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structures and differences of Non-rising stem(NRS) and rising stem(RS) gate valve

July 8, 2021

structures and differences of Non-rising stem(NRS) gate valve and rising stem(RS) gate valve
RS gate valve structure picture, NRS gate valve structure picture

rising stem gate valve-OS&Y

RS gate valve and NRS gate valve are different from the transmission mode. RS gate valve is a handwheel that drives a nut to rotate in place, and the stem is linearly raised and lowered to complete the switch; NRS gate valve is a handwheel that drives the stem to rotate, and there are threads in the gate. Nut) to move up and down to complete the switch.

Structural principle of gate valve:
1. NRS gate valve structure: The stem nut is in the valve body and is in direct contact with the medium. When opening and closing the gate, it is realized by rotating the valve stem.
2. RS gate valve structure: the stem nut is on the bonnet or bracket. When opening and closing the gate, the stem nut is rotated to realize the lifting of the stem.
The difference between RS gate valve and NRS gate valve:
1. RS gate valve can see the screw, but NRS can not see the screw;
2. The RS gate valve raises or lowers the disc through the threaded transmission of the valve stem and the steering wheel; when the NRS gate valve is switched on and off, the steering wheel and the valve stem are connected and relatively immobile. It drives the valve through the rotation of the valve stem at a fixed point. The flap is lifted up and down to complete the opening and closing;

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

3. The transmission thread of the NRS gate valve is located inside the valve body. During the opening and closing process, the valve stem only rotates, and the gate is raised and lowered in the valve body; the valve stem of the RS gate valve drives the gate to rise and fall together, and the drive thread on the valve stem Outside the valve body, the opening and closing and position of the gate can be intuitively judged according to the movement direction and position of the valve stem;
4. The height of the NRS gate valve is small; the RS gate valve requires a larger installation space;
5. The structure of the RS gate valve is beneficial to the lubrication of the valve stem, and the degree of opening and closing is obvious; the thread of the valve stem of the NRS gate valve is not only unable to be lubricated, but it is directly corroded by the medium and is easily damaged. Therefore, the RS gate valve is more widely used.

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 Pneumatic Globe Valve

July 7, 2021

Principle of Pneumatic Globe Valve, Working Principle of Pneumatic Globe Valve
Working principle of pneumatic stop valve:
Pneumatic shut-off valve is a valve that uses compressed air as the power source. It adopts remote control. The main control room manually or automatically triggers the action command to activate the inlet and exhaust solenoid

pneumatic globe valve

valves to supply and discharge compressed air into the actuator. Compressed air acts on the piston or diaphragm to overcome the frictional force of the valve action and the spring force on the valve stem, thereby depressing (for the loss of air to open the valve) or lifting (for the loss of air to close the valve) the valve stem, driving the valve core to move up and down , Make the valve open or close. When the valve loses air and there is no compressed air in the drive head, the valve will be in a safe position of fully open or fully closed according to the requirements of the system. Compressed air for power plant instruments, the supply pressure is generally 4-9bar. Before entering the valve, the compressed air is first filtered and purified through the filter, and then reduced by the pressure reducing valve. The reading of the inlet pressure gauge does not exceed 4bar. Pressure adjustment can be achieved by adjusting the adjustment screw installed on the top of the pressure reducing valve, and the protective cover must be loosened before adjustment.
Pneumatic globe valve installation instructions:
Pneumatic shut-off valve is usually used in fully closed and fully open gas and liquid unidirectional flow pipelines. It has a longer structure and shorter length than gate valves. When the medium is highly corrosive, a low-inlet and high-outlet stop valve should be used. When the medium pressure is high or the valve stem is frequently opened and closed, the valve stem should be thickened to avoid bending of the valve stem caused by the thrust of the medium. Compared with other valves, the flow resistance of the pneumatic shut-off valve is larger. Pay attention to the problems of the air source pressure and the pressure and corrosion resistance of the valve stem during use. Pneumatic shut-off valve is not suitable for media with particles, high viscosity and easy to coke.

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

Ventilation butterfly valve installation instructions

July 5, 2021

Ventilation butterfly valve installation | instructions for use
Instructions for use of the ventilation butterfly valve:
The structural design of the ventilation butterfly valve should be combined with the operating conditions of the valve.

ventilation butterfly valve (2)

