The　failure　of　suction/discharge　valves　is　the　most　common　cause　of　unscheduled　compressor　shutdowns;　therefore,　the　in-time　fault　diagnosis　of　valves　is　crucial　to　the　reliable　operation　of　reciprocating　compressors.　Major　valve　faults　include　leakage,　valve　flutter,　delayed　closing,　and　improper　lift.　To　determine　the　features　for　diagnosing　these　typical　valve　faults,　this　paper　presents　an　experimental　study　of　the　fault　diagnosis　of　reciprocating　compressor　valves　with　acoustic　emission　technology　and　simulated　valve　motion.　The　measured　AE　signals　and　simulated　valve　motions　of　normal　and　failed　valves　are　studied.　The　results　of　the　fault　diagnosis　indicate　that　an　earlier　occurrence　of　the　suction　process　can　diagnose　suction　valve　leakage　and　that　an　earlier　occurrence　of　the　discharge　process　can　be　used　for　detecting　discharge　valve　leakage.　The　leakage　also　causes　an　increase　in　the　amplitude　of　the　continuous　acoustic　emission　signal.　Valve　faults　resulting　from　improper　valve　lift　can　be　diagnosed　by　the　amplitude　of　the　burst　acoustic　emission　signal.　The　number　of　burst　acoustic　emission　signals　and　the　shape　of　the　simulated　valve　motion　can　be　used　to　monitor　the　valve　flutter　conditions.　The　location　where　the　valve　closes　can　diagnose　a　valve-delayed　closing　fault.