AWWA C708:2019 pdf download.Cold-Water Meters—Multijet Type
4.1.1 General. Materials used in the manufacture of water meters shall conform to the requirements stipulated in the following section. Where plastic materials are allowed, the manufacturer may provide any plastic materials that meet the performance requirements specified; typical examples are provided.
4.1.1.1 Materials* shall be selected for their strength and resistance to corrosion and shall not impart to the water objectionable taste or odor, nor toxic substances in normalized concentrations exceeding the maximum contaminant levels (MCLs) as defined by the US Environmental Protection Agency (USEPA).
If engineering plastic materials are used, only virgin, or first-generation- grade, rigid engineering plastic materials shall be used in the manufacture of the main casings, covers, and bottoms; these engineering plastic materials shall be compounded with ultraviolet stabilizers.
4.1.2 Main casings. Main casings shall be made of a copper alloy containing not less than 75 percent copper, such as UNS C89510, C89520, C89833, or C89836, or a similar copper alloy as listed in ASTM B584; or a cast austenitic stainless steel as listed in ASTM A351; or a suitable engineering plastic, such as polycarbonate (PC) in accordance with ASTM D3935, polyphenylene ether (PPE) in accordance with ASTM D4349, or nylon (PA) in accordance with ASTM D4066.
4.1.4 Measuring cages or chambers. Measuring cages or chambers shall be made of a copper alloy containing not less than 85 percent copper, such as UNS C89510, C89520, C89833, or C89836, or a similar copper alloy as listed in ASTM B584; or a cast austenitic stainless steel as listed in ASTM A351; or a suitable engineering plastic, such as PPE in accordance with ASTM D4349, PA in accordance with ASTM D4066, polyethylene in accordance with ASTM D1248, or polystyrene in accordance with ASTM D4549.
Measuring cages or chambers shall have sufficient dimensional stability to retain operating clearances at working temperatures of up to 80°F (27°C) and shall not warp or deform when exposed to operating temperatures of 100°F (38°C).AWWA C708 pdf download.