Submitter's message Please note that a new version of this document has just been published. NSF employees will be able to view it in MasterControl (document #16885); others can use the link below. Thank you for your contributions to this document! -- Amanda Zeoli Document Name : NSF/ANSI 358-3-2021: Cross-linked Polyethylene (PEX) Pipe and Fittings for Water-Based Ground-Source (Geothermal) Heat Pump Systems Description The physical and performance requirements in this standard apply to plastic piping system components as well as non-plastic components of the ground loop heat exchanger including but not limited to cross-linked polyethylene (PEX) pipes and fittings used in water-based ground-source heat pump systems. This standard does not cover refrigerant based ground loop heat exchangers such as direct expansion (DX) systems. This Standard does not cover hydronic heating or cooling systems within buildings. Download Latest Revision Submitter : Amanda Zeoli Group : Joint Committee on Plastics and RV Plumbing Components Folder : Standards Date submitted : 2021-07-07 06:48:00 Revision : 2