7 Best Uses for a Pipe Reducer

A pipe reducer, as the name implies, is used when you need to go from one width of pipe to another that has a smaller diameter. It’s used to connect the two, making it very versatile and with a number of different applications. Pipe reducers come in different sizes and have their uses in a number of different projects.

Rain Diverter

If you’re building a rain diverter to provide water for the garden, then you’ll need a pipe reducer in order to reach the barrel. It will be used in the pipe coming off the downspout which will need to be smaller to go into the rain barrel (the rain barrel should have a cap on it to keep out debris). In this you might need two pipe reducers to reach the diameter you need to enter the barrel.


Pipe reducers are also pipe expanders. You can use them in plumbing in the house as you go from outlets from sinks and toilets into the main sewer line from the house. PVC pipe reducers are east to fit and use and work very well in these instances as the pipe you’ll be working with will be PVC.

Concentric Reducer

Apart from regular pipe reducers there are also concentric and eccentric pipe reducers, each of which has a special function. A concentric reducer is symmetrical and conical, with the reduction equal around the centreline. With an eccentric pipe reducer that symmetry doesn’t exist. A concentric reducer would be used in a steam system, either for a wet return or to give proper drainage.


With a chimney you’ll need a pipe reducer in the flue to go from the hearth to the inside of the chimney. This will be made of cast iron to take the heat and there are different sizes, depending on the side of the flue and the chimney.

Below Ground Drainage

There will be times when you’re putting in below ground drainage, such as to remove water from some area, and you’ll use a pipe reducer as the pipe move to another area, as a thinner pipe will give a better flow. Again you’ll use PVC pipe as this will hold up well below the ground. The longer your run of pipe the more you’ll want to reduce it over it’s course. When you reach a drier area you should have holes drilled in the pipe.


You will find pipe reducers used in some cars (on Minis, for example) where there can be an exhaust sleeve reducer pipe. This can increase the pressure that’s forced through the system.

Home Brewing

Even home brewing can use a pipe reducer in the tubing that runs from the boiler to the sparging arm. In this instance you’ll use a reducer to connect the 15 millimeter copper tube to a smaller 8 millimeter tube. These are easy to buy, both from plumbing and brewing outlets, and are a cheap item that makes a difference.