Plast-O-Matic Valves, Inc. has launched their new Anti-Siphon Valves to protect chemical process systems from unwanted tank siphoning, permitting flow only under controlled pumping. Used mainly to prevent gravity-induced siphonage from storage tanks, the Series RVDT remains closed under the pressure created by the presence of liquid in a tank in piping system but opens under pump pressure. In chemical process applications, the anti-siphon valve is frequently used to protect a system from unwanted flow through a pump due to negative pressure in a pipeline. The Plast-O-Matic RVDT actually closes tighter under the presence of vacuum at the valve outlet; yet it opens and allows chemicals to enter the system under controlled pumping.
The pressure set-point is infinitely adjustable, but a low set-point is common for most anti-siphon applications. Once the set pressure is reached, the valve begins to open. It will allow the rated full flow at approximately 40% over the set pressure.
Anti-Siphon Valves are available in pipe sizes from ¼”-2” with various body materials including Grade 1, Type 1 PVC, Polypropylene, Corzan (CPVC), Kynar (PVDF) and Teflon (PTFE). Primary Seal is a Teflon diaphragm. Flow rates range from 2 to 75 GPM and set pressures from 5 to 150 PSI. The valves can be factory modified for special applications.