Importance of Pressure relief
- In a reactive situation where something has already gone wrong, pressure relief systems can be used to reduce the consequences of the incident.
- These systems are designed to prevent harm to people from chemicals and equipment that may disintegrate, create a pressure wave, or produce shrapnel.
- They also help to prevent harm to the environment from the loss of chemicals and prevent expensive equipment damage.
- The use of pressure relief systems may be regulated by legislation and local and national regulations.
OSHA has submitted Pressure Equipment summary in USA in 1999 as follows, About 40 % had at least one deficiency
Identified Causes were,
⤻ PHA studies were performed but did not adequately identify relief situations
⤻ Reliance on equipment supplier
⤻ Poor documentation and use of data sheets
➭ Although correctly designed and installed originally, relief system has either not worked or actually caused hazards and incidents due to
➥ Poor Management of Change (MOC)
➥ Poor Inspection or Maintenance
➥ Lack of Awareness
- Pressure Relief System is like a life jacket or an Air bag – hopefully never needed but must be in constant state of readiness
- Properly Sized but relief at Unsafe Location
- Properly designed, installed , relief location is safe but isolation valve at inlet / outlet is closed