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The lead-free component above was cast in C89833, while the water meter at right was cast in C89836 lead-free copper-bismuth.

previous EPA Safe Drinking Water Act, Section 1417. T e rules exempt material used for water not antici- pated for human consumption, such as non-potable services, service saddles, distribution main gate valves, and fi re hydrants. However, many of those components have been converted to no-lead casting alloys as well. Copper alloy castings are part of water distribution for industry and homeowners in four primary areas: hydrants, the water delivery system (the water main to the in-house meter), water meters, and in-home plumbing components (water meter to the faucet). More than 30 copper alloys are listed in the ASTM standards as containing a maximum of 0.1% lead, and several more are listed that contain a maximum of 0.25% lead, the limit set in the new regulations. In addition, research is ongoing and new alloys continue to be developed and enter the marketplace. T e following is a review of common alloys, current applications and relevant industry specifi cations. T e alloys are listed using the industry standard Uni- fi ed Numbering System (UNS). Fire Hydrants—Historically,

hydrants have been cast in a sev- eral different ASTM bronzes and brasses. Although exempted from the new regulations, hydrants are currently made in a variety of lead- free ASTM bronzes, brasses, and stainless steel. Hydrants are manu- factured to meet American Water Works Association (AWWA) Fire Hydrant Standards.

Waterworks Products (water main to the residence)—Previously cast in leaded brass alloy C83600, commonly known as 85-5-5-5 (containing 4.0-6.0 % lead), these components have been converted and are now cast in lead-free cop- per alloys. T e primary alloys used are C89520 (bismuth selenium), C89833 (bismuth-brass) and C89836 (bismuth-bronze). Components are manufactured to AWWA Standard C800 for underground service. Water Meters—Traditionally

produced in lead containing alloys C83600 and C84400, meters are now manufactured in a number of lead-free cast and forged copper alloys, as well as stainless steel, and plastic/composite

materials to adhere to AWWA Water Meter Standards. Plumbing Products (in-home

devices, faucets etc.)—Formerly produced as copper alloy castings, brass forgings, die castings and bar stock, most are now made in a vari- ety of lead-free cast copper alloys, stainless steel, and plastic/composite materials to meet various plumbing codes, standards, and certifications. While metalcasters have many no-

lead alloy choices that meet current government regulations, some alloys are more suitable for certain types of applications. Each alloy has proper- ties that make it unique and provide specifi c benefi ts. And, each alloy also has melting and casting production challenges. Materials are generally selected to provide the optimum component performance at the low- est cost to the consumer. Relevant specifi cations and standards provide guidance for material selection. Some of the factors to consider when select- ing an alloy include: • Castability, including fluidity to fill the mold cavity, pouring tempera- tures, melting concerns (gas pick up, etc.).

• Mechanical properties reflecting cast- ing integrity and microstructure.

Metalcasting facilities have been producing lead-free copper components for potable water applications for years.

• Chemical composition. • Pressure tightness. • Machinability and related issues. • Soldering and brazing capability. • Recycling—both in house recycling and external scrap stream.

• Component specifications and September 2016 MODERN CASTING | 33

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