Fiberglass piping can create its own flexible joint provided that there is a straight run of at least how many feet between directional changes?

Fiberglass piping is designed for flexibility and can accommodate directional changes through its unique joint system. The requirement for a straight run of at least 4 feet between directional changes allows the piping to expand and contract appropriately without stressing the joints or creating potential points of failure.

This distance ensures that the pressure and flow are stable, as well as facilitates the proper installation and maintenance of the piping system. If the run were shorter, the angles could put undue stress on the piping system, potentially leading to leaks or failures. Thus, establishing a minimum length of 4 feet promotes longevity and reliability in the performance of the fiberglass piping within underground storage tank applications.