An actuation system for a valve is disclosed. The actuation system comprises a housing having an end wall. A first piston and a second piston is slidably positioned within the housing. The second piston is positioned between the first piston and the end wall. A piston rod is coupled to the first piston and slidably extends through the second piston and the end wall. The piston rod is configured to be coupled with the valve. A first spring is arranged between the first piston and the second piston. Further, a second spring is arranged between the second piston and the end wall. The first spring and the second spring are configured to bias the valve to a closed position.

A gas shut-off valve assembly designed to automatically close gas flow in a gas conduit in response to a seismic vibration comprises a door which may be parallel to a port in the conduit and a weight above the door. In some embodiments, the door may be mostly out of the conduit passageway and out of the gas flow allowing for improved gas flow efficiency in the normally open state. Upon sensing a seismic vibration, the weight falls from a platform onto the door causing the door to move into the conduit passageway sealing the passageway. In some embodiments, a port in the passageway is perpendicular to the door's default position in the open state. When the door closes the passageway, the door rotates ninety degrees about an axis into the second closed position to become parallel with the port.

An explosion isolation device is disclosed. The explosion isolation device may comprise a conduit having a flap configured to rotate between an open position and a closed position within the conduit, and a holding mechanism configured to hold the flap in the open position. The holding mechanism may be configured to release the flap in the event of an explosion and the flap may be configured to rotate into the closed position after it is released. The device may include a sensor and an actuator configured to actuate the holding mechanism when an explosion is sensed. The conduit may be vertical.

The emergency shutoff device is provided with a casing (21) in which inflow ports (22) through which control oil flows into a space (A1) provided therein and a plurality of outflow ports (23) through which the control oil flows outside of the space (A1) are formed; and a switching unit (24) configured to slide along an inner circumferential surface of the casing (21) in which the space (A1) is formed, to change its position relative to the plurality of outflow ports (23), and thus to switch a circulation state of the control oil in the space (A1). The switching unit (24) switches the circulation state between the first circulation state in which the control oil is circulated from a first inflow port (221) to a first outflow port (231) and the third circulation state in which an open and closed state of a test outflow port (236) is switched while the control oil is being circulated from the first inflow port (221) to the first outflow port (231).

A break check valve includes a valve body defining a mating surface and a valve inner cavity; a pivot pin positioned inside the valve inner cavity and secured to the valve body, an axis of the pivot pin offset in a radial direction with respect to a longitudinal axis of the valve body; and a valve member positioned within the valve inner cavity and configured to rotate about the pivot pin from an open position to a closed position of the valve, the valve member comprising a plate and an arm extending from the plate, the valve member configured to remain in the open position of the valve as long as a mating surface of a hydrant remains in contact with the mating surface of the valve body and configured to close when the mating surface of the hydrant is separated from the mating surface of the valve body.

A check valve for a fluid distribution system can include a valve body defining a valve bore defining a cylindrical shape, the valve body comprising an annular body and a fixed cross member secured to the valve body and extending across the valve bore, a position block secured to the cross member of the valve body, extending from the cross member, and defining a pivot bore; a pivot pin positioned within the valve body and extending through the pivot bore of the position block, the pivot pin positioned entirely within the cylindrical shape of the valve bore; and a valve member positioned within the valve body and configured to rotate about the pivot pin to a closed position when a pipe system termination fitting attached to the valve body is dislocated fr om the valve body or when the fluid moves in a negative flow direction of the check valve.

A break-away check valve is provided. The check valve may be configured between two passageways and may regulate the flow of liquid between the passageways. The check valve may include an actuation assembly that may actuate the check valve upon the system becoming dislodged or otherwise dislocated from at least one of the passageways.

An automatic shutoff valve for breakaway wet barrel fire hydrant is disclosed. In general, one aspect disclosed features an apparatus comprising: a valve housing comprising a valve body, a flange, and a valve seat; a valve pedal configured to engage the valve seat and prevent fluid flow through the valve seat in a closed position, and to permit fluid flow through the valve seat in an open position; a lockout tab disposed within the valve body, wherein the lockout tab maintains the valve pedal in the open position; a lockout bar disposed distally from the valve body; and an activation rod mechanically coupled to the lockout bar and configured to keep the valve pedal engaged with the lockout tab.

A solar fail-safe device according to an embodiment of the present disclosure is capable of operating a valve by using sunlight and operating the valve in an emergency in which electricity is not supplied to an actuator unit moving the valve. A solar fail-safe device may include a solar panel module producing electricity from solar energy, an actuator unit including an actuator moving a valve by using electricity as a power source, and a fail-safe part moving the valve by using emergency electricity with which the fail-safe part is pre-charged, and a control unit receiving the electricity produced from the solar panel module to charge a first and a second battery and to supply the electricity to the actuator unit. The actuator may move the valve by using the emergency electricity when a voltage at which the electricity is applied from the control unit is less than a predetermined value.

A valve closure device for a check valve can include a first valve member configured to rotate from an open position to a closed position; a second valve member configured to rotate from an open position of the second valve member to a closed position of the second valve member; and a hydraulic dampener coupled to each of the first valve member and the second valve member in each of the open position and the closed position of each of the first valve member and the second valve member, the hydraulic dampener configured to resist rotation of the first valve member towards the closed position of the first valve member and the second valve member towards the closed position of the second valve member.