Ablutionary shower systems

Abstract

An automatic drain-off valve for an ablutionary shower system is provided at the lowest point of the supply pipe at or from the shower control or mixing valve to the shower spray head. The drain valve (30) comprises a body (1) having a chamber (7) in which a clack valve (3) is mounted and which is normally biassed into the open position relative to a port (16) surrounded by a seating (8). The port (16) comprises a series of through bores opening to the bottom of the valve for discharging water from the chamber (7) to waste. When water flows through the supply pipe of the shower system, the chamber (7) fills and pressure on the clack valve overcomes the bias applied to the valve spindle (4) by a spring (14) so that the valve close on the seating (8). A clearance gap (9) is provided between the periphery of the clack valve and the internal wall of the chamber (7) to ensure that when the valve is open water can drain through the valve, but the gap is small and restricts flow when the chamber (7) is filled and cause pressure build-up in the chamber (7) to close the valve. In a modification, the spring bias is adjustable. Automatic drain-off in shower systems is considered as a preventative measure with regard to Legionnaire's disease as well as for other advantages avoiding stagnation of water in the shower head supply pipe. Various installations are described.