1. Welding Inspection Acceptance Criteria Requirements
2. Welding Inspection Acceptance Criteria Template
3. Visual Weld Inspection Acceptance Criteria Asme
4. Welding Inspection Acceptance Criteria Example
5. Visual Weld Inspection Acceptance Criteria Asme B31.3

The first issue considered by NCIG covers v1sual acceptance criteria for inspection of com leted structural welds. The resolution of that issue is contained in document NCIG-OI, 'Visual Meld Acceptance Criteria for Structural Melding at Nuclear Poer Plants' (VMAC). VMAC development involved the participation of a number of different organizations: UtilityCompan1es Architect/Engineers. Code or specification(including category or service) that defines the acceptance criteria used to perform this inspection The LANL Approved Welding Inspector is responsible to complete and sign this form or one containing the information specified in ESM, Chapter 13-Welding, Volume 1, General Welding Standard (GWS) 1-02 Para. Enter the Identification # or other description of the project that will provide a document trail to the welds inspected. Stage 1 - Welding Inspection Prior to Welding Work Welding symbols and weld sizes clearly specified in drawing and related documents. Weld joint designs and dimensions clearly specified in drawings and related documents. Weld maps identify the welding procedure specification (WPS) to be used for specific weld joints. Below Visual Inspection Acceptance Criteria as per API 1104: # The crack, of any size or location in the weld, is not a shallow crater crack or star crack shall be rejected. The crack is a shallow crater crack or star crack with a length that exceeds 5/32 in. (4 mm) also rejected.

Weld Surface and Volumetric Acceptance Criteria – Aluminum Alloys. Surface and Volumetric Acceptance Criteria – Steels, Heat Resistant Alloys. Weld Surface and Volumetric Acceptance Criteria – Titanium Alloys.

Welding Inspection Acceptance Criteria Requirements

I had a welding engineering student ask me why weld inspection to Canada's structural steel welding code seemed like a confusing task. To his credit, he was trying to follow code requirements in an assigned inspection task and chose not to take a shortcut to make accept/reject decisions on weld quality. In thinking about that question and looking at ways to simplify the task of weld quality inspection as per CSA W59, I quickly found that proper inspection per code requirements will remain a task requiring diligence in the interpretation of documented acceptance criteria. This article will attempt to clarify some aspects of the evaluation of weld quality made in accordance with CSA W59-2018: Welded Steel Construction.

In evaluating weld quality, inspectors should make accept/reject decisions based on comparison of the discontinuity with the applicable acceptance criteria as shown below.

This criteria is usually defined in the applicable code while in other cases may be defined by the customer. In an ideal world, this criteria would provide clear instructions or features to make rejection decisions of all potential discontinuities. The reality however, is that many considerations can influence the acceptance evaluation making decisions a challenging task. In at least some cases, this results in Inspectors taking shortcuts in making judgement calls especially for discontinuities including porosity, undercut or convex fillet welds. Due diligence to evaluate based on code requirements would require taking the time and using suitable gauges, perhaps a magnifying glass and yes, arithmetic.

Considerations

In making accept/reject decisions, the following items may need to be considered:

• Is fabrication statically loaded (clause 11) or dynamically loaded (clause 12)
• All welds must be visually inspected per clause 11.5.4.2 or 12.5.4.2 but welds subjected to additional NDE inspection may have further criteria defined
• In clause 12, porosity criteria differs for groove and fillet welds
• In clause 12, undercut criteria differs when direction is transverse vs parallel to primary stresses
• Each discontinuity needs to be identified with the correct industry standard term as criteria differs based on the type of discontinuity

The Inspector should have the clear confirmation from the Engineer regarding the first four points above for proper weld quality evaluation.

The Easy Stuff

Away from the complexity of the considerations listed above, some discontinuities are simple to evaluate. For both clause 11 and 12, any discontinuities interpreted as the following have a zero tolerance and must be rejected:

• No surface cracks
• No visible lack of fusion between welds and base metal
• No craters

Weld Profile Evaluation

All welds for both clause 11 and 12 must have shapes or profiles in accordance with clause 5.9 which in turn references Fig. 5.3 and is shown below. I'm not so sure the maximum convexity criteria from this always gets proper scrutiny with the steps required to properly evaluate. In some cases, judgement call shortcuts may be taken instead of using the steps described here.

The illustration below shows the steps to evaluate the maximum convexity of a 3/8 inch fillet weld in using this criteria and measuring the actual throat. While the profile requirements are the same for statically and dynamically loaded structures, this criterion is especially important for clause 12 inspections. As convexity increases so does that notch effect or stress concentration at the fillet toe as a location for crack initiation in fatigue loading applications.

