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INSPECTOR’S INSIGHT
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TThe topic of fit-up and dimensional inspections is important
due to the number of deficiencies reported on ASME and
National Board Qualification Review Reports for ASME and
NBIC symbol stamps. These reports indicate that fit-up and
dimensional inspections are not always being conducted or
documented during fabrication or repair operations.
ASME Code Sections I, IV, and VIII, Div. 1, 2, and 3, include
responsibilities and duties of manufacturers and Authorized
Inspectors (AIs) with regard to certain examinations and
inspections. These duties include performance of fit-up and
dimensional examinations as required by PG-90 of Section I;
HG-515 of Section IV; UG-90 and UG-96 of Section VIII, Div. 1;
AG-300 and AG-303 of Section VIII, Div. 2; and KG-300 of
Section VIII, Div. 3. Because of these code requirements,
examinations need to be identified on the drawing(s), the
traveler, checklist, or process sheets to ensure that instructions
are transmitted from engineering to production during the
construction or repair phase. Furthermore, the AI is responsible
for verifying that these examinations are performed in
accordance with the specific code section and the organization’s
quality system.
There are usually a couple reasons why descriptions of fit-up
and dimensional examinations are sometimes lacking. First,
engineers and designers may overlook the geometric dimensioning
and tolerance requirements of welded joints that satisfy code and
customer requirements. Second, production systems may not
provide sufficient guidance to construction personnel to adequately
fabricate the unit to satisfy all applicable code requirements.
Instructions should be identified on the applicable drawings and
that information transferred to the production traveler,
NATIONAL BOARD BULLETIN/FALL 2003
Fit-Up and Dimensional
Inspections
BY CHUCK WALTERS, ASSISTANT DIRECTOR OF INSPECTIONS
checklist, or process sheet. In many cases the drawings are
mute to this subject, and are left to production personnel to
determine whether fit-up and dimensional examinations are
necessary. This condition is not satisfied because the AI rarely
designates these two categories as hold points for examination.
To correct this problem, the AI should analyze the company’s
program to ensure that there is sufficient information on
drawings or other documents and that resultant examinations
are documented on a traveler, checklist, or process sheet.
A suggested way to accomplish this task is for the AI to meet
with the appropriate personnel to determine how adherence to
code requirements is being formulated and distributed from
engineering to production. Once this is established, all concerned
personnel should be involved in developing a vehicle that
will adequately address the manufacturer’s or repair
organization’s examination requirements. Also, the quality
control inspector should become more involved in the examination
process by establishing inspection points that recognize
these requirements. This can also be accomplished by developing
a thorough monitoring program by the AI.
This is not an easy task and will differ from organization to
organization. However, the code is clear and fit-up and dimensional
examinations are required. Not only are there concerns
for code compliance, but also concerns for customer requirements.
Once the manufacturer or repair organization has developed
requirements for performing the inspections, quality control
inspection and production personnel can be trained to implement
the requirements. Without this information, the pressure-retaining
item may not fully satisfy the applicable code requirements. ❖