In planning for decommissioning, which step should take priority and be done first?

• A. Isolate and reduce the system pressure
• B. Paint the piping to prevent corrosion
• C. Label all new components
• D. Install a temporary bypass

Answer: (A)

The priority is to stop the flow and relieve pressure so the system is safe to work on. Isolating the system means closing the correct valves and applying lockout/tagout to prevent any accidental re-energization. This reduces the hazard from pressurized fluids, allows controlled draining, and protects workers from leaks, sprays, or sudden releases as work proceeds.

Painting the piping isn’t a safety measure and doesn’t reduce risk during decommissioning, so it’s not performed first. Labeling components is useful for future identification, but it doesn’t address immediate safety risks, so it follows isolation. A temporary bypass might be needed later to maintain operation or for commissioning, but it can defeat isolation if done before the main shutdown, so it isn’t the initial step.