NONDESTRUCTIVE TESTS AND
If leather protective clothing is not available,
INSPECTIONS
woolen garments rather than cotton garments
should be worn. Wood does not ignite as readily as
A number of nondestructive techniques are used
cotton, and it affords greater protection from
to determine the quality of welds and welded
changes in temperature. Cotton clothing, if it must
be used, should be chemically treated to reduce its
structures. Nondestructive tests and inspections
include visual examination, magnetic particle
flammability. Synthetic fabrics should not be worn.
inspection, liquid penetrant inspection, radiographic
inspection, and ultrasonic tests. Some of these
Report all injuries to the medical department as
techniques are widely used throughout the Navy,
soon as possible. Even a slight burn or scratch
and others are used only at large production or
should be treated promptly to prevent infection.
repair activities. These tests will be described in
Eye burns should be treated IMMEDIATELY. All
chapter 11 of this training manual.
eye burns should be seen as soon as possible by
medical personnel.
VISUAL EXAMINATION
SOURCES OF INFORMATION
Prior to being tested by any other nondestructive
To keep abreast of changes in the field of
test, all welds must pass a visual examination.
welding, it is essential that you be familiar with a
Visual inspection of welds is useful for detecting
number of sources of information. There are
undercutting, large cracks, inaccurate dimensions,
numerous Navy and commercial publications
and other obvious defects. However, there are
pertaining to welding. Some of these publications
many serious defects that cannot be detected by
have already been mentioned earlier in this chapter.
visual inspection, even by an experienced inspector.
In the field of welding, as in so many other fields,
Visual examination of welds is NOT adequate for
official publications are constantly under revision;
determining the internal soundness of welds or for
therefore, it is important to make an effort to keep
detecting very small surface defects.
up with the latest changes as they are issued.
The basic naval reference on welding and allied
SUMMARY
processes is NSTM, chapter 074, volume 1.
This chapter has covered several areas of basic
welding. You now have the basic knowledge of the
HYDROSTATIC TESTS
welding processes, basic sequences, and the
positions of welding. You were given the basic
All welded piping must be subjected to
information on joints, welds, weld symbols, welding
hydrostatic tests to prove the tightness and the
symbols, weld defects, and filler metals. With the
strength of the joints. Test pressures are usually
knowledge gained from this chapter, you are on
included in the instructions or specifications for the
your way to learning to become a good, safe, and
welding. If test pressures are not specified, the
conscientious welder. Safety can never be stressed
hydrostatic test is normally performed at 135
enough.
percent of the maximum working pressure.
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