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How do I become a certified welder?
You need to take a test. This test is a
practical exam that explores your ability to make sound welds. For most codes
there is no written test or training requirements.
Can I do the welding at my facility and
send
the test assembly to you for evaluation?
Yes, most Codes
do allow this.
Which test do I take?
This is the big question. It all depends on
what type of work you are doing and which code you are working to. Each code
has its own test that, if passed, will qualify you to do work to that code and
only that code.
Can you give me some examples of the various
tests?
Yes, they are
as follows:
A. If you are welding structural
steel like a car trailer, a machine support or a handrail, then probably
AWS D1.1 is the right thing to do. If you test and pass on a 3/8"
thick plate, using a single vee groove with backing, in the vertical
position, you’ll be qualified to weld in the flat, horizontal and
vertical positions on 1/8" to 3/4" thick steel members.
B. If you are welding pipe that is
being used to contain a fluid or gas, such as a high temperature water
line, then ASME Section IX is probably the way to go. If you test and pass
on a 5" Schedule 80 (3/8" thick wall) steel pipe in the 6G (45
degree incline position), you will be qualified to weld 2.875" OD
pipe, 3/4" wall thickness and less, in all positions.
Is a welder who has passed an ASME Section
IX qualification automatically qualified for AWS D1.1?
No, each
Code only qualifies for itself. There is no hierarchy. However, sometimes the
owner can be persuaded that one Code is as good or better than the other.
Are all welds created equal?
No,
there is no such thing as the perfect weld. All welds contain discontinuities.
Each Code determines the extent of the discontinuity before it is classified a
defect and must be repaired. For example, B31 .1 does not allow any lack of
penetration. While B31 .9 only requires that the lack of penetration does not
exceed more than 1.5" in any 6" length of weld and that the incomplete
root penetration does not exceed the lesser of 1/32" or 20% of the required
thickness.
If the work is being done to B31.1 and the
temperature is 300 F at 500 psig,do we have to RT?
No, these
conditions require VT only. (See table 136.4 of B31 .1) or read the above Code
section, to determine when RT/UT is required.
What do I do if work is being done to B31.
1, and the service conditions only require VT, and the owner requests, outside
of the contract, that RT be performed?
Inform him that for the service conditions
the Code specifies that only VT be performed. This is due to the fact that the
Code has a large enough safety factor built into the design that even if there
were discontinuities contained inside the weld, that VT could not detect, that
it would still give acceptable service life.
How good do the welds have to be if the
contract states that conformance to B31. 1 is required and the service
conditions would require only VT by Code, but the contract has a provision that
the owner may perform random RT?
A. If the specifications do not
specify what the acceptance criteria is to be, then you could make the
argument that the acceptance criteria is the same for RT as it is for VT.
That is, only root and face conditions will be considered and that any
discontinuities contained within the weld will be ignored. This scenario
does not raise the cost of producing the welds. It only increases the cost
of inspection.
B. If the specifications state the
acceptance criteria, then that quality of weld must be present on all
welds. This scenario could radically increase the cost of producing the
welds.
Do we have to produce a weld map to meet the
requirements of B31?
No, The B31
Codes only require that examination be performed on 100% of the welds. A weld
map certainly helps to verify that you have performed this function but it is
not required.
Is there a difference between examination
and inspection?
Yes, B31 .1
states that there is a difference between the two. Inspection performs a Quality
Assurance function while examination performs a Quality Control function. That
is, the examiner is the one who physically performs the NDE and records the
results. An inspector has the right to audit any examination, to inspect the
piping using any appropriate examination method required by the engineering
design of the Code, and to review all certifications and records. The intent of
B3.1 is to have the contractor perform the examination and the owner perform
inspection
Do we have to hire an outside testing agency
to meet the VT requirements for B31. 1?
No, Paragraph
136.3.1 states that examination denotes the function performed by the
manufacturer, fabricator, erector or a party authorized by the owner. Paragraph
136.3.2 states the requirements for that examiner. The examiner can be qualified to
SNT-TC-1A, CP-189, AWS QC-1 or may be someone that has been qualified in
accordance with a program that is based on the following requirements-
a. instruction in the fundaments of
the NDE method;
b. on-the-job training;
c. an eye examination performed at
least once each year;
d. pass an oral or written examination
e. shall have performed the NDE method
at least once per year.
We have a job where the piping system is
clearly within the scope of B3 1.9 and outside the scope of B31. 1; however, the
contract requires B31. 1. Can we perform the work to B31.9?
No, if the
contract requirements exceed the Code requirements you must meet the contract
requirements. In this case the work would have to be performed in accordance
with B31 .1. It could benefit both parties to review the requirements after the
contract is signed. If the owner is enlightened to the fact that the higher
quality requirements will not increase service life, a change to the appropriate
code could result in savings to the owner and additional profit to the
contractor.
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