instrument air consumption of a process plant

First of all, an investigation shall be made to determine air applications(consumers) The applications(consumers) are generally instruments(air operated valves, …), plant air. The total requirement of instrument air depends on the types of process facilities and instruments installed. Based on existence experience the following can be useful for your request:

1- By rule of thumb, the instrument air requirement can be considered about 1-1.6 Sm3/h of dry air for each instrument pilot in process units.

(2)-For a simple process plant(like NGL Recovery),total compressed air=inst. air+plant air

3- Min. plant air consumption is usually about 1/3 times (2)

4- Air leakage of the air generation unit~ 10% to the estimated amount of consumption(3)

5- Considering 25% as Over design capacity

it should be noted that for oil refinery other req. shall be added to (2)