valve Archives

Valve actuator / actuation -(1)-introduction

August 19, 2020

The valve actuator is an indispensable part of the valve automatic control system. Its function is to accept the control signal sent by the controller, change the size of the controlled medium, so as to maintain the controlled variable at

21 manual-actuator-lever-handwheel-worm-gear-box

the required value or within a certain range. According to their energy form, actuators can be divided into three categories: pneumatic, hydraulic and electric. Pneumatic actuators use compressed air as energy source. They are characterized by simple structure, reliable action, stable operation, large output thrust, convenient maintenance, fire and explosion prevention, and low price. Therefore, they are widely used in chemical, paper, and oil refining production processes. It can be conveniently used in conjunction with passive instruments. Even when using electric instruments or computer control, as long as the electric signal is converted into a standard pressure signal of 20-100kPa by an electric-pneumatic converter or an electric-pneumatic valve positioner, pneumatic actuators can still be used. The electric actuator has convenient energy access and rapid signal transmission, but the structure is complex and the explosion-proof performance is poor. The hydraulic actuator is basically not used in the chemical, oil refining and other production processes. It is characterized by a large output thrust.

Definition of valve actuator:
The actuator is a combination of the actuator and the control valve in the automatic control system. Its role in the automation control system is to receive the signal from the regulator or computer (DCS, PLC, etc.), and adjust the flow of the process medium based on its position and characteristics in the process pipeline, so that the controlled automation instrument is in production Within the range required by the process.

electric actuator for butterfly valve

Basic composition of valve actuator:
Types of valve actuators:
In the process control system, the actuator is composed of two parts: the actuator and the automatic adjustment mechanism. The automatic adjustment mechanism directly changes the parameters of the production process through the actuator, so that the production process meets the predetermined requirements. The actuator accepts the control signal from the controller and converts it into the output of the drive adjustment mechanism (such as angular displacement or linear displacement output). It also uses appropriate actuators, but the requirements are different from the adjustment mechanism. The actuator is installed directly on the production site, sometimes with harsh working conditions. Whether it can maintain normal operation directly affects the safety and reliability of the automatic adjustment system.

The structure of the valve actuator:
A device in an automated control technology tool that accepts control signals and exerts a control function on the controlled object. According to the driving energy used, the actuators are divided into 3 categories: pneumatic, electric and hydraulic actuators.

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

Valves’ sealing requirements and daily maintenance

August 18, 2020

The sealing performance of the valve refers to the ability of each sealing part of the valve to prevent the leakage of the medium. It is the most important technical performance index of the valve. There are three sealing parts of the valve:

marine valve seat

the contact between the opening and closing parts and the two sealing surfaces of the valve seat; the matching place between the packing and the valve stem and the stuffing box; the connection between the valve body and the valve cover. One of the previous leakage is called internal leakage, which is commonly referred to as lax closure, which will affect the valve’s ability to cut off the medium. For shut-off valves, internal leakage is not allowed. The latter two leaks are called external leakage, that is, the medium leakage from the valve to the outside of the valve will cause material loss, pollute the environment, and cause accidents in severe cases. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance.

Daily maintenance of the valve:
1. Pay attention to the storage environment of the valve. It should be stored in a dry and ventilated room, and both ends of the passage should be blocked.

2. The valve should be inspected regularly, the dirt on it should be removed, and anti-rust oil should be applied to its surface.

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

3. The valve after installation and application should be overhauled regularly to ensure its normal operation.

4. Check whether the sealing surface of the valve is worn or not, and repair or replace it according to the situation.

5. Check the wear of the trapezoidal thread of the valve stem and the valve stem nut, whether the packing is out of date and invalid, etc., and replace it if necessary.

6. The sealing performance of the valve should be tested to ensure its performance.

7. The valve in operation should be intact, the bolts on the flange and the bracket are complete, the threads are not damaged, and there is no looseness.

