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The City of Portland, Oregon

Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.

Customer Service: 503-823-7770


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Reduced Pressure Detector Assembly

Help prevent backflow!

The Reduced Pressure Detector Assembly (RPDA) is an outgrowth of the Double Check Detector Assembly and is typically only used on fire line applications.

However, this assembly is intended to protect the potable water supply from fire sprinkler systems that contain chemical additives or can be connected to an auxiliary non-potable water source.

This assembly is comprised of a mainline reduced pressure backflow assembly equipped with OS&Y gate valves, a bypass arrangement containing a smaller reduced pressure backflow assembly and water meter. The RPDA must be installed at least 12" above finished grade or the 100 year flood plain which ever is greater.