Valve disc assemblies for fluid valves having soft seats are disclosed herein. An example valve disc assembly for a fluid valve comprises a first portion to slidably engage a wall of the fluid valve to guide movement of the valve disc assembly and a second portion to receive a valve stem to control a position of the valve disc assembly, the second portion including an angled surface to retain a seal between the first and second portions.

A valve assembly includes a valve housing defining a flow path to allow fluid flow between a first end configured to be connected to a fluid source and a second end and that defines a valve seat in the flow path, a valve member located in the valve seat moveable within the housing between a closed position and an open position, and biasing means within the valve housing and connected to the valve member to bias the valve member in the closed position. The valve member has formed therein across at least part of the radial dimension of the flow path, a frangible part configured to rupture if, while the valve member is in the closed position, a pressure and/or temperature acting on the frangible part exceeds a rupture threshold, thus allowing flow along the flow path.

A vent control valve for a fuel tank controls a ventilation between a fuel tank and an outside. The vent control valve includes: a case having a tube shape that forms a passage for ventilation; a movable valve object arranged in the case to be movable in an axial direction of the case to open and close the passage; and a baffle component disposed between the case and the movable valve object and located on an outer side of the movable valve object in a radial direction. An outer passage is defined between the case and the baffle component, and the baffle component restricts a contact between a fluid flowing through the outer passage and the movable valve object.

A fuel vapor switching and venting valve for an internal combustion engine. The fuel vapor switching and venting valve includes an electromagnet with an armature, a first connection, a second connection, a first valve seat which is arranged between the first connection and the second connection, a spring, a flow limiting element, a second valve seat which is arranged on the flow limiting element, and a valve body coupled to the armature of the electromagnet. The valve body has a first contact surface with which the valve body can be lowered onto and lifted off of the first valve seat, and a second contact surface with which the valve body can be moved against the second valve seat. The second valve seat is axially displaceable. The spring loads the second valve seat in a direction of the valve body.

A fuel vapor switching and venting valve for an internal combustion engine. The fuel vapor switching and venting valve includes an electromagnet with an armature, a first connection, a second connection, a first valve seat which is arranged between the first connection and the second connection, a spring, a flow limiting element, a second valve seat which is arranged on the flow limiting element, and a valve body coupled to the armature of the electromagnet. The valve body has a first contact surface with which the valve body can be lowered onto and lifted off of the first valve seat, and a second contact surface with which the valve body can be moved against the second valve seat. The second valve seat is axially displaceable. The spring loads the second valve seat in a direction of the valve body.

A P/V valve that can be positioned at a working height above grade (i.e., a height reachable by a service technician positioned at grade) while still providing appropriate resistance to fire and explosion by venting to atmosphere at an appropriate height above grade (e.g., 12 feet) is disclosed. In certain exemplifications of the present disclosure, the P/V valve features a diaphragm actuated two-way poppet valve actuatable by a valve piston. In alternative exemplifications of the present disclosure, the P/V valve is positioned intermediate grade and the distal end of a P/V valve riser pipe and is contained in a vault fluidly connected to the P/V valve riser pipe, the P/V valve locally venting in the vault, which is hermetically sealed to the P/V valve riser pipe.

A water hammer mitigation system includes a branch connection with ends coupled to a main pipeline, where a first end connects at a surge point on the main pipeline and a second end fluidly connects to the main pipeline at a distal point. A bi-directional surge relief device is disposed on the branch connection, and is operable to move to a first open configuration to permit pipeline fluid within the main pipeline to flow through the branch connection when surge point pressure reaches a designated pressure. The device can also move to a second open configuration when surge point pressure reaches another designated pressure. The device is closeable when surge point pressure is between the designated pressures.

A water hammer mitigation system includes a branch connection with ends coupled to a main pipeline, where a first end connects at a surge point on the main pipeline and a second end fluidly connects to the main pipeline at a distal point. A bi-directional surge relief device is disposed on the branch connection, and is operable to move to a first open configuration to permit pipeline fluid within the main pipeline to flow through the branch connection when surge point pressure reaches a designated pressure. The device can also move to a second open configuration when surge point pressure reaches another designated pressure. The device is closeable when surge point pressure is between the designated pressures.

A relief valve relieves hydraulic fluid from a first port to a second port, and includes a housing and an adjustment member capable of advancing and retracting; a seat member with a relief passage connecting to the two ports; a relief valve body that is unseated from or seated on the seat member to open or close the relief passage, and that receives pressure of the first port in a direction of opening the relief passage; a first biasing member that biases the relief valve body against the pressure of the first port, with a force adjusted by the adjustment member; a check valve body that opens or closes a check passage connecting to the two ports, and that receives pressure of the second port in a direction of opening the check passage; and a second biasing member that biases the check valve body.

A pilot valve assembly, for operating a pressure reducing valve disposed within a fuel tank, can include a housing including a first chamber and a second chamber, a first port in fluid communication with the first and second chambers, the first port being configured to receive an atmospheric pressure, a second port in fluid communication with the first and second chambers, the second port being configured to receive a fuel tank pressure, a first pilot valve arranged within the first chamber and configured to open only when a predetermined positive pressure differential exists between the first and second ports, and a second pilot valve arranged within the second chamber and configured to open only when a predetermined negative pressure differential exists between the first and second ports.