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Maintenance Methods of Common Valves

September 14, 2021

Common valve failures include leakage, opening and closing parts damage and failure, etc. One of the most important reasons for the valve failure problem is that the valve is not well maintained. The valve is an important part of the pipeline transportation system. Maintenance and maintenance can make the valve better serve us. At the same time, it can also prevent valve failure from the source and reduce production accidents caused by valve failure. Therefore, this article will talk about the maintenance methods of commonly used valves.

marine valve; butterfly valve; check valve; gate valve; manufacturer in China

1. For valves that are not in use for a long time, they must be cleaned regularly to remove dirt and dust on the exposed surface of the valve, and at the same time, they must be sealed to ensure that the inside of the valve is clean and dry. Store the valve neatly in a ventilated and dry place indoors, and it is strictly forbidden to stack it or store it in the open air. When storing, the butterfly valve is the easiest to store, just keep the butterfly plate in the closed state. For gate valves, globe valves and check valves, both ends of the passage should be blocked during storage, and the valve plate should be closed. The storage of the ball valve requires that both ends are blocked and in an open state.
2. Before installing the valve, you need to check the pressure and diameter of the valve again, and clean up the dirt on the valve during transportation.
3. When installing the valve, install the valve correctly according to the connection method of the valve. Generally, the commonly used valves can be installed at any position in the pipeline, but it is necessary to consider whether the operation of the operator is convenient after installation and whether it is convenient for future valve maintenance .
4. When the gate valve and ball valve are working, they are only used for fully open and fully closed. They cannot be used for flow adjustment, otherwise the sealing surface will be severely washed and corroded, and the opening and closing parts of the valve will be greatly worn.
5. When the handle valve and handwheel valve are opened or closed, levers, wrenches or other tools cannot be used to avoid damage to the valves.
6. Tighten the bolts on the valve packing gland evenly. Don’t beat the gland to make the gland tilt, which will damage or hinder the movement of the valve stem and cause valve leakage.
7. During use, the valve should be maintained regularly to keep the valve clean, and the transmission part should be regularly lubricated. Once the valve is found to be malfunctioning, it must be stopped immediately to find out the cause of the malfunction and clean up the malfunction.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

What is the difference between butterfly valve and ball valve

September 13, 2021

What is the difference between butterfly valve and ball valve? The butterfly valve has a simple structure and a wider application range. The ball valve is only suitable for fluid medium pipelines without particulate impurities; the ball valve has better sealing performance and higher cost. In one sentence, the difference between butterfly valves and

lug type butterfly valve, ductile iron, center lined,

ball valves in use is that small-diameter ball valves are selected, and large-diameter butterfly valves are used.
Under normal circumstances, it is more cost-effective to choose threaded ball valves for small diameters below DN50, while ball valves above DN50 are generally flanged. Because of the processing technology and materials, the price is more expensive.
The sealing performance of the ball valve and its own flow characteristics make it widely used in the paper industry, natural gas industry and high-pressure fields.
Butterfly valves are usually used in large diameter occasions above DN50. Compared with ball valves, butterfly valves have simpler structure and relatively low price. They are generally used in working conditions below PN16. Of course, the applicable pressure of metal-sealed eccentric butterfly valves can reach PN40. . However, the sealing performance of butterfly valves is worse than that of ball valves.

pneumatic V type ball valve

The biggest difference between a butterfly valve and a ball valve is that the opening and closing part of the butterfly valve is a disc-shaped butterfly plate, and the opening and closing part of the ball valve is a round sphere. The opening and closing methods of the two are the same. The butterfly plate of the butterfly valve and the spool sphere of the ball valve rotate around the axis of the valve stem to realize the opening and closing of the valve. The sealing surfaces of butterfly valves and ball valves are also different. The seat sealing surface of butterfly valves is an annular cylinder, while the seat sealing surface of ball valves is spherical.
The butterfly valve is characterized by very fast opening and closing, very simple structure, relatively low cost, and suitable for large-diameter valves. The disadvantage is that the sealing performance and pressure-bearing capacity are poor. The ball valve has good sealing performance and is suitable for fluid media without particles and impurities, with strong pressure resistance and low pressure loss. The disadvantage is that the cost is high, the price is expensive, and limited by its own volume and opening and closing resistance, it cannot be made large.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Design Features of Electric Gate Valve

