Constant water flow (velocity) can wear out pipes

Plumbing · Flow and Pressure · printed page 259 (PDF page 260)

Book index entries

Plumbing – Constant Water Flow can wear out Pipes Supply Plumbing – Constant Water Flow Can Wear Out Pipes Water Flow – can wear out Plumbing Pipes Flow and Pressure of Water in Supply Plumbing Supply Plumbing – Flow and Pressure Water Flow – and Pressure in Supply Plumbing

Text in the illustration

check valve
hot water recirculating systems can prematurely wear out thin wall (type "M") copper piping because water is constantly flowing through the pipes
floor framing
cold
hot
hot water recirculating loop
hot water recirculating pump
gas water heater
gas
main shut off valve
foundation wall
basement
cross section

Generated explanation

A basement cross section shows a gas water heater connected to cold-water supply piping, hot-water distribution piping, and a hot-water recirculating loop. Arrows indicate flow through the supply, heater, and pumped return loop, which connects to the heater's cold-water inlet piping through a check valve. The incoming water service has a main shutoff valve near the basement floor. An annotation warns that constant circulation can prematurely wear out thin-wall Type M copper piping; no actual pipe perforation or leak is drawn.