Viable connection technology requires reliability, flexibility, and compatibility. The Steam-Thru product line includes several valve and termination options that provide the flexibility needed to meet today’s mounting and flow requirements. The connection is attached to single-use bag systems or tubing, then presterilized by gamma irradiation up to 50 kiloGrays or autoclaved up to 128°C for 30 minutes, depending on the product configuration.
For mounting to the processing equipment, manufacturers can specify the connection with either a 3/4-inch or 1 1/2-inch sanitary termination on the middle port. Tri-clover clamps are used to secure the middle sanitary to the equipment and the lower sanitary to the steam trap.
Once attached, these two lower ports allow a true steam-through SIP process that eliminates potential dead legs where contaminants could grow. With Steam-Thru II, an SIP cycle of up to 135°C or 35 PSI can be performed for up to 60 minutes to steam on the connector to the equipment.
Effectiveness of the steam-on cycle was confirmed through bacterial challenge testing using Bacillus stearotheromphilus performed at the University of Minnesota’s Biotechnology Research Center.
Once the SIP cycle is complete, the operator depresses the thumb latch to allow valve transition from the steam position to the flow position (Figure 2). This creates a sterile flow path between the stainless equipment and the single-use system, allowing aseptic fluid transfer to occur. A benefit of the Steam-Thru II valve design is a maximum Cv value of 8.2, which translates to a flow rate of 43.9 L/min at 2 PSI, making it appropriate for high-volume applications.
Once fluid transfer is complete, depressing the thumb latch again allows repositioning of the valve back to the steam position for a second SIP or steam-off cycle. This eliminates any biologic residual remaining between the process equipment and the single-use system, minimizing the potential of environmental contamination at disconnection.
In addition to the bacterial challenge testing completed on the steam-on cycle, bacterial challenge tests were performed following media transfer on the steam-off cycle. Bacterial ingress tests using Brevendimonas diminuta were conducted by SGS Northview Labs (www.northviewlabs.com) to verify post-sterilization seal performance.
Additional performance tests, including helium/steam leak, tensile, and maximum burst, were completed to assure design and process integrity. The Steam-Thru II is composed of nonanimal origin USP Class VI polysulfone and platinum-cured silicone seals, which were tested for biocompatibility.