Pneumatic control valve supply pressure
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Pneumatic single-seat control valve, heat transfer oil pipelines DN80 and DN50, gauge pressure of 0.6 MPa; cooling water pipelines DN80 and DN50, gauge pressure of 0.3 MPa. Should the supply air pressure be set at 0.14 MPa (0.02–0.1 MPa) or 0.4 MPa (0.08–0.24 MPa)?
Your question is asked in a rather inappropriate way! The supply pressure is not determined by the size of the valve; it is chosen according to the specifications indicated on the control valve’s label. If you really don’t understand or know nothing about this, you can still set the supply pressure to 0.25 – it will work just fine!
I am referring to how to choose the parameter specifications on the nameplate of the control valve, not the air supply pressure. This specification should be related to the pipe diameter and pressure, right?
If it is for design or ordering, the pressure of the instrument air system in the relevant area should be considered first; the supply pressure for control valves should be one pressure level lower than that of the system. If it is the instrument air pressure at the filter pressure regulator that is set upon the arrival of the valve, then it can be set according to the requirements for the air supply pressure at the valve positioner.
Our factory uses 0.4MPA; a higher pressure will result in greater force, but it must not exceed the maximum pressure that the pneumatic valve can handle.
This question is indeed asked in the wrong way; pneumatic valves operate using instrument air, and the specific values are provided by the valve manufacturer. There are two pressure settings for the instrument air at the air supply point: one is 500–700 kPa, and the other is 300–500 kPa. If the operating pressure of the valve is relatively low, a pressure reducing valve can be used; it is one of the components in the pneumatic trio for valves.
I think it has to do with the caliber; just like people, adults and children have different appetites.
The pressure of the main instrument air supply pipe in the plant is fixed, and pneumatic triple units or double units are used for adjustment according to the requirements of each valve.
It mainly depends on the gas consumption; valves from the same manufacturer generally have the same supply pressure, and the diameter determines the amount of gas consumed
It is usually around 0.4 MPa; the difference isn’t very large
Generally, you only need to provide a gas source – a clean gas source with a stable pressure of 0.2 to 0.5 MPa. The locator is equipped with its own pressure regulator; the specific pressure is set by the manufacturer at the time of production