanding gate functioning

Knife Gates

Knife gate valves are for thick fluids and dry bulk solids. The gate is only one piece of metal, which is typically pointed. These valves are self-cleaning as they pass the seat rings every time they open and close.

Stem design

The gate is raised and lowered by the spinning of a threaded stem. A manual wheel or actuator spins the stem. Depending on the design, the stem is either considered rising or non-rising. So, as you spin the stem it either raises or stays in place with the spin as seen in Figure 7.

Outside Screw and Yoke (OS&Y), also referred to as rising stems, are fixed to the gate. Therefore, the threads are on the actuation side. So, as the gates raised or lowered, the stem moves with it up and down. Consequently, they have built-in visual indicators of the state of the valve and are easily lubricated. Since they have moving components, they cannot be used with bevel gears or actuators. Therefore, rising gate valves are suitable for manual actuation.

On the other hand, a non-rising stem is fixed to the actuator and threaded into the gate. An indicator is often threaded onto the stem to show the open or closed state of the valve. Non-rising gate valves are common in underground installations and applications with limited vertical space.

Mechanism of rising stem gate valves vs non-rising stem gate valvesFigure 7: Mechanism of rising stem gate valves vs non-rising stem gate valves

FAQ

What is a gate valve?

A gate valve controls the medias flow by lifting the gate (open) and lowering the gate (closed).

How does a gate valve work?

By rotating the manual handle, the threaded stem moves the gate up and down. As the gate goes up it opens and down it closes the media flow.

What is a gate valve used for?

A gate valve is for on and off flow control.

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STV Delivers Wafer Check Valves to a Thailand Customer

China dual check valve,spring loaded check valve,Wafer Check Valve,Wafer Swing Check Valve,stainless steel check valve Manufacturer with high quality and competitive price

The valve made by stainless steel ASTM A351 CF8

We just delivered some special material check valves to a Thailand customer.

Generally:
Dual-plate check valve, wafer type
***design as per API 594
***for mounting between two flanges, as per ASME B16.5

***body: ASTM ASTM A351 CF8
***disc: ASTM ASTM A351 CF8
***trim: ASTM A182 F304
***spring: INCONEL X750
***body seat: stellite

10″-150 LB    25pcs
10″-150 LB    25pcs

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