A damped check valve having multi-pressure operation is provided. The check valve includes a liner with a poppet movable within the liner. The liner defines a flow passage aligned along a longitudinal axis defined by the liner. A biasing element is operably coupled between the poppet and the liner to bias a first flow face of the poppet against an annular seat. The first flow face is configured such that a first fluid pressure is required to move the poppet from the closed position to an open position wherein the poppet is unseated from the annular seat and a second fluid pressure is required to hold the poppet in the open position, the second pressure being less than the first pressure. There is a sufficient diametrical clearance between the poppet and the liner which allows for flow control at pressures which are less than the initial opening pressure.

Flow control valves may be positioned downstream of water meters to increase pressure and compress entrained water vapour passing through the meters. However, turbulence within such valves can cause the valve's head to move radially, bending a shaft within the valve which may break. Accordingly, there is provided a flow control valve comprising: a housing having a flow passage; a valve seat defined within the flow passage; a valve head moveable to a closed position to engage the valve seat and seal the flow passage; a shaft secured to the valve head; a support slidingly mounting the shaft within the housing; a spring biasing the valve head to the closed position and configured to maintain the valve head in the closed position until a predetermined pressure is applied; and a guide assembly extending along at least a portion of the flow passage to constrain radial movement of the valve head.

A pressure relief valve includes a valve body including a monitored pressure inlet leading to a monitored pressure region, a piston having a shear seal bore and a surface facing the monitored pressure region, a vent passage and a the shear seal assembly comprising a seal plate having a sealing surface thereon, and the shear seal assembly includes a sealing surface facing the seal plate and having a first annular area, and a first surface having an annular surface area at least twice as large as the first area of the sealing surface, the first surface facing away from the first area, and a biasing seal in contact with the first surface.

A pressure relief valve includes a valve body including a monitored pressure inlet leading to a monitored pressure region, a piston having a shear seal bore and a surface facing the monitored pressure region, a vent passage and a the shear seal assembly comprising a seal plate having a sealing surface thereon, and the shear seal assembly includes a sealing surface facing the seal plate and having a first annular area, and a first surface having an annular surface area at least twice as large as the first area of the sealing surface, the first surface facing away from the first area, and a biasing seal in contact with the first surface.

Flow control valves may be positioned downstream of water meters to increase pressure and compress entrained water vapour passing through the meters. However, turbulence within such valves can cause the valve's head to move radially, bending a shaft within the valve which may break. Accordingly, there is provided a flow control valve comprising: a housing having a flow passage; a valve seat defined within the flow passage; a valve head moveable to a closed position to engage the valve seat and seal the flow passage; a shaft secured to the valve head; a support slidingly mounting the shaft within the housing; a spring biasing the valve head to the closed position and configured to maintain the valve head in the closed position until a predetermined pressure is applied; and a guide assembly extending along at least a portion of the flow passage to constrain radial movement of the valve head.

A dynamic seal assembly is disclosed for use in a valve having an upstream pressure side and a downstream pressure side, the dynamic seal assembly including an annular seal member having a generally C-shaped cross-section and including opposed upstream and downstream legs defining an internal cavity with an opening facing toward the upstream pressure side of the valve, wherein the upstream leg has a radial length that is greater than a radial length of the downstream leg and includes a retaining foot that extends angularly away from the upstream leg in an upstream direction at an angle of between about 0° and 90°, and a metallic spring is disposed within the internal cavity of the seal member for providing a constant sealing force to the seal member.

A piston check valve system includes a body including an upstream end and a downstream end, a bonnet secured to a proximal opening of the body, and a piston secured within the body, the piston being moveable between a closed position in which the piston rests upon a valve seat and an open position in which the piston is spaced away from the valve seat. The piston check valve system also includes a retainer configured to guide and retain the piston and to secure the valve seat within the body.

Flow control valves may be positioned downstream of water meters to increase pressure and compress entrained water vapour passing through the meters. However, turbulence within such valves can cause the valve's head to move radially, bending a shaft within the valve which may break. Accordingly, there is provided a flow control valve comprising: a housing having a flow passage; a valve seat defined within the flow passage; a valve head moveable to a closed position to engage the valve seat and seal the flow passage; a shaft secured to the valve head; a support slidingly mounting the shaft within the housing; a spring biasing the valve head to the closed position and configured to maintain the valve head in the closed position until a predetermined pressure is applied; and a guide assembly extending along at least a portion of the flow passage to constrain radial movement of the valve head.

The present invention discloses a compressor comprising: an outer pipe being connected from an outside to pass through the vessel; an inner pipe being closely inserted into the outer pipe; a compression mechanism including a suction hole formed of a blind hole and a suction valve in the suction hole. The suction valve includes a seal on a side facing an opening of the suction hole to seal an entire end of the inner pipe on a side facing the suction valve when the compressor stops.

Flow control valves may be positioned downstream of water meters to increase pressure and compress entrained water vapour passing through the meters. However, turbulence within such valves can cause the valve's head to move radially, bending a shaft within the valve which may break. Accordingly, there is provided a flow control valve comprising: a housing having a flow passage; a valve seat defined within the flow passage; a valve head moveable to a closed position to engage the valve seat and seal the flow passage; a shaft secured to the valve head; a support slidingly mounting the shaft within the housing; a spring biasing the valve head to the closed position and configured to maintain the valve head in the closed position until a predetermined pressure is applied; and a guide assembly extending along at least a portion of the flow passage to constrain radial movement of the valve head.