Abstract: A pillar tap has a main water chamber and a control chamber housed within the main chamber. The control chamber has two different sized openings. The smaller opening which is located opposite the main outlet valve seat of the main chamber supports a membrane. The membrane in turn supports a valve member for movement into and out of engagement with the valve seat. The larger of the two openings is closed by a resilient diaphragm. A pair of control valves and control the admission and release of water to and from the control chamber. By controlling the control valves and the pressure differential between the main and control chambers and can be varied and so used to control the degree to which the valve member is opened. Once the flow rate through valve seat has been set, the diaphragm responds to pressure variations in the main chamber to alter the position of the valve member in a sense to maintain a substantially constant flow rate irrespective of the pressure variations.

Abstract: A domestic pillar faucet has a main flow path and a control flow path, both connected to the same inlet. A diaphragm supports a valve member for displacement between a position in which the valve member is held open and a position in which the valve member closes the main flow path. Displacement of the diaphragm is controlled by fluid from the control flow path. The control flow path includes an inlet valve and an outlet valve and the section of the control flow path between the valves communicates with the diaphragm. By opening the outlet valve, the force on the diaphragm is reduced and the valve member will open. By closing the outlet valve and opening the inlet valve, the force on the diaphragm is increased and the valve member will close. The valves are operated by a lever through push buttons. The faucet is thus operated in a power assisted manner, not needing the dexterity required when opening or closing conventional faucets.