With the July 2011 deadline approaching for compliance with NFPA 58, we think it makes a lot of sense to inspect all vital components of your bulk plant. One of the most important safety components of your LP-gas storage vessel is the internal relief valve system. LP-gas relief valves are intended to open only under the excessive pressure conditions indicated below. The container pressure will get high enough to open relief valves under the following conditions:
- Filling containers not purged of air
- Overfilled container exposed to heat, which includes radiant heat (sun).
- Use of an incorrect product such as propane in a container with relief valve set for butane pressures (Low set pressure for service)
- All containers exposed to extreme heat (fire).
- Excessive pressures created during filling
