As the typical type of fiuoro plastic, PTFE and PVDF have the most excellent anti-corrosion performance. Among them PTFE is the best of all. It could be used in all the strong acid and alkali application, including HF and smoke formation(H2SO4HNO3 or HCL (98%)above) etc. and could be in high temperature application. PTFE could be used to 180℃ and PVDF to 150℃. But PTFE has very low mechanical strength, easy to be out of shape and have large dimension change when the temperature rise or reduce. So it couldn’t be used in heavy load and high- speed occasion.
Compared with PTFE, PVDF has as better compositive performance. Generally the rings and cage are made of PTFE or PVDF, Balls is glass, ceramic or stainless ones.
