Fittings 4 min read Updated 25 June 2026 Trade verified

How to Fit a Speedfit Push-Fit Fitting — Trade Method

JG Speedfit is the fastest way to join 10, 15, 22 or 28mm pipe — copper or PB plastic. WRAS-approved, rated to 95°C at 12 bar, and re-usable. Here is the correct trade method plus the two mistakes that cause 90% of leaks.

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Step-by-step method

1. Cut the pipe square

Use a proper pipe slicer (not a hacksaw). A ragged or angled cut damages the O-ring on insertion. On copper, deburr the inside edge with a reamer.

2. Fit a pipe insert on plastic pipe only

Plastic pipe MUST have a Speedfit-brand insert pushed into the cut end — it stops the pipe collapsing under the grab-ring. Copper does not need an insert. This is mistake #1 UK plumbers see on failed joints.

3. Mark the insertion depth

Measure the depth from the fitting body (25mm for 15mm, 27mm for 22mm) and mark the pipe with a pencil. This tells you the joint is fully home.

4. Push firmly until the mark disappears

Push the pipe straight in, no twisting. You'll feel it pass the grab-ring then hit the pipe stop. If the mark isn't hidden, it isn't home — this is mistake #2 and causes slow drips 48 hours later.

5. Tug-test

Pull firmly on the pipe. If it moves, it isn't seated. Fitted correctly, it will not budge. Pressure-test at 1.5x working pressure before boxing in.

Frequently asked questions

Can I use Speedfit on the boiler flow and return?+

Yes, up to 1m from the boiler as long as it's not directly on the boiler tails — manufacturers require a short copper tail first.

Can I re-use a Speedfit fitting?+

Yes. Push the collet inward against the fitting and pull the pipe out. Inspect the O-ring for damage before re-use.

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