Plast-O-MaticValves”Series TRVDT three-port, in-line relief valve is a good fit forsystems requiring minimal footprint or where the use of a piping tee isnot practical. The valve has an economical, heavy-duty design andallows for easy replacement in existing systems. When closed, the valvehas a straight-through flow pattern. The pressure setpoint isinfinitely adjustable between 50 PSI and 100 PSI, with a maximum inletpressure of 150 PSI.  Once the set pressure is reached, thediaphragm is lifted off the center port, and the excess liquid flowsout through the third port at the bottom of the valve. The valvefeatures a PTFE diaphragm seal with no wetted metals or elastomers. Thisdiaphragm allows the valve to support highly aggressive, corrosiveliquids. The large area of the diaphragm makes for higher sensitivityand a lower pressure drop with high-flow conditions. An additionalnonwetted, u-cup seal design includes the patented fail-dry vent, which provides visual warning of impending seal malfunction. This allows the valve tocontinue operating until maintenance can be performed on the system.Valves are available in pipe sizes of _”, _”, and one inch in PVC,natural polypropylene, PTFE, and Kynar PVDF.