News Archives

Pneumatic ball valve model preparation method

June 30, 2021

Pneumatic ball valve model preparation method/code name establishment in China.
With the rapid development of my country’s industrial modernization, the use of valves is also increasing. Pneumatic ball valves have the advantages of fast opening and closing speed, and not only can switch and cut off, but also control flow, etc., and become the most widely used valve type. one! However, due to the wide variety of pneumatic ball valves, including the use of pressure, temperature and control methods, the corresponding ball valve models are also different. In order to avoid errors in the selection of the user, and to ensure that the pneumatic ball valve can be used normally, more instruments Self-Control Valve Company hereby provides instructions for the preparation of pneumatic ball valve models for everyone to understand and recognize!

Pneumatic electric high platform ball valve

Pneumatic ball valve model editing instructions are mainly from the increase of additional conditions of the pneumatic ball valve, the selection of the drive mode, the difference of the connection form, the change of the structure form, the type of sealing material, the level of valve pressure and the material of the valve body, etc. to facilitate the explanation, hope It is helpful to the majority of users.
Pneumatic ball valve model representation method:
Ball valve additional code: V means the valve core has a V-shaped structure, D means low temperature, B means heat preservation, P means eccentric structure, U, S and DY mostly mean top-mounted type;
Ball valve name code: Q means ball valve; Ball valve drive code: 2 means electro-hydraulic, 3 means turbine, 6 means pneumatic, 7 means hydraulic, 9 means electric, manual without code;
Code of connection method: 1 means internal thread, 4 means flange type, 6 means welding, 7 means wafer type;
Structural type code: Floating type: 1 means straight-through runner, 2 means Y-type tee, 4 means L-type tee, 5 means T-type tee; Fixed type: 0 means hemispherical through, 6 means four-way runner, 7 Means straight-through flow to, 8 means L-type tee, 9 means Y-type tee;
Sealing material code: B babbitt alloy, F fluorine rubber, F46 lining fluorine, H stainless steel, J rubber lining, M Monel alloy, N nylon plastic, Monel P, Y cemented carbide, W valve body directly processed;
Pressure rating code: 16 means the pressure is 16 kg (1.6Mpa) and the maximum can reach 64Mpa; 150LB means the American standard pound pressure, and the maximum pressure rating can reach 2500LB (150LB=1.6MPA/300LB=2.5-4.0mpa/400LB=6.4 mpa/600LB=10mpa); 5K means Japanese pressure, maximum pressure is 63K; Valve body material code: A titanium and titanium alloy, C carbon steel, I chromium molybdenum steel, P18-8 series stainless steel, RMo2Ti series stainless steel, S plastic.
Pneumatic ball valve model editing instructions:
Q645F-16P Stainless steel pneumatic flange three-way ball valve
1. Q: represents the ball valve;
2. 6: It means that the transmission mode is pneumatic;
3. 4: The connection method is flange connection;
4. 5: The structure is a floating T-type tee;
5. F: The sealing material is fluorine rubber;
6. 16: Indicates that the nominal pressure is 1.6MPa;
7. P: indicates that the valve body is made of stainless steel.

More details for valve model establishment, you can visit another article: https://www.tanghaivalve.com/valve-model-establishment-and-meaning/

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

Working principle of electric gate valve

June 30, 2021

Principle of electric gate valve, Working principle of electric gate valve
Principle of electric gate valve:
Electric gate valve, as the name suggests, is to control the gate valve with an electric actuator, which is mainly