8. If the handwheel is lost, it should be prepared in time and cannot be replaced with an adjustable wrench.

9. The packing gland is not allowed to be skewed or without pre-tightening clearance.

10. If the valve is used in a harsh environment and is easily contaminated by rain, snow, dust, sand and other dirt, a protective cover should be installed for the valve stem. 11. The ruler on the valve should be complete, accurate and clear, and the valve should be sealed and capped.

12. The insulation jacket should be free of dents and cracks.

13. Avoid hitting the valve during operation, or supporting heavy objects.

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

Stainless steel valve material parameters and specific applications

August 18, 2020

The following are several stainless steel valve material parameters and specific applications:

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

(1) Angle stroke includes ball valve, butterfly valve, plug valve, etc.

(2) Straight stroke includes gate valve, globe valve, angle seat valve, etc.

This classification method is divided according to the principle, function and structure. It is the most commonly used international and domestic classification method. General gate valve, cut-off

Valves, throttle valves, instrument valves, plunger valves, diaphragm valves, plug valves, ball valves, butterfly valves, check valves, pressure relief valves, safety valves, traps, regulators Valves, bottom valves, filters, drain valves, etc.

Because the valve has a wide range of uses, it also plays a great role. For example, in power plants, valves can control the operation of boilers and steam turbines; in petroleum and chemical production, valves also control the normal operation of all production equipment and technological processes. The same is true in other departments. Nevertheless, the comparison of valves with other products is often overlooked. For example: When installing machinery and equipment, people tend to focus on the main machinery and equipment, but ignore the valve. This will reduce the overall production efficiency or stop production, or cause various other accidents. Therefore, serious and responsible work must be carried out on the selection, installation and use of valves.

double-wing-check-valve-3

Electric drive valve is a commonly used drive valve. The drive device of this drive device form is usually called the valve electric device. The characteristics of the valve electric device are as follows: 1) Rapid opening and closing can greatly shorten the time required to open and close the valve; 2) It can greatly reduce the labor intensity of the operator, especially suitable for high-pressure, large-diameter valves; 3) Suitable for installation in locations that cannot be manually operated or difficult to access, easy to achieve remote control, and the installation height is not limited; 4 ) Conducive to the automation of the entire system; 5) Power is easier to obtain than air and liquid sources, and the laying and maintenance of its wires are much simpler than compressed air and hydraulic pipelines.

The disadvantage of the valve electric device is its complex structure, and it is more difficult to use it in wet places. When used in explosive media, explosion-proof measures are required. Valve electric devices can be divided into two categories: Z-type and Q-type according to the type of valve they drive. The output shaft of the Z-type valve electric

stainless steel ball valve (8)

device can rotate many times, which is suitable for driving gate valves, stop valves, diaphragm valves, etc.; the output shaft of the Q-type valve electric device can only rotate 90. , Suitable for driving plug valves, ball valves and butterfly valves. According to its protection type, there are ordinary type, explosion-proof type (represented by B), heat-resistant type (represented by R) and three-in-one type (ie outdoor, anti-corrosion, explosion-proof, represented by S).

The valve electric device is generally composed of a transmission mechanism (reducer), a motor, a stroke control mechanism, a torque limit mechanism, a manual-electric switching mechanism, and an opening indicator.

Pneumatic and hydraulic valves:

Pneumatic valves and hydraulics use a certain pressure of air, water or oil as the power source, and use the movement of cylinders (or hydraulic cylinders) and pistons to drive the valves. Generally, the pneumatic air pressure is less than 0.8MPa, and the hydraulic water pressure or The oil pressure is 2.5MPa~25MPa. For example, it is used to drive a diaphragm valve; the rotary gas and liquid drive device is used to drive a ball valve, a butterfly valve or a plug valve. The hydraulic device has a large driving force and is suitable for driving large-diameter valves. If it is used to drive plug valves, ball valves and butterfly valves, the reciprocating motion of the piston must be converted into a rotary motion. In addition to using the piston of a cylinder or a hydraulic cylinder to drive, there is also a pneumatic film drive. Because of its small stroke and driving force, it is mainly used for regulating valves.

