Alert: Due to routine maintenance on the OSHA website, some pages are temporarily unavailable.
To report an emergency, file a complaint with OSHA or ask a safety and health question, call 1-800-321-6742 (OSHA).
Case Study 3: Replacement of Nitrogen Pressure Vessel Seals
A group of employees are assigned to replace the head seals on twelve large nitrogen
pressure vessels (accumulator bottles) at a manufacturing facility. Each pressure vessel
has an operating pressure of about 5,000 psig. Replacement of the seals on each vessel
requires that its head be opened, releasing any vessel contents to the atmosphere. The
vessels lack individual gauges to indicate internal pressure levels.