Instrument air pressure requirements
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What is the pressure range for instrument air, and what determines the minimum pressure requirement?
In accordance with the requirements for pneumatic instruments, the output pressure range of the air supply unit is divided into the following two categories: 500–700 KPa (G) and 300–500 KPa (G). For detailed requirements regarding the air supply, refer to **SH 3020-2001 Standards for the Design of Air Supply Systems in Petrochemical Industries**
Check Volume 7 of the instrument procedures; it has everything there. I won’t say anything more about it.
It is generally controlled at around 500 kPa; the minimum value depends on the requirements of the instrument parameters and the line losses.
It mainly depends on the operating pressure required by the valve and the total gas volume.
The instrument air pressure only needs to be sufficient for the proper operation of the pneumatic control valve; it is generally required to be above 0.4 Mpa and not exceed 0.6 Mpa.
For control valves, 3 kilograms is usually sufficient, while cylinders require 5 to 6 kilograms.
4-7 kilograms. There is a filter-reducing valve in front of each control valve, so it doesn’t matter if the value is a bit high. Apart from the control valves and shut-off valves, I don’t seem to see many pneumatic instruments
From the site perspective, the pressure is usually around 800 kPa when it comes from the source; after being stored in the gas collection tank at the site, it drops to around 700 kPa, and at the equipment on site it ranges between 600 kPa and 700 kPa.
Anything over 5 kilograms is fine; as long as it’s below 8 kilograms, there should be no problem