Scope of the proposed deliverable This document focuses on recommended condition monitoring techniques for detecting and diagnosing developing machine faults associated with the most common potential failure modes for reciprocating compressors. It is intended to improve the reliability of implementing an effective condition monitoring approach for the compressors. It is also intended to help create a mutual understanding of the criteria for successful reciprocating compressor condition monitoring and to foster cooperation between the various application stakeholders. This document is intended for end-users, contractors, consultants, service providers, machine and parts manufacturers and instrument suppliers. The condition monitoring and diagnostics strategy and techniques described in this standard technically apply to reciprocating compressors with many different machine configurations (e.g. vertical/horizontal/L-type/V-type/W-type cylinder orientation, number of stages, speed range, lubrication, capacity control, cylinder cooling, etc.) and used in many different industrial applications. From a cost benefits perspective, however, this standard is most relevant for critical, possibly un-spared units and/or medium to large sized units that are over 1000 kW. As the vast majority of these types of reciprocating compressors are used primarily in the hydrocarbon processing and natural gas industry, the focus will be on these applications but this by no means excludes critical applications in other industries. This standard focuses on the compressor itself (cylinders, distance pieces, frame and all internal parts) and not on the driver or the external systems such as foundation/skid/pedestal, piping, scrubbers, pulsation vessels, and pulsation control devices. The scope does not include monitoring the auxiliary systems such as for lubrication, cylinder cooling, intercoolers and gas purging, but process parameters from these systems are often monitored. The scope doesn’t cover installation analyses of systems either, such as pulsation and mechanical response analysis of the piping, thermal analysis of piping, etc. This document covers online (permanently installed) and portable instrument condition monitoring and diagnostic techniques for operational reciprocating compressors during steady-state and transient conditions. Machine testing, i.e. that which is only done during shutdown, although very important, is not part of the scope of this document. Nor is one-time acceptance and performance testing within the scope. The condition monitoring techniques presented in this document cover a wide range of continuous and interval-based monitoring techniques under generalized conditions for a wide range of applications. The actual monitoring approach required, however, can be different from one application to another.