Manual valve:

Manual valve is the most basic drive valve. It includes direct drive by handwheel, handle or wrench and drive by transmission mechanism. When the opening torque of the valve is large, it can be driven by gear or worm gear to save effort. Gear transmission is divided into spur gear transmission and bevel gear transmission. Gear transmission reduction ratio is small, suitable for gate valves and globe valves, worm gear transmission reduction ratio is relatively large, suitable for plug valves, ball valves and butterfly valves.

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 attentions for valves

August 18, 2020

Precautions for valve installation:

Globe valves, throttle valves, pressure reducing valves, check valves and other valves are all directional. If the throttle valve is installed upside down, it will affect the use effect and life. If the pressure reducing valve does not work at all, if it is stopped The return valve can even cause danger.

lift-swing-check-valve-2

Generally, the valve has a direction mark on the valve body; if not, it should be correctly identified according to the working principle of the valve.

The valve cavity of the shut-off valve is asymmetrical left and right, and the fluid must pass through the valve port from bottom to top, so that the fluid resistance is small (determined by the shape), and the opening is labor-saving (due to the upward pressure of the medium), and the medium does not press the packing after closing, which is convenient for maintenance . This is the reason why the globe valve cannot be reversed. Other valves also have their own characteristics.

The valve installation location must be convenient for operation; even if the installation is temporarily difficult, it is necessary to consider the long-term work of the operator.

It is best to keep the valve hand wheel flush with the chest (usually 1.2 meters away from the operating floor), so that opening and closing the valve is easier. The hand wheel of the floor valve should be upward, do not tilt, to avoid

Globe valve (9)

awkward operation. The valve of the wall machine and the equipment should also leave room for the operator to stand. It is necessary to avoid operating from the sky, especially acid and alkali, toxic media, etc., otherwise it is very unsafe.

Do not install the gate valve upside down (that is, the handwheel is down), otherwise the medium will remain in the valve cover space for a long time, which will easily corrode the valve stem, and it is taboo for certain process requirements. At the same time, it is extremely inconvenient to replace the packing.

1. The pressure reducing valve should be installed upright on the horizontal pipeline, and not inclined in all directions.

2. As for the lift check valve, make sure its valve flap is vertical when installing it so that it can be lifted flexibly.

3. Swing check valve, ensure that its pin shaft is level when installing, so that it can swing flexibly.

4. Do not install the rising stem gate valve underground, otherwise the exposed stem will be corroded due to moisture.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves, gate valve and globe valves. Key words: 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…)

Current status and development of Chinese valves

August 18, 2020

Domestic status: In terms of technical support for valve production and R&D, domestic valves are not lagging behind foreign valves. On the contrary, many products are comparable to international companies in terms of technology

lug type butterfly valve-ductile iron

and innovation. The development of the domestic valve industry should move towards high-end modernization.

Driven by the four major forces of industrialization, urbanization, reform and globalization, the prospects of my country’s valve equipment manufacturing industry are still broad. In the future, high-end, localization, and modernization of the valve industry will be the main development direction of the valve industry in the future. Pursuing continuous innovation and creating a new market for valve companies can enable companies to survive and develop in the increasingly competitive pump and valve industry.

With the continuous development of valve technology and the continuous expansion of valve application fields, corresponding valve standards are becoming more and more indispensable. The valve industry products have entered a period of innovation. Not only the product categories need to be updated, but the internal management of the enterprise also needs to deepen the reform according to the industry standards.

Therefore, it is necessary to make full use of existing standards while looking forward to the future, and to develop new standards and new systems that can be used in the future, so as to promote the higher-level development of valve technology. In the future, the valve industry will develop in two main directions: one is to develop from a single variety to multiple varieties and specifications; the other is to develop in the direction of energy saving.

According to industry insiders, pump and valve companies can only effectively and clearly understand the status quo of the industry, continuously strengthen and optimize their products, strengthen their awareness of danger, strengthen corporate culture and market service concepts, and only achieve fastness in stability, refinement in fastness, and stability in refinement. Only in this way can companies survive and develop in the increasingly competitive pump and valve industry.

