UPC Section 606 sets where the water supply system needs valves. The main building supply needs a full-way valve so the whole structure can be shut off in one place. Each dwelling unit in a multi-unit building gets its own control valve. The section also covers valves for groups of fixtures, where a check valve is required, and a draindown valve.
The Uniform Plumbing Code is published and copyrighted by IAPMO. This page explains the section in our own words with a short excerpt only. Read the full official text at the source.
Every plumbing system needs places to turn the water off. You should be able to shut off one fixture, one unit, or the whole building without draining the rest. UPC Section 606 sets where those valves are required. Good valve placement is what lets a plumber fix a leak on one line while the rest of the water stays on.
What Section 606 covers
Section 606 sits in Chapter 6, Water Supply and Distribution. It deals with valves on the water supply piping. The UPC calls the main isolation valve a full-way valve. A full-way valve opens to the full width of the pipe, like a gate valve or a ball valve, so it does not choke the flow when it is open. The section names several places a valve is required:
606.2.1 Full-Way Valve Installation Location 606.3 Multidwelling Units 606.7 Multiple Fixtures 606.8 Check Valve Required 606.10 Draindown Valve
Where valves are required
The building water supply needs a full-way valve so the whole structure can be shut off in one spot. Under 606.3, each dwelling unit in a multi-unit building gets its own control valve. That way one apartment can be isolated for a repair while the other units keep their water. 606.7 covers groups of fixtures fed by a branch, and 606.4 addresses when one valve may serve multiple openings. 606.8 calls out where a check valve is required to keep water from flowing backward. 606.10 covers a draindown valve. The exact wording drives what an inspector checks, so confirm each location in the section itself.
Fixture stops
Beyond the main valves, most fixtures also get their own small shutoff, called a stop or angle stop. It sits under a sink or behind a toilet. It lets you turn off water to that one fixture to swap a faucet or a fill valve while the rest of the home keeps running. If a fixture has no working stop, a small repair turns into a whole-house shutoff. See how to shut off water to a fixture.
Why it matters
Valve placement decides how big a shutoff has to be for any repair. If a building has no unit valves, or the main valve is seized, a small job means shutting water to everyone. Older Phoenix homes often have one aging gate valve on the main that no longer seals fully. That is worth replacing with a quarter-turn ball valve before you need it in a hurry. To find your main, see how to find the main water shutoff. For a larger building, plan ahead with planning a commercial water shutoff.
Full text and source
UPC Section 606 is part of the Uniform Plumbing Code. IAPMO publishes it and holds the copyright, so only the section headings and short notes are shown here. Phoenix enforces the 2024 UPC with local amendments. Read the section on the UPC viewer at UpCodes, review the official code at IAPMO, or confirm local amendments with the City of Phoenix Planning & Development Department at phoenix.gov/pdd.
Keep Reading
- UPC 609: Water Piping Installation and Testing
- UPC Section 720: The Required Gap Between Water and Sewer Lines
- UPC 1003: Which Fixture Traps Are Allowed (and Banned)
- UPC 1007: Trap Seal Protection for Floor Drains
- How do I shut off the water to just one fixture?
- Where is the main water shutoff valve in a Phoenix home?
- How do I plan a water shutoff for my commercial building?
- Why is my water pressure low throughout the whole house?