Plast-O-Matic Valves, Inc. announces the addition of Series TRVDT three-port, in-line relief valves. They feature a minimal footprint, an economical, heavy-duty design and a PTFE diaphragm seal with no wetted metals or elastomers. Valves are available in pipe sizes 0.5, 0.75 and 1.0 inch (12.7, 19.05 and 25.4 mm) in PVC, natural polypropylene, PTFE and Kynar PVDF. The units allow for easy replacement in existing systems. Factory modification for special applications is available.www.plastomatic.cominfo@plastomatic.com