Service Valve Positions

The suction and discharge service valves provide connections for the gauge manifold to the compressor for system diagnosis, service, and repair. Familiarize yourself with these valve positions:

Back-seated: Normal operating position. The service valve is fully closed:

Valve Fully Counterclockwise (Back-seated)

Front-seated: Checking and removing the compressor. The service valve is open, and access to the system is closed:

Valve Fully Clockwise (Front-seated)

    Danger
  • Risk of Injury
  • Anytime the suction service valve or the discharge service valve is front seated (closed), take precautions to ensure the unit and the bus will not accidentally start while you are servicing the system.
    Danger
  • Risk of Injury
  • If the compressor is operated with the service valves closed, an explosion may occur that could result in serious injury or death.
Open to Service Port: Servicing position. Access to the system and the service ports:

Valve Turned Half Way In (Open to Service Port)

Parent topic: Refrigeration Maintenance