A float or a near neutral buoyancy weight operated liquid pressure control valve includes a body which together with an end cap form a cavity and retain a diaphragm therein. A back-pressure chamber is formed between the end cap and the diaphragm and the diaphragm includes a seal section which seats on an inlet port. The diaphragm seal also separates the inlet from an outlet formed in the body. A float support arm reciprocally operates a valve opening and closing control pin mounted in an associated bleed passage formed longitudinally through a control pin mounting. In an open mode the bleed passage vents the chamber. In a closed mode the pressure in the chamber displaces the diaphragm to close the valve. A slide is coupled to the diaphragm so as to be displaced therewith and prevent excessive pressure to distort the diaphragm once the seal closes on port.

A rigid piston assembly for use in a conventional flush valve includes a rigid piston configured to fixedly engage within the valve body. The present invention is also directed to a flush valve for a plumbing fixture as well as a method of retrofitting a rigid piston into a diaphragm flush valve body.

A rigid piston assembly for use in a conventional flush valve includes a rigid piston and a solenoid configured to fixedly engage within the valve body. A flush valve for a plumbing fixture as well as a method of retrofitting a piston valve into a diaphragm flush valve body which includes a rigid piston and solenoid configuration.

A rigid piston assembly for use in a conventional flush valve includes a rigid piston and a solenoid configured to fixedly engage within the valve body. A flush valve for a plumbing fixture as well as a method of retrofitting a piston valve into a diaphragm flush valve body which includes a rigid piston and solenoid configuration.