What could be the cause of compressor first stage discharge pressure is abnormally low?
Possible causes are as per below list:
Reduced volume, efficiency and reduced discharge air volume due to failure of stage 1 inlet/discharge valve. check the stage 1 inlet/discharge valve and replace or repair.
Much leak of compressed air into crankcase due to failure of piston ring, resulting is reduced volume efficiency. Remove the piston and check the ring damage, excess wear or lack of tension. If faulty, replace it.
Air leakage exists somewhere in the piping and air volume is reduced.
1) Check the air passage from stage 1 inlet side to stage 2 inlet side as follows and repair the leakage place.
2) Check joints for improper tightening or faulty packing.
3) Check welded parts for any pinhole.
4) Check the drain valve for opening or leakage or check the drain trap for malfunction (especially water shortage in float chamber.
5) Check the solenoid valve for any leakage