electric stainless steel gate valve

divided into an upper part and a lower part. The upper part is an electric actuator, and the lower part is a gate valve. Connect the actuator and the gate valve, and the electric actuator controls the opening and closing of the gate valve to work to achieve the on-off of the pipeline medium. Gate valves are generally suitable for on-off occasions and are normally open and normally closed valves. If you need to adjust the working conditions, generally choose electric control valve, electric ball valve, electric butterfly valve, electric shut-off valve, etc.
Working principle of electric gate valve:
The electric gate valve is powered by electric energy to turn on the electric actuator to drive the valve, and the valve stem is connected to drive the valve plate to move up and down or open and close, so that the valve can control the switch of the pipeline medium. It can be remotely controlled when it is added into the control box and other accessories, which is convenient and trouble-free.
Classification of electric gate valve actuators:
There are two common types of rotary electric actuators and linear electric actuators. Angular-stroke electric actuator: the angular-stroke electric actuator is used in conjunction with the angular-stroke valve to realize the internal rotation of the valve within 90 degrees to control the flow of the pipeline.
Straight-stroke electric actuator: a straight-stroke electric actuator is used in conjunction with a straight-stroke valve to realize the up and down movement of the valve plate to control the on-off of the pipeline fluid. It is usually used in conjunction with equipment with a higher degree of automation.

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

Three-way ball valve T type vs L type

June 29, 2021

The difference between pneumatic three-way ball valve T type and L type
Pneumatic three-way ball valve is a new type of valve that has been widely used in recent years. It is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. According to the different internal structure, it can be divided into L type and T type, but From the appearance, there is no difference between the two! So what is the difference between the principles and applicable working conditions of the T-type and L-type pneumatic three-way ball valves? How to choose?

pneumatic-electric-three way ball valve-flange-crew-T-L-type

Pneumatic flanged three-way ball valve Pneumatic internal threaded three-way ball valve The common connection method of pneumatic three-way ball valve is flange or internal thread. Choose according to the actual working conditions of the pipeline! Then in the process of use, you should choose different structural forms according to different working conditions. From the technological point of view, the T-type ball valve can replace the L-type ball valve. The working principle diagrams of the two are as follows:
The L-type pneumatic three-way ball valve is used to switch the flow direction of the medium, which can connect two perpendicular channels (such as the L-type flow diagram). The T-type pneumatic three-way ball valve can not only switch the flow direction of the medium, but also make the three channels communicate with each other. At the same time, it can also close any channel to connect the other two channels to flexibly control the merging or splitting of the media in the pipeline.

Flow diagram-three way ball valve-T-type-L-type

The difference between T-type electric three-way ball valve and L-type electric three-way ball valve
Electric three-way ball valve is a new type of three-way port switching ball valve, which can be used to control the direction, split or merge of the three pipeline media. According to the different ball core structure, it can be divided into T-type or L-type, T-type electric The difference between the three-way ball valve and the L-type electric three-way ball valve is mainly the difference in the internal structure, and there is no difference in appearance! The T-shaped ball valve can connect three orthogonal pipelines with each other and cut off the third channel to split and merge, while the L-shaped ball valve can only connect two orthogonal pipelines, and cannot maintain the third pipeline at the same time. Connectivity only plays a role of distribution.
As can be seen from the above figure, the T-type ball valve is mainly used for the diversion or mixing of media, and the L-type ball valve is mainly used for reversing! L-type three-way ball valve is used for distribution and switching that do not require 3-way, and the operation is more convenient. There are only two valve positions, and there are positioning, and it can be turned 90 degrees without error; T-type three-way ball valve has a wide range of channels to choose from , There are many valve positions, generally there is no positioning, if you replace the L-type, it should be turned 180 degrees.
Electric flanged three-way ball valve Electric internal threaded three-way ball valve From the technological point of view, the T-type electric three-way ball valve can replace the L-type electric three-way ball valve, but the L-type ball valve cannot replace the T-type ball valve! In the process of use, different structures should be selected according to different working conditions, and the T-type ball valve can flow through but the L-type ball valve cannot.

