Only materials that are compatible with hydrogen should be used for pressure equipment in hydrogen service.
Equipment used at pressures above 15 psig should be designed and constructed by qualified individuals for use at the expected temperature, pressure, and other operating conditions affecting safety. Excess flow valves or flow restrictors should be used to control maximum hydrogen flow, particularly when using ganged cylinders.
Pressure equipment should be fitted with a pressure relief device (PRD), such as a rupture disc or a relief valve. The PRD should be vented to a safe location.
Equipment operated at pressures above 15 psig, such as reactors and calorimeters, should be operated and maintained according to manufacturers’ instructions, the design limitations of the equipment, and applicable codes and regulations.
Such equipment should be inspected on a regular basis.
Properly purge or otherwise evacuate air from all vessels and piping before introducing hydrogen to prevent potential explosive mixtures from occurring.
The physical condition of pressure vessels and seals should be inspected periodically.
Pressure vessels should be leak-checked regularly.
If there is any significant change in the condition of the equipment (e.g., corrosion, cracks, distortion, scale formation, general chemical attack, weakening of the closure, inability of the equipment to maintain pressure), it should be removed from service immediately and not returned to service until approved by a qualified person.
Any pressure equipment found to be degraded should be de-rated or discarded as appropriate.