The introduction of pneumatic retaining valve, the working principle of pneumatic retaining valve?

Pneumatic retaining valve is also called pneumatic locking valve, and the CHT-400 pneumatic retaining valve produced by Sichuan and Shanghai valves is a common accessory for pneumatic valves. When the pressure of the air supply is lower than the set pressure, the pressure is detected in time and the channel can be automatically cut off.

Which is the best manufacturer of valves in Shanghai? There are many valve manufacturers in Shanghai, specifically which one is the best, in fact, it is very difficult, this depends on where you can evaluate it conveniently, each manufacturer produces different valve products, and the fields involved are also very different, for example, some are doing water systems, some are doing industrial systems, and industrial systems are divided into many fields, such as: electric power, chemical industry, petroleum, pharmaceuticals and many other fields.

Here is a brief introduction to a few companies, Shanghai Qizhong valve in the field of water system, Suzhou Neway valve, Shanghai Guanlong valve this unit is not bad, industrial valve field can also be.

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. Although the ranking may change due to time and market conditions, the following brands are generally considered to be one of the top brands in the valve industry: water system valves and industrial valves The following more influential first-line brands can be used as a reference, and the following are the top ten domestic first-line valve brand manufacturers in 2022-2023, but for reference only:

Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Suyan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

The position retention valve, also known as the pneumatic locking valve, is an auxiliary component of the pneumatic unit instrument cluster. When the air source system fails, the position holding valve can automatically cut off the channel between the regulating instrument and the regulating valve, so that the opening of the regulating valve can be guaranteed to stop at the position before the failure, so that the process can be operated normally. After the air supply fault is eliminated, it can automatically resume normal operation.

Therefore, the guard valve can be used as a safety protection device in the automatic control circuit.

Product principle. When the pressure of the air supply is lower than the set pressure, the position holding valve is a device that detects the pressure in time and can automatically cut off the channel. When the compressed air source fails and the gas supply is stopped, the valve control channel is cut off by the gas elimination lock valve, so that the valve position is maintained in the position before the gas cut-off.

In order to ensure the normal progress of the process, until the accident in the system is eliminated and the dry front gas is re-supplied, the position retention valve will open the channel and return to normal control.

When the compressed air source fails and the gas supply is stopped, the pneumatic position retention valve is used to cut off the valve control channel, so that the valve position is kept in the position before the air is cut off. In order to ensure the normal progress of the process, the pneumatic position valve will not open the channel until the accident is eliminated in the system and the air supply is re-supplied to restore the normal control. The operating pressure of the pneumatic position keeper valve is adjustable, usually adjusted to the left and right.

When the air source signal enters the air chamber B, the force acting on the comparison part 2 is compared with the force acting on the spring 1. In the normal state, the thrust of the diaphragm comparison part 2 is greater than the given spring force, and the plate valve core 3 is lifted at this moment, and the nozzle 4 is opened, and the channel is in the normal working state. When the air supply is interrupted when the air supply is faulty, the pressure of the air chamber B drops, and under the action of spring force, the flat valve core 3 covers the nozzle, and the passage between the air chamber A and the output port is cut off.

That is, the air chamber of the pneumatic actuator is sealed, so that the working position of the regulating valve is kept in the original position, which plays the role of maintaining the valve position.

The working principle of the pneumatic retaining valve is that when there is an air source failure, the position of the valve at that time!

Pneumatic retaining valve Pneumatic retaining valve, also known as pneumatic locking valve, is a device that detects the pressure in time and can automatically cut off the channel when the air supply pressure is lower than the set pressure.

The function is that when the compressed air source fails and the gas supply is stopped, the position retention valve is used to cut off the valve control channel, so that the valve position is maintained in the position before the gas is cut off. In order to ensure the normal progress of the process, until the accident in the system is eliminated and the gas supply is re-supplied, the retaining valve will open the channel and resume the normal control.

When the air source pressure of the instrument is interrupted or the air supply system fails, the position retention valve can automatically cut off the channel between the regulator and the control valve air chamber or the positioner output and the control valve air chamber, so that the valve position of the control valve can maintain the original control position, so as to ensure that the process parameters in the control circuit remain unchanged. In this way, the adjusted action of the medium is not interrupted, and the position retention valve returns to its normal position immediately after the fault is eliminated.

The working principle of the pneumatic position retaining valve is:

When there is a gas supply failure is the position of the valve at that time!

Project. Form.

Single-acting. Double work is used as clever and bright.

Maximum signal pressure.

7kgf/? 100psi)

Set the pressure range and slag width.

20~100psi)

Airlock pressure. The widest gear height is 7kgf?100psi) highest input and output.

140psi)

Action pressure differentialHereinafter. Hysteresis.

Flow coefficient. Ambient temperature. 20 70 (4 158°F) input-output signal interface.

pt 1/4

Material. Die-cast aluminum. Weight.

1. Due to the small size and light weight of the product, there is no need for another bracket, and it can be connected with metal pipes.

2. It is also sensitive to the following small pressure differences.

3. Epoxy resin coating is used, which has good corrosion resistance.

4. Limit switches and indicators can also be added to monitor the switching status of CHT-400.