5 Steps for Making a Bicone Connection

Contents

    – Step 1: Thread the nut onto the tube

    – Step 2: Thread the olive onto the tube

    – Step 3: Present the fitting

    – Step 4: Screw the nut onto the fitting

    – Step 5: Check for leaks

Two-cone fittings, also called olive fittings, are quick-connect fittings used in plumbing to avoid soldering. Their principle is similar to that of the compression fitting in that a nut compresses a deformable element that guarantees the tightness of the assembly: in this case, a brass ring (olive). 

The bicone or biconical fittings owe their name to the ring with 2 opposite cones, which ensure their tightness. The fitting must match the pipe diameter (outside) exactly. It is pushed onto the pipe (after the nut) and pressed into the fitting.

Two-cone fittings are available in a variety of versions:

    – Socket to join two pipes of the same diameter;

    – sleeve with a reduction to join two pipes of different diameters;

    – 90° elbow to avoid bending;

    – 90° elbow (peg) to connect a wall fitting;

    – T-bend (with or without reduction) to connect a 90° branch to a straight pipe.

Here is how to make a bicone fitting.

1. Thread the nut onto the pipe

    – Separate the nut from the fitting to be installed (without losing the olive).

    – Thread the nut onto the tube.

2. Thread the olive onto the tube

    – Thread the olive onto the tube.

Good to know: for the olive to be installed without problems and for the fitting to be tight, the end of the tube must be cut straight and without burrs. The best way to do this is to use a pipe cutter.

    – Position it 3 to 5 mm after the end of the tube. Do not place it a little bit in front of the tube. Otherwise, it will be crushed in part in front of the tube.

3. Present the fitting

    – Place the fitting at the end of the tube held horizontally (or vertically, olive up).

    – Hold the tube at the bottom of the fitting so it moves smoothly (this would be the same as placing the olive incorrectly).

Note: If the fitting is angled or T-shaped, orient it correctly.

4. Screw the nut onto the fitting

    – Slide the nut onto the fitting.

    – Tighten the nut by hand (always keeping the tube at the bottom of the fitting).

    – As soon as it becomes impossible to continue, use an open-end wrench.

    – Hold the fitting with another wrench if it is straight or with pliers if it is angled or T-shaped. Be careful not to damage the fitting.

    – Tighten the nut firmly but not too much: brass is a soft metal.

5. Check for leaks

    – If the water was initially cut off in the system, reopen the shut-off valve.

    – If drips appear at the fitting, it usually needs to be tightened enough. Tighten it again.

    – If the leakage persists, reconnect the water and disassemble the fitting.

    – Look at the olive: it is probably deformed like the tube.

    – Slide the nut on the tube away from the olive.

    – With a tube cutter, cut the tube behind the olive (or beyond its deformed part).

    – Replace the olive and tighten the nut on the fitting.

Materials needed to install a two-cone fitting

Flat wrench 

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