1. Under the smelting conditions with high temperature and high dust content, the design of the ventilation butterfly valve can adopt a flat inclined plate structure. There is a gap between the butterfly plate and the valve body of this structure. The gap value is based on the valve diameter and workmanship. The operating conditions are determined, and generally controlled within 0.5% of the channel area, which can meet the requirements of the ventilation butterfly valve installation, temperature changes in working conditions, and melting process requirements. To
2. Under the condition of high temperature and low dust content, the design of the ventilation butterfly valve can adopt the vertical plate structure. The sealing surface of the structure is easy to process, and the gap value of the sealing surface is controlled within 0.2% of the channel area. The dimensional accuracy of the valve body and butterfly plate sealing pair can meet the design requirements through mechanical processing.
3. For working conditions with high temperature, low pressure and strict sealing requirements, the design of the ventilation butterfly valve adopts a lever-type plane structure. The sealing pair preparation and butterfly plate running track can meet the technological requirements of high sealing performance pipe network equipment.
The main body seal of the ventilation butterfly valve selects different structures according to different working conditions, which is conducive to the production and use of the valve. The shaft end structure design of the ventilating butterfly valve adopts an external support structure with excellent heat insulation and sealing effects, which can realize the function of sealing the second shaft end of the valve and then supporting it, which is convenient for adjustment, and will not cause shaft end jam. When the direct connection or the crank connecting rod mechanism is connected with the transmission mechanism, the installation of the heat insulation sleeve can effectively keep away the influence of the high temperature environment on the transmission device and ensure the normal operation of the valve. The valve body and butterfly plate of the large-diameter ventilating butterfly valve should be cast or welded according to the requirements of the working conditions, and ribs should be configured, and reasonable process plans and materials should be selected to improve the rigidity of the product and prevent product deformation.
Precautions for installation of ventilation butterfly valve:
The installation position of the ventilation butterfly valve in the pipe network and the pipe network layout also affect the use of the valve. The closed funnel is designed at the opening end of the valve or the corner of the valve connection for the pipe with large smoke and dust. Regular dust removal can prevent excessive dust accumulation, which is beneficial The rotation of the butterfly board. There are several issues that should be paid attention to when installing the ventilation butterfly valve.
1. The use of metal gaskets must ensure that the load is uniform, and avoid the additional pressure of the valve due to the influence of temperature and self-weight or the stress caused by welding, and the deformation of the valve flange and pipeline.
2. When the valve is installed in a place with a long pipeline, a support frame should be installed.
3. The valve installation should pay attention to the medium flow direction, so that the opening direction of the butterfly plate is consistent with the pipeline medium flow direction, which is beneficial to the self-cleaning effect of the medium flow rate.
4. Strengthen the protection of the overall insulation layer of the pipe network so that the pipe wall temperature is above the dew point, which can reduce the low-temperature cohesive dust accumulation. If the pipe wall temperature is higher than the acid dew point of the flue gas, the condensation of acid vapor on the heated pipe wall can be avoided, and the generation rate of sulfur trioxide can be controlled, and the valve will be more effective. To
The installation position of the ventilation butterfly valve varies according to the design of the pipeline, such as horizontal, vertical and angled. Generally, vertical pipe installation of the ventilation butterfly valve has a better effect and is not easy to accumulate dust, followed by horizontal pipes, and has the worst effect at angles. The turning points on both sides of the valve inlet and outlet are most likely to form drift and ash blockage, and the valve operating torque will increase.
Related Products: Electric Ventilation Butterfly Valve Pneumatic Ventilation 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

Electric globe valve model coding method

July 2, 2021

Representation method of electric shut-off valve model in China. Globe valve is also called cut-off valve or stop valve.
As a cut-off valve, the electric shut-off valve is the most widely used and one of the most important valves. It is not only suitable for medium and low pressure pipelines, but also for high pressure places, and is relatively durable. It

Globe valve (9)

relies on electric thrust to control the flow of the medium. However, since there are many types of electric shut-off valves and their structural forms are changeable, users should be familiar with the expression method of their model preparation when choosing electric shut-off valves, so as to avoid problems such as selecting the wrong type, replacing goods and returning goods!
The description of the electric shut-off valve model is represented by the code of the shut-off valve type, drive mode, connection mode, structure form, sealing material, nominal pressure, valve body material, etc., mainly for the model description of the existing electric shut-off valve products, such as customized When the material and structure of the globe valve products change, please select according to the valve preparation method.
The method of preparing the model of the electric shut-off valve:
Additional code for stop valve: W: means bellows, D: means low temperature, B: means heat preservation;
1) Type code of globe valve: J: means globe valve;
2) Stop valve transmission mode: manual without code, 5: bevel gear, 6: pneumatic, 9: electric;
3) Connection mode of stop valve: 4: flange connection, 6: welding;
4) The structure of the globe valve: 1 straight-through type, 2 Z-type straight-through, 3 three-way, 4-angle type, 5 Y-type DC type, 6 balanced straight-through type, 7 balanced angle type, 8-pin type;
5) Seal material of globe valve: F: fluorine rubber, H: stainless steel, N: nylon plastic, Y: cemented carbide, M: Monel alloy, W: valve body directly processed;
6) The nominal pressure of the shut-off valve: 16: means that the pressure of 1.6mpa is 16 kilograms, PN1.6-32mpa, IN150LB-1500LB, 5-63K;
7) Globe valve body material: A: titanium alloy, C: carbon steel, I: chromium molybdenum steel, P: stainless steel 304, R: stainless steel 316;
Examples of electric shut-off valve model preparation:

