This Code contains requirements for the materials, design, fabrication, assembly, erection, test, and inspection of refrigerant, heat transfer components, and secondary coolant piping for temperatures as low as -320°F (-196°C), whether erected on the premises or factory assembled. Users are advised that other piping Code Sections may provide requirements for refrigeration piping in their respective jurisdictions. This Code does not apply to: (a) any self- contained or unit systems subject to the requirements of Underwriters Laboratories or other nationally recognized testing laboratory: (b) water piping; (c) piping designed for external or internal gage pressure not exceeding 15 psi (105 kPa) regardless of size; or (d) pressure vessels, compressors, or pumps, but does include all connecting refrigerant and secondary coolant piping starting at the first joint adjacent to such apparatus.