With a pressure relief valve included, the tankless water heater kits consist of separate hot and cold valves. The hot and cold valves are available in union x threaded or union x solder ends with an integral ¾-inch FNPT relief valve port. Made of brass and steel with an EPDM O-ring, they carry a 600# nonshock rating. Both valves have a full port, ¼-turn design, blow-out proof stem, and an integral hose end drain/purge port and cap. The companion ¾-inch pressure relief valve is a 150#, and designed specifically for protection of hot-water supply systems. Compact and economical, the pressure relief valve is installed directly on the tank or in a tee and can go on either side of the water heater. It automatically resets after providing pressure relief. Made of bronze, brass, and stainless steel, with a silicone seat disc, the pressure relief valve carries ASME Section IV, ANSI Z21, and CSA 4.4 certifications.