A valve assembly includes an inlet and an outlet, which open into a working chamber of the valve assembly, and an actuator. In a non-actuated state of the actuator, a flow passage between the inlet and the outlet is blocked. The actuator is optionally a shape-memory actuator that can be actuated one time or comprises a shape-memory actuator, which suddenly changes its external shape upon reaching a conversion temperature, which is dependent on the alloy composition thereof, and which can be generated by a controllable electrical heating device of the valve assembly. The actuator irreversibly destroys a pipe element separating the inlet from the outlet in the working chamber upon actuation, whereby the inlet and the outlet are connected to one another with respect to flow via the working chamber.

A method of stimulating a subterranean formation using a tubular member with one or more burst disks therein.

A rupture disk for use in a fluid control system includes a membrane and a compressible flange, around a perimeter of the membrane. The flange defines at least one perimetrically extending void.

A pressure relief device including a gas-permeable body to which a membrane adheres that is preferably impermeable to moisture. The membrane can be a rubber membrane that is formed by applying liquid rubber to the pressure relief body and, optionally, a component which supports the liquid rubber and surrounds the pressure relief body.

A rupture disk for use in a fluid control system includes a membrane and a compressible flange, around a perimeter of the membrane. The flange defines at least one perimetrically extending void.

A safety head is disclosed. More particularly, a safety head comprising a circular flange portion and at least one protrusion is disclosed, wherein the at least one protrusion has a face exhibiting a blended radius of curvature. The circular flange portion may be thicker than the at least one protrusion. A safety head assembly is also disclosed, wherein the safety head assembly comprises an inlet safety head and an outlet safety head. Additionally, a safety head assembly is disclosed wherein the inlet safety head comprises a peripheral protrusion, the outlet safety head comprises a peripheral protrusion, and a clamp ring is configured to engage with the peripheral protrusions.

According to one aspect, a pressure relief valve assembly includes a clamped rupture disc. The rupture disc is adapted to rupture when a pressure differential across the pressure relief valve assembly reaches or exceeds a predetermined pressure differential. According to another aspect, there is provided a method of retrofitting a pressure relief valve assembly. According to yet another aspect, there is provided a method of assembling a pressure relief valve assembly.

A rupture disk (20), along with associated methods, is disclosed. More particularly, a miniaturized rupture disk is disclosed, comprising a transition area (23) configured to determine a pressure at which the rupture able portion will rupture. A method for forming a rupture disk is also disclosed, wherein a radius (R) of a transition area is configured to set the burst pressure of the rupture disk. A rupture disk having an indent at its apex (24) and a circular line of weakness configured to improve opening performance is also disclosed. Additionally, a method of relieving pressure in a pressurized system is disclosed, wherein a set of rupture disks is provided, wherein each rupture disk in the set has a different radius of transition area. A rupture disk may be selected from the set and installed based on a burst pressure set by the radius of transition area.

A pressure relief device including a gas-permeable body to which a membrane adheres that is preferably impermeable to moisture. The membrane can be a rubber membrane that is formed by applying liquid rubber to the pressure relief body and, optionally, a component which supports the liquid rubber and surrounds the pressure relief body.

A control regulator includes a diaphragm assembly with an integrated pressure relief mechanism. The diaphragm assembly includes a diaphragm with a locally weakened area and a diaphragm plate with an opening aligned with the locally weakened area.