PROCEDURES FOR BRAZING
PIPE AND TUBING

If the tank has a delivery pressure gauge set the delivery pressure at 14-15 psi. If the tank has only a contents gauge, delivery pressure is preset at the factory so open the regulator adjusting screw all the way by turning it clockwise until it “bottoms”. Open the torch handle value. Opening about 3/4 of a turn will provide sufficient fuel gas delivery. Do not try to meter pressure, (reducing the flame), by using the torch handle valve. If a higher or lower flame is required change to a different tip size.

Heating the joint area. Always keep the torch in short motion.

Then...
1. Begin by heating the tube, first applying the flame at a point adjacent to the coulpling. Heat around the tube to conduct heat inside the fitting.

2. After this preheat move the torch to the coupling. Angle the flame towards the tube as shown. When a flux is used it will be a good temperature guide. Watch for the flux to pass the “bubbling” temperature range and become fluid and transpar ent, (the appearance of water.)

3. Sweep the torch between the tube and coupling on all joint sides. This will help bring both parts to brazing temperature.

4. Move the flame to the coupling base. Molten brazing filler metal will flow towards the heat. Directing the flame to the coupling promotes flow into the joint.

5. Apply the filler metal only when both parts have reached brazing temperature. (The flame may be briefly deflected to the filler metal end to begin the melting process). As tube diameter increases you will need to apply filler metal at several points around the tube circumference to ensure complete joint fill.

When making vertical alloy-up joints heat the tube first, then apply heat to the fitting. It is important to bring both pieces up to temperature evenly. Keep the flame directed toward the fitting. If the tube is overheated, the brazing alloy may run down the tube rather than into the joint

When making horizontal joints heat the circumference of the tube first, then apply heat to the fitting. Deciding where to start feeding the alloy will depend on the size of the pipe and operator preference. On large diameter pipe, however, sometimes the best approach is to start at the bottom of the pipe. As the alloy solidifies, it will create a “dam” and help prevent the brazing alloy from running out of the joint as the remainder of the connection is filled. When adding alloy, make sure both the pipe and fitting are up to temperature.