Hazards
Uncontrolled release of energy or a hazardous material during the opening of piping or equipment.
When Important
- When unbolting, unscrewing, drilling or cutting of process equipment.
- While working on live equipment.
Challenges in the Field
- Working at the wrong location.
- Complexity of piping or break points arrangements.
- Double block and bleed not possible.
- Plugging of vents or drains / leaking valves.
- Installing blinds.
- Drains at the wrong location.
Options to Get it Right
- Have a validated isolation plan available, that indicates numbered isolation points in the right sequence on a P&ID.
- Apply LOTO to avoid that equipment can be reenergised: that is providing locks and labels.
- Empty and clean equipment properly.
- Check the completion of the isolation plan by an independent operator, before signing the permit to work.
- Wear selected PPE for residual chemicals that might not be purged or drained and provide absorbents for leaking fluids.
- Perform a Last Minute Risk Assessment by the mechanic or contractor, before opening, to validate that the pressure indicator is zero, the drain is open, the system is at ambient temperature, there is no flow and assure you are at the right equipment.
- Use blinds according pipe spec, that is indicated on the isolation list.
- Upon changes, validate that isolation remains intact.
This page only summarises the guidance – refer to the EPSC website for further information.
For more information on our Process Safety Fundamentals (or other) playing cards please contact us.
