How Do Compression Fit Shut Off Valves Work?

Compression fit shut off valves are a basic plumbing mechanism that stops the flow of water. Most commonly they are used in bathroom and kitchen faucets and in the shut off valves bringing water to these faucets. These valves generally control water to one fixture, such as a toilet, to allow it to be serviced without turning off the water to the entire house. Compression fittings are well suited to this application, as these valves are usually located in confined spaces where copper pipe would be difficult to solder and could cause a fire.

Compression Fitting Parts

The compression fitting is made up of an outer compression nut and an inner ring called a compression ring. This is usually made of brass or copper. When the nut is tightened, it clamps down on the ferrule, causing it to compress tightly against the ferrule creating a liquid tight seal.

Ability to Create a Tight Seal

These valves are also commonly used to shut off gas and oil lines as they create such a tight seal when compressed. Compression fittings form a tight seal by applying a compressive force to the pipes and pipe fitting. The fitting is compressed against the pipe tight enough to eliminate all space in the joint, preventing fluid from leaking.