Series-Coupled Pressure Relief Valve Assembly for Subsea Sealing Reliability

The pressure relief valve is divided into two separate stages, each with its own poppet and sealing mechanism. The first stage valve handles initial pressure relief while the second stage valve provides backup relief capability. This segmentation eliminates the single point of failure problem by ensuring that if one stage fails due to corrosion or fouling, the other stage remains functional to prevent catastrophic pressure buildup.

The patent implements a backup sealing mechanism where the second stage valve serves as a predetermined safeguard against the potential failure of the first stage valve. This prior cushioning approach ensures that even if corrosion or fouling compromises the primary sealing, the secondary sealing mechanism is already in place to prevent failure, eliminating the need for additional complex corrosion resistant materials throughout the entire valve structure.

The valve system is segmented into two independently operating stages, each capable of functioning autonomously. The mechanical coupling between stages is designed to allow independent operation, meaning that if the coupling mechanism fails or if one stage becomes fouled, the other stage can still perform pressure relief functions. This segmentation fundamentally eliminates the single point of failure risk by ensuring that failure in one segment does not necessarily compromise the entire system.