Compressor Station Purge Valve & Controls Upgrade

Confidential Midstream Client Kentucky, USA



The owner sought to upgrade, repair, and automate the purge/vent/pressurization process on eight (8) natural gas reciprocating compressor units. These units include five (5) Cooper Bessemer 8V-250 units (2700 HP), two (2) Ingersoll Rand KVR-616 units (6000 HP), and one (1) Cooper Bessemer 16Z-330 unit (10833 HP).

We provided engineering design for both mechanical and controls modifications. The new designs not only remediate existing deficiencies with the compressor station, but allow for remote operations, eliminating the need for on-site personnel.

Solution Details
  • Provided multidiscipline design packages, integrating new piping and controls with existing installations and systems
  • Designed the addition of new 2” purge valves, piping and orifice plates around eight (8) compressor inlet suction valves.
  • Selected and designed five (5) replacement inlet suction valves to replace leaking units.
  • Selected and specified five (5) actuators and associated controls to allow for remote suction operation.
  • Upgraded existing station control logic for the addition of purge valve automation and replacement suction actuators.
  • Designed modifications of existing controls panels to allow for station operators to visually identify new valve positions
  • Verified new pipe and material selections consistent with station design criteria and operating conditions.
  • Developed demolition drawings and documents for contractor use
  • Developed a contractor scope of work (CSOW) for bidding
  • Maintained a design basis memorandum (DBM) document throughout the life of the project to capture and outline all design considerations

Entech performed an initial site visit to document existing conditions and speak with station operators. The original station configuration did not allow for automatic purging and pressurizing of the units during a unit startup sequence, requiring on-site operation. Review of existing drawings, field conditions and discussion with station operators allowed Entech to provide a preliminary design of purge/pressurizing valves and related piping, fittings, electrical system, and controls. To automate this process, purge control valves were installed on 2” purge lines that bypass the suction unit valve.

In addition to the purge valve and automation, five (5) leaking compressor suction valves needed replacement. The original actuation on these suction valves did not allow for remote operation. The leaking inlet suction valves and new actuators were also installed along with appropriate controls to allow for remote operation.
The Entech design team developed an electrical controls design utilizing the existing control panels and provided design revisions utilizing existing plant drawings provided by the client. Progress deliverables were provided at various stages of design to solicit client comments and culminated with a full set of construction
plans. These construction documents integrated the new design with the station’s as-built drawings – revised and annotated to reflect improvements.


  • Site visit and review of facility with operations personnel
  • Gather and interpret existing drawings and plans
  • Provide complete mechanical design drawings, including Plan and Sections,
  • Equipment Details, and Bill of Materials, all as annotations and revisions to the existing plant drawings.
  • Provide complete electrical design drawings, including Electrical Outline and
  • Layout Diagrams and Electrical Control plans.
  • Annotate existing as-built drawings with proposed equipment and electrical designs. Provided clouded revision key notes.

Design Tools

  • AutoCAD Plant 3D – modeling software for mechanical piping modifications and design
  • AutoCAD MEP – 2D design software for electrical design and existing client drawing editing
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8 natural gas reciprocating compressor units

5 replacement inlet suction valves

5 actuators and associated controls

By Service