A hot water recirculation pump must have a housing made of which material?

A hot water recirculation pump must have a housing made of which material?

• A. Plastic
• B. Aluminum
• C. Bronze or Stainless
• D. Cast Iron

Answer: (C)

Hot water recirculation pumps sit in contact with hot, often chemically active potable water, so the housing must resist corrosion, hold up under high temperatures, and not contaminate the water. Bronze or stainless steel meet these needs, making them the best choice. Bronze (a copper-tin alloy) offers excellent corrosion resistance in hot, chlorinated or mineral-rich water and helps prevent problems like dezincification that can weaken other copper alloys. Stainless steel also provides strong, durable corrosion resistance across a range of temperatures and water chemistries, maintaining water quality over time. Plastic housings can soften or warp under hot-water conditions and may not reliably meet the temperature, pressure, or potable-water certification requirements. Aluminum can corrode in hot water and with certain water chemistries, and cast iron tends to rust and can contaminate the water, making it unsuitable for potable hot-water service.

Hot water recirculation pumps sit in contact with hot, often chemically active potable water, so the housing must resist corrosion, hold up under high temperatures, and not contaminate the water. Bronze or stainless steel meet these needs, making them the best choice. Bronze (a copper-tin alloy) offers excellent corrosion resistance in hot, chlorinated or mineral-rich water and helps prevent problems like dezincification that can weaken other copper alloys. Stainless steel also provides strong, durable corrosion resistance across a range of temperatures and water chemistries, maintaining water quality over time.

Plastic housings can soften or warp under hot-water conditions and may not reliably meet the temperature, pressure, or potable-water certification requirements. Aluminum can corrode in hot water and with certain water chemistries, and cast iron tends to rust and can contaminate the water, making it unsuitable for potable hot-water service.