Handbook

7. SOLDERED JOINTS
The American Welding Society denes soldering
as "a group of joining processes that produce
coalescence of materials by heating them to a
soldering temperature and by using a ller metal
(solder) having a liquidus not exceeding 840°F and
below the solidus of the base metals." In actual
practice, most soldering is done at temperatures
from about 350°F to 600°F.
To consistently make satisfactory joints, the following
sequence of joint preparation and operations, based
on ASTM Standard Practice B 828, should be
followed:
 Measuring and Cutting
 Reaming
 Cleaning
 Applying Flux
 Assembly and Support
 Heating
 Applying Solder
 Cooling and Cleaning
 Testing
The techniques described produce leak-tight
soldered joints between copper and copper alloy
tube and ttings, either in shop operations or in the
eld. Skill and knowledge are required to produce a
satisfactorily soldered joint.
Measuring and Cutting
Accurately measure the length of each tube segment
(Figure 7.1). Inaccuracy can compromise joint
quality. If the tube is too short, it will not reach all
the way into the cup of the tting and a proper joint
cannot be made. If the tube segment is too long,
system strain may be introduced which could aect
service life.
Cut the tube to the measured lengths. Cutting can
be accomplished in a number of dierent ways to
produce a satisfactory squared end. The tube can
be cut with a disc-type tube cutter (Figure 7.2), a
hacksaw, an abrasive wheel, or with a stationary
or portable band saw. Care must be taken that the
tube is not deformed while being cut. Regardless of
method, the cut must be square to the run of the
tube so that the tube will seat properly in the tting
cup.
Figure 7.1. Measuring
Figure 7.2. Cutting
35
CDA Publication A4015-14/20: Copper Tube Handbook
7. SOLDERED JOINTS