Hydrogen release from a CGH2 trailer

The burst disc activated prematurely on a small hydrogen tube trailer. The pressure at which the activation occurred was between 80 and 100 bar (1200 and 1500 psig).
The design activation pressure at which these burst discs activate is approximately 230 bar (3300 psig). The entire tube trailer emptied through the single rupture disc as the tubes were interconnected. No one was hurt, no equipment was damaged, and no fire resulted.
The investigation discovered that vent pipe of the storage tube relief device of each tube did not have weather caps on their outlets, as required. The cause of the incident was water which got into the vent pipes and froze, deforming the rupture disc. The deformation caused the disc to open prematurely between 1200 and 1500 psig. The biggest contributing factor was that the ambient temperature had dropped to -10 C (15 Deg F), very unusual for this area.

The INITIATING CAUSE was the premature activation of the burst disc due to environmental damage.
A CONTRIBUTING CAUSE was the very low ambient temperature, atypical for the area.
The ROOT CAUSE was the failure to follow the operating procedures. This could be attributed to a human failure, but also to shortcoming in the verification of the execution of the procedures.

burst disc

DESCRIPTION OF THE UNIT
The trailer had multiple tubes on the chassis. Each tube was equipped with a burst disc connected to an individual vent pipe.
The source does not provide data on the number of the tubes and the quantity transported

The hydrogen cotnained I nthe affected tube was lost.

The H2TOOLS report provide as lesson the need to follow CGA G-5.5 vent end system designs. The CGA G-5.5 is a CGA "Standard for Hydrogen Vent Systems", applicable in the US.

The absence of ice caps was a violation of CGA G-5.5 design requirements. The tube trailer was taken off site by the industrial gas company for end of vent cap additions.