What is the required backfill material for an underground LP-gas container?

The required backfill material for an underground LP-gas container is earth or sand that is free of rocks or abrasives. This specification is critical for several reasons.

Firstly, using smooth materials like sand ensures that the backfill can effectively support the container without causing undue stress or damage. Rocks or abrasive materials could lead to puncturing or degrading the container over time, potentially resulting in leaks or failures that pose significant safety hazards.

Moreover, the use of non-abrasive soil or sand helps facilitate drainage. Proper drainage is vital to prevent water accumulation, which can contribute to corrosion of the LP-gas container. The ideal backfill should also allow for some compression, adapting to any settling that might occur as the surrounding soil compacts.

Therefore, by selecting earth or sand free of rocks or abrasives as the backfill material, safety and the integrity of the underground LP-gas container are maintained, aligning with the standards outlined in NFPA 58 for safe handling and installation of liquefied petroleum gas systems.