Brochure

PH: 513-754-2000
THE HARRIS PRODUCTS GROUP
www.harrisproductsgroup.com
10
PH: 513-754-2000
THE HARRIS PRODUCTS GROUP
www.harrisproductsgroup.com
11
APPLY THE BRAZING ALLOY.
Feed the alloy into the joint between the tube and the fitting. Only after
the base metals have been heated to brazing temperatures should the filler
metal be added. At that time, the flame may be deflected momentarily to
the tip of the filler metal to begin the melting process. Always keep both the
fitting and the tube heated by playing the flame over the tube and the fitting
as the brazing alloy is drawn into the joint. The brazing alloy will diffuse
into and completely fill all joint areas. Do not continue feeding brazing alloy
after the joint area is filled. Excess fillets do not improve the quality or the
dependability of the braze and are a waste of material.
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.
CLEAN AFTER BRAZING
All flux residue must be removed for inspection and pressure testing.
Immediately after the brazing alloy has set, quench or apply a wet brush
or swab to crack and remove the flux residue. Use emery cloth or a wire
brush, if necessary.
TO SEPARATE A BRAZING JOINT
First clean the joint thoroughly, then flux the visible alloy and all adjacent
areas of the tube and fitting. Next, heat the joint (tube and fitting) evenly,
especially the flange of the fitting. When brazing alloy becomes fluid
throughout the joint area, the tube can be easily removed. To re-braze the
joint, clean the tube end and the inside of the fitting and proceed as directed
to make a new brazed joint.
1010
PROCEDURES FOR
BRAZING PIPE AND TUBING
PROCEDURES FOR
BRAZING PIPE AND TUBING
NITROGEN PURGE
During braze heating, oxide scale forms on the inside of the copper tube.
These dark scales flake off and are carried by refrigerant and can potentially
clog small orifices.
For HVAC/R and medical gas installations flow nitrogen through the tube
during brazing to prevent internal scale formation. Use a low flow rate to
avoid excess pressure inside the tube. A small hole at the line end will allow
the nitrogen to escape.
BRAZING PIPE AND TUBING