General steps for repairing or replacing equipment in hydrogen service include:
- Preparing the system including isolating energy sources via Lockout/Tagout (LOTO) and purging hydrogen out of the equipment (see Purging)
- Doing the work
- Leak testing
- Purging air out of the equipment (see Purging)
Maintenance procedures provide guidelines that, if followed, will control hazards at an acceptable level of risk. The process for development of maintenance procedures should be the same as for the development of Operating Procedures.
Written procedures should detail the means for establishing that equipment (See Note below.) is safe to work on. Standard procedures should be developed at least for the following:
- Lockout/tagout (LOTO) – This describes the isolation of energized electrical and pressurized systems so that equipment can be worked on safely. See OSHA standard 1910.147 The Control of Hazardous Energy (lockout/tagout).
- Confined space entry – This describes the need to verify a space has and will continue to have sufficient breathable air for safe entry. See OSHA standard 1910.146 Permit-required confined spaces.
- Verifying equipment is “Fit for Maintenance” – This procedure should describe inspection of equipment prior to work, depressurization of the system, purging hydrogen out of the system and testing for residual hydrogen before declaring the equipment fit for maintenance. See Purging
- Work permit – Work permits are used to control workplace hazards during maintenance. The procedure should describe how a permit is written, communicated to workers in the area, and managed across shifts.
- A hot work permit should be issued for hot work operations to be conducted in or near an area close to hydrogen equipment.
- Permit should document requirements in 29 CFR 1910.252(a) Fire prevention and protection for Welding, Cutting and Brazing have been implemented prior to beginning the hot work
- Permit should indicate the date(s) authorized for hot work and identify equipment being worked on
- Applicable compliance with LOTO, confined space entry and “Fit for Maintenance” should be verified.
All personnel should be trained on the use of the procedures.
Job Safety Analysis (JSA)
Before starting any activity, workers should develop a Job Safety Analysis to ensure all hazards are addressed and work can be performed safely.
- Also known as a Job Hazard Analysis (JHA).
- JSA is a technique that focuses on job tasks to identify hazards before they occur.
- JSA focuses on the relationship between the worker, the task, the tools, and the work environment.
- JSA becomes a valuable tool for training new employees in the steps required to perform their jobs safely.
- To be effective, management must demonstrate its commitment to safety and health and follow through to correct any uncontrolled hazards identified.
Some elements of the JSA development include:
- Involvement of the people that will do the work.
- Divide the job into observable steps.
- Identify the potential hazards associated with each step. Questions to ask:
- What can go wrong?
- What are the consequences?
- How could it happen?
- What are other contributing factors?
- How likely is it that the hazard will occur?
- Specify control measures for each step.
- Documentation of the job process (see form below)
Note: As used in this section, “equipment” is an all-inclusive term that includes piping, instruments, and controls as well as those hydrogen system components commonly known as equipment.