Adam Attig, Emerson, USA, reveals how new technology can instantly detect leaks in relief valve bellows, eliminating the need for manual rounds and reducing fugitive emissions.
P
ressure relief valves (PRVs) are a critical layer of overpressure protection for many industries. Under normal operating conditions, the PRV remains closed, but when there is a process upset, the PRV must instantly open to vent the excess process media and avoid overpressure conditions. When backpressure may be encountered in a relief valve header, a bellows PRV design is often employed. These relief devices work well, but under cycling or corrosive chemical applications, the bellows may be damaged, leaking potentially hazardous media to the environment and
adversely impacting PRV performance. Unfortunately, these leaks can be significant and often go undetected for years. This article discusses an innovative PRV design and technology that immediately detects leaks, alerts plant personnel, and limits leak rates significantly, while allowing the PRV to continue operating as designed despite damage to the bellows.
Conventional vs bellows PRV operation A PRV consists of an inlet nozzle attached to the process, which is contained by a disc held tightly against the nozzle
HYDROCARBON 37
ENGINEERING
December 2023