Sweat Ball Valves

What Are Sweat Ball Valves Used for in Plumbing?

A sweat ball valve is a shut-off valve designed to be soldered (sweated) onto copper pipe. Its main purpose is to:

Turn water flow ON or OFF to a section of piping or a fixture.

What Sweat Ball Valves Are Used For

• Shutting off water to fixtures (sinks, toilets, tubs, showers)
• Isolating sections of a plumbing system
• Main or branch water shutoff valves
• Water heater connections
• Boiler and hydronic heating systems
• They allow maintenance or repairs without shutting down the entire building.

How They Work

Inside the valve is a solid brass ball with a hole through it:

• Handle parallel to pipe → valve OPEN
• Handle perpendicular to pipe → valve CLOSED
• The valve only needs a quarter-turn (90°) to operate.

How a Sweat Ball Valve Is Installed

• Clean and deburr copper pipe
• Apply flux to pipe and valve sockets
• Slide valve onto pipe
• Heat joint with torch
• Apply solder until joint fills
• Let cool and test
• This creates a permanent, watertight soldered joint.

Sweat valves are very common in traditional copper plumbing systems.

Simple Example

A ½" copper line feeds a bathroom sink. Installing a ½" sweat ball valve on that line lets you shut off just the sink if the faucet needs replacement.

In Plain English

Sweat ball valves are used to control and shut off water flow on copper piping using soldered connections.

If you tell me the pipe size and whether it’s for water or heating, I can help confirm the right valve type.