AWWA WQTC64037

AWWA WQTC64037 Manufacturers Experience with Non-leaded Alloys and Components
Conference Proceeding by American Water Works Association, 11/01/2006

Weed, Robert

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In an effort to comply with the requirements of NSF Standard 61, sections 8 and 9,manufacturers investigated a number of new processes and materials. This paper discusses theopportunities and challenges presented to manufacturers with the use of copper alloys with lowerlead content. Many copper and brass alloys, with very low lead content, have been known tometallurgists for decades. However, none of these alloys possessed the properties necessary toeffectively fabricate them into components for valves, meters and faucets.A number of new cast alloys were developed to help manufacturers meet these NSFrequirements. An industry consortium of the Copper Development Association (CDA), Brassand Bronze Ingot Manufacturers (BBIM), the American Foundrymen's Society (AFS), and theMaterials Technology Laboratory of CANMET in Canada conducted research and developed aseries of copper alloys which use bismuth and selenium as replacements for lead (commerciallyavailable as EnviroBrass also known as SeBiLOY). The Federal Metal Company hasconcurrently developed a group of proprietary alloys containing bismuth and lanthanides (commercially available as FederAlloy). Silicon brass alloys have been developed asreplacements for traditional leaded alloys and alloy C89836 has been developed andcommercialized using bismuth but without selenium. No lead is added to these alloys, and theminimal amount of lead present is due to the lead contained in recycled materials and ore that areused as the source metals. These alloys are formed by substituting bismuth, selenium or siliconfor lead, to enhance the machinability and self-sealing characteristics that are the desirableconsequences of lead addition. Bismuth is used because it behaves similarly to lead in themanufacturing process and selenium is used to enhance the effects of bismuth.There are a number of issues impacting manufacturers who utilize these alloys to create avariety of drinking water components as described in this paper. Includes 14 references, tables.