What makes a MPTFE faced diaphragms “steam grade”?

Steam-grade MPTFE faced diaphragms are manufactured in a specific way to increase their life expectancy under repeated SIP (Steam-In-Place) conditions that occur during bioburden control of a pharmaceutical system. Modified PTFE (MPTFE) is used for steam-grade-rated diaphragms in lieu of virgin PTFE due to its superior physical and mechanical properties. The finished MPTFE diaphragm face has both increased resistance to cold flow (deformation of the material itself under load), and the ability to withstand both intermittent and constant elevated temperatures due to SIP.

Steel & O’Brien MPTFE faced steam grade diaphragms are manufactured under a unique high-pressure molding process that ensures a fully homogenous part and virtually eliminates the inherent micro-fissures that are found in traditional diaphragms that are simply molded straight from base resin. This unique manufacturing process ensures longevity during repeated automation and the repeated exposure conditions of SIP. All Steel & O’Brien MPTFE faced diaphragm grades 1KS, 1PS, and BK are steam grade and have been fully tested to resist SIP conditions.