butterfly valve Archives

The difference between fluorine-lined butterfly valve and metal butterfly valve

September 17, 2021

Butterfly valve is one of the most commonly used valves in industrial pipelines. It has a simple structure and is mainly composed of a valve body, a valve stem, a butterfly plate and a sealing ring. It is easy to operate and can be equipped with different driving devices, such as turbine devices, electric devices, and pneumatics. Equipment, etc., to adapt to more working conditions. Compared with other valves of the same caliber, the overall cost of butterfly valves can be reduced by 1.5 to 2 times, which is economical and practical. Therefore, butterfly valves are most suitable for large-diameter valves and are often used in occasions with larger calibers and flow rates.

Fluorine lined butterfly valve-PTFE-WAFER (8)

According to the sealing form of the butterfly valve, we can divide the butterfly valve into two categories: soft sealing butterfly valve and hard sealing butterfly valve. The two butterfly valves with different sealing forms play different roles in the corresponding application pipelines, and it can even be said that there are big differences. Therefore, users should understand the difference between the two types of butterfly valves when choosing butterfly valves, and choose butterfly valve products reasonably and correctly according to their own operating conditions.
Among soft seal butterfly valves and hard seal butterfly valves, our most common and commonly used ones are soft seal fluorine lined butterfly valves and metal seated butterfly valves. The difference between fluorine lined butterfly valves and metal seal butterfly valves is that fluorine lined butterfly valves are generally used for flowing media containing corrosion. In the flexible pipeline, the sealing effect is excellent, and zero leakage can be achieved. However, due to its own material limitation, this type of butterfly valve is only suitable for use in normal temperature and pressure

triple offset butterfly valve-double flange- (4)

conditions. The metal-sealed butterfly valve can be used in working conditions with relatively high temperature and pressure, and it also has certain anti-corrosion performance, but its sealing performance is poor. Specifically, the difference between fluorine-lined butterfly valve and metal sealing butterfly valve is as follows:
1. The difference in structure:
Both sides of the metal seal butterfly valve seal pair are made of metal materials. As for the fluorine-lined butterfly valve of soft sealing butterfly valve, the butterfly plate and valve seat are both wrapped with PTFE;
2. The difference in sealing performance:
The sealing material of fluorine-lined butterfly valve is tetrafluoroplastic, which has excellent sealing performance, but it is prone to aging, abrasion and short service life. The sealing performance of the metal sealing butterfly valve is relatively poor, but it is corrosion-resistant, wear-resistant and has a long service life.
3. The difference in applicable working conditions:
The fluorine-lined butterfly valve has strong corrosion resistance and can be used in corrosive media pipelines. It is only suitable for normal temperature and pressure environments. The metal sealing butterfly valve has poor sealing performance and is generally used in high temperature and high pressure environments.
4. The difference in manufacturing process:
In terms of working principle, the difference between fluorine-lined butterfly valve and metal-sealed butterfly valve is not big. The difference in manufacturing process between the two is mainly in the valve seat. The seat material of the fluorine-lined butterfly valve is non-metallic PTFE and metal-sealed butterfly valve. The valve seat is made of metal materials, and the commonly used materials are copper alloy, chromium stainless steel, stellite alloy, nickel-based alloy and so on.

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 debugging and installation of butterfly valves

September 16, 2021

Butterfly valve is one of the fastest-growing valve varieties at present. The application range of butterfly valves is very wide, and the varieties and specifications continue to expand, and they are developing in the direction of high pressure, large diameter, high sealing, long life, ultra-low temperature, and ultra-high temperature. Butterfly valves can do Emergency cutoff has the characteristic of regulating flow. And it has partially replaced gate valves, globe valves and ball valves, and has become more and more important in pipelines, and its applications have become

