I'm getting the 6-port valve from my Tekmar 3000 resurfaced. VICI says that the "T" material in the valve is good up to 350C but that I might want to use a lower temperature range material since I typically run my Tekmar 3000 oven at 150C and that temperature is below the optimal range for the "T" valve material. This got me wondering, why would Tekmar spec such a high temperature valve material when purge and trap ovens are typically run at temps below 225C? Could it be a permeability/absorption issue with respect to the 8260 VOC list? Or are there purge and trap methods that actually use much higher valve temperatures?