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

bellows globe valve vs ordinary globe valve

June 29, 2021

The difference and comparison between bellows globe valve and ordinary globe valve
The bellows globe valve is also called the bellows seal globe valve. Through automatic seam welding, a metal barrier is formed between the fluid medium and the atmosphere to ensure the design of zero leakage of the valve stem. Compared with traditional globe valves, it has the following advantages:

Globe valve (9)

1. The bellows globe valve has a long service life, reduces the number of maintenance and lowers operating costs. The sturdy and durable bellows seal design ensures zero leakage of the valve stem and provides maintenance-free conditions.
2. The valve opening and closing torque is small, reducing labor intensity, and can drive any form of driving device, which is convenient for remote control.
3. The appearance is beautiful, the valve channel has a smooth streamline, and the flow resistance coefficient of the valve is reduced. It is a high-quality energy-saving product.
4. The outer seal of the valve adopts bellows seal and graphite, stainless steel gasket seal, the seal is reliable, and the sealing packing does not need to be replaced for long-term use. In industrial use, the leakage caused by the stop valve: high temperature, highly toxic, flammable and explosive, radiant medium, etc., not only pollute the environment, but also often cause significant personal and property losses. However, this type of valve is much safer and more stable, and strictly adopts foreign advanced standards in design and manufacturing.

Advantages and application of bellows globe valve The bellows globe valve has no leakage, and it is safer to be used in high-risk media. Ordinary globe valve is sealed with packing, the valve stem and packing will slide, and it is easy to leak at low temperature (spool).
The bellows cut-off valve uses a closed bellows that can be stretched and compressed to replace the packing seal, which can effectively prevent external leakage caused by packing loss. It is generally used for the transmission of highly permeable media, such as valves on hydrogen systems, as long as the bellows is not damaged, there is generally no leakage; while the general shut-off valve is sealed with packing, which is prone to leakage.
The opening or closing stroke of the valve stem of this kind of valve is relatively short, and it has a very reliable cut-off function. Also, because the change of the valve seat port is proportional to the stroke of the valve disc, it is very suitable for flow adjustment. Therefore, this type of valve is very suitable for use as a shut-off or adjustment and throttling.

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

O type |V type ball valve structure principle

June 28, 2021

Ball valve structure diagram, O-type ball valve structure principle, V-type ball valve structure principle
Ball valve structure:
Ball valves have many structures, but they are basically the same. They are all round cores with opening and closing parts. They are mainly composed of valve seats, balls, sealing rings, valve stems and other driving devices, which can be realized by rotating the valve stem by 90 degrees. The opening and closing of the valve is used in the pipeline to shut off, distribute, adjust the flow rate and change the flow direction of the medium. The valve seat uses different valve seat sealing forms according to different working conditions. The valve body structure has one-piece type, two-stage type and three-stage type.

ball valve (3)

O-type ball valve structure:
The O-shaped ball valve has a ball with a middle through hole installed inside the valve body. A through hole with the same diameter as the pipe diameter is opened on the ball. The ball can rotate in the sealing seat, and there is a ring-shaped elasticity on both sides of the pipeline direction. Body to achieve sealing. By rotating the ball 90°, the direction of the through hole can be changed, thereby realizing the opening and closing of the ball valve.
O-type ball valve core (ball) is spherical. From the structural point of view, the ball seat is embedded on the side seat of the valve body when sealing. Relatively moving parts are made of self-lubricating materials with a very small friction coefficient, so the operating torque is small. In addition, the long-term sealing of the sealing grease makes the operation more flexible. It is generally used for two-position adjustment, and the flow characteristic is quick opening.

Principle of O type ball valve:
When the O-type ball valve is fully opened, the two sides are unobstructed valves, forming a straight pipe channel, two-way sealing, with the best “self-cleaning” performance, and suitable for two-position cutting occasions with particularly dirty and fiber-containing media. The ball core always creates friction with the valve during the opening and closing of the valve. At the same time, the seal between the valve core and the valve seat is achieved by the pre-tightening force of the valve seat pressing the ball core, but due to the soft sealing of the valve seat. Excellent mechanical and physical properties make it particularly tight.
V-shaped ball valve structure:
The V-shaped ball valve core has a V-shaped structure. The valve core is a 1/4 spherical shell with a V-shaped gap. It has a large flow capacity, a large adjustable range, a shear force, and a tight closing. It is especially suitable for fluids. Working conditions where the substance is fibrous. Generally, V-type ball valves are single-sealed ball valves. Not suitable for bidirectional use.
The edge of the valve core is V-shaped, and there is a V-shaped opening on the sphere. With the rotation of the ball, the change in the opening area of the middle can be used to adjust the flow, and the impurities in the fluid can be cut off and closed. It is suitable for pulp, Control of mortar and viscous fluid.

