Balanced solenoid valves

Abstract From the Canadian patent

A proportional-control solenoid-actuated fluid valve, capable of governing relatively large volumes and rates of flow swiftly and accurately with expenditure of relatively little electrical power, includes a movable valving member positioned by an armature having a substantially frictionless spring suspension the armature, being under influence of a special force-counter-balancer is the form of a bellows proportioned and disposed to exert upon it, automatically, neutralizing forces which are substantially equal and opposite to unavoidable pressureinduced imbalances afflicting the valving member. The same pressures which tend to unbalance the valve member are impressed upon opposite sides of …