September 9, 2021

An electric gate valve is a gate valve that uses an electric actuator to control the opening and closing of the valve. Its structure can be divided into upper and lower parts, the upper part is the electric actuator, and the lower part is the gate valve body. Connect the electric actuator and the gate valve, after installation and debugging, it becomes an electric gate valve. The electric gate valve uses electric energy to realize the opening and closing of the valve, so as to control the interception and circulation of the pipeline medium.

DN1000-DIN-F5-NRS gate valve-IS&Y (6)

The switching speed of the electric gate valve can be adjusted, the structure is relatively simple, and the maintenance is easier. Its design structure also has its own characteristics.
1. The electric gate valve adopts pressure self-tightening seal, which has excellent sealing performance and is reliable and safe to use.
2. The electric gate valve adopts a double gate with a universal roof structure in the middle, which can automatically adjust the degree of sealing between the gate and the valve seat to ensure the sealing performance of the valve. At the same time, this structure is very convenient to maintain and save costs.
3. The sealing surface of the gate and the valve seat is made of cobalt-chromium-tungsten cemented carbide by plasma spray welding. The sealing surface has high hardness, and is very wear-resistant and corrosion-resistant, which prolongs the service life of the valve.
4. The valve stem is made of nitrided steel, and the surface is nitrided, which has high hardness, good performance and long life.
5. The electric device of the electric gate valve is equipped with a torque control mechanism, an on-site operating mechanism and a hand and electric switching mechanism. It can also carry out remote operation and intelligent control. It is suitable for use in situations where manual operation is difficult or the pipeline environment is complex and dangerous.
6. When the electric gate valve is used for the first time, during installation and debugging, it is necessary to manually open the valve to about half of the position, so as to avoid the valve or electrical equipment damage due to the reverse connection of the motor phase sequence.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Precautions for butterfly valve maintenance

September 8, 2021

Butterfly valve is a kind of valve, it is a control component in fluid conveying system, it has the function of intercepting and adjusting the fluid flow of pipeline system. Butterfly valve is one of the most widely used valves,

U-type-flange-butterfly-valve-2

which can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, and oil. It is not only widely used in petroleum, gas, chemical, water treatment and other general industries, but also in municipal construction, water conservancy projects, and even cooling water systems in thermal power stations. As a control component, the butterfly valve needs periodic maintenance. Here are the precautions for butterfly valve maintenance:
1. The butterfly valve needs to be fully open and fully closed periodically during the working process to maintain the flexible lubricity of the valve parts and avoid rusting.
2. When closing the butterfly valve, if it is not tightly closed, you can first fully open the butterfly valve again, use the pressure of the fluid in the pipeline to flush out the impurities on the inner wall of the valve, and then close the valve again.
3. Try to filter the impurities in the pipeline as much as possible to avoid squeezing the sealing surface when the butterfly valve is closed, causing the valve to fail to close completely, causing leakage, and causing safety hazards.
4. The opening state of the butterfly plate of the butterfly valve should be greater than 15°, because if the butterfly valve is in a state with a large throttle range, the back of the butterfly plate is prone to cavitation and the valve is at risk of damage.
5. When the butterfly valve is in the middle opening, the operating mechanism needs to be self-locking.
6. Prevent the butterfly valve from mechanical damage, and don’t let the sediments, chemicals, damp gas and other substances in the air corrode the valve and affect the quality of the valve.
7. The threads, bearings, gears and other parts of the working interface of the butterfly valve should be regularly lubricated.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Characteristics of soft seal /resilient seated gate valves

September 7, 2021

Title: what are the characteristics of soft seal /resilient seated gate valves?

