material could cause the failure of the system and result
interfere with other fixtures or the operation of other
in flooding, fire, equipment damage, even the loss of
piping systems. Also, be sure you have enough of the
materials on hand to complete the job before you start
it. Blueprints contain lists of materials needed and the
9. Report any unsafe act or condition to your
amount of each material required for that system or
immediate supervisor before proceeding with the task
subsystem. If blueprints are not available, you will have
to compute the amount of materials you need.
REPAIR OF PIPING
Repairs to piping systems are classified as
permanent or temporary. The type of repair used
Before you begin the work, make a diagram, and
depends upon the circumstances at the time the repairs
note on it the measurements of the new assembly. These
are made. If the system can be secured, isolated,
measurements can be taken in any one or all of four
drained, and the necessary material is available, you
ways: end-to-end, face-to-face, center-to-center, and
should make permanent repairs. If not, then you should
end-to-center. Figure 16-1 illustrates these four
make a temporary repair to restore the system for use
methods of measuring pipe. The center-to-center
until permanent repairs can be made. Since temporary
method, by which a large number of measurements can
repairs are a damage control function in nature, this
be taken, is the method most commonly used.
chapter will only discuss permanent repairs to piping
systems. For further information on temporary repairs
Measurements give the overall picture. However,
and to become proficient in their uses, it is highly
when actually cutting a length of pipe, you must add
recommended that you study the Damage Controlman
allowances to the "as taken" measurements. For
training manual and qualify in DC PQS for pipe
example, a l/8-inch IPS threaded pipe will screw 1/4
patching and repair.
inch into a threaded fitting. When computing the pipe
length, you need to allow for that extra 1/4 inch. Figure
16-2 shows the amount of allowance required to make
a tight joint for other sizes of pipe.
A repair is considered permanent if it meets two
NOTE: Threaded fittings have a limited use in
requirements. First, it must restore the piping system to
shipboard piping systems. They are not permitted in
its original service requirements. Second, it must be
critical or hazardous systems.
expected to last the life of the system.
A critical or hazardous system is defined as a
The method of repair depends on several things.
system where a joint may fail and cause one of the
First, evaluate the nature of the damage. Next, consider
the operating conditions of the system. Finally, consider
the materials from which the system is made. Normally,
Major damage to the ship
you will replace the complete section of damaged
piping or the damaged fitting. However, if the damage
is minor, you can often make the repair by brazing,
welding, or even patching. Permanent minor repairs
made in this way will normally save you time and
expense when compared with the replacement of the
entire section of the system.
Numerous details are involved in replacing a
system or part of a system with new material. You will
normally work from a blueprint, if available. If not, you
will have to make your own plans or sketches. Whether
you use blueprints or sketches, visualize what the
completed job will look like. When you make your own
Figure 16-1.--Methods of measuring pipe.
plans, make sure your completed repairs will not