Pressure limiting valve of water feed, used e.g. in water heaters

摘要

When the pressure in the chamber (C1) is greater than a predetermined level, the valve (5) opens to feed the water into the chamber (C3) which builds up a pressure on the back of the diaphragm (M2). This forces the mushroom head (7) forward against the resistance of the spring (R) which drives the plunger (8) against the membrane (M1) thus forcing it against the seat (12) and cutting off the water flow. When the pressure in the chamber (C1) is restored to normal, the water in the chamber (C3) is evacuated via. the escape valve (14).