The society is an era of information explosion. It is inevitable for companies to encounter competitors in products. There is competition in the industry, which is a good thing for some companies. Because of competition, enterprises have improved the quality of products and services, and consumers have obtained better or more consumption and services with less money. The market is a “screen”. While the industry is developing and progressing, the market is also surviving the fittest enterprises in the industry. Although the current status of the development of the butterfly valve industry is gaining momentum, the national support policies have been greatly improved, and the market demand has continued to increase. Due to the fierce competition in the industry, the pump and valve industry has also made domestic pump and valve related technologies to improve, but many interference factors indicate The development prospects of the pump valve industry are not optimistic.

For some large competitive enterprises, through competition, the scale of the enterprise has become larger and larger, and the popularity has become higher and higher. However, for some small and medium-sized enterprises that are not competitive, they may face the risk of being merged or going bankrupt. In the increasingly fierce valve market, only companies with core competitiveness can gain a foothold in the market, and innovation becomes a weapon for companies to win the market.

Valve cleaning steps and assembly requirements

August 18, 2020

Valve cleaning steps:

The valve parts must go through the following processes before assembly:

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

According to the processing requirements, some parts need to be polished, and the surface must not have processing burrs, etc.;
All parts are degreased;
After degreasing is completed, pickling passivation is carried out, and the cleaning agent does not contain phosphorus;
Rinse with pure water after pickling and purification, and there should be no residues of medicament, and this step is omitted for carbon steel parts;
Dry the parts one by one with a non-woven cloth, and do not leave the surface of the parts such as wire wool or dry with clean nitrogen;
Use non-woven fabric or precision filter paper dipped in analytical pure alcohol to wipe each part until there is no dirty color.

Valve assembly requirements:

The cleaned parts must be sealed and stored for installation. The requirements for the installation process are as follows:

The installation workshop must be clean, or set up a temporary clean area, such as newly purchased color striped cloth or plastic film, to prevent dust from entering during the installation process.
Assemblers must wear clean cotton overalls, cotton caps, no leakage of hair, clean shoes on feet, and plastic gloves on hands.
Assembly tools must be degreased and cleaned before assembly to ensure cleanliness.

other requirements:

1. Purge the assembled valve with nitrogen for at least 1 minute.
2. The air tightness test must use pure nitrogen.
3. After passing the air tightness test, encapsulate and seal with a clean polyethylene cap. The polyethylene cap should be soaked in organic solvent and wiped clean before use.
4. Then seal it with a vacuum bag.
5. Final packing.
6. Measures must be taken to ensure that the package is not damaged during transportation.
4. Acceptance requirements
The acceptance is followed. Before assembly, each component is wiped with clean precision filter paper. If the dead corner of the component is selected, the filter paper does not change color as qualified.

Tanghai Valve is the best manufacturer of valves in China. We produce the best quality products with competitive low prices. Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest butterfly valve manufacturers in China, main products are butterfly valves, check valves, gate valve and globe valves. Key words: 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…)

Basic knowledge of valve

August 18, 2020

A valve is a device used to control the direction, pressure and flow of fluid in a fluid system. A valve is a device that allows the medium (liquid, gas, powder) in the piping and equipment to flow or stop and can control its flow.

lug type butterfly valve, ductile iron, center lined,

The valve is a control component in the pipeline fluid conveying system. It is used to change the passage section and the flow direction of the medium. It has the functions of diversion, cutoff, throttling, check, diversion or overflow pressure relief. Valves used for fluid control, from the simplest shut-off valves to the various valves used in extremely complex automatic control systems, have a wide range of varieties and specifications. The nominal diameter of the valve ranges from extremely small instrument valves to large diameters of 10m. Valves for industrial pipelines. The valve can be used to control the flow of various types of fluids such as water, steam, oil, gas, mud, various corrosive media, liquid metals, and radioactive fluids. The working pressure of the valve can be from 0.0013MPa to 1000MPa ultra-high pressure and working temperature From the ultra-low temperature of -270℃ to the high temperature of 1430℃. The valve can be controlled by a variety of transmission methods, such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electromagnetic hydraulic,

Electro-hydraulic, pneumatic-hydraulic, spur gear, bevel gear drive, etc.; it can act according to predetermined requirements under the action of pressure, temperature or other forms of sensing signals, or simply open or close without relying on sensing signals , The valve relies on the drive or automatic mechanism to make the opening and closing parts move up, down, sliding, swinging or rotating, thereby changing the size of the flow channel area to achieve its control function.