Traditional gate valves often have water leakage and corrosion. In order to overcome this shortcoming, the soft-seal gate valve appeared. As an updated product of the traditional gate valve, the soft-seal gate valve overcomes the shortcomings of poor sealing performance, poor elasticity, and easy corrosion of general gate valves.
The soft-seal gate valve uses a flexible rubber-wrapped gate, which uses the elastic energy of rubber to produce a small amount of deformation compensation, so that the valve can achieve a good sealing effect. The characteristics of the soft seal gate valve are as follows:

DIN-F5-BB-NRS-soft seated-wedge gate valve (10)

1. The gate is made of integral rubber
Use high-quality rubber to tightly wrap the gate of the soft-seal gate valve as a whole, which improves the sealing performance and is not easy to fall off.
2. The valve body is not easy to rust and corrosion resistant
The use of powder epoxy resin to coat the valve body of the soft-seal gate valve can effectively prevent the valve body from being oxidized, not easy to rust, and also prevent the valve body from being corroded. Soft-seal gate valves are often used in sewage treatment systems.
3. The valve seat is designed with a flat bottom
Traditional gate valves usually have a groove at the bottom of the valve seat. When the medium in the pipeline flows through the valve, impurities and particles contained in the medium will settle and silt in the bottom groove, which will make the valve unable to close tightly and cause leakage. Cause an accident. The bottom of the valve seat of the soft sealing gate valve is designed with a flat bottom and has no groove. After the medium in the pipeline flows through, there will be no siltation of impurities and particles, and the sealing performance of the valve is guaranteed to avoid leakage.
4. Precision casting valve body
The valve body of the soft sealing gate valve adopts precision casting, the size is accurate, and the inside of the valve body does not need to do any fine processing, and the sealing performance of the valve body is guaranteed.
5. Ductile iron valve body, light weight
The soft seal gate valve uses ductile iron as the valve body material. The overall weight of the valve is 20%-30% lighter than the traditional gate valve. The lighter weight makes the soft seal gate valve easier to install and maintain.
6. The inside of the valve body is not easy to be corroded
The valve body of the soft sealing gate valve is coated with non-toxic epoxy resin, and the gate is completely wrapped by rubber, which can effectively prevent the inside of the valve body from being corroded by the medium in the pipeline.
7. Three “O” seal ring seal design
The valve stem of the triple “O” seal ring seal design greatly reduces the friction resistance of the soft seal gate valve when it is closed, and the sealing performance is reliable, and no water leakage occurs; the unique design structure also makes the “O” seal ring It can be replaced under pressure and is maintenance-free.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

The Basic Knowledge of Butterfly Valves

September 6, 2021

Butterfly valve is also called butterfly type valve or flap valve, which is a kind of regulating valve with very simple structure. Its main structure is composed of valve body, butterfly plate, valve stem, valve seat, transmission device and operating mechanism.
How does the butterfly valve work?
The working principle of the butterfly valve is that a disc-shaped butterfly plate is used as the opening and closing part, which is connected with the valve stem and rotates with the valve stem around its own axis in the valve body to realize the opening and closing and adjustment of the pipeline. When the butterfly plate rotates 90° in the closed position, the valve is in a fully open state. At this time, the thickness of the butterfly plate is the only resistance to the flow of the medium, and the resistance is very small. In addition, changing the angle of the butterfly plate can be used to adjust the media flow. Butterfly valves are generally installed in the diameter direction of the pipeline and can be installed at any position.
The structural principle of the butterfly valve is very suitable for making large-diameter valves, which are used in general industries such as petroleum, gas, chemical industry, and water treatment. The most common fault in the use of butterfly valves is that the sealing surface rubber of the butterfly valve is corroded, worn and teared, aging or even falling off during long-term continuous use, which causes the valve to jam and cannot be closed normally, which affects the valve’s performance. Sealing performance. In order to solve this problem, the structure of the butterfly valve has been continuously optimized.
The simplest butterfly valve is the concentric butterfly valve, that is, the shaft center of the valve stem, the center of the butterfly plate, and the center of the body are in the same position. The structure of this kind of butterfly valve is very simple. The disadvantage is that the butterfly plate and the valve seat are severely squeezed and scratched, and the sealing surface wears quickly.
In order to make up for the shortcomings of the concentric butterfly valve, the single eccentric butterfly valve was born. The stem axis of the single eccentric butterfly valve deviated from the sealing center of the valve plate, so that the lower end of the butterfly plate is no longer the center of rotation, and the lower end of the butterfly plate and the valve seat are reduced. The pressure brought by the excessive squeeze.

