Asahi/America Inc. has released a newly designed diaphragm valve, know as 3-piece design Teflon diaphragm. Supplied on Asahi’s Type-14, Type-15, and Type-G diaphragm valves, this design offers safety and protection against harsh chemicals. The 3-piece design Teflon diaphragm provides extra safety by creating a gas barrier that prohibits leakage associated with other diaphragm designs. The diaphragm is made up of three separate layers which perform three specific functions. The first layer is the “wetted” part of the diaphragm-the only part that comes in direct contact with the media. This is the white layer of Teflon which has chemical resistance properties, however it is a permeable membrane which means it allows vapors to pass through it. The second layer is a unique thin opaque layer of Polyvinylidene Fluoride (PVDF) which prevents the migration of vapors in applications where off-gassing can occur. Third is a layer of black rubber EPDM, an elastomeric material. When EPDM backs Teflon, it allows for a lower sealing torque requirement by providing elasticity to the Teflon and PVDF layers. These diaphragm valves are suitable for water and wastewater treatment and chemical processing.
