DN:50-800
PN:10/16
Also known as: "waterproof hammer air valve, buffer type exhaust valve, three-hole exhaust valve, three-stage exhaust valve". However, it is important to note that this type of air valve can only prevent "bridging water hammer", that is, water hammer due to high-speed water column bridging. Its structure is expanded by adding a waterproof hammer buffer device on the basis of the compound intake and exhaust valve.