ductile iron, DI, butterfly valve, manufacturer, center line, TH valvedoes

The double eccentric butterfly valve is an improvement based on the single eccentric butterfly valve. The stem axis of the double eccentric butterfly valve deviates from the center of the seal and the center of the valve body. The advantage of the double eccentric butterfly valve is that the butterfly plate can be quickly separated from the valve seat after the valve is opened, which largely eliminates unnecessary squeezing and scratching between the butterfly plate and the valve seat, and also reduces the opening and closing of the valve. Resistance, wear and tear are reduced, and the life of the valve seat is improved.
All of the above valves have a shortcoming. They are all soft-sealed and cannot withstand high temperatures, but the use of high-temperature resistant metal materials to make butterfly valves has no guarantee of sealing performance. In order to solve this problem, a triple eccentric butterfly valve was developed.
The biggest feature of the triple eccentric butterfly valve is that it fundamentally changes the sealing structure of the butterfly valve. The triple eccentric butterfly valve is a torsion seal, not a position seal, that is to say, it no longer relies on the elastic deformation of the valve seat to seal, but completely relies on The contact surface pressure of the valve seat achieves the sealing effect. Therefore, the triple eccentric butterfly valve is resistant to high temperature, high pressure, and corrosion, but also has a good sealing effect.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

The correct operation method of manual valve

September 3, 2021

The manual valve is operated by the operator with the help of a handle or a hand wheel to manipulate the opening and closing of the valve by manpower. When the valve opening and closing torque is large, a turbine device needs to be installed between the handle or hand wheel and the valve stem, which is more labor-saving. . Normally, the switching direction of a manual valve is to pull the handle or handwheel of the valve, turn it clockwise in the thorium direction to close, and turn it counterclockwise to open the valve. However, under special circumstances, the opening and closing direction of the manual valve may be reversed. This requires operators, especially those experienced

Wafer type butterfly valve with worm gear

operators, to not directly operate the valve based on experience, and check the valve before operation. Open and close signs to avoid losses caused by improper operation. The correct operation method of manual valve is as follows:
1. The operation of manual valve requires the person who manipulates the valve to hold the handle or hand wheel to operate. It is not possible to switch the valve with levers and long wrenches to avoid damage to the handle or hand wheel due to excessive force, let alone violent operation to avoid accidents. happen.
Under normal circumstances, the length of the handle or the diameter of the handwheel is less than 320mm, and only one person is allowed to operate; when the diameter of the handwheel is equal to or greater than 320mm, two people are allowed to complete the operation together, or a single person can appropriately use tools, levers or wrenches. Operate, but pay attention to the lever length not to exceed 0.5m.

manual valve installation site-method

2. Both manual gate valve and manual stop valve are operated with the help of handwheels. After the valve is fully opened or closed, it must be rotated 1/4 to 1/2 circle to make the threads tightly fit better and avoid the valve at the same time. Overtightening may cause damage.
3. To operate the manual steam valve, preheat the pipe before opening it to discharge the condensed water in the pipe; open the valve slowly to prevent the occurrence of water hammer and cause damage to the valve and pipeline equipment.
4. The sealing surface of the normally open manual valve is easy to stick to impurities and dirt. Before closing and closing, slightly open a slit to allow the high-speed flowing medium to wash away these foreign objects, and then gently close it to improve the sealing effect .
5. In some pipelines with over-temperature medium, when the manual valve is closed, the temperature in the valve body drops, because the thermal expansion and contraction cause the valve to shrink, and there will be some small gaps in the sealing surface, and the valve will leak. In this case, after closing the manual valve, close it again after a while.

