Underground piping buried outside of buildings shall have an installation procedure to what while being backfilled?

When installing underground piping that will be buried outside of buildings, it is essential to focus on how to protect the piping during the backfilling process. Proper protection maintains the integrity of the piping system and ensures that it can function reliably over time.

Protection involves taking appropriate steps to prevent damage caused by the backfill material, environmental conditions, and external forces. This may include ensuring that the backfill is done in a manner that avoids excessive pressure on the pipes, as well as using protective materials like sand or foam to cushion the pipes and avoid direct contact with rocks and sharp objects that could cause punctures or structural failures.

The other options, while related to pipe installation, do not specifically address the critical aspect of safeguarding the piping during backfilling. Coating refers to applying a protective layer to the pipes before installation, draining pertains to the management of water around the piping, and freezing involves temperature considerations but doesn't relate directly to the protective measures needed during installation and backfill. Thus, the option regarding protection is the appropriate choice for ensuring the longevity and reliability of underground piping systems.