Principle of V-type ball valve:
V-shaped edge cuts off impurities. During the rotation of the ball, the V-shaped knife edge of the ball is tangent to the valve seat, thereby cutting off the fiber and solid matter in the fluid. However, the general ball valve does not have this function, so it is easy to cause the fiber impurities to get stuck when closed, which will cause maintenance and repair. Maintenance brings great inconvenience. The valve core of the V-shaped ball valve will not be jammed by the fiber. In addition, due to the use of flange connection, it is easy to disassemble and assemble, no special tools are needed, and maintenance is simple and easy. When the valve is closed. There is a wedge-shaped scissors effect between the V-shaped notch and the valve seat, which not only has the function of self-cleaning but also prevents the ball from jamming. The valve body, bonnet and valve seat adopt a metal point-to-point structure, and a smaller friction coefficient is used. The stem spring, therefore, has a small operating torque and is very stable.

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

Electric ball valve model preparation/code name designation method

June 24, 2021

Electric ball valve model preparation/code name designation method in China.
As an important equipment in the industrial automation control system, the electric ball valve has been used more and more in recent years due to its simple structure and convenient operation. It can not only be used to cut off or connect the medium in the pipeline, but also can be used for fluid Regulation and control! But because of the different working conditions of the pipeline, the electric ball valve models used are all different! The user should have a detailed understanding and cognition of the method of preparing the electric ball valve model!

Pneumatic electric high platform ball valve

This electric ball valve model editing method includes the addition of additional conditions for the ball valve, the selection of the drive mode, the different connection form, the change of the structure form, the type of sealing material, the level of the valve pressure and the valve body material, etc.!
Electric ball valve model representation method:
Ball valve additional code:
V means the spool has a V-shaped structure, D means low temperature, B means heat preservation, P means eccentric structure, U, S and DY mostly mean top-mounted type;
Ball valve name code: Q means ball valve; Ball valve drive code: 2 means electro-hydraulic, 3 means turbine, 6 means pneumatic, 7 means hydraulic, 9 means electric, manual without code;
Code of connection method: 1 means internal thread, 4 means flange type, 6 means welding, 7 means wafer type;
Structure type code:
Floating type: 1 means straight flow channel, 2 means Y-type tee, 4 means L-type tee, 5 means T-type tee;
Fixed: 0 means hemispherical straight through, 6 means four-way flow channel, 7 means straight flow to, 8 means L-type tee, 9 means Y-type tee;
Sealing material code: B babbitt alloy, F fluorine rubber, F46 lining fluorine, H stainless steel, J rubber lining, M Monel alloy, N nylon plastic, Monel P, Y cemented carbide, W valve body directly processed;
Pressure rating code: 16 means the pressure is 16 kg (1.6Mpa) and the maximum can reach 64Mpa; 150LB means the American standard pound pressure, and the maximum pressure rating can reach 2500LB (150LB=1.6MPA/300LB=2.5-4.0mpa/400LB=6.4 mpa/600LB=10mpa); 5K means daily pressure, the maximum pressure is 63K;
Valve body material code: A titanium and titanium alloy, C carbon steel, I chromium molybdenum steel, P18-8 series stainless steel, RMo2Ti series stainless steel, S plastic.
Editing instructions for electric ball valve model:
VQ947F-16P Stainless steel electric flange V-shaped ball valve
1. V: indicates that the spool has a V-shaped structure
2. Q: represents the ball valve;
3. 9: indicates that the transmission mode is electric;
4. 4: The connection method is flange connection;
5. 7: The structure is a fixed straight flow channel;
6. F: The sealing material is fluorine rubber;
7. 16: Indicates that the nominal pressure is 1.6MPa;
8. P: indicates that the valve body is made of stainless steel.

