(under the class definition) Subject matter wherein the valve is so related to the fluid controlled that the pressure bias imparted by the line pressure is balanced by opposing surfaces related to the valve, so that the effect of the line pressure tending to open or close the valve is cancelled out at least in part and a lesser external force is necessary to actuate the valve.
SEE OR SEARCH THIS CLASS, SUBCLASS:
305+, for butterfly valves.
SEE OR SEARCH CLASS
137, Fluid Handling,
196, for float controlled discriminating outlets for liquid having a pressure balanced valve, subclasses 219+ for Larner-Johnson type valves, which have an inherent balance in many types, subclass 289 for hydrants provided with balanced valves, subclass 450 for float arm operated balanced valves, subclasses 494+, for line condition responsive valves having a separate connected reactor surface, subclasses 599+ for plural valving surfaces many of which are inherently relatively balanced, subclasses 625.28+ for valves balanced by dividing the flow into branches which co-act with opposing surfaces, subclasses 628+, especially subclasses 630.19+ for
balanced spool type valves having heads with relative movement with respect to each other and subclasses 629+ for valves which are balanced by admitting fluid to the low pressure side before opening force is applied to the valve, and see the search notes to subclass 629.
