NSF ANSI 358-4:2018 pdf free download – Polyethylene of Raised Temperature (PE-RT) Tubing and Fittings for Water-Based Ground-Source (Geothermal) Heat Pump Systems
1.2 Scope
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, polyethylene of raised temperature (PE-RT) tubing and fttings 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.
2 Normative references
The following documents contain provisions that, through reference, constitute provisions of this NSF Standard. At the time this Standard was balloted, the editions listed below were valid. All documents are subject to revision, and parties are encouraged to investigate the possibility of applying the recent editions of the documents indicated below. For undated references, the most recent version shall be referenced. These are normative references for Polyethylene of Raised Temperature (PE- RT) tubing and Fittings for Water-Based Ground- Source (Geothermal) Heat Pump Systems.
3.6 hydrostatic design basis (HDB): One of a series of established stress values specified in ASTM D2837 for a plastic compound, obtained by categorizing the long-term hydrostatic strength determined in accordance with ASTM D2837.
3.7 hydrostatic design stress (HDS): The estimated maximum tensile stress a material is capable of withstanding continuously with a high degree of certainty that failure of the tubing will not occur. This stress is circumferential when internal hydrostatic water pressure is applied.
3.8 joint: The location at which two pieces of tubing or a tubing and a ftting are connected together. Various joint types not defined in this standard shall be defined by ASTM F412.
3.9 mechanical joint: a connection between two pieces of pipe or a pipe and a ftting using a physical force to establish a seal or alignment.
3.10 plastic pipe: A hollow cylinder of plastic, in which the wall thicknesses are usually small when compared to the diameter, and in which the inside and outside walls are essentially concentric.
3.11 plastic: A material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight, is solid in its finished state, and at some stage in its manufacture or processing into finished articles, can be shaped by flow.
3.12 pressure rating: The estimated maximum water pressure at a specified temperature that tubing is capable of withstanding continuously with a high degree of certainty that failure of the tubing will not occur.
3.13 quality assurance: A formal system for verifying that products conform to specific standards.Quality assurance is intended as an audit of quality control testing.
3.14 quality control: The methods used to ensure that a production process yields products in conformance with the appropriate specifications established by the quality assurance program.
3.15  steady-state: An operational condition of the manufacturing process that does not change with time .
3.16 thermoplastic: noun- A plastic that can be repeatedly softened by heating and hardened by cooling through a temperature range characteristic of the plastic, and in the softened state, can be shaped by flow through molding or extrusion. adj. – Capable of being repeatedly softened by heating and hardened by cooling through a temperature range characteristic of the plastic, and able in the softened state to be shaped by flow into articles by molding or extrusion.