April 19, 2021 Compression Fittings, Installation Guide How to install Compression Fittings in 4 simple steps.

Some say that Compression fittings have been around as long as time itself, and in the world of plumbing they are very common. They are a very simple way to connect to copper pipe, and as they don't require the use of heat they are also safe.

Sustainably, Compression Fittings are ace as well. Made from brass, they can be fully recycled and used again.

We have outlined below the equipment needed and 4 simple steps to create the perfect compression joint on copper pipe.

What equipment do I need?

Along with the compression fitting and copper pipe to BS EN 1057 you will need:

Pre installation checks

First off, you should check that the tube conforms to the BS EN 1057 and that the outer diameter of the tube matches the size of the fitting. Both the fitting and tube should be checked to see that they are clean, damage and imperfection free.

Manufacturers also stress that fittings must be installed with the olives that come from the same manufacturer.


1. Cut your pipe to size

It is important that you cut your pipe cleanly across the tube diameter using a good quality pipe cutter or rotary pipe cutter. If you don't do this, you could impact on the quality of your jointing. If your cut is not flat, or your pipe is too short, the pipe may not hit the pipe stop, and the joint may not form correctly. Too long and you may introduce strain into the whole system.

2. Cleaning

It is really important to clean both the socket and the outside of the pipe. The socket can be cleaned using your deburring tool. This will ensure the pipe is smooth and will not interfere with the flow.
The outside of the pipe needs to be cleaned to ensure that there is no pipe residue, dirt of grit present near the joint.

3. Assembly

First off, remove the compression nut and compression olive from the fitting and then put the nut on the tube, followed by the olive. Insert the tube end up to the fitting's tube stop. Slide the olive and the nut down to the fitting body. Tighten the nut using your fingers to secure the fitting in place.

4. Tightening

Tighten the nut further using open ended or adjustable spanners. A few drops of light oil can be used on the threads to assist the turning.

Do not over-tighten the nuts as this can be detrimental to both the nut and the olive, weakening the joint and causing issues later when servicing. Generally the nuts will need one whole turn after hand tightening.

Further Installation Advice

Threaded Connections

Threaded connectors have taper male or parallel female BSP threads, and the most popular sizes have parallel male BSP threads. These are for jointing pipework to boilers, pumps or backplate elbows.

When installing parallel male threads, a good quality jointing washer should be used. For taper male threads, a small amount of inert jointing compound or PTFE tape should be applied before installation.


Some authorities and system specifications don't allow the use of jointing compounds or require that only specific types of material may be used. Before utilising jointing compound, you should make sure that yours is compliant.


All systems should be thoroughly tested upon completion. Whenever possible, completed systems should also be flushed to remove debris.

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