The testing involved in facility utility pure steam validation requires a continuous supply of saturated steam; preferably sourced from the actual line that supplies your sterilization systems. Too high a level of non-condensable gases will prevent the attainment of sterilization and too little moisture carried in suspension may allow the steam to become super-heated during expansion into the chamber, while excess moisture may cause damp loads.
To detect Non-condensable Gas, Dryness, Superheat.
Non-condensable gases originate from the water that the steam is generated from. The effect of such gases being present in the steam supply to a sterilizer can be the same as air, none sterilization of the volume they occupy.
Wet steam is undesirable as it has less energy than dry steam and more importantly can cause wet loads. The packaging used for sterile products prevents reinfection when dry, but its bacterial retentive properties will be adversely affected by the presence of moisture. Wet loads can be considered to be un-sterile. The dryness fraction describes how dry steam is, with a value of 1 representing steam that is 100% dry, and dry, and therefore free of entrained moisture. Steam with a dryness fraction of 0.99 consists of 99% steam and 1% water. If we measure the latent heat present in steam that has a dryness fraction of 0.99 we will find that it possesses 99% of the full quotient of latent heat
