| |
|
|
|
About Your
Plumbing
How To Figure And Cut
Copper Tubing
The same kind of mathematics applies to determining the
proper length of cuts for copper tubing as is used in galvanized
pipe. Each size of tubing has a set of specifications for
the various fittings.
From these, a fitting allowance can be computed. and the
length of cut adjusted accordingly. Copper tubing is easily
cut with a cutter and should be reamed to make sure the
inside diameter is not reduced at the joint and that all
burrs are removed.
|
|
|
|
|
|
|
|
|
|
 |
"Hard"
Copper Tubing
"Hard" copper tubing is also commonly used for
original plumbing. Joints are made by soldering fittings
into position. As always, local codes should be followed.
The tools needed to make installations using "hard"
copper tubing are: cutter, reamer, torch, pliers, wrenches,
measuring tape, flux, solder (lead free), level, emery cloth
or emery paper, and steel wool
|
|
| |
|
|
|
|
|
|
|
|
How
To "Sweat" A Copper Joint |
|
|
|
|
|
|
1. Make sure that the surtaces to be soldered are clean
and bright using steel wool, sand cloth or a wire brush.
3. Insert the tubing into the fitting until it bottoms
on the shoulder.
|
|
|
|
2. Apply flux
to all surfaces to be joined.
4. Apply heat to the fitting until the solder melts
when touched to the joint. The solder should he drawn
into the crevice between the tubing and fitting, filling
and sealing the opening.
|
|
| |
|
|
|
|
|
5. While the solder is still
hot and fluid, remove any excess solder with a small brush
or rag.
6. Support the new joint
until the solder hardens. A wet rag can be applied to the
joint to speed cooling and hardening of the solder.
When applying heat to copper fittings for
the purpose of sealing a joint, be sure to insulate plastic
components, control valves, bypass valve seals and other
heat-sensitive components. Copper is an excellent conductor
of heat which may travel a considerable distance from the
point where the sealing joint is being formed. To protect
your system, wrap a wet cloth around the copper pipe between
the joint and the heat-sensitive part. The wet cloth will
keep the pipe cool enough to prevent damage. If a wet cloth
cannot be used (often the case when installing some byass
valves), those parts that may be damaged by heat will have
to be removed until the heating process is completed.
"Soft"
Copper Tubing
Annealed or "soft" copper tubing should be avoided
whenever possible as it is much more subject to physical
damage, it kinks readily when being bent, and rarely results
in a sound, neat installation. It should only be used when
absolutely necessary because of physical clearances or unusual
bends, Even then, the full diameter should be maintained.
As always, local codes must be followed.Soft copper tubing
comes in rolls, and joints are made by flaring the ends
of the tubing and using threaded brass fittings Tools required
are cutter, reamer, flaring tools, pliers, wrench and measuring
tape. Figuring lengths of cut is much less critical with
soft copper since it can be bent to adjust for slight excesses
in length.When creating a joint for soft copper, be sure
to slip the fastening nut over the tubing before inserting
the tubing into the flaring tool. The threaded end of the
nut should be facing the flaring tool. Then proceed to flare
the end of the tubing.
Pipe Measurements
In order to "come out even," an installer must
he able to figure lengths for the piece of pipe to be used
in running from one point to another. To do this, allowances
must be made for the length of threads, the size of the
fittings. etc.Each size of pipe has a set of specifications
to cover all fittings available. For example, with 3/4"
pipe, the standard thread engagement for all fittings is
9/16". This means that when a length of pipe is tightened
securely into a fitting, 9/16" of the length of pipe
will be inside the fitting. In other words, the pipe must
be 9/16" longer at each end than the measurement between
the faces of the fittings.Consider an installation where
the pipe runs vertically, then horizontally for five feet,
and then back down again, 60" between the centerlines
of the two vertical pipes.To calculate the length of the
horizontal piece of pipe, first, figure the fitting allowance
for an elbow. This is the distance between the end of the
pipe, inside the elbow, and the intersection of the centerlines
of the two pipes. Do this by checking the specifications
and determining the standard dimension of an elbow for the
distance between the intersection of the centerlines and
the face of the elbow.The fitting allowance is 3/4".
The length of pipe must be reduced by 3/4" for each
elbow that is included in the five-foot run you are making.
This is because the distance from the end of the pipe, inside
the fitting, to the intersection of the centerlines is actuallv
3/4".Since there will be two elbows, subtract 1- 1/2"
(2 x 3/4") from the theoretical 60'' run, which makes
the pipe length for cutting 58-1/2" long. Each end
will be threaded 9/16" into each of the two elbows.
Follow the same procedure for all fittings to determine
actual lengths of pipe.
Cutting Pipe
Although it is possible to make cuts that are "square"
or perpendicular to the centerline of the pipe with a hack
saw, pipe is easier to cut with a pipe cutter. In order
to properly thread galvanized pipe, a square cut is necessary.
When cutting pipe and when cutting threads with a die, a
pipe vise should be used to hold the pipe. After cutting
the pipe, the end should be reamed so that the inside diameter
is full size and no burrs remain.When cutting threads, cutting
oil should be applied three or four times. This reduces
the heat which is generated by the cutting die and prevents
threads from being torn. It also keeps the dies from becoming
dull prematurely. When the end of the die is even with the
face of the pipe, the threads are cut to standard length.Before
engaging threads in the fitting, they should be cleaned
of chips and burrs and then wrapped with pipe thread tape
or coated with pipe dope (pipe joint compound). Only the
male threads should be coated.
How To Tighten A
Fitting
Engage the threads of the pipe
and the fitting and tighten by hand until they are tight.
Then place a wrench on the bead of the fitting and turn about
one turn. Two turns may possibly be required, but no more.
PIPE OR FITTING GOUGING CAN BE MINIMIZED BY NOT CHANGING THE
POSITION OF THE WRENCH. Too much tightening may expand a fitting
so that it will leak and have to be replaced. Brass fittings
are more likely to expand than steel fittings. Use a wrench
that is properly sized for the diameter of pipe being installed.
|
|
|
|
|
|
|
|
|
