Long time reader, first time poster.
On the weekend we had a rupture disc fail on a liquid nitrogen storage vessel (100T capacity, 25% full, 11.5 bar), resulting in the entire vessel contents being lost to the atmosphere.
The plant trends showed the vessel pressure was being controlled by a vent valve at 11.5 bar at the time of failure.
The vessel is fitted with a PSV and RD in parallel, with the SP of the PSV 12.5 bar and the RD 13.75 bar. The PSV was not activated before the RD failure.
What could be some possible causes of a premature RD failure?
Thanks in advance!