The Plastics Pipe Institute (PPI) has released a new Model Specification document that provides guidance to specifiers, engineers, designers, and others about selecting, specifying and installing plastic piping materials for ground source geothermal systems.  Prepared by PPI’s Building & Construction Division, PPI MS-7 Model Specification for Plastic Piping Materials for Ground Source Geothermal Applications applies to plastic piping materials for open- and closed-loop, horizontal and vertical, direct-buried, and submerged water-based ground-source geothermal heat exchange systems.

PPI MS-7 includes detailed specifications for four plastic piping materials which have been proven in ground-source heat exchange systems: HDPE, PE-RT, PEX, and PP (PP-R and PP-RCT).  According to PPI, the definitions, terms and other information can be readily used in bid documents, for example.  The model specification provides language related to pipe and tubing materials, fittings, and joining procedures.  Installation and pressure testing recommendations are also provided.  It complements another PPI document, PPI TN-55 Plastic Piping Materials for Ground Source Geothermal Heating and Cooling Applications.