PRIMUS occasionally hears feedback from end users regarding condensate issues (wet packs) following sterilization. A wet load requires that the sterilized materials be rejected and re-sterilized. This, in turn, can cause surgery delays and lost revenue in Healthcare settings.

Wet packs are the most difficult and complex technical issue to resolve in steam sterilization because of the numerous potential causes of excess condensation.

When working to identify the source of the problem, the following troubleshooting protocol is used by PRIMUS based on over thirty years’ experience.
Check the most common suspect first – steam quality.

PRIMUS’ experience, along with that of numerous other sterilization experts, has shown that poor steam quality accounts for >95% of all wet pack issues!

Steam Quality

The first thing that end users must evaluate is the quality of the steam supplied to the sterilizer. Poor quality steam is defined as less than 97% (greater than 3% water content by weight) and can lead to excessive condensate formation within the sterilizer.

Things to check and evaluate:

  • Determine if excessive demand is being placed on the in-house boiler. Excess demand can cause the carryover of water into the steam supply system
  • Examine the steam supply system for potential areas of condensate formation such as dead legs or improperly trapped or insulated piping
  • If the sterilizer is not physically close to the boiler, condensate will form and will need to be removed from the piping before the steam reaches the sterilizer. This is accomplished by properly located steam traps and filters along the route of the steam piping
  • Insulating the steam piping will help reduce heat losses and in turn, reduce condensate formation
  • Check the jacket and chamber steam traps and the check valve at the drain port to ensure they are functioning properly

Project Design for High-Quality Steam

For organizations that do not have in-depth experience with proper steam supply design, PRIMUS highly recommends a steam consultant be used very early in the design and construction phases of the project. PRIMUS recommends Thermo Diagnostics Company, LLC for this service. Please contact Dave Schall, PRIMUS Director Sales/Service/Aftermarket, at 402-344-4200 Ext. 1212 for a referral or Chuck D’Angelone, Director of Healthcare Service and Project Manager, at 402-344-4200 Ext. 3010.

If it is positively determined that the steam supply is not the source of excess condensate, the next step is to evaluate what is being loaded into the sterilizer.

Load and Load Configuration

Another potential cause of wet packs is the load itself. Overly dense packing is frequently a cause of excessive condensation which cannot then be completely “flashed off” by subsequent steam injections. Large quantities of hard goods or complex packaging can prevent proper steam circulation. Proper load packing procedures are thoroughly described by AAMI and should be followed.

When steam enters the chamber and contacts the product, the steam will condense on the product when a portion of its heat energy (latent heat of condensation) is transferred to the load being sterilized.

The resulting condensate will fall to the chamber floor and be discharged through the drain system. Proper removal of the excess water is crucial to prevent insulating the load from the steam.

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 or Chuck D’Angelone, Director of Healthcare Service and Project Manager, at 877.679.7800 extension 3010 or email at cdangelone@spire-is.com.

Visit us at spire-is.com

Back to Blog