All liquid cycles end with a flow-cooling phase. However, the cycle behavior differs depending on the pressure in the chamber at the end of Slow Exhaust (as set by the SLO EXH END POINT parameter).
Flow Cooling
If the controller detects pressure below atmospheric in the chamber at the end of Slow Exhaust, it starts an initial FLOW COOLING phase. In this phase, the Drain and Air-in valves are opened and the vacuum system turns on for a period of time equal to half the LIQUID COOLING TIME.
This draws air through the chamber to cool the liquid. At the end of this time, the gasket(s) is (are) retracted and a secondary FLOW COOLING phase continues with the Drain, Air-in, and vacuum system on for the remainder of the LIQUID COOLING TIME.
Liquid Cooling
If the controller detects pressure in the chamber at the end of Slow Exhaust, it starts a Liquid Cooling phase. In this phase, the Drain and Air-in valves remain closed and the vacuum system remains off as the chamber temperature is allowed to slowly degrade for a period of time equal to half the LIQUID COOLING TIME.
If the chamber pressure is greater than 0.7 PSIG at the end of this time, the drain is opened until the pressure drops below 0.7 PSIG. At this point, the FLOW COOLING phase starts which is the same as the secondary FLOW COOLING phase above.
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.
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