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Two oil field mechanics die in a pressure vessel rupture at an oil refinery in California.

Public Health Institute
Morgantown, WV: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, FACE 95CA014, 1996 Sep; :1-5
A 48-year-old male craftsman (victim #1) and a 38-year-old male pipefitter (victim #2) died when a pressure vessel (sulfur recovery unit) ruptured at an oil refinery. The upper stage of the unit had been purged with nitrogen to remove residual hydrogen sulfide (H2S) and sulfur dioxide (SO2). This upper unit was designed to withstand a pressure of 3 pounds per square inch (psi) although the company typically ran the process at 5-7 psi. An operator noted a rise in the upper stage pressure during the purging procedure to over 20 psi. A few hours after beginning to purge the upper stage, members of the maintenance team were sent inside the lower stage to scrape catalyst and shovel the residue into a bucket. Victim #1 and a co-worker climbed through an upper manway to the lower stage. Victim #2 was stationed outside the unit. Victim #1 was crushed to death when the dome which divided the upper and lower stages of the unit collapsed on him. The co-worker working with victim #1 was able to crawl out from the manway and survived. Victim #2 was blown off the platform through a metal guardrail and fell approximately 12 feet to his death. The CA/FACE investigator concluded that in order to prevent similar future occurrences employers should: 1. not permit any confined space entry into a vessel while pressurization is taking place in any part of that vessel. 2. require that harnesses and retrieval lines be available for workers who are working in confined spaces. 3. install a pressure regulator in the purge (nitrogen) line set to no more than the design limits of the vessel (3 psi). 4. ensure that pressure relief mechanisms are installed and maintained in all pressure vessels. 5. implement a policy that states that any time a vessel is stressed beyond its design limits that an inspection must take place, and clearance given, before any work begins or resumes, or before the vessel is placed back into service.
Region-9; Accident-analysis; Accident-prevention; Accidents; Injuries; Injury-prevention; Traumatic-injuries; Work-operations; Work-analysis; Work-areas; Work-performance; Work-practices; Safety-education; Safety-equipment; Safety-measures; Safety-monitoring; Protective-measures; Protective-equipment; Equipment-design; Confined-spaces; Oil-industry; Oil-refineries; Oil-refinery-workers
Publication Date
Document Type
Field Studies; Fatality Assessment and Control Evaluation
Funding Type
Cooperative Agreement
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
FACE-95CA014; Cooperative-Agreement-Number-U60-CCU-907284
SIC Code
Source Name
National Institute for Occupational Safety and Health
Performing Organization
Public Health Institute
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division