Various implementations include a safety valve for mounting in a landing nipple in a wellbore. The safety valve includes a composite housing having a central passage, a shutoff element and a control mechanism. The shutoff element includes a collet and a movable mandrel having stops located in the upper part. When the shutoff element moves axially, the stops extend through the composite housing to interact with a landing nipple stop surface. The control mechanism includes a spring-loaded tubular plunger having a ring piston on its upper outer surface and longitudinal openings in its lower part, the openings being configured to align with openings in the composite housing. The movable mandrel is connected to the safety valve head at the mandrel top and rests against the plunger at the mandrel bottom. The movable mandrel has grooves and shoulders on its outer surface, which allow for taking one of the fixed positions.

Relevant specifications in the field of gas supply provide for different safety devices for installation in a gas-supply system, in particular, an acetylene-supply system. To provide such a safety device, which is characterized by a compact structure and a high level of operational reliability, this invention proposes that a valve body (1) incorporates an over-pressure valve (4; 104) of a quick-action shut-off device, a control valve (3; 103) of a pressure-limiting device, and a safety valve (2; 102), whereby the safety valve (2; 102) can be fluidically connected to the over-pressure valve (4; 104) and the control valve (3; 103), and closes either when the over-pressure valve (4; 104) opens due to an inlet pressure that is above the inlet-pressure limit value or when the control valve (3; 103) opens due to an outlet pressure that is above an outlet-pressure limit value.

A pressure relief arrangement for a gas turbine engine comprises a panel and a plurality of pressure relief mechanisms provided in the panel. The mechanisms have a first configuration and a second configuration. In the first configuration the panel is sealed to prevent fluid flow through the panel in a thickness direction and in the second configuration the mechanisms are arranged so that a plurality of holes are provided in the panel so fluid can flow through the panel in a thickness direction.

A needle valve capable of adopting at least one closed position and one open position, a piston sensitive to the fluid flow and able to adopt at least one low-flow position and one high-flow position. The needle valve and the piston are arranged in such a way that as long as the piston is in the high flow position, the needle valve is prevented from occupying the closed position.

A valve comprising a first chamber (111) and a second chamber (112), wherein a movable member (204) is arranged to selectably bring the first and second chambers into and out of fluid communication with one another, the movable member arranged such that when in an open position wherein the first and second chambers are in fluid communication, gas at a first pressure in the first chamber provides a closing force to a first surface area (222) of the movable member to overcome an opening force provided by gas at a second pressure in the second chamber on a second surface area (223) of the movable member whereby the movable member moves to a closed position to isolate the first and second chambers, and further arranged wherein as the movable member moves to the closed position, the second surface area of the movable member exposed within the second chamber is reduced thus reducing the opening force provided by the gas at the second pressure and providing a bias towards the closed position.

A pressure compensation device for compensating an internal pressure in a housing of an electrochemical device includes: at least one gas-permeable membrane for gas exchange between an interior of the housing and surroundings of the electrochemical device; and a valve body that can be transferred from a home position resting on a valve seat into a use position remote from the valve seat, the valve body including a gas throughflow opening that is sealed by the gas-permeable membrane.

A downhole tool includes a body defining a bore axially therethrough and a port in communication with the bore and extending radially through the body, an inner cap positioned in the port, the inner cap sealing the port, and an outer cap positioned in the port. The outer cap is spaced apart from the inner cap, and the outer cap seals the port, such that a chamber is defined between the inner and outer caps in the port. The inner cap is configured to move toward outer cap in response to a first pressure differential between bore and the chamber across the outer cap. The inner cap is configured to dislodge the outer cap from the port in response to the inner cap engaging the outer cap and a second pressure differential between the bore and an exterior of the downhole tool being reached across the inner cap.

A vacuum resistant pressure relief device is (100) disclosed. In one embodiment, a pressure relief device may be an explosion vent. The explosion vent may be provided with one or more ribbed features, which may be radial ribbed features (101).

A valve (5) for relieving fluid pressure comprises a fluid inlet (8), a fluid outlet (9) and a piston (20) in communication with the fluid inlet (8) and configured to move in response to a fluid pressure at the inlet above a predetermined threshold so as to connect the fluid inlet (8) with the fluid outlet (9) and thereby relieve fluid pressure. One or more dampers (100; 80) are configured to damp the movement of the piston (20).

A pressure relief valve having a housing with an inlet port, an outlet port and a curvilinearly extending housing interior sidewall that defines a flow passageway through the housing from the inlet port to the outlet port. A piston assembly that is moveable between a closed position to establish a fluid-tight seal between the inlet port and the outlet port, and an open position to permit fluidic flow of pressurized fluid from the inlet port to the outlet port. The piston assembly has a piston head having a parabolically shaped piston face and elliptical perimeter that, when the inlet piston assembly is moved to the open position, aligns with the housing interior sidewall to provide a continuous transition from a position immediately upstream of the piston to a position immediately downstream of the piston.