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 accessories for pneumatic valves?

August 18, 2020

Pneumatic valves have the advantages of fast switching and low price. Correct selection of pneumatic valves requires the use and characteristics of related accessories to achieve stable performance and long service life. In addition to improving the quality of the valve, it is also The matching of accessories is also very important. Here, I will introduce the characteristics and uses of several main accessories of pneumatic valves.

pnumatic actuator for butterfly valve

Accessory 1: Solenoid valve

The exact name of the solenoid valve should be the electromagnetic directional valve. The solenoid valve equipped with pneumatic valve mainly has two five-way and two-way three-way. The two-position five-way solenoid valve is usually used in conjunction with a double-acting pneumatic actuator, and the two-position three-way solenoid valve is used in conjunction with a single-acting pneumatic actuator. The pneumatic valve is used to switch the air intake and the air source through the solenoid valve. The air is discharged to achieve the function of opening and closing the valve. The solenoid valve has a single electric control solenoid valve and a double electric control solenoid valve. Explosion-proof solenoid valves should be used in special flammable and explosive occasions.

5 double-eccentric-butterfly-valve-2

Accessory 2: Limit switch

The limit switch is a long-distance transmission signal for opening or closing of the valve. The explosion-proof limit switch should be used in special flammable and explosive occasions.

Accessories 3: Air source treatment triple

Air source treatment triples include pressure reducer, filter, and oil mist device. The pressure reducer is mainly used to stabilize the air source and can adjust the pressure of the cylinder. The greater the pressure, the faster the valve opening and closing speed, which increases the friction of the valve and easily damages the sealing ring, thus affecting the service life of the valve; filter and The lubricator can filter the impurities in the air, clean and automatically add lubricant to the cylinder. Therefore, we recommend that the user is equipped with a three-piece valve for each valve, so that the pneumatic actuator can be better maintained and used for a longer time.

Product features and advantages of ball valve

August 14, 2020

Product features of ball valve:
1. The three-way ball valve adopts an integrated structure in structure, with a four-sided valve seat sealing type, fewer flange connections, high reliability, and a lightweight design.

ball valve (8)

2. The three-way ball core is divided into T type and L type, with long service life, large circulation capacity and low resistance.

3. The ball valve is divided into two types: single-acting and double-acting according to the action type. The single-acting type is characterized in that once the power source fails, the ball valve will be in the state required by the control system.

Advantages of ball valve:

1. The fluid resistance is small, and its resistance coefficient is equal to that of a pipe section of the same length.

2. Simple structure, small size and light weight.

3. It is tight and reliable, and the sealing surface material of the ball valve is widely used in plastics and has good sealing performance. It has also been widely used in vacuum systems.

4. 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.

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. It has a wide range of applications, with a diameter ranging from a few millimeters to a few meters, and can be applied in high vacuum or high pressure.

This type of valve is a high-pressure ball valve commonly used in existing mines. It bears high pressure and adopts a U-shaped card quick connection method. It can be quickly installed and disassembled in the daily production and use of the mine, and is convenient to use.

The ash unloading ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. The ash unloading ball valve can be divided into floating ball type, fixed ball type, and elastic ball type. The ash unloading ball valve is mainly used to cut off or connect the medium in the pipeline. It can also be used for fluid adjustment and control. The ash unloading ball valve Compared with other valve types, it has angular stroke output torque, opens quickly, is stable and reliable, and is widely applicable. The working principle of the ash unloading ball valve is to make the valve unblocked or blocked by rotating the valve.

