ANSI AWWA C904-16 pdf free download – Crosslinked Polyethylene (PEX) Pressure Tubing, ½ In. (13 mm) Through 3 In. (76 mm), for Water Service
6. Purchaser: Te person, company, or organization that purchases any materials or work to be performed.
7. Standard dimension ratio (SDR): A specifc ratio of the average speci- fed outside diameter to the minimum wall thickness. For PEX tubing, the SDR is calculated by dividing the average outside diameter of the tubing by the minimum wall thickness (OD/t). If the wall thickness calculated by this formula is less than 0.070 in. (1.78 mm), it shall be increased to 0.070 in. Te SDR values shall be rounded to the nearest 0.5.
8. Supplier: Te party that supplies materials or services. A supplier may or may not be the manufacturer.
9. Surge pressure: Surge pressure is the maximum positive transient increase (commonly called water hammer) that is anticipated in the system as the result of a change in velocity of the water column.
10. Working pressure: Working pressure (WP) is the maximum anticipated sustained operating pressure applied to the tubing exclusive of transient pressures.
Te selection of materials is critical for water service and distribution tubing in locations where the tubing will be exposed to signifcant concentrations of pollut- ants comprised of low-molecular-weight petroleum products or organic solvents or their vapors. Research has documented that tubing materials, such as polyethylene, polybutylene, polyvinyl chloride, PEX, and asbestos cement, and elastomers used in joining gaskets and packing glands are subject to permeation by low-molecular- weight organic solvents or petroleum products. If potable water tubing must pass through such a contaminated area or an area subject to contamination, consult with the manufacturer regarding permeation of tubing walls, jointing materials, and so forth before selecting materials for use in that area. Additional resources about permeation of elastomeric joint gaskets and plastic tubing are provided in appendix B.
4.2.1.1 Tubing covered by this standard shall conform, as a minimum, with the requirements of PEX 1306 as classifed in ASTM F876. PEX classifed with a material designation code of PEX 3306 and PEX 5306 also meets this requirement.
4.2.1.2 Te material shall be crosslinked by peroxides or silane compounds in extrusion or by electron beam after extrusion so the tubing meets or exceeds the performance requirements in this standard. Te minimum percent of crosslinking shall be 70 percent for peroxides, 65 percent for silane compounds, and 65 per- cent for electron beam when tested in accordance with ASTM D2765, Method B, as defned in ASTM F876. Tubing may incorporate an optional polymeric outer layer. Tubing with outer layers must meet technical requirements as per established policies defned within ASTM F876 and PPI TR-3.
4.2.1.3 PEX tubing shall have a long-term HDS (hydrostatic design stress) equal to or better than given in Table 1, when the HDB (hydrostatic design basis) is determined in accordance with ASTM D2837. HDS and HDB ratings shall be listed in accordance with procedures no less restrictive than those of PPI TR-3.
4.2.2 Reworked material. Te use of reclaimed, recycled, or reworked materials is not permitted.
4.2.3 Certifcation. PEX tubing covered by ANSI/AWWA C904 shall be tested and certifed for use with potable water by an accredited testing agency. Product testing shall be no less stringent than required by NSF/ANSI 61 or the health efects portion of NSF/ANSI 14. Tis applies to applications for potable water, wastewater, and reclaimed water systems as described in Sec. 4.2.1.