Using a flaring block

Step-by-Step

The first thing to remember: Slip the flaring nut on before you flare the end of the tubing.

Choose the hole in the flaring block that matches the outside diameter of the tubing. Clamp the tool onto the tubing. Align the compression cone on the tubing's end, and tighten the screw. As you turn the handle, the cone flares the tubing's end. Inspect your work carefully after removing the tubing from the block. If the end has split, cut off the flared portion and repeat the process.

Flare/nut union

Seat the flare union against one of the flared ends of the tubing, slide the nut down, and hand-tighten. Do the same on the other side. No pipe joint compound is necessary.

Tightening a flare fitting

Place one wrench on the union and one on a nut. Don't over-tighten a flared joint. Once snug, give it a half turn on each nut. Turn the water on and test. If the joint leaks, tighten it carefully until the leak stops. If tightening won?t stop the leak, dismantle the joint and examine it to see if the tubing was cut squarely. Make sure that the nut was not cross-threaded on the fitting. Anchor or support the tubing within 2 feet of either side of the flare fitting.