Electric ball valve structure is composed of only a few parts, saving data; small size, light weight, small installation size, electric ball valve structure diagram, small driving torque, pressure regulating valve, easy and agile operation, only need to rotate 90° Fast opening and closing; and also has a good flow regulation effect and sealing characteristics at the same time, in the application of large and medium caliber, medium and low pressure, electric ball valve is the dominant valve form. When the electric ball valve is in the fully open position, the thickness of the butterfly plate is the resistance when the medium flows through the valve body, so the pressure drop that occurs through the valve is small, so it has better flow control characteristics. Electric ball valves have two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate. Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the disadvantage of being limited by temperature. If the electric ball valve is requested to be used as a flow control, it is important to accurately select the size and type of the valve. The construction principle of the electric ball valve is particularly suitable for manufacturing large diameter valves. Electric ball valves are not only widely used in general industries such as petroleum, gas, chemical, and water disposal, but also used in cooling water systems of thermal power stations. Commonly used electric ball valves include wafer type electric ball valves and flange type electric ball valves. Wafer type electric ball valve uses double-head bolts to connect the valve between two pipe flanges. Flange type electric ball valve is equipped with flanges on the valve. The two flanges on the valve are connected to the pipe flanges with bolts. The strength performance of the valve refers to the ability of the valve to withstand medium pressure. The valve is a mechanical product that is subjected to internal pressure, so it must have sufficient strength and rigidity to ensure long-term use without cracking or deformation. Pneumatic ball valve is composed of ball valve and pneumatic actuator. Pneumatic actuator is divided into double-acting pneumatic actuator and single-acting pneumatic actuator. Through solenoid valve control, ball valve switching action is realized. The pneumatic ball valve can realize intelligent control, quickly open or close the pipeline, and can effectively control and manage the pipe network.

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 and working principle of silent check valve

August 11, 2020

Silent check valve refers to a valve that automatically opens and closes the disc depending on the flow of the medium itself to prevent the medium from flowing back. It is also called check valve, one-way valve, silence check valve, reverse flow valve, and back pressure valve. Check valve is a kind of automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and discharge the container medium. Check valves can also be used to supply pipelines for auxiliary systems whose pressure may rise above the system pressure. Check valves can be divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis).
Features of silent check valve:
1. The valve clack adopts a “bullet” shape design, and the valve body adopts a “waist drum” shape design to improve the flow direction of the medium and reduce the flow resistance coefficient.

2. The valve adopts a short structure. Although the head loss is slightly larger than that of the lift-type silent check valve, it is small in size and inexpensive.

3. Compact structure, non-metallic lubrication sleeve is installed between the guide shaft and the guide frame, and the valve flap can be raised and lowered flexibly without locking phenomenon.

4. The skeleton type rubber sealing ring is directly embedded in the valve body, which avoids the direct erosion of the sealing ring by the medium for a long time, and the service life is si

silent check valve (11)

gnificantly prolonged, and it is strong and durable.

5. The valve flap has a short opening and closing stroke, which can effectively prevent water hammer

6. It is suitable for water supply and drainage system and high-rise building pipe network. It can be installed at the outlet of the pump. The structure is slightly modified, and it can be used as a suction bottom valve, but it is not suitable for sewage pipe network.

7. It has small size, light weight, low fluid resistance, fatigue resistance and long life
working principle of silent check valve:
When the medium flows in the specified direction, the valve flap is opened by the force of the medium; when the medium flows backward, the valve flap is tightly closed with the sealing surface of the valve seat due to the weight of the valve flap and the opposing force of the medium. Closed to achieve the purpose of preventing the backflow of the medium.

Check valve is an automatic valve, its main function is to prevent the back flow of the medium, prevent the pump and drive motor from reversing, and the release of the container medium. Check valves can also be used to supply pipelines for auxiliary systems whose pressure may rise above the system pressure.

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

Posts

Valve actuator / actuation -(1)-introduction

Valves’ sealing requirements and daily maintenance

Stainless steel valve material parameters and specific applications

Installation attentions for valves

Current status and development of Chinese valves

Valve cleaning steps and assembly requirements

Basic knowledge of valve

What are the accessories for pneumatic valves?

Product features and advantages of ball valve

Features and working principle of silent check valve

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