English to Greek Tech/Engineering Mechanics / Mech Engineering

THIS COMPRESSOR MUST NOT BE OPERATED UNLESS RELIEF VALVES ARE IN A FULLY OPERATIONAL CONDITION AND ARE CORRECTLY SET TO THE CORRECT RELIEF PRESSURE.
Protection Equipment - All protection, control switches and circuits must be regularly checked for correct operation.
Switches can be tested by checking in calibration rigs, or by carefully controlled simulation of fault conditions at the actual machine.