More details for valve model establishment, you can visit another article: https://www.tanghaivalve.com/valve-model-establishment-and-meaning/

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 working principle of the ball valve (GIF)

June 23, 2021

Principle of Ball Valve (GIF), Principle of Ball Valve Working Principle

The opening and closing part of the ball valve is a sphere with a circular channel, which rotates around an axis perpendicular to the channel, and the sphere rotates with the valve stem to achieve the purpose of opening and closing the channel. The ball valve can be closed tightly with only a 90-degree rotation and a small torque. According to the requirements of the working conditions, different driving devices can be assembled to form ball valves with different control methods, such as electric ball valves, pneumatic ball valves, hydraulic ball valves, etc.
The working principle of the ball valve: When the ball valve rotates 90 degrees, the inlet and outlet should all show a spherical surface, thereby closing the valve and cutting off the flow of the medium.

ball valve working diagram-3D GIF animated presentation

When the ball valve rotates 90 degrees, all the ball ports should be present at the inlet and outlet, so as to open the flow, and there is basically no flow resistance.
The structure principle of the ball valve:
1. The ball valve is not restricted by the installation direction, and the flow direction of the medium can be arbitrary. The fluid resistance is small, and the full-bore ball valve basically has no flow resistance.
2. The ball valve has a simple structure, relatively small size, light weight and easy maintenance.
3. Close and reliable. It has two sealing surfaces, and the current sealing surface materials of ball valves are widely used in various plastics, which have good sealing performance and can achieve complete sealing. It has also been widely used in vacuum systems.
4. The ball valve is suitable for frequent operation, opening and closing quickly and lightly. It is easy to operate and open and close quickly. It only needs to rotate 90° from fully open to fully closed, which is convenient for remote control.

ball valve (4)

5. The maintenance is convenient, the structure of the ball valve is simple, the sealing ring is generally movable, and it is convenient to disassemble and replace.
6. The ball valve has good sealing performance. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium, and the medium will not cause erosion of the valve sealing surface when the medium passes.
7. It has a wide range of applications, with a diameter ranging from a few millimeters to a few meters, and can be applied from high vacuum to high pressure.
8. Since the ball valve has wiping properties during opening and closing, it can be used in media with suspended solid particles.
9. The ball valve has low fluid resistance, no vibration, and low noise.

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

Selection and application of eccentric butterfly valve

June 23, 2021

Selection and application of eccentric butterfly valve
The advantages of eccentric butterfly valves and other butterfly valves are very prominent, so they are widely used in all aspects of life and work to meet various requirements. Moreover, with the continuous development of eccentric sealing butterfly valve technology, the space for its use becomes more and more extensive. TH valve company can produce double eccentric butterfly valve and triple eccentric butterfly valves, with good quality and reasonable prices.

Double eccentric-wafer butterfly valve-D372F-150lbP-stainless steel (1)

Application of double eccentric sealing butterfly valve
The double eccentric sealing butterfly valve adopts an eccentric structure design. The main structure of the valve is composed of valve body, butterfly plate, valve seat, valve stem and transmission mechanism. The valve seat adopts a detachable structure and can be based on the physical and chemical properties of different media. Corresponding corrosion-resistant, light-resistant, and aging-resistant materials are selected, which can be widely used in fluid pipelines such as water supply and drainage, sewage, construction, air conditioning, petroleum, chemical, food, medicine, textile, papermaking, hydropower, shipbuilding, metallurgy, energy systems, etc. Used as a regulating and intercepting device. The double eccentric butterfly valve usually uses tetrafluoroethylene material as its sealing seat, and can also use metal sealing seat to expand its application in the high temperature field. However, the seal of the double eccentric butterfly valve with metal sealing seat is still a positional sealing structure, that is, the sealing surface of the butterfly plate and the seat is in line contact, so it cannot withstand high pressure, and it will inevitably lead to greater leakage when used in a high pressure system. Therefore, double eccentric butterfly valves with metal seal seats should be avoided as far as possible in high-pressure or tight shut-off systems.