The correctness of manual valve operation affects the service life of the valve and even production safety, so it is necessary to master the correct valve operation method. Safe production, start with small things.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Commonly used valves for Water Supply and Drainage System

September 2, 2021

Valves often used in water supply and drainage piping systems include butterfly valve, gate valve, check valve.
This article introduces common water supply and drainage system valves one by one.
1. Butterfly valve: a simple regulating valve, generally used in low-pressure medium pipelines for cutting off and intercepting. It is also one of the common valves in water supply and drainage piping systems. It regulates and intercepts the flow of water on the water supply and drainage pipeline. The butterfly valve is small in size, light in weight, easy to install and operate, but the opening and closing torque is relatively large.

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

The butterfly valve can be divided into wafer butterfly valve and flange butterfly valve according to the connection mode; according to the different driving mode, it can be divided into handle butterfly valve, turbine butterfly valve, electric butterfly valve, pneumatic butterfly valve, etc.
2. Gate valve: It can only be a kind of valve that can cut off the flow of the pipeline medium. The structure of the gate valve is more complicated. It can only be fully opened and fully closed. The opening and closing torque is small, the fluid resistance in the pipeline is small, and it can flow in both directions. The gate valve is most suitable for media that does not contain particles, such as water, because the sealing surface of the gate is easy to wear with impurities or particles in the medium. In addition, impurities precipitate to the bottom of the valve body, which will affect the sealing performance of the gate valve. Causes the defect that the valve is not closed tightly.

dual plate wafer type check valve (1)

The gate valve is only suitable for use in pipelines that need to be normally open or normally closed, because if the gate valve is frequently opened and closed, it may cause the valve plate to fall off and make the system lose its control ability.
The gate valve can be divided into parallel plate gate valve and wedge plate gate valve according to the difference of the gate. According to the difference of valve stem, it can be divided into open stem gate valve and dark stem gate valve.
3. Shut-off valve: similar to gate valve, the functions of the two are similar when the medium in the pipeline is cut off. But the difference between the globe valve and the gate valve is that the globe valve has a simpler structure and is more convenient to maintain, but the force used to switch the valve is greater than that of the gate valve. In addition, the globe valve is a one-way valve. When installing, pay attention to the valve body. The instructions on the operation must not be reversed.
4. Check valve: It is also a list valve and check valve, which has strict directio

AWWA C509-C515-resilient seated wedge gate valve-DN80-150lb (4)

nality and stipulates that the medium is only allowed to flow in one direction. The check valve is used in pipelines where the medium is water, and is mainly used to prevent backflow of water.
Commonly used check valves include butterfly check valves, muffler check valves, swing check valves and so on. When installing, according to the type of valve, determine whether to install on a vertical pipeline or a horizontal pipeline, and install it strictly in the direction marked by the arrow on the valve body, and the installation cannot be reversed.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Advantages and disadvantages of gate valve and its scope of application

September 1, 2021

This article will explain the advantages and disadvantages of gate valves and the scope of application. A gate valve is a valve in which the opening and closing part moves along the vertical direction of the pipeline channel axis. The

DIN-F5-BB-NRS-soft seated-wedge gate valve (10)

opening and closing part is called a gate, which is mainly used to cut off the flowing medium in the pipeline and can only be used fully open or fully closed. Therefore, the gate valve cannot be used as a regulating valve to regulate flow. Gate valves of different materials are adapted to different environments and temperatures, but gate valves are generally not used in pipelines that transport mud and other media, because these media contain impurities, which will affect the sealing effect of the gate.