electric globe valve

J941F46-16C Electric flange fluorine-lined globe valve
1. J: indicates the stop valve;
2. 9: indicates that the transmission mode is electric;
3. 4: The connection method is flange connection;
4. 1: The structure is a straight flow channel;
5. F: The sealing material is fluorine rubber;
6. 16: Indicates that the nominal pressure is 1.6MPa;
7. C: Indicates that the valve body material is carbon steel.

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 globe valve model preparation method

July 1, 2021

Pneumatic globe valve /cut-off valve model preparation method
Pneumatic shut-off valve is used to open and close the pipeline medium by compressed air, and the action speed is relatively faster. Different materials and seals are selected, which can be applied to various pressure, temperature

and medium conditions, and the seal is reliable and the performance is excellent. However, since there are many types of pneumatic stop valves and their structural forms are changeable, users should be familiar with their model designation method when choosing pneumatic stop valves, so as to avoid problems such as selecting the wrong type, replacing goods and returning goods!
Pneumatic globe valve model preparation instructions are represented by the code of the globe valve type, drive mode, connection mode, structure form, sealing material, nominal pressure, valve body material, etc., mainly for the model description of the existing pneumatic globe valve products, such as customized When the material and structure of the globe valve products change, please select according to the valve preparation method.
Pneumatic shut-off valve model preparation method:
Additional code for stop valve: W means bellows, D means low temperature, B means heat preservation;
1) Type code of globe valve: J means globe valve;
2) Stop valve transmission mode: manual without code, 5 bevel gear, 6 pneumatic, 9 electric;
3) Connection mode of stop valve: 4 flange connection, 6 welding;
4) The structure of the globe valve: 1 straight-through type, 2 Z-type straight-through, 3 three-way, 4-angle type, 5 Y-type DC type, 6 balanced straight-through type, 7 balanced angle type, 8-pin type;
5) Seal material of globe valve: F fluorine rubber, H stainless steel, N nylon plastic, Y cemented carbide, M Monel alloy, W valve body directly processed;
6) The nominal pressure of the shut-off valve: 16 means that the pressure of 1.6mpa is 16 kilograms, PN1.6-32mpa, IN150LB-1500LB, 5-63K;
7) Globe valve body material: A titanium alloy, C carbon steel, I chromium molybdenum steel, P stainless steel 304, R stainless steel 316;
Examples for the compilation of pneumatic shut-off valve models:

pneumatic globe valve

WJ641H-16C Pneumatic Bellows Globe Valve
1. W: means bellows
2. J: represents the stop valve;
3. 6: indicates that the transmission mode is pneumatic;
4. 4: The connection method is flange connection;
5. 1: The structure is a straight flow channel;
6. H: Hard seal made of stainless steel for the sealing pair;
7. 16: Indicates that the nominal pressure is 1.6MPa;
8. C: Indicates that the valve body material is carbon steel.

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 Pneumatic Gate Valve

June 29, 2021

Brief introduction of pneumatic gate valve:
The pneumatic gate valve is equipped with a pneumatic actuator, which is driven by compressed air to control the gate valve. The valve core is composed of a wedge-shaped structure and a parallel structure, which is suitable for the emergency cut-off and discharge of gas and liquid pipelines.

pneumatic gate valve (3)

Working principle of pneumatic gate valve:
When using the air source to operate the gate valve, the small handle of the manual device must be turned to the pneumatic position to open and close the nut and the screw rod. When the compressed air enters from the upper pipeline of the cylinder, the piston and the piston rod in the cylinder are pushed straight When the compressed air enters from the lower pipe, the gas pushes the piston and piston rod in the cylinder to move upwards, and at the same time drives the valve stem to move upwards to open the valve. When there is no air source, the screw rod and the opening and closing nut can be used to open and close the valve. First, the upper and lower intake pipes of the cylinder are in the exhaust state, and the small handle of the manual part is in the manual position, so that the opening and closing nut and the screw are in the manual position. In the normal meshing state, turn the large handwheel at the manual part at this time. When the handwheel is turned clockwise, the valve is closed, and when the handwheel is turned counterclockwise, the valve is opened. When the air source is introduced from the upper air inlet, the valve stem drives the valve plate to move downward, and the valve is closed.
When the air source is introduced from the lower air inlet, the valve stem drives the valve plate to move upward, and the valve opens.
Pneumatic gate valve parameters:
Actuator: cylinder piston structure;
Optional accessories: manual device, filter, solenoid valve, echo device, control box;
Main material: ductile iron, cast steel, stainless steel; Caliber: DN50-500;
Pressure: PN1.6-6.4mpa;
Temperature: Q-29～350℃, C-29～450℃, P-30～540℃;
Medium range: water, steam, petroleum, gas, fluid, medium containing hard particles and impurities.

