Instrument air supply
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How to determine the air supply pressure and flow rate for pneumatic valves； How is the pressure of the online purge gas supply for the flue and air pressure transmitters in circulating fluidized bed boilers, as well as the amount of gas required for purging each pressure transmitter, determined?
The required supply pressure is 6–10 kilograms; different valves adjust the necessary pressure after pressure reduction. In engineering terms, the air volume is generally calculated based on 1 cubic meter of air consumed per hour by each valve.
The supply pressure for general instruments is 750 KPA, while the actual operating pressure is around 450 KPA. The air consumption of the valve can be referred to in the standard HGT20510 gas supply specifications, which contain the calculation formulas. As for the amount of purging gas to be used, this falls under process purging. The quantity and pressure of the gas must be determined based on the pressure of the medium within the pipeline. This should be decided by the process engineers according to their specific circumstances.