Although an infrequent occurrence, PRIMUS does periodically receive Customer Service Call Log (CSCL) help requests due to a steam-to-jacket valve not firing.

Typically, in the field the first indication of this problem is that the sterilizer will not come up to temperature.

Possible Causes and Corrective Actions

Sterilizer Controller Thinks the Jacket is Below Freezing

  • Check the jacket temperature in CAL mode
  • If the jacket RTD has failed, the jacket will read significantly below freezing
  • The steam-to-jacket valve will not fire if the controller thinks the jacket is below freezing
  • Replace the RTD and calibrate. The steam-to-jacket valve will then operate normally

Jacket Valve Stuck in the Closed Position

  • If debris becomes lodged in the valve, the valve could be prevented from opening. This could happen with high contamination levels in the steam

Coil on the Jacket Valve Shorted or Melted

  • Ultimately, all coils will eventually fail. The steam-to-jacket valve is a very “high-use” valve and can undergo thousands of cycles per day
  • Coil failure is the most common cause of a steam-to-jacket valve not firing
  • Simply replace the coil, if possible. If the coil has melted, it can be virtually impossible to remove the coil from the valve. In this case, the entire valve must be replaced

Blown Fuse on the Jacket Relay, Power Control Relay, or Master Power Relay

Normally, if the coil fails on the steam-to-jacket valve, it will also blow the fuses on the Steam to Jacket Relay, Power Control Relay, and the Master Power Relay. These three relays all use fuse PRIMUS P/N 500035

No Steam to the Sterilizer

Check that plant steam or integral boiler steam is being properly provided to the sterilizer

Have a question or having difficulties? Talk to Dave Schall, our PRIMUS sterilizer expert who is here to assist you anytime at 877.679.7800 extension 1212 or email at dschall@spire-is.com.

Visit us at spire-is.com

Back to Blog