FDI P2131, Technical Manual, Page: 13 / 161

3. Exposure – Steam flowing into the chamber slows and the temperature sensor, PLC, and
heaters begin controlling the temperature inside the chamber so that it stays within a
specified range during the entire exposure time selected.
NOTE: The P2131 is controlled by temperature, not by pressure, during exposure.
4. Drying – A deep vacuum is drawn on the chamber to remove the steam and residual
moisture from the sterilized items.
5. Venting – The vacuum is released by bringing in outside air through the HEPA filter so the
chamber door can be opened by the operator.
2.5 Water Supply Quality
It is critical to the long ‐ term reliability and performance of the P2131 sterilizer that only potable
water (i.e., water safe for human consumption) should be used as the feedwater to the SWS. The
feedwater should meet FDA bottled water criteria for total coliform (i.e., a disinfectant such as
chlorine should be present). Reference Appendix A.6 for suggested maximum values of
contaminants in the feed water.
The P2131 sterilizer can operate for 14 days or 100 cycles with only 10 gallons of water. However,
the FDA requires that the water in the SMU and WRS must be drained and refilled every 14 days
or 100 cycles (whichever comes first). Reference Section 3.4.
CAUTION : It is critical to use and maintain the SWS. Reference Sections 3.4 and 4.3.4.
If a pressurized potable water system is available, a hose can be connected directly to the inlet
of the SWS. As water flows through the SWS, calcium, magnesium, and other contaminants are
removed from the water, preventing deposits (i.e., scale buildup) on the heating elements, jacket
walls, and other components. This deionized water will also prevent premature corrosion of the
metal components. If a pressurized water system is not available, the SWS is equipped with a
manual hand pump, suction hose, and inlet strainer. This will allow potable water to be manually
pumped from a bucket or Jerry can through the SWS and into the WRS for use in the SMU. The
three important benefits of using the SWS are:
1. Eliminates costly sterilizer downtime and maintenance labor to replace heating elements
and to scrape and clean the boiler surfaces.
2. Improves sterilizer cycle times by keeping heatup times short (1.6 mm of scale buildup on
the heating elements causes a 12% loss in heating efficiency).
3. Improves safety by eliminating the potential for sterilizer rupture due to localized hot
spots or premature corrosion that cause weakening of the aluminum.
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