D1.1 Qualification for CWI Part C: Clauses 5 and 6

What qualification questions ask

AWS's Part C information guide sets qualification at a minimum of 25% of the scored questions, the same as fabrication and inspection. With about two minutes per question, you cannot read the code during the exam. You need to know which clause, part and table to open.

Most qualification questions fall into three groups:

• Does this WPS need testing, or does it meet the prequalification conditions?
• If it was qualified by test, what does the test cover, and which specimens were needed?
• Is this welder qualified for this position, thickness and process?

The map: Clauses 5 and 6

Clause numbers in this guide follow D1.1:2020, the edition AWS lists for Part C. If you learned from the 2015 edition, the content moved but is largely the same.

• Clause 5, Prequalification of WPSs (Clause 3 in 2015). The conditions a WPS must meet to be used without testing. They cover processes, base and filler metals, joint details, preheat and the prequalified WPS requirements table.
• Clause 6, Qualification (Clause 4 in 2015). Part A has general requirements, including how long a qualification lasts. Part B covers WPS qualification by test. Part C covers welders, welding operators and tack welders. Part D covers CVN (impact) testing.

A quick way to sort a question: if it asks whether a WPS needs testing, start in Clause 5. If it asks what a test covers, go to Clause 6, Part B for procedures or Part C for people.

Prequalified WPSs

A prequalified WPS skips the procedure qualification record. It does not skip the rest of the code:

• It must still be written. "The joint is prequalified, so we have no WPS" is never an acceptable answer.
• Every condition must be met. Examples of a failed condition are an unlisted steel, a joint detail outside its tolerances, or a parameter outside the requirements table. If any one fails, the WPS has to be qualified by test.
• Welders still need qualification. Prequalification covers the procedure, never the person.

Clause 5 opens by naming the processes that can be prequalified. Read that list closely, because the exam likes the exceptions, such as GMAW with short-circuiting transfer (GMAW-S).

The prequalified WPS requirements table

This table sets limits by process: electrode size, current, layer thickness, single-pass fillet size and so on, often split by welding position. To read it:

1. Find the process column or row.
2. Find the variable the question asks about.
3. Pick the position column last, and check you are not reading the row above or below.

Prequalified joint designations

The joint figures in Clause 5 use a short code. It reads left to right. First comes the joint type, then a letter for penetration and thickness. Next is a number for the groove type, then an optional lowercase letter for a variation. The legend that goes with the figures explains every symbol, so tab it.

Worked example: in B-U2a, B is a butt joint and U means CJP of unlimited thickness. The 2 is the single-V groove, and "a" marks one variation of that detail. Once you can decode the name, you can go straight to the right figure. There you read its root opening, groove angle, allowed positions and processes.

WPS qualification by test

When a WPS is qualified by test, Clause 6, Part B sets the test weld, the specimens and the range qualified. Two kinds of table do most of the work:

• The essential variable tables. They list the changes to a qualified WPS that require requalification. Read the column for your process.
• The specimen and range tables. They cover each test type: CJP groove, PJP groove and fillet. For each, they give the specimens required and the thickness range qualified for a given test thickness.

To use a specimen and range table, find the test type, then the row for the test plate thickness. Then read across for both the specimens and the range.

Worked example: a CJP groove test on 1 in. plate needs two reduced-section tension specimens and four side bends. The plate must first pass visual examination and NDT. It qualifies 1/8 in. and over, with no upper limit.

When the contract calls for CVN testing, Part D adds specimen locations, test temperatures and supplementary essential variables. If the contract does not call for it, Part D does not apply.

Welder qualification

Clause 6, Part C covers the people. It has its own tables, separate from the WPS tables:

• Positions qualified. One table lists, for each test position on plate, pipe or tubing, the production positions qualified for groove and fillet welds.
• Specimens and thickness qualified. Another table gives the bend specimens required and the thickness range qualified for each test plate or pipe.

Worked example: a welder passes a 3G groove test on plate. The positions table shows that this covers groove and fillet welds in the flat, horizontal and vertical positions. Overhead needs a test made overhead, such as 4G or 4F.

Other welder rules sit in the text rather than the tables. Know where each one is:

• Period of effectiveness (Part A). Qualification has no fixed expiry. It lapses after a stated gap without using the process, or when there is reason to question the welder's skill.
• Previous qualification (Part A). Tests made for another employer can be accepted under stated conditions.
• Retests (Part C). The rule differs for an immediate retest and a retest after more training.
• RT in place of bend tests (Part C). Allowed for most processes, with an exception you should mark.

Bend test acceptance

Bend specimens are judged on the convex surface with three separate checks:

1. The size of the largest single discontinuity.
2. The combined length of the smaller discontinuities.
3. A separate allowance for corner cracks, which changes when slag or another fusion discontinuity caused the crack.

Work the checks in that order, and do the sums on scratch paper. A specimen can pass check 1 and still fail check 2. For example, take four indications of 1/8 in. each. Their total is 1/2 in., which is over the total allowed, even though none is too large alone.

How to study this area

1. Tab the start of Clause 5, the prequalified WPS requirements table, the base and filler metal tables and the joint detail legend.
2. Tab Clause 6, Parts A to D, and each table in Parts B and C.
3. Practice reading each table row by row. Many wrong answers on the exam are values from the row next to the right one.
4. When a question names a welder test, write the position, thickness and process on scratch paper before you look anything up.

Mark J. Curry tip: highlight the column headings in the qualification tables, not just the values. Under time pressure, the heading is what keeps you in the right column.

Common traps

• Confusing procedure qualification (the WPS works) with performance qualification (the welder can make it).
• Treating "prequalified" as "no paperwork.".
• Using the welder thickness table for a WPS question, or the reverse.
• Forgetting that GMAW-S is outside prequalification and has its own exception in the welder rules.
• Reading 2015 clause numbers into a 2020 book. If your training material is older, convert: 2015 Clause 3 is 2020 Clause 5, and 2015 Clause 4 is 2020 Clause 6.

Related: how to pass CWI Part C with the D1.1 code book.

Practice this domain

Sources

The D1.1 Qualification questions cite these documents, by document and, where we can confirm it, chapter or section. We never reproduce them.

1. AWS D1.1 (43 questions)

Found a mistake? Use "Report a problem" under any question, and Mark J. Curry checks it.

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