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, API6

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

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

Fire-proof and anti-static ball valve and ordinary ball valve

June 18, 2021

The difference and selection of fire-proof and anti-static ball valve and ordinary ball valve
The fire-proof and anti-static ball valve is a kind of pipeline that can be used for natural gas, artificial coal gas, liquefied gas, city gas and non-corrosive gas. It has anti-static and fire-proof devices, that is, it is installed between

fixed ball valve

the ball and the valve stem, the valve stem and the valve body. The conductive spring enables the static electricity generated in the opening process of the valve to be introduced into the underground through the set static electricity channel, so as to achieve the purpose of eliminating static electricity. Avoid static sparking and ignite flammable media to ensure system safety. The fire protection device, that is, the ball valve is designed with double seals. When the soft gasket melts due to high temperature, the valve core ball is again designed to form a right-angle hard seal with the soft seal behind, forming a sealing relationship again.
The fire-proof anti-static ball valve is compared with the conventional ordinary ball valve. It will be widely used in many industries, and its safety performance has been improved a lot. For occasions prone to fire, it can effectively prevent internal leakage. The realization of this function mainly depends on the ball valve. Sealing ring, this kind of sealing ring is a double-layer seal, a layer of soft seal and a layer of metal seal, when the soft seal layer is destroyed by combustion, the metal seal can further fill the air, play a key alternate sealing role, can be to a certain extent It prevents a large amount of media from leaking out and the spread of fire.

electric ball valve

When the fire-proof and anti-static ball valve is switched, there will be friction between the ball and the valve seat, and the static electricity generated by the friction will accumulate on the ball. This is not allowed for the ball valves used on the gas, fuel, and chemical pipelines. , It may cause pipeline explosion accidents. The anti-static structure of the ball valve is equipped with an electrostatic discharge device, which can extract the electrostatic charge gathered in the sphere in the first time, effectively ensuring the safe operation of the pipeline; generally, elastic components are usually used at home and abroad According to the standard, the connection between the ball and the valve body and the valve stem and the ball is below 12VDC, and the resistance value is below 10 ohms.
It should be noted that the fire and anti-static functions of ball valves are not omnipotent. They can only play an emergency role and give more time to solve accidents. In addition to the use of fire-resistant and anti-static ball valves in gas and oil pipelines, they also It should be equipped with certain fire-fighting measures such as explosion-proof and fire-prevention, and strictly abide by relevant national regulations.

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

Installation instructions of the wafer type butterfly valve

July 21, 2020

Preparation before installation of wafer type butterfly valve:
1. Check whether the specifications and materials of the butterfly valve conform to the design before installation.

wafer type butterfly valve, EPDM seat (10)

2. Before installation, clean the internal sand, dust, foreign matter and debris to avoid irregular movement or leakage.
3. The related piping should be properly suspended and fixed according to regulations before installation to avoid improper stress on the valve after installation.
4. The two flange faces of the piping must be aligned parallel and concentric.
5. No additional gasket is needed between butterfly valve and flange during installation.
6. Where the butterfly valve is close to the check valve or the pump, use a divergent joint between the two so that the valve disc will not be hindered from turning off.

Installation steps of wafer type butterfly valve:
1. Open the valve disc 10 degrees before installation. (The same before disassembly)
2. Set auxiliary screws at appropriate positions to adjust the distance between the two flange surfaces.
3. Insert the butterfly valve without touching the two flange surfaces and at the same time penetrate the remaining bolts.
4. After confirming that the center of the butterfly valve is concentric with the center of the flange and the switch position of the valve disc is not the inner diameter of the flange or the adjacent parts are obstructed, the bolts are locked repeatedly in a diagonal and gradual manner until the flange surface touches the end surface of the valve body.
5. After the installation is completed, the degree of full open and full close should be confirmed again.

Operation:
1. Before starting the operation, use air spray to remove foreign objects on the piping, and clean the inner surface of the piping with clean water.
2. Open the valve to check the angle indicator plate, avoid torsion exceeding the opening width, and the closing position cannot be exceeded.
3. The operation of the switch is completely based on the indicator. If other hand tools are applied, the angle indicating plate and the switch will be damaged.
4. When the pressure test of piping is to be done, the valve should be opened.
5. After piping, the valve is in a fully closed state for a long time, and it should be switched on and off once or twice a month to avoid fixation.

Tianjin Tanghaidongyang Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves. main products: butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)

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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