The maximum safe pressure for a given plastic pipe is determined by the pipe's wall thickness and Hydrostatic Design Basis (HDB), the plastic pipe industry’s pressure rating method. The resultant maximum safe pressure is then modified by a design factor of 0.32 (established by the Department of Transportation) to arrive at a design pressure rating.
PE pipe's operating temperature range is from -20°F to 140°F in pressure service. The U.S. Department of Transportation suggests that systems and fittings not be operated above 100°F unless components have demonstrated that gas can be safely transported at the higher temperature and expected pressure. PA 11 and PEX pipe may be operated up to 200°F, which make them attractive for higher temperature applications, such as gas lines installed close to steam lines.
Cold ambient temperature does not have an adverse effect on plastic pipe strength or characteristics.