D943H-16C-metal seated stainless steel electric triple offset butterfly valve

more and more extensive, becoming the choice of many end users. This article talks about the debugging and installation of the butterfly valve.
1. Debugging of butterfly valve
1. Whether it is a manual butterfly valve or a butterfly valve with pneumatic, hydraulic or electric actuators, it must be strictly debugged before leaving the factory. Fix it, then close the butterfly valve, apply pressure to the inlet side, and then observe whether the valve leaks on the outlet side. In the strength test of the pipeline, the butterfly plate of the butterfly valve should be opened to prevent damage to the sealing pair.
2. Although the butterfly valve has been rigorously debugged before leaving the factory, it is not ruled out that some products have loosened screws during transportation. The user needs to re-check and adjust the valve after receiving the valve. Pneumatic, hydraulic and For electric devices, please refer to the instruction manual of the supporting drive device.
3. When the electric butterfly valve leaves the factory, the opening and closing strokes of the electric control mechanism have been adjusted. But to be safe, to prevent the wrong direction when the power is turned on, after the user gets the valve and turns on the power for the first time, first manually open the valve to the half-open position, and then press the electric switch to check whether the direction of the indicator plate is consistent with the closing direction of the valve That’s it.
Second, the installation of the butterfly valve
1. Before the butterfly valve is installed, it is necessary to confirm whether the performance of the product and the arrow of the medium flow direction are consistent with the working conditions and parameters of the medium in the pipeline. The inner cavity of the valve must be clean. Never close the butterfly plate before cleaning, so as not to damage the sealing ring.
2. To install the matching flange of the butterfly valve to the clip, a special flange for the butterfly valve is required.
3. The best installation position of the butterfly valve on the pipeline is vertical installation, and inverted installation is not allowed.
4. When the butterfly valve needs to be used to adjust the flow, use the turbine box for control.
5. For butterfly valves that are frequently opened and closed, it is necessary to open the turbine box cover regularly (about two months) to check whether the butter is normal, and to ensure an appropriate amount of butter.
6. Regularly check all parts of the valve, and promptly remove any faults found.

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

Features of Stainless Steel Valves

September 15, 2021

Generally speaking, stainless steel valves are valves made of stainless steel. They are classified according to the stainless steel material grade of the valve body. They are mainly 301, 304, 316, 304L, 316L, etc. According to international standards, they can be divided into CF8, CF3, CF8M, CF3M, the quality of the material

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

CF8<CF3<CF8M<CF3M. Because stainless steel has strong corrosion resistance, is easy to form, has high compatibility, and can remain strong in a wide temperature range, many advantages make stainless steel valves widely used in heavy industry, light industry, daily necessities industry and architectural decoration industry. middle.
Stainless steel refers to steel that is resistant to corrosion by weak corrosive media such as air, steam, water and chemical corrosive media such as acids, alkalis, and salts. It is also called stainless acid-resistant steel. Stainless steel valves are also stainless acid-resistant steel valves. , And resistant to acid and alkali corrosion. Research tests have shown that the corrosion resistance of steel in weak media such as the atmosphere and water and oxidizing media such as nitric acid will increase with the increase of the chromium water content in the steel. When the chromium content reaches a certain percentage, the corrosion resistance of steel The sex changes, that is, from easy to rust to not easy to rust, from no corrosion resistance to corrosion resistance.
Common stainless steel valves mainly include stainless steel butterfly valves and stainless steel ball valves. The gate valve is rarely made of stainless steel, because the gate valve is usually used for low corrosive media such as water.
Stainless steel butterfly valve, also known as stainless steel flap valve, usually adopts three-eccentric metal hard sealing structure. The valve body, valve seat and butterfly plate sealing surface are all made of stainless steel with different hardness, which has strong corrosion resistance and long service life. It is widely used in metallurgical, electric power, petrochemical, water supply and drainage, municipal construction and other industrial pipelines with fluid pipeline medium temperature ≤ 425°C.
Stainless steel ball valves usually require horizontal installation in the pipeline. Stainless steel ball valves can be divided into stainless steel pneumatic ball valves, stainless steel electric ball valves, and stainless steel manual ball valves according to the driving mode. According to different stainless steel materials, it is divided into 304, 316, 321 stainless steel ball valves. The stainless steel ball valve switch is light and can also be made into a large diameter. It has reliable sealing, simple structure and convenient maintenance. The sealing surface and spherical surface are often in a closed state and are not easily eroded by the medium. It has applications in various industries.

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

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

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

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

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

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

What are the commonly used valves

August 27, 2021

The valve is a pipeline accessory, used to open and close the pipeline and control the flow of fluid medium in the pipeline. The functions of the valve in the pipeline include cut-off, regulation, diversion, prevention of reverse flow, stabilization, diversion or overflow and pressure relief. There are many types of valves. As the control components of fluid control systems, from the simplest butterfly valves and gate valves to the various valves used in extremely complex automatic control systems, there are many varieties and specifications.

