In North America, NSF / ANSI 14 is a certification standard established for the physical properties, health effects, quality assurance and record maintenance requirements of plastic piping system components and related materials. NSF 14 requirements for plastic piping and system components are as follows:
• Long-term hydrostatic strength assessment of pressurized tubing;
• the physical properties of the material;
• Physical properties of pipe and system components;
• Antioxidant test;
• Material safety (impact on health);
• Quality control tests.
The evaluation of the antioxidant properties of plastic pipes for hot and cold water is an important indicator of the NSF 14 standard.
When the plastic pipe for hot and cold water is used for long-term delivery of oxidized water (chlorinated), the relevant product standard also requires testing of the oxidation resistance of the pipe to demonstrate that it has a service life of at least 50 years. For cross-linked polyethylene (PEX) tubing, the UV resistance of the product can also be evaluated against the chlorine resistance test. These requirements from NSF 14 and related product standards are tested in accordance with ASTM F2023 and F2263.
Recently, the ASTM D3350 polyethylene plastic pipe and pipe fittings standard specifications has been amended to increase the resistance of the PE resin requirements.