Application of triple eccentric sealing butterfly valve
The triple eccentric butterfly valve, as the crystallization of the latest technology of valves, takes advantage of the advantages of various valves and avoids the shortcomings of various valves, and has attracted more and more

cryogenic triple offset butterfly valve 1

attention from users and designers. The maximum pressure level can reach 2500 pounds, the standard caliber can reach 48 inches, and the clamp, lug, flange, ring connection, butt welding, jacket, various structural lengths, etc. can be corresponded, due to the room for material selection Very large, high and low temperature, various acids, alkalis and other corrosive media can also respond freely. Especially in the aspect of large diameter, with its zero leakage advantage, it is constantly replacing the thick gate valve and ball valve in the shut-off valve. Similarly, with its excellent control function, it is also constantly replacing the bulky control valve. Shut-off valve. So far, triple eccentric sealing butterfly valves have been used in various important pipelines including China’s oil and gas exploration, offshore platforms, petroleum refining, petrochemicals, inorganic chemicals, energy power generation and other major industrial fields such as process control. In actual engineering, if the working pressure of the system is not less than 1.0 MPa or in important parts that need to be opened frequently, triple eccentric butterfly valves can be used.
Related knowledge: common sense of eccentric butterfly valve
Related products: Electric triple eccentric butterfly valve Pneumatic triple eccentric butterfly valve

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

full bore ball valve vs reduced bore ball valve

June 22, 2021

The difference and selection of full bore ball valve and reduced bore ball valve
Ball valve is currently the most widely used mechanical product in all valve markets. It is mainly composed of valve body, valve seat, ball, valve stem and transmission device. The ball core is driven to rotate through the actuator to achieve the function of switching or adjusting. . In the chemical industry, environmental protection, water treatment, urban construction, machinery, and food industries, it is widely used and very popular! there are Electric ball valve and Pneumatic ball valve, and other actuated ball valves.

Pneumatic electric high platform ball valve

There are many types of ball valves, which can be combined into various products with different functions through different structures, connection methods, pressure levels, drive forms, etc., but from the most basic point of view, ball valves have two types: full-diameter ball valves and reduced-diameter ball valves. The difference between major categories. Generally speaking, when the inner diameter of the valve ball is less than or equal to 85% of the inner diameter of the ball valve port, it is called a reduced-diameter ball valve, and when the inner diameter of the ball valve is greater than 95% of the inner diameter of the ball valve port, it is called a full-bore ball valve. So what is the difference between the two in the selection or application?
The definition of full bore ball valve and reduced bore ball valve:

fixed ball valve

1. The full-bore ball valve has equal-width flow channels, that is to say, the size of the orifices from inflow to outflow is the same, and its size cannot be less than the value specified by the standard, which is roughly equivalent to the nominal diameter of the specification, such as DN50 full-diameter The diameter of the ball valve flow path also needs to be about 50;
2. The inlet of the reduced diameter ball valve is wider than the diameter of the flow path, and the actual diameter of the flow path is about one specification smaller than this specification. For example, the diameter of the DN50 reduced diameter ball valve is about 38, which is roughly equivalent to the specification of DN40. One specification is reduced within DN250 and two specifications are reduced from 250-600. Above 600 depends on the actual situation.
Applicable medium for full bore ball valve and reduced bore ball valve:
1. The full-bore ball valve is generally used on pipelines for conveying viscous and slagging media. Because of its low fluid resistance, it can be said that there is basically no flow resistance, and it is convenient for regular wax scrapers to pass through.
2. Reduced diameter ball valve is suitable for conveying gas or pipelines with physical properties similar to water. Because its weight is about 30% lighter than a full-diameter ball valve, and its flow resistance is only 1/7 of that of a stop valve of the same diameter. about. It is helpful to reduce the pipeline load and reduce the cost.
Applicable process for full bore ball valve and reduced bore ball valve:
1. For pipelines that require regular pigging, no matter what kind of medium is transported, full-diameter ball valves must be used. The medium passing through the full-bore ball valve will not reduce the flow, and the flow resistance is small, which is an ideal product for pipeline control, especially for strict working conditions. Especially when the main line in the oil pipeline and gas pipeline needs to be buried underground, full-diameter welded ball valves must be used.
2. The reduced diameter ball valve is suitable for some working conditions such as low requirements and small convection resistance requirements. When the inner diameter of the valve is greater than 80% of the inner diameter of the pipe end, it has almost no effect on the pipeline fluid passing capacity. Many valves have a reduced diameter, which is generally controlled within 0.8. On the one hand, the reduced diameter reduces the flow capacity of the valve, that is, the Kv value of the valve, and increases the pressure drop at both ends of the valve, causing energy loss. That said, there is not much impact, and it may increase the erosion of the pipeline.
The advantages and disadvantages of full-bore ball valves and reduced-bore ball valves are compared:
1. Installation space: The reduced-diameter ball valve has a small volume, so its installation space requirements are smaller. Because its weight is about 30% lighter than a full-diameter ball valve, it is beneficial to reduce the pipeline load, reduce the transportation load and reduce the cost.
2. Cost: Reduced-diameter ball valves are one grade lower than full-diameter ball valves. Considering the cost performance, it is generally accepted internationally that adjacent pipe diameters use the same ball-diameter valve body. For example, dn32 and dn40, dn50 and dn63, dn90 and dn110, dn160 and dn200, dn250 and dn315 use the same sphere.
Note: Since the inner diameter of the reduced diameter ball valve is small, the torque on the valve stem is small, which is more suitable for prolonging the service life of the valve switch. Especially the low-torque design of large-diameter valves. However, the diameter cannot be reduced too much, otherwise the system resistance will increase. However, if the diameter is not reduced, the purchase cost will be increased, and the control characteristics of the valve will generally be reduced, which will make the adjustment effect worse. For example, if the regulating valve is always used at a small opening, the service life of the valve will be reduced.

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

Application of low temperature butterfly valve

June 22, 2021

Article title: Application of low temperature triple eccentric butterfly valve
With the rapid development of industrial technology, more stringent requirements have been put forward for valves, especially for butterfly valves used in low temperature media. In addition to meeting the performance of general valves, it is more important that butterfly valves seal under low temperature conditions. Reliability, flexibility of action and some other special requirements for cryogenic valves. Now combined with its structural characteristics, a brief introduction to the performance of the cryogenic butterfly valve is given. Remarks: The cryogenic butterfly valve we are talking about here specifically refers to the low temperature triple eccentric butterfly valve.

triple offset valve parts-after-cryogenic process

Requirements for sealing performance of low temperature triple eccentric butterfly valve:
There are two main reasons for the leakage of the low temperature triple eccentric butterfly valve, one is internal leakage; the other is external leakage.
1. Internal leakage of butterfly valve:
The main reason for the internal leakage of the valve is the deformation of the sealing pair in the low temperature state. When the temperature of the medium drops to a phase change of the material, the volume changes, which causes the sealing surface with high grinding accuracy to warp and deform, resulting in poor low-temperature sealing. We conducted a low temperature test on the DN250 valve. The medium was liquid nitrogen (-196 ℃) and the butterfly plate material was 1Cr18Ni9Ti (without low temperature treatment). It was found that the sealing surface warped and deformed up to about

