08-04-2014, 04:48 PM
ULTRASONIC EXAMINATION METHODS FOR WELDS
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SCOPE
This Article provides or references requirements for
weld examinations, which are to be used in selecting
and developing ultrasonic examination procedures when
examination to any part of this Article is a requirement
of a referencing Code Section. These procedures are to
be used for the ultrasonic examination of welds and the
dimensioning of indications for comparison with accept-
ance standards when required by the referencing Code
Section; the referencing Code Section shall be consulted
for specific requirements for the following:
(a) personnel qualification /certification requirements
(b) procedure requirements /demonstration, qualifica-
tion, acceptance
© examination system characteristics
(d) retention and control of calibration blocks
(e) extent of examination and /or volume to be scanned
(f) acceptance standards
(g) retention of records
(h) report requirements
EQUIPMENT
Instrument Requirements
A pulse-echo-type of ultrasonic instrument shall be
used. The instrument shall be capable of operation at
frequencies over the range of at least 1 MHz to 5 MHz
and shall be equipped with a stepped gain control in units
of 2.0 dB or less. If the instrument has a damping control,
it may be used if it does not reduce the sensitivity of
the examination. The reject control shall be in the “off”
position for all examinations, unless it can be demon-
strated that it does not affect the linearity of the exami-
nation.
The instrument, when required because of the tech-
nique being used, shall have both send and receive jacks
for operation of dual search units or a single search unit
with send and receive transducers.
Computerized Imaging Techniques
The major attribute of Computerized Imaging Tech-
niques (CITs) is their effectiveness when used to charac-
terize and evaluate indications; however, CITs may also
be used to perform the basic scanning functions required
for flaw detection. Computer-processed data analysis and
display techniques are used in conjunction with automatic
or semi-automatic scanning mechanisms to produce two
and three-dimensional images of flaws, which provides
an enhanced capability for examining critical components
and structures. Computer processes may be used to quan-
titatively evaluate the type, size, shape
Examination Records
For each ultrasonic examination, the following infor-
mation shall be recorded:
(a) procedure identification and revision;
(b) ultrasonic instrument identification (including
manufacturer’s serial number);
© search unit(s) identification (including manufactur-
er’s serial number, frequency, and size);
(d) beam angle(s) used;
(e) couplant used, brand name or type;
(f) search unit cable(s) used, type and length;
(g) special equipment when used (search units,
wedges, shoes, automatic scanning equipment, recording
equipment, etc.);