A sensor for sensing the integrity of a pressure relief device, along with associated systems and methods, are disclosed. The sensor may sense a designed area of weakness of a pressure relief device, such as an explosion vent or rupture disk. A monitor may monitor a signal from the sensor, which may be transmitted between the sensor and monitor by way of a sensor loop. In response to a change in the designed area of weakness, the signal from the sensor may be altered or interrupted, indicating that the designed area of weakness has changed. The signal from the sensor may be, for example, an electrical signal, optical signal, or an air flow in a pneumatic loop.

A stress reactive valve includes a valve body disposed in a subsea safety system or other elongated components of hydrocarbon production systems. The valve body includes a frangible or breakable material such that when the subsea safety system or other elongated system undergoes a stress, such as a bending stress, the frangible valve body can react to the stress by breaking and thereby establishing fluid communication or a fluid path across the valve body. In a first or unbroken condition of the valve body, the valve body prevents fluid communication between a fluid inlet and a fluid outlet. In a second or broken condition of the valve body, fluid communication is allowed between the fluid inlet and outlet. The fluid communication can be used to actuate a device, or the fluid pressure can be used as pilot pressure to actuate a pilot operated valve system.

A fluid check valve incorporating a temporary elastomeric functional barrier membrane, the check valve having a sealing member comprising a first elastomer and a barrier membrane comprising a second elastomer, different from the first elastomer, disposed directly upon the surface of the sealing member so as to form a continuous layer over at least a seal opening of the sealing member. The barrier membrane may include a photoinitiator and coagent which aids in the ultraviolet (UV) curing of the second elastomer after application upon the first. The barrier membrane may applied as a solution of monomers, photoinitiator, and optional coagent, the solvent evaporated, and the deposited solutes exposed to ultraviolet so as to form the barrier membrane material.