What Is a Compression Fitting?
A compression fitting is a plumbing connector that joins pipes or tubing without soldering, threading, or glue. The fitting uses a threaded nut and a compression ring, also called a ferrule. Tightening the nut presses the ring against the pipe and fitting body, creating a sealed connection for many water line repairs.
Quick Facts About Compression Fitting
Category
Mechanical pipe connector
Used for
Joining water supply tubing
Common confusion
Often mistaken for a push-fit connector
Also called
Compression Connector
Often discussed with
Water Line Repair
Key Takeaways About Compression Fitting
- A compression ring forms the seal around the pipe.
- The connection can be tightened with common hand tools.
- Compression fittings are not the same as push-fit connectors.
How Compression Fitting Works
A compression fitting joins a pipe by tightening a nut over a compression ring. The ring grips the pipe and presses against the fitting body. This pressure creates the seal around the connection.
Related glossary terms: Water Shutoff Valve, Fixture Shutoff Valve, Water Pressure.
Compression fittings come in straight, angled, and adapting designs. A compression ring must match the pipe size and material. The fitting can connect tubing to a valve, another pipe, or a fixture connection. The pipe end must sit fully inside the fitting before the nut is tightened.
These fittings are common on water supply lines because they do not need heat or solvent. A water shutoff valve may use a compression connection where the valve meets the supply tube. The connection should stay aligned while the nut is tightened.
Expert Note
When we inspect a compression fitting, we check the pipe end, ring, nut, and fitting body. We look for movement, corrosion, moisture, or damage around the seal. During water line repair, we also confirm that the pipe enters the fitting fully and that the connection stays aligned after tightening.
Compression Fitting in Practice: A Real-World Example
A small water line under a sink may have a compression fitting where the supply tube connects to the shutoff valve. We inspect the ring and pipe end, then replace damaged parts when the connection cannot seal properly.
Related Services
Related Terms
Water Shutoff Valve
A Water Shutoff Valve is a plumbing control that stops water flow through a supply pipe…
Fixture Shutoff Valve
A fixture shutoff valve is a small control valve installed on a water supply line near…
Water Pressure
Water Pressure is the force that moves water through supply pipes, valves, and fixtures. The force…
Pressure Test
A Pressure Test is a plumbing check that applies controlled air or water pressure to a…
PlumbingKentwa.link
Have Questions About Compression Fitting?
Contact PlumbingKentwa.link for practical guidance on Compression Fitting and related plumber work in Kent.