The LFN36-M1 vacuum relief valve is used in water heater and water tank applications to automatically allow air to enter into the piping system to prevent vacuum conditions that could siphon the water from the system and damage water heater or water tank equipment. It is suitable for low pressure steam and water service, and is ideal for use in domestic water heaters and supply tanks, table top heaters, jacketed steam kettles, unit heaters, low pressure steam systems, and steam coil heaters. It is NOT designed or approved as back siphonage backflow preventers. Maximum Working Pressure: 200psi (13.8 bar), maximum steam pressure: 15psi (103 kPa) and maximum temperature 250 degrees.This valve is lead free has a brass body, low profile design with a protective cap.