Plast-O-Matic Valves, Inc. has introduced a new automatic valve that performs multiple functions in a piping system, including pressure relief, backpressure control, pump bypass, and anti-siphon protection. The new, ½” size, lug-mounted Series RVDT uses an adjustable non-wetted spring to control backpressure in a piping system.  The set-point is adjustable, and 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.  This operation enables the valve to provide a controlled obstruction in a piping system as needed.  This is invaluable in providing backpressure on a pump, or backpressure to maintain flow to points of use.  It can also be employed to open and relieve dangerous pressure in a system.  These same characteristics enable the valve to remain closed in the event of downstream vacuum, and prevent siphoning of hazardous chemicals.  
 
All wetted materials are thermoplastic; the metal spring is isolated from the process liquid by a PTFE diaphragm.  The ½” lug-mounted RVDT is offered in body materials of
Geon® PVC, Natural Polypropylene, Corzan® CPVC,  and Kynar® PVDF.  Pressure can be set infinitely from 5 to 150 PSI.  The valves can be factory modified for special applications.