AWWA C703:2015 pdf download.Cold-Water Meters—Fire-Service Type
4.1.5 Measuring turbines, discs, and pistons. Turbines, discs, and pistons shall be made of a suitable engineering plastic, such as propylene in accordance with ASTM D4101, styrene-acrylonitrile (SAN) in accordance with ASTM D4203, or nylon (PA) in accordance with ASTM D4066, such that the specifc gravity approximately equals that of water. Turbines, discs, and pistons shall have sufcient dimensional stability to retain operating clearances at working temperatures of up to 80°F (27°C) and not warp or deform when exposed to operating temperatures of 100°F (38°C).
4.1.6 Disc, piston, and turbine spindles. Measuring-chamber spindles shall be made of phosphor bronze, stainless steel as listed in ASTM A276, monel, ceramic, tungsten carbide, or suitable engineering plastic. Measuring-chamber spindles shall have sufcient 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).
4.1.7 Intermediate gear trains. Frames, gears, and pinions of intermediate gear trains exposed to water shall be made of a copper alloy containing not less than 85 percent copper; or of other suitable corrosion-resistant metals; or of a suit- able engineering plastic, such as polyphenylene oxide in accordance with ASTM D4349, acetal (POM) in accordance with ASTM D4181, nylon (PA) in accor- dance with ASTM D4066, or polyphenylene sulfde (PPS) in accordance with ASTM D4067.
4.1.11 Bypass check valve. Meters using a bypass system shall be pro- vided with a check valve in the piping downstream of the bypass (low-fow mea- suring) meter. Te check valve interior mechanisms shall be of a copper alloy, such as UNS C89510, C89520, C89833, or C89836, or a similar copper alloy as listed in ASTM B584, or other suitable nonferrous material, such as rubber, as classifed in ASTM D2000. Te check valve shall efectively prevent reverse fow and shall not bind or stick while in service. Te check valve shall be of sufcient size to be used to test either the main line or the bypass meter at the fow rates required by AWWA for the respective meters. If the bypass check valve cannot be used to perform in-line feld testing at the required AWWA fow rates, a separate plug shall be provided.AWWA C703 pdf download.