Mixing valve with inlet pressure compensation - has double piston stage reacting to pressure variations to regulate flow through compensating orifices

摘要

A mixing valve for achieving a constant temperature flow from hot and cold water has a pressure compensating stage to eliminate the effects of supply pressure variations. An axially constrained valve sleeve is located in a housing block and may be adjusted rotationally. The sleeve has two pistons that are spring loaded into contact with two temperature sensitive bellows, one of which reacts to temperature increases and the other to decreases. Inlet flow rate is initially set by rotating the valve sleeve to cause two cam tracks to open the spring loaded inlet valves. The two flows pass through orifices into the central mixing region.