Advantages of gate valve:
1. It can only be fully open and fully closed. When the gate is fully open, the resistance of the fluid through the valve is small;
2. The torque required for opening and closing is small and labor-saving;
3. It can be used in pipelines where the medium flows in both directions, and the flow direction of the medium is not restricted;
4. Compared with the shut-off valve, when the gate valve is fully opened, the degree of erosion and erosion of the sealing surface by the fluid medium is low;
5. Simple structure, convenient installation and use, and good manufacturing technology;
6. The overall structure length of the valve is relatively short.

Disadvantages of gate valve:
1. The overall dimensions and opening height are relatively large, which requires a large installation space;
2. When the gate is opened and closed, the friction with the sealing surface of the valve seat is large, causing certain wear on the sealing surface;
3. Usually the gate valve has two sealing surfaces, which is difficult to process and grind, and it is quite troublesome to maintain;
4. It takes a long time to open and close.

Gate valves usually have more applications in the following areas:
1. Oil and natural gas pipelines.
2. Transportation pipeline and storage equipment of refined oil.
3. Wellhead equipment for oil and natural gas exploitation.
4. City gas transmission pipeline.
5. Tap water and sewage treatment projects.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Commonly Used Seat Materials for Butterfly Valve

August 30, 2021

The valve seat is a detachable part inside the valve. Its main function is to support the valve core to be fully closed or fully closed, and to form a sealing pair. Under normal circumstances, the diameter of the valve seat is the size of the valve. The butterfly valve seat is made of a wide range of materials, but the commonly used materials include soft-seal EPDM, nitrile rubber (NBR), polytetrafluoroethylene (PTFE), and metal hard-seal hard alloy materials. kind. Let’s introduce them one by one below.

wafer type butterfly valve, EPDM seat (10)

1. EPDM: Compared with other general-purpose rubbers, EPDM has great advantages.
①The cost performance is very high. Among the commonly used rubbers, EPDM has the lightest raw rubber density and can be filled in a large amount, reducing the cost of the rubber.
②EPDM material is resistant to aging, sun exposure, heat resistance, moisture resistance, and radiation resistance, and is suitable for weak acid and weak alkali media. Good insulation properties.
③The applicable temperature range can be as low as -40℃–60℃, and it can be used for a long time under the temperature condition of 130℃.
2. Nitrile rubber (NBR): oil resistance, heat resistance, abrasion resistance and good water resistance, air tightness and excellent bonding properties. It is widely used in petroleum pipelines. The disadvantage is that it is not resistant to low temperature, ozone, poor insulation performance, and general elasticity.
3. Polytetrafluoroethylene (PTFE): A fluoroplastic, this material has strong resistance to acids, alkalis, and various organic solvents. At the same time, the material is resistant to high temperatures and can be used continuously at 260°C, and the maximum use temperature can reach 290-320°C. The emergence of PTFE has successfully solved many problems in the chemical, petroleum, pharmaceutical and other industries.

Fluorine lined butterfly valve-PTFE-WAFER (8)

4. Metal hard seal (hard alloy): The material of the metal hard seal valve seat has very good high temperature and high pressure resistance, corrosion resistance, wear resistance and other characteristics, which makes up for the defects of soft seal material that is not resistant to high temperature and high pressure. However, the hard seal material has high requirements on the processing technology. The only disadvantage of the metal hard seal valve seat is that the sealing performance is poor, and leakage will occur after a long time of operation.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Maintenance Methods of Common Valves

What is the difference between butterfly valve and ball valve

Design Features of Electric Gate Valve

Precautions for butterfly valve maintenance

Characteristics of soft seal /resilient seated gate valves

The Basic Knowledge of Butterfly Valves

The correct operation method of manual valve

Commonly used valves for Water Supply and Drainage System

Advantages and disadvantages of gate valve and its scope of application

Commonly Used Seat Materials for Butterfly Valve

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