This　paper　proposes　a　method　of　diagnosing　faults　in　reciprocating　compressor　valves　using　the　acoustic　emission　signal　coupled　with　the　simulated　valve　motion.　The　actual　working　condition　of　a　valve　can　be　obtained　by　analyzing　the　acoustic　emission　signal　in　the　crank　angle　domain　and　the　valve　movement　can　be　predicted　by　simulating　the　valve　motion.　The　exact　opening　and　closing　locations　of　a　normal　valve,　provided　by　the　simulated　valve　motion,　can　be　used　as　references　for　the　valve　fault　diagnosis.　The　typical　valve　faults　are　diagnosed　to　validate　the　feasibility　and　accuracy　of　the　proposed　method.　The　experimental　results　indicate　that　this　method　can　easily　distinguish　the　normal　valve,　valve　flutter　and　valve　delayed　closing　conditions.　The　characteristic　locations　of　the　opening　and　closing　of　the　suction　and　discharge　valves　can　be　clearly　identified　in　the　waveform　of　the　acoustic　emission　signal　and　the　simulated　valve　motion.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.