Pure PTFE Packing Materials 1.size 4x4~100x100mm 2.ph value 2 ... high-low temperature,etc... This kind of packing is made of 100% pure PTFE, with no other addition so it is widely ... used in pumps and valves with highly clearing request and ... following industry:oil,chemistry, chemical fertilizer, dye, coat, chemical fiber, pharmacy, food stuff,etc.