What might happen if air enters the piping system?

When air enters the piping system of an underground storage tank (UST), it can lead to several issues, one of which is that the product may not drain safely. This occurs because air can create air pockets or bubbles within the liquid product, disrupting the proper flow of the product through the pipes. These air pockets may cause blockages or slow the movement of the product, leading to inadequate drainage.

Additionally, in certain situations, the presence of air can cause turbulence, which can result in incomplete filling of the pipes with liquid. This, in turn, can lead to improper operation of the dispensing equipment, as it relies on a consistent and unobstructed flow of the liquid product.

While other options mention issues such as over-pressurization or inefficient pump operation, the most direct consequence relating to air entering the piping system is the safety and effectiveness of product drainage. Therefore, understanding this concept is crucial for maintaining proper functioning and safety standards in UST systems.