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NSF/ANSI 358-2-2022
Polypropylene Pipe and Fittings for Water-Based Ground-Source “Geothermal” Heat Pump Systems
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 pipes and fittings used in water-based ground-source heat pump systems.
NSF International [nsf]