Plast-O-Matic Valves’ 1/2-inch, lug-mounted Series RVDT has applications in water & wastewater pump control, backpressure control in ultrapure water and chemical distribution systems, pressure relief in any liquid piping system, and siphon prevention in potable water treatment. It uses an adjustable non-wetted spring to control backpressure in a liquid 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 percent over the set pressure. This operation enables the valve to provide a controlled obstruction in a piping system as needed, which helps provide 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 1/2-inch, 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 are 100 percent manufactured in the United States and can be factory modified for special applications.