What is a pneumatic control valve?

Generally speaking, the so-called air-opening regulating valve is to open when there is air and close when there is no air, that is, to open when there is no air and no electricity. The selection of gas opening and gas closing is completely based on the process safety setting.

Give a simple example: for example, if the medium is flammable, explosive or dangerous and toxic fluid, add a block valve to the main gas pipeline. We should choose whether to turn it on or off.

In the normal production process, which branch pipe suddenly leaks (toxic gas) or catches fire, etc. And the people at the scene couldn't get in, and the control failed again. When this happens, the main isolation valve cannot be cut off in time, which will cause great losses and so on, so we need to set the water supply valve to be airtight.

In other words, it can automatically turn off the partition protection device under special circumstances such as power failure to avoid accidents.

Extended data:

First, the working principle of control valve

The regulating valve is used to regulate the flow, pressure and liquid level of the medium. According to the signal of adjusting position, the opening of the valve is automatically controlled, so as to adjust the medium flow, pressure and liquid level. Regulating valves are divided into electric regulating valves, pneumatic regulating valves and hydraulic regulating valves.

The regulating valve is composed of electric actuator or pneumatic actuator and regulating valve. Regulating valves are usually divided into straight-through single-seat regulating valves and straight-through double-seat regulating valves. The latter has the characteristics of large circulation capacity, small imbalance and stable operation, and is usually especially suitable for occasions with large flow, high pressure drop and less leakage.

Second, the use of control valve matters needing attention

1, control valve should be stored in a dry room, both ends of the channel must be blocked, and stacking is not allowed.

2. The regulating valve stored for a long time should be inspected regularly to remove dirt, and the moving parts and machined surfaces should be coated with antirust oil to prevent rusting.

3, regulating valve should be installed on the horizontal pipeline, forced vertical installation. The valve stem is up.

4. Installation must be carried out according to the sliding medium shown by the arrow in the figure.

References:

Baidu encyclopedia-regulating valve