How to Install Tubing Flare Fittings

Flare fittings are a type of compression fitting with metal tubing. It is also a method to join 2 flexible copper tubes. A flare nut is used to secure the tubing flare fitting, which creates a pressure resistant and leak tight seal. These fittings provide long term reliability. Hence, they are used for inaccessible locations, like the high pressure gas distribution or water distribution, where the fitting must provide a tight connection. To perform this task, you will need soft tubing and tools specialized for this purpose. You require a flare tubing set the same size as the tubing. The flare fittings are later secured onto the soft tubing, after tightening the flare tool. The steps to install tubing flare fittings are given below.

Materials Needed

  • Flare tool
  • Flaring nut
  • Tubing
  • Tube cutter
  • Wrenches
  • Screwdriver

Step 1: Cutting the Tubing

Use a tube cutter and cut the tubing square at its end. This is done to install the flare fittings to the metal tubing.

Step 2: Placing the Flare Nut

Take the flare nut, put it over the end of pipe, and slide it back, to make some room for the rest of the work to be done. If you find it difficult to slide the flare nut at the cut end of pipe,  cut that unevenly cut pipe end properly and carefully. Repeat the cut until the flare fits on evenly and smoothly.  

Step 3: Placing the Flare Tool

Place the base of the flaring tool around the tube. Make sure its of the accurate diameter size.

Step 4: Installing the Flare Cone

On top of the tube opening, fix the flare cone using a screwdriver. Use the wrench and keep tightening it until the cone is strongly fixed inside the base.

Step 5: Checking the Tubing

Take out the tubing from the base, and check its ends for splits. Now, bring back the flare nut, up to the end of the tubing. Sometimes, over-tightening the base of the metal tubing can cause splits. If splits are found, they have to be checked and repaired by replacing the tubing. Finally, finish the tubing with flare fittings.  

Step 6: Fixing the Flare Tubing Nut

Examine for snug fittings, at the bottom of the flare nut. Currently, it will still be loose. Now connect the end of the flared tubing nut to the end of the threaded nipple. 

Step 7: Testing

Now examine for the leaks. This can be done by varying the pressure in the line with flare fittings. If there is a leak, patch it with teflon tape. The teflon taping seals the air and water at the nipple connection in a water line or a gas line. You have successfully installed tubing flare fittings.

Tips And Warnings

  • Flare fittings are very expensive, but they are worthwhile on projects that need the best resilience.
  • Redo the cut if the flare is rough or uneven.
  • Copper tubing is soft, and hence can grow splits at their ends, if you over-tighten them.