Emerson has announced the release of two new-to-the-world technologies for the Crosby J-Series pressure relief valve (PRV) product line. The first is a Balanced Diaphragm, which eliminates the need for bellows in PRVs, while providing balanced operation against backpressure to lower cost of ownership and enhance performance. The second technology is Bellows Leak Detection, enabling remote detection of bellows ruptures in PRVs, with the capability to reduce and accurately calculate volumetric emissions in real-time.

Where backpressure is present, spring-loaded PRVs often utilize bellows to ensure balanced operation. Data analysis from 30,000 PRV service records across different industries and valve brands shows a bellows failure rate between 2% to 6%. In other words, a plant with 1,000 bellows PRVs may have between 20 to 60 PRVs continuously operating with damaged bellows. The most common causes of bellows failures are excessive backpressure and rapid cycling. Ruptured bellows will cause fugitive emissions and may prevent valve operation at the designed set pressure, with the risk of catastrophic overpressure events.