This specification covers the requirements and test methods for material, dimensions, hydrostatic burst strength, tensile strength, chemical resistance, sustained pressure, heat fusion, and impact resistance of plastic pipes, tubing, and fittings used for direct burial and reliner applications in fuel gas mains and services for the distribution of natural gas. This specification does not cover threaded pipe. The plastic used to make the pipes and fittings shall be virgin plastic or reworked plastic having Plastics Pipe Institute (PPI) long-term hydrostatic design stress and hydrostatic design basis rating.