1.1 ,This practice covers procedures for testing single joints of thermoplastic pipe for gravity flow (non-pressure) sewer lines, when using either air or water under low pressure to demonstrate the integrity of the joint. This practice is used for testing 27-in. (675-mm) and larger inside diameter PVC (Polyvinyl Chloride), HDPE (High Density Polyethylene) and PP (Polypropylene) sewer lines utilizing flexible gasketed joints with elastomeric seals, Specification F477.