Water system check valves are mainly used for clean water, hot and cold circulating water, domestic water supply and industrial water system, widely used in building water supply and drainage, HVAC, fire fighting and industrial water treatment and other fields. It is suitable for normal temperature and pressure to medium pressure working condition, and the working temperature range is generally from 0℃ to 120℃. Its function is to prevent backflow, protect pumps and system equipment, and ensure the safety of water quality. The valve relies on media pressure to open and close automatically, compact structure, opening and closing sensitive. Commonly used materials are ductile cast iron, brass, stainless steel, etc., the sealing surface can be rubber, PTFE, etc., good corrosion resistance, easy maintenance.