A check valve has an internal gate having an adjustable retention force, such that in the event that if the differential pressure between the upstream and downstream pressure changes, the force required to allow flow through the valve may be adjusted without removal of the valve from the piping system.

A valve apparatus comprises a housing defining a flowpath extending between a valve inlet and a valve outlet and an access port formed in a wall of the housing separately from the valve inlet and the valve outlet to provide access to the flowpath at a location which is intermediate the valve inlet and valve outlet. A valve mechanism is mounted within the flowpath, wherein the valve mechanism in insertable through the access port.

A combination control and check valve assembly for a wet piping system includes a control valve in the form of a ball valve and a one-way check valve mounted within the flow pathway of the ball valve. A valve actuation assembly is mounted to the valve assembly to selectively rotate the ball valve between the open and closed positions thereof. The valve actuation assembly is mounted to a first side of the valve assembly and rotationally fixed to the ball, whereby rotation of the valve actuation assembly rotates the ball between the open and closed positions. A side opening is formed in a second side of the valve assembly that is angularly spaced from the first side. The side opening is positioned to align with the fluid flow pathway of the ball valve in the closed position thereof to provide access to the check valve.

A channel baffle structure comprises a pipe, a swing check plate and a driving apparatus, wherein the main part of the swing check plate is located inside the pipe, and the driving apparatus is disposed outside the pipe. A connection structure is used for connecting the driving apparatus and the swing check plate. The check plate can be opened and closed passively by gravity and fluid pressure, but can also be actively opened and closed by the driving apparatus, such that requirements for multiple operating conditions of the channel can be satisfied.

A backwater valve has a hollow valve body having an inlet and an outlet, and a valve member pivotally movable about a pivot axis disposed above the inlet. The valve member pivots between an open position in which the valve member is away from the inlet and a closed position in which the valve member closes the inlet. A cam is rotatably mounted above the inlet. The cam has a first rotary position in which the valve member is permitted to move to the open position and a second rotary position in which the cam engages the valve member to secure the valve member in the closed position. With the valve member in the open position, the cam pushes the valve member toward the close position as the cam moves toward the second rotary position.

A check valve can include a pressure actuator or an electromagnetic actuator. The check valve includes a valve inlet, a valve outlet, and flap disposed between the valve inlet and the valve outlet. The check valve has an open state and a closed state. The pressure actuator in fluid communication with the valve inlet. The check valve has an open state and a closed state. The check valve is configured to allow an input gas to flow from the valve inlet to the valve outlet when the check valve is in the open state. The check valve is configured to preclude the input gas from flowing from the valve inlet to the valve outlet when the check valve is in the closed state. Upon actuation of the pressure actuator or the electromagnetic actuator, the flap moves away from the valve inlet to allow the inlet gas to move from the valve inlet to the valve outlet.

A check valve (1) which comprises an obturator (2) and a biasing mechanism, the biasing mechanism arranged to urge the obturator towards a closed condition, and the check valve further comprising an actuator assembly (5, 7a, 7b) which is arranged to be selectively activated to cause the obturator to be in an open condition, and the check valve comprising a controller which has a control signal input to cause the controller to selectively activate the actuator assembly.

A check valve can include a pressure actuator or an electromagnetic actuator. The check valve includes a valve inlet, a valve outlet, and flap disposed between the valve inlet and the valve outlet. The check valve has an open state and a closed state. The pressure actuator in fluid communication with the valve inlet. The check valve has an open state and a closed state. The check valve is configured to allow an input gas to flow from the valve inlet to the valve outlet when the check valve is in the open state. The check valve is configured to preclude the input gas from flowing from the valve inlet to the valve outlet when the check valve is in the closed state. Upon actuation of the pressure actuator or the electromagnetic actuator, the flap moves away from the valve inlet to allow the inlet gas to move from the valve inlet to the valve outlet.

A combination control and check valve assembly for a wet piping system includes a control valve in the form of a ball valve and a one-way check valve mounted within the flow pathway of the ball valve. A valve actuation assembly is mounted to the valve assembly to selectively rotate the ball valve between the open and closed positions thereof. The valve actuation assembly is mounted to a first side of the valve assembly and rotationally fixed to the ball, whereby rotation of the valve actuation assembly rotates the ball between the open and closed positions. A side opening is formed in a second side of the valve assembly that is angularly spaced from the first side. The side opening is positioned to align with the fluid flow pathway of the ball valve in the closed position thereof to provide access to the check valve.

A backwater valve has a hollow valve body with an inlet and an outlet and a valve member pivotally movable about a pivot axis disposed above the inlet. The valve member is movable between a closed position covering the inlet and an open position. The valve member has a specific gravity that is greater than water and has a basin that causes the valve member to be buoyant when the basin is filled with air. A releasable latch holds the valve member in the open position and releases the valve member when the valve member pivots to a release position. A rotational stop engages the valve member at a fill position permitting water to overflow into the basin.