Page 158 - Root Cause Failure Analysis
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146       Root Cause Failure Analysis


                                             4.  WHEN THE VALVE
                                             SETTlNG IS REACHED,
                                             THE POPPET "OPENS"   7.  VENT CONNECTION
                                             LIMITING PRESSURE   PERMITS UNLOADING
                                           .  IN UPPER CHAMBER.   PUMP THROUGH
                                                             RELIEF VALVE.

















                              2.  IS SENSED ABOVE
                              PISTON AND AT  PILOT   'IVERT   OUTPUT   5.  WHEN THIS
                              VALVE THROUGH    DIRECTLY TO TANK.   PRESSURE IS 20 psi
                                                                 HIGHER THAN IN
                              ORIFICE IN PISTON.                 UPPER CHAMBER.. .
                              WEWA               W   A
                              CLOSED             CRACKED          RELIEW NG
                Figure 10-15  Illustrates how a safety valve functions.




                Operating Methods
                Compressors can  be  hazardous to  work  around because they  have  moving  parts.
                Ensure that clothing is kept away from belt drives, couplings, and exposed shafts. In
                addition,  high-temperature  surfaces  around  cylinders  and  discharge  piping  are
                exposed. Compressors are notoriously noisy, so ear protection should be worn. These
                machines are used to generate high-pressure gas so, when working around them, it is
                important to wear safety glasses and to avoid searching for leaks with bare hands.
                High-pressure leaks can cause severe friction burns.
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