As　an　established　method　to　analyse　the　thermodynamic　process　inside　a　cylinder,　the　pressure-volume　(p-V)　diagram　can　identify　typical　faults　within　industrial　reciprocating　compressors,　such　as　leakages　through　the　sealing　rings　and　self-acting　valves,　and　loosening　and　fluttering　of　the　valves.　However,　the　installation　of　a　pressure　sensor　within　the　cylinder　for　recording　the　p-V　diagram　may　lead　to　degraded　strength　and　potential　leakage　associated　with　the　cylinder　and　hence,　deteriorated　integrity　of　the　cylinder.　This　study　proposes　a　new　nondestructive　method　to　record　the　p-V　diagram　of　the　reciprocating　compressor　by　measuring　the　piston　rod　strain.　An　algorithm　for　reconstructing　the　p-V　diagram　was　proposed　based　on　the　key　feature　points　on　the　piston　rod　load　curve　that　reflects　the　opening　and　closing　events　of　the　compressor　valves.　The　algorithm　was　validated　by　comparing　the　p-V　diagrams　obtained　from　direct　pressure　measurement　and　strain-based　derivation.　The　reconstructed　p-V　diagrams　were　further　used　for　the　fault　diagnosis　of　the　reciprocating　compressors.　The　results　indicate　that　this　method　is　able　to　easily　monitor　the　operating　conditions　and　identify　whether　and　where　faults　such　as　leakage　and　fluttering　of　the　valves　occur,　and　it　can　be　utilized　as　a　powerful　tool　in　the　nondestructive　condition　monitoring　and　fault　diagnosis　of　the　reciprocating　compressors.　(C)　2019　Elsevier　Ltd.　All　rights　reserved.