QGD-75

Inspect compressor head gaskets, piston rod seals and pressure port connections for visible oil leakage, weeping or corrosion; check pressure gauges for stability at rated PSI and measure actual discharge pressure vs. nameplate specification

Verify crankcase oil level (oil-type compressors only), check oil color/clarity for contamination, measure oil pressure relief valve function; inspect oil filter differential pressure indicator and verify proper oil type per nameplate

Check all mounting bolts for tightness using torque wrench (per manual specifications); measure vibration levels on frame using vibration meter at specified measurement points; inspect frame welds and base for cracks or deformation

Verify intake filter element condition and differential pressure indicator (replace if colored/clogged); inspect discharge valve seats for fouling; measure intake air temperature and verify inter-cooler (two-stage models) operation at temperature setpoint

Test pressure relief valve by slowly increasing system pressure and verifying relief discharge at nameplate setpoint; verify unloader valve operation on multi-stage units; check emergency stop controls and verify alarm/shutdown circuits (marine duty models with IEEE-45 certification)