An example manual actuation mechanism includes (i) a piston having: (a) a first flanged portion with a first annular surface area, (b) a second flanged portion with a second annular surface area, (c) a longitudinal cavity bounded by an interior peripheral surface of the piston, and (d) a shoulder on the interior peripheral surface of the piston; and (ii) a pin disposed in the longitudinal cavity of the piston, where the pin has an area with an enlarged diameter configured to interface with and rest against the shoulder of the piston, such that a force applied on the pin in a given axial direction is transferred to the piston, and where a difference between the second annular surface area of the second flanged portion and the first annular surface of the first flanged portion is substantially equal to a cross-sectional area of the pin.

A pressure control valve provided with: a main valve section provided with a main valve body having a backpressure chamber on the inside thereof, and a valve housing body that is provided with a main valve seat in which said main valve body can be seated and has a pilot chamber for slidably housing the main valve body; and a pilot valve section that is provided with a pilot valve body and a pilot valve seat member having a pilot valve seat in which said pilot valve body can be seated, and in which the pilot valve body separates from the pilot valve seat to open when the pressure inside the pilot chamber has exceeded a prescribed pressure.

An example manual actuation mechanism includes (i) a piston having: (a) a first flanged portion with a first annular surface area, (b) a second flanged portion with a second annular surface area, (c) a longitudinal cavity bounded by an interior peripheral surface of the piston, and (d) a shoulder on the interior peripheral surface of the piston; and (ii) a pin disposed in the longitudinal cavity of the piston, where the pin has an area with an enlarged diameter configured to interface with and rest against the shoulder of the piston, such that a force applied on the pin in a given axial direction is transferred to the piston, and where a difference between the second annular surface area of the second flanged portion and the first annular surface of the first flanged portion is substantially equal to a cross-sectional area of the pin.

A pressure control valve provided with: a main valve section provided with a main valve body having a backpressure chamber on the inside thereof, and a valve housing body that is provided with a main valve seat in which said main valve body can be seated and has a pilot chamber for slidably housing the main valve body; and a pilot valve section that is provided with a pilot valve body and a pilot valve seat member having a pilot valve seat in which said pilot valve body can be seated, and in which the pilot valve body separates from the pilot valve seat to open when the pressure inside the pilot chamber has exceeded a prescribed pressure.

A flushometer valve includes a hollow body and a piston assembly disposed inside the hollow body for controlling operation of the flushometer valve. The piston assembly and hollow body define an inlet chamber, an outlet chamber and a pressure chamber. The piston assembly includes a flow guide, a piston top, and an insert. The flow guide is movable relative to the hollow body between an open position, in which the outlet chamber is fluidly connected to the inlet chamber, and a closed position, in which the outlet chamber is fluidly disconnected from the inlet chamber. The piston top is coupled to the flow guide, includes a first material, and has a bleed passage that fluidly connects the pressure chamber and the inlet chamber. The insert is disposed within the bleed passage, includes a second material, and has a bore that fluidly connects the bleed passage and the pressure chamber.

An oil level regulating apparatus includes a valve unit and a solenoid unit. The valve unit includes a housing having an inflow hole, an outflow hole, and a leak hole, a partition separating the outflow hole and the leak hole, defining a valve chamber close to the outflow hole, and having a partition continuous hole, a valve dividing the valve chamber into an introduction chamber and a pressure chamber and having a valve continuous hole, and a valve biasing member biasing the valve. The solenoid unit has a shaft configured to open and close a leak channel. The shaft can open and close the leak channel on the downstream side of the pressure chamber. When the shaft closes the leak channel, the valve is switched to a closed valve state of closing the outflow hole.

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.

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 valve apparatus includes a body with a supply passage for gas and a solenoid valve housed in the body. The solenoid valve includes a tubular sleeve internally having a flow passage leading to the supply passage, and a valve element and a valve seat that open and close the flow passage. The solenoid valve includes a driving portion that opens and closes the valve element. A seal member is disposed between an outer wall of the sleeve and an inner wall of the body. A tip of the sleeve on a downstream side of the valve element is exposed from the body.