cryogenic triple offset butterfly valve 1

0.12mm, which is the main cause of internal leakage. And if the plane seal of the butterfly valve is changed to a cone seal. The valve seat is an oblique cone ellipse sealing surface, which forms a sealing pair with a round elastic sealing ring embedded on the butterfly plate. The sealing ring can float radially in the butterfly plate groove. When the valve is closed, the elastic sealing ring first contacts the short axis of the elliptical sealing surface. As the valve stem rotates, the sealing ring is gradually pushed inward, forcing the elastic ring to contact the long axis of the oblique cone surface, and finally the elastic sealing ring All contact with the oval sealing surface. Its sealing is achieved by the deformation of the elastic ring. Therefore, when the valve body or butterfly plate is deformed at low temperature, it will be absorbed and compensated by the elastic sealing ring, and leakage and jamming will not occur. When the valve is opened, this elastic deformation disappears immediately, and there is basically no relative friction during the opening and closing process, so the service life is long.
2. Leakage of butterfly valve:
One is that when the valve and the pipeline are connected by flanges, leakage occurs due to the unsynchronized contraction and relaxation of the connecting gasket, connecting bolts, and connecting materials at low temperatures. Therefore, we changed the connection between the valve body and the pipeline from a flange connection to a welded structure to avoid low temperature leakage. The second is leakage at the valve stem and packing. Generally, most valve packing adopts F4 because of its good self-sliding performance, low friction coefficient (friction coefficient for steel f=0.05 ~ 0.1), and unique chemical stability, so it is widely used. However, F4 also has shortcomings. First, the tendency of cold flow is large; second, the linear expansion coefficient is large, and the cold shrinkage at low temperature causes leakage, which causes a large amount of ice at the valve stem, so that the valve fails to open. The low-temperature triple-eccentric butterfly valve developed for this purpose adopts a self-shrinking sealing structure, that is, taking advantage of the large expansion coefficient of F4, and achieves the purpose of sealing at room temperature and low temperature through the reserved gap.
Design requirements for low temperature triple eccentric butterfly valve body and stem bushing:
1. The structure and shape of the cryogenic valve shell. The correct selection of materials is of great significance to the normal and reliable operation of the valve. Compared with the stop valve and gate valve, the structural characteristics of the butterfly valve not only avoid the irregular shape and uneven shell wall thickness, which can cause problems at low temperatures. Due to the small size of the butterfly valve, the shape of the valve body is basically symmetrical, so the heat capacity is small; the pre-cooling consumption is also small; the shape is regular and it is convenient to take measures to keep the valve cold. ,
2. Selection of stem bushing: Some low-temperature triple-eccentric butterfly valves are in operation, the rotating parts of the valve are sticky, and seizure occurs from time to time. The main reason is: unreasonable selection of matching materials, too small pre-cooling clearance, and processing Causes such as low accuracy. In the development of cryogenic valves, a series of measures have been taken to prevent the occurrence of the above phenomena. For the upper and lower bushings of the valve stem, SF-1 type composite bearings with low friction coefficient and self-lubricating properties are selected, which can be suitable for some special needs of cryogenic valves. The metal-sealed butterfly valve has the characteristics that some ordinary valves do not have, especially the small flow resistance, reliable sealing, rapid opening and closing, and long service life. The triple eccentric metal sealing butterfly valve is sealed by the deformation of the elastic ring, so it does not need to rely on the force of the medium, so it can be used for two-way sealing.
Related information: The difference of cryogenic valve and ordinary temperature valve; Cryogenic valve principle |standard |illustration |selection

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

Pneumatic ball valve model preparation method

Working principle of electric gate valve

Three-way ball valve T type vs L type

bellows globe valve vs ordinary globe valve

O type |V type ball valve structure principle

Electric ball valve model preparation/code name designation method

The working principle of the ball valve (GIF)

Selection and application of eccentric butterfly valve

full bore ball valve vs reduced bore ball valve

Application of low temperature butterfly valve

TH VALVE • PROFESSIONAL VALVE MANUFACTURER

GET IN TOUCH WITH US