Advanced Fitting Solutions for Cleanliness and Performance
The Versapass™ fitting was developed and patented as a result of end users looking for a variable feed-through fitting that offered a cleaner alternative to the modified industrial fittings that are commonly used for this purpose. Variable insertion feed-through fittings are required in pharmaceutical research and pilot plants to optimize the measurement point of a probe or the sampling/addition point of a dip tube in a reactor vessel or sanitary fluid stream.
In addition to cleanliness in a variable feed-through fitting, two other key design objectives are critical to end users; performance and inert materials of construction. Performance is defined as the capacity of the Versapass™ fitting to seal and grip a probe or dip tube without deforming it under conditions of pressure, temperature, or vacuum. Inert materials of construction are required to withstand the effects of corrosive media, as well as being free of extractable elements that can leach and contaminate a system fluid.
All three of these design goals, cleanliness, performance, and inert materials of construction are in alignment with BPE (Bioprocessing Equipment) guidelines. Although BPE does not cover variable feed-through fittings, they do offer extensive recommendations regarding good design practices for component selection. When evaluating Versapass™ as a solution, it is important to consider that the combination of all three design goals in one fitting design is more challenging than a solution that only offers one or two of them.
The Cleanliness aspect of Versapass™ is inherent in the design elements of the fitting (figure 1). These are outlined below.
Cleanliness design elements
- The point of seal to a probe or dip tube is bottom loaded and on the same plane as the process side of the fitting.
- The process side of the fitting employs a patented geometry in which the PFA seal containment sweeps away from the point of immersion of the probe, allowing for CIP/SIP exposure and access to the point of seal.
- End users have recognized this design is superior to other fitting designs including bored through compression and o-ring-based fitting designs which have far more dead volume and entrapment of process fluids
Conventional feed-through fitting example shown with a thermocouple probe.
These fittings seal the probe or tube away from the process stream and trap process fluid (dead volume). This design is acceptable for industrial applications, but not for pharmaceutical certain chemical, or vacuum systems where entrapment leads to contamination.
The wetted materials of Versapass™ are PFA and 316 stainless steel or C276. Most end users prefer PFA because it does not react with most fluids as compared to other polymers and elastomers which can leach, absorb, and degrade under certain system conditions. Versapass™ components are manufactured from certified 316 stainless steel or C276. The standard surface finish is 20 Ra.
In addition to sanitary applications, Versapass™ is an excellent choice for other process and research industries. Versapass™ has been vacuum leak tested to 1x10E-9 by helium mass spectrometer and can be deployed in semiconductors and other vacuum processes for research and industry.
Versapass™ offers a unique line of bulkhead fittings for applications that require a clean feed through into sanitary or vacuum chambers and/or vacuum piping systems, or other applications.