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

Valves can be used to control the flow of various types of fluids, such as air, water, steam, various corrosive media, mud, oil, liquid metal, and radioactive media. The application range covers various industries. Although there are many types of valves, what are the commonly used valves? This article introduces you one by one:

There are five types of commonly used valves: butterfly valves, gate valves, check valves, ball valves, and stop valves.

Butterfly valve:
The butterfly valve, also known as the flap valve, is a simple and easy-to-use regulating valve. The butterfly plate in the body of the butterfly valve is the closing part of the valve, which is in the shape of a disc. The working principle is that the butterfly plate rotates around the valve shaft to realize the valve. Open and close, usually, the butterfly plate is driven by the valve stem and rotates 90° to complete one opening and closing, and achieve the purpose of interception. If you change the deflection angle of the butterfly plate, it can also be used as a flow control. Under normal circumstances, butterfly valves are often used for on-off control of low-pressure pipeline media.
Wafer butterfly valve and flange butterfly valve are the two connection forms of butterfly valve. The butterfly valve is suitable for making large-diameter valves, suitable for natural gas, liquefied petroleum gas, city gas, cold and hot air, chemical smelting and power generation, environmental protection, building water supply and drainage, etc. It is used to regulate and cut off the flow of media on the pipelines that transport various corrosive and non-corrosive fluid media in the system.

gate valve:

non-rising-stem-gate-valve-IS&Y

Gate valves are usually used for interception in pipeline systems. Its opening and closing parts are gates. The movement direction of the gate is perpendicular to the direction of the medium flow in the pipeline. The gate rises and the valve opens to realize the flow of the pipeline medium; the gate falls, The valve is closed, and the flow of the pipeline medium is cut off. The gate valve can only be fully opened or fully closed to cut off the flow of the medium, and cannot be used for adjustment and throttling. Therefore, the gate valve is generally used to keep the gate valve gate plate fully open and fully closed, and is used in a pipeline environment that does not need to be opened and closed frequently.
According to the structure of the gate, the gate valve can be divided into two types: wedge gate valve and parallel gate valve. Wedge gate valves can be divided into three types: single gate valve, double gate valve and elastic gate valve.

Check valve:
The check valve is also a list valve or check valve, which is an automatic valve, which

double-wing-check-valve-3

means that the check valve works automatically and does not require manual operation. When the medium flows through the check valve, under the pressure impact of the fluid medium, the check valve The valve flap of the return valve opens automatically and the medium passes through; after the medium flow is cut off, the valve flap automatically closes under the force of its own spring device to prevent the medium from flowing back and backflow.
Check valves are only suitable for installation in pipelines where the medium flows in one direction. The main function is to prevent the medium from flowing backwards, to prevent the pump and drive motor from reversing, and to discharge the container medium.

Globe valve:
The globe valve, also known as the shut-off valve, is a forced-sealing valve. That is to say, unlike the automatic operation of a check valve, the shut-off valve must apply pressure to the disc when it is closed to force the sealing

globe valve body

surface to not leak. When the medium enters the valve from below the disc, the flow direction changes, so the resistance that needs to be overcome to close the shut-off valve is the friction between the valve stem and the packing, as well as the thrust generated by the pressure of the medium, and the force to close the valve. The force is larger than that of opening the valve, so the diameter of the valve stem should be larger, otherwise the valve stem will bend failure. The flow resistance of the stop valve is higher than other valves.
The shut-off valve can be used to cut off the medium like a gate valve, but more often, people use the shut-off valve to adjust the flow.

Ball valve:
The ball valve evolved from the rotary valve. It is the same as the butterfly valve in that it also needs to be rotated 90 degrees to open and close. The difference is that the butterfly

ball valve (8)

valve is a butterfly plate, and the cock of the ball valve is a sphere, with a circular through hole or channel passing through its axis.
The ball valve can cut off, distribute and change the flow direction of the medium in the pipeline, and only need to rotate 90 degrees and a small torque can be closed tightly. Therefore, the ball valve is most suitable for use as a switch and shut-off valve. At present, it has been widely used in petroleum refining, long-distance pipeline, chemical industry, papermaking and other industries.

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

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