Event Overview

In layman's terms, this short course explains how reciprocating compressor cylinders work by focusing on the pressure-volume (P-V) diagram and the governing fundamental thermodynamic principles. This includes discussions of pressure-time and pressure-volume diagrams, volumetric efficiency, capacity, and power as derived from the P-V diagrams, and compression efficiency. It also covers the effects on the P-V diagram of changing conditions (pressure, rotating speed, thermodynamic properties, etc.), gas analysis, temperature, and pulsation. Mechanical design details are covered only very generally. Understanding the pressure-volume diagram and the basic thermodynamics is vital and forms a solid foundation for a deeper understanding of the mechanical aspects.

Attendees will receive 4 Professional Development Hours upon completion.


Learning Objectives

  • The primary objective is to leave the course with a complete understanding of the pressure versus time and pressure versus volume diagram sequences.
  • Understand how a cylinder end’s capacity is derived and calculated from the pressure-volume diagram using volumetric efficiency.
  • Understand that the power required to compress a volume of gas is also derived from the pressure-volume diagram.
  • Understand that the power required to compress a certain volume of gas is a sum of adiabatic, valve loss and friction and how each is calculated.


Who Should Attend

  • This workshop is great for design engineers and project managers who are responsible for compression projects and is good for both beginner and intermediate levels.



Greg Phillippi, Ariel Corporation

Greg Phillippi is a specialist – product and distributor support for Ariel Corporation in Mount Vernon, Ohio.  Greg began his career as a design engineer at Cooper Energy Services in 1978, joined Ariel in 1985, moved to ACI Services Inc. in 2000, and back to Ariel in 2004.  Greg received a bachelor of science in mechanical engineering from Ohio Northern University in 1978 and a master in business administration from Ashland University in 2000.  Greg’s entire 43-year career has been focused on various aspects of reciprocating compressors.  His experience includes developing a thorough understanding of gas compression thermodynamics and compressor cylinder mechanical design, and an appreciation for marketing and sales. Today Greg is deeply involved with Ariel’s end-user and distributor training effort and manages audits of Ariel’s distributors.