How to install a PEX crimp fitting

PEX crimp fittings, like all other types of PEX pipe fittings, are used to make connections to fixtures and between pipes without the need for soldering. A barbed fitting is inserted into the pipe before a crimping ring is fitted over the top to create a strong, watertight seal.

PEX crimp fittings are the most reliable and safest of all PEX fittings. In fact, a crimp fitting is the only type of PEX fitting that can be placed within or behind walls, partition walls or in concrete slabs. However, bear in mind that once the fitting is in place, it cannot be removed.

Steps

1. Assemble the crimp fitting

2. Fit the fitting to the PEX pipe

3. Secure the crimp ring

Once you are confident that you have measured the PEX pipe accurately, cut it to the correct length and deburr the ends. Depending on the type of PEX crimp fitting you plan to use, you may have to fit some parts of the fitting before others.

Some crimp fittings feature a fixed crimp ring while others require the ring to be fitted first.

If you have a fitting with a fixed ring, you can go straight to installing the fitting onto the pipe. Otherwise, slide the crimp ring over the pipe first.

Insert the fitting directly into the PEX pipe. Check that the pipe is sitting in the correct position between the fitting and the crimp ring. If you have trouble inserting the fitting, you can use pipe lubricant but do not in any circumstances attempt to flare the pipe as it will be impossible to secure later on.

Similarly, do not use heat to make the PEX pipe more flexible. Once the fitting is in place, check that you can see the end of the PEX pipe through the depth indicator featured on most crimp fittings.

It's worth noting that PEX crimp fittings with fixed crimp rings are actually more flexible since you can always remove the ring from the fitting if you have difficulty securing it (to lubricate the end of the fitting, for example).

Start by preparing your crimping tool. Fit the correct insert into the jaws of the crimping tool. The insert must match the size of the PEX pipe.

Checking that it is held stable, open the crimping tool, insert the crimp ring into the insert and press the tool firmly but gently until it closes entirely.

Test the connection by pulling on the PEX fitting. You should generally see a bump on the crimp ring if it has been fitted correctly.

Required skills

You don't need a lot of plumbing experience to fit a PEX pipe fitting. As with all types of PEX fitting, there is no need to solder anything. That said, even if you don't need to be a plumber to carry out the job, you do need to have the right tools including a special crimping tool with a set of inserts in different sizes to match all PEX pipe sizes as well as pipe cutters and a deburring tool.

Approx. 5 mins

Number of people required

1 person

Tools and equipment

• Pipe cutters

• A crimping tool with inserts

• A deburring tool

• Pipe lubricant (if required)