An inlet support structure for use with a rupture disc, the inlet support structure including an annular member having an inner diameter, an outer diameter, a plurality of spaced apart cut-outs extending from the inner diameter towards the outer diameter, a central non-circular opening extending through the annular member and including the cut-outs, the cut-outs providing additional space for the petals of a rupture disc to be received therein when the rupture disc ruptures so as to provide a greater flow area through the rupture disc.

An inlet support structure for use with a rupture disc, the inlet support structure including an annular member having an inner diameter, an outer diameter, a plurality of spaced apart cut-outs extending from the inner diameter towards the outer diameter, a central non-circular opening extending through the annular member and including the cut-outs, the cut-outs providing additional space for the petals of a rupture disc to be received therein when the rupture disc ruptures so as to provide a greater flow area through the rupture disc.

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.

A pressure relief device and a hydraulic fracturing system having a pressure relief device are provided. In one form, the pressure relief device has a valve body with a linearly extending throughbore between the inlet and outlet thereof. A rupture disc is secured in the valve body so that a frangible dome wall portion thereof has a reverse-acting orientation in the valve body bore. The hydraulic fracturing system includes a pump and a delivery line that receives pressurized fracturing fluid from the pump and delivers it to a well. A pressure relief device is installed along the delivery line. A sensor detects fluid flow downstream of the pressure relief device which allows the pump to be shut down when the downstream fluid flow is detected. The pressure relief device can have a body with a domed rupture disc and the sensor therein.

A well choke, and an actuation mechanism for the well choke are described. The actuation mechanism includes a linearly translating drive mechanism which is coupled to a valve member drive assembly through a fluid coupling which facilitates a change in the overall length of the actuation mechanism. Fluid in the fluid coupling can be released in response to fluid pressure exerted on the valve member when it is proximate a valve seat of the choke, to achieve this change in length. In some embodiments, the fluid coupling will provide a retained fluid column and the valve member drive assembly will include a piston with in the fluid coupling which is movable from a fully extended to a compressed, by the release of fluid from the coupling in response to pressure in the chamber reaching a threshold level.

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.