Once the maximum throat dimension for a specific fillet size is known, it can then be measured as shown on the right. The bridge cam gauge shows a measured actual throat of 3/8 or 0.375' (9 mm). This should be rejected based on the convexity criteria resulting in a maximum throat dimension of 0.364. If the arithmetic required is too cumbersome during shop floor inspection, it is simple enough to make your own reference table using this method to list maximum throat dimensions permitted for common fillet sizes like these examples:

Fillet Leg Length = Max Actual Throat: 1/4 = 0.264, 3/8 = 0.364, 1/2 = 0.465

Porosity Evaluation

As a rounded discontinuity, porosity tends not to result in stress concentrations leading to crack initiation which is the rationale for structural codes permitting it in specified amounts.

Clause 11 Porosity Acceptance Criteria

• The sum of diameters of visible porosity does not exceed 3/8' in any 1' length of weld;
• The sum of diameters of visible porosity does not exceed 3/4' in any 12' length of weld;
• Any individual porosity pore shall not have a dimension exceeding 3/32'

Clause 12 Porosity Acceptance Criteria

• The frequency of visible porosity in fillet welds does not exceed one in any 4' length of weld and it's diameter does not exceed 3/32';
• For fillet welds connecting intermediate transverse stiffeners to the web, the sum of the diameters of visible porosity does not exceed 3/8' in any linear 1' of weld and the sum of diameters of visible porosity does not exceed 3/4' in any 12' length of weld;
• In groove welds, no porosity is permitted

Undercut Evaluation

Important differences exist in W59 with regards to the amount of undercut permitted in clause 11 vs clause 12. In the previous 2013 version of W59, the mandated Fig 11.4 was difficult to interpret particularly for thinner member thicknesses. Thankfully, that figure is no longer specified although it is still shown in the latest 2018 version.

Clause 11 Undercut Acceptance Criteria

• Material less than 1' thick: not exceeding 1/32' deep for any length or 1/16' deep for any accumulated length of 2' in any 12' length of weld
• Material 1' or thicker: not exceeding 1/16' deep for any length of weld

Clause 12 Undercut Acceptance Criteria

• Undercut is not more than 0.01' deep when its direction is transverse to the primary stress in the part or not more than 3/32' deep when its direction is parallel to the primary stress in the part

Nondestructive Evaluation Criteria

When NDE is specified after visual inspection, additional acceptance criteria may be specified based on which NDE method is used.

Welding Inspection Acceptance Criteria Template

Penetrant Testing

In PT testing, the same criteria used in visual inspection are used.

Radiographic and Magnetic Particle Testing

Although the visual inspection criteria permits no fusion type discontinuities, during RT or MT inspection specified amounts are permitted based on total length compared to weld throat size. Refer to clause 11.5.4.4 or 12.5.4.4 for details including stress loading and spacing of discontinuities.

Ultrasonic Testing

Depending on the UT technique used, the NDE inspector would refer to the following tables in evaluating inspection results.

• Fixed attenuation (FA) technique = Table 11.3 (clause 11) or Table 12.5 (clause 12)
• Time corrected gain (TCG) technique = Table X.6 (clause 11) or Table X.7 (clause 12)

This article describes ASME Section IX Radiography requirements. The RT acceptance criteria that have been addressed on QW- 191.1.2.2 refers to the welder or welding operator performance qualification. This acceptance criterion should not be confused with actual work radiographic testing acceptance criteria.

This acceptance criteria is stricter than for actual welding work that addressed in UW-51 (Full Radiography) and UW-52 (Spot Radiography). This stringency seems reasonable because with this acceptance criteria we are testing the skill of our welder and not actual welding work.

So it possible a weld seam radiographic testing to be rejected by the criteria in ASME Code Section IX but being acceptable based on the UW-51 on the ASME Section VIII Div 1.

So please make sure when you are interpreting a radiograph for welder performance qualification refer to the section IX and when it is an actual work, e.g., long, or girth seam of a pressure vessel refer to the section VIII.

ASME Section IX Radiography Acceptance Criteria

Based on the requirements of QW-191.1.2.2 in ASME Section IX any crack and incomplete fusion is unacceptable.

The length of elongated inclusion depends on the test piece thickness, for instance, any elongated slag inclusion will be unacceptable if the length is more than 1/8 inch when the thickness of the specimen is between 0 to 3/8 inch.

Visual Weld Inspection Acceptance Criteria Asme

Similarly, one-third of test specimen thickness if the specimen thickness between 3/8 inch (over) to 2 1/4 inch.

The maximum allowable rounded indication is 1/8 inch or 20 % of thickness whichever is smaller, and if there is cluster pattern then Figure QW-191.1.2.2(b)(4) must be referred. This figure shows the acceptance criteria for porosity (rounded indication) dispersion level.

The ASME Section IX Training Course is 2 days video training course and available online and the student that successfully pass the exam, receive I4I academy certificate with 16 hours training credit.

Welding Inspection Acceptance Criteria Example

Did you find this article useful? Click on below Like and G+1 buttons!

Visual Weld Inspection Acceptance Criteria Asme B31.3