The NIBCO® Ring Check® valve is designed with an in-line, spring assisted self-closing disc. The two-piece valve features a stainless steel stem and resilient PTFE disc. The valve is recommended for domestic hot and cold water, HVAC (condensers, chilled water, hot water heating). The NIBCO® Press System® is user friendly, quick and easy to install. When properly crimped a unique ''''N'''' witness mark is clearly visible. Please refer to NIBCO technical data sheets and catalogs for engineering and installation information. NIBCO® Press System® applies the proven performance of press technology to NIBCO valves and fittings -- the most specified flow control products in the industry. The NIBCO® Press System® features a full range of precision engineered copper fittings, bronze valves, accessories, pressing tools, jaws and chains. NIBCO® Press System® valves are backed by a 5-year limited warranty. Because of its longstanding reputation for innovation and precision in design and manufacturing, NIBCO is the preferred brand in the industry.