Blowout from air compressor stage safety valve

The safety valve adjusted to release a pressure exceeding it's set point. Check and test the safety valve itself. Repair or replace the valve seat or spring if abnormalities found.
If safety valve found in good condition check for causes of sudden pressure increase which leads to safety valve lift up as follows:

1. Failure of a stage discharge valve or following stage inlet valve.
   Check and replace or repair the inlet/discharge valves in question.
   
2. Clogging of cooler of the stage following the safety valve.
   Stop the compressor. Inspect and clean the interior of the heat exchanger pipe.
3. Excessive rise of pressure in air reservoir (in case of last stage) Immediately stop the compressor and after the pressure in the air reservoir is reduced, adjust or replace the automatic stopping pressure switch.
4. Clogging of check valve or air reservoir inlet valve. Inspect the check valve or air reservoir inlet valve and repair or replace.
5. Close on of the valves from the compressor to receiver.
   Check the line setup. Open all required valves.