1. Piping must be made of nontoxic material, resistant to corrosion and able to withstand operating pressures. Pipes must be identified by color code, tags or labels. All plastic piping and fittings used in the recirculation system must be designated by the NSF International as complying with all applicable requirements of NSF International Standard 14 or Standard 61 for potable water applications or in the absence of applicable requirements, be approved by the health authority. The piping must be imprinted with the manufacturer's name and the potable water mark of the NSF International, "NSF-pw," the make that indicates compliance with Standard 61, "NSF-61," or an equivalent mark.2. The water velocity in spa piping other than copper piping must not exceed 10 feet per second (3.05 meters per second) for discharge piping. The velocity for copper piping must not exceed 6 feet per second (1.83 meters per second). Suction velocity for all piping must not exceed 6 feet per second (1.83 meters per second).3. Piping around the spa which is subject to damage by freezing must be sloped for adequate drainage and supported at sufficiently close intervals so that sagging between supports will not trap water. Provisions must be made for expansion and contraction of pipes.Nev. Admin. Code § 444.482
Bd. of Health, Public Spa Reg. Art. 18 §§ 18.6-18.8, eff. 11-27-79-NAC A 11-2-88; 1-16-96