The S90 Reverse Buckling Rupture Disks from BS&B and HMA INSTRUMENTATION is a domed, solid-metal, precision-scored, reverse buckling disk. Upon overpressure, the disk reverses and opens along pre-weakened cross-scored lines so as to provide a full and complete opening.

The S90 disk offers an extended service life under pressure cycling conditions, compared to a conventional tension loaded disk. As the S90 is under compression, it features excellent fatigue resistance under cyclic conditions, surviving a million pressure cycles from 0% to 90% of its marked burst pressure.

In addition, it is designed for non-fragmentation, and can withstand full vacuum and back pressure equal to or less than burst pressure (higher is available upon request). The S90 is suitable for operating pressure to 90% of the marked burst pressure, and 95% of the minimum burst pressure. Gas service means it is acceptable for liquid service, with a compressible gas/vapour pocket between the liquid and disk. Other benefits are optimum fatigue resistance in pressure pulsating or cycling conditions, ideal for safety relief valve isolation, and optional fluoropolymer/plastic liners to enhance corrosion resistance.