Asahi/America, Inc., the leader in thermoplastic fluid flow technologies, has expanded its offering of PVC wafer check valves to include sizes 4", 6", and 8". Wafer check valves are installed on the discharge side of pumps in applications such as aquariums, water attractions, water treatment and municipalities to prevent back-flow flooding that could seriously damage pump systems.
Asahi's new wafer check valve's body, disc and stopper assembly are machined from solid PVC plate stock, which conforms to ASTM D1784 Cell Classification 12454A. This material was selected based on its excellent chemical resistance and mechanical properties. The wafer check valves are machined, assembled and tested at Asahi/America's corporate headquarters in Malden, MA.
The wafer check valve conforms to ISO 5752 face-to-face dimensions and is easily installed by slip-fitting the valve between two mating flanges. The valve body automatically centers on the mating flanges, once the stud pack is installed. A directional flow arrow on the valve body indicates the upstream and downstream sides of the valve. The lack of a bolt pattern allows one valve style to accommodate ANSI/DIN/JIS mating flange dimensions. The unique design of the disc and stopper permits the disc to fully open when upstream flow is present, without interfering with schedule piping and mating flanges.
In vertical applications, minimal back pressure provides a positive shut-off tight seal. In horizontal applications, an ETFE-coated stainless steel spring pulls the disc back to the closed position, with minimal back pressure required to fully shut off. A high Cv value ensures that user flow rates will be achieved.
Asahi's wafer check valve is available in PVC, 4" thru 12", with EPDM seals and no spring, standard. All 4" – 8" wafer check valves operate at a maximum pressure of 150 psi, 10" and 12" valves at 90 psi and up to 120o F. Optional seals in FKM and an ETFE-coated stainless steel spring round out the offering.