What are the Major Differences between Structural Welders’ Qualifications and those of Pressure Welders?

In Canada, in most instances, welding personnel are required to be qualified in accordance with the governing welding Standards for the type of work being performed under the company’s scope of operation. For steel structural work in Canada, the governing welding Standard for testing welder’s is CSA W47.1 the Certification of Companies for Fusion welding of steel. 

For pressure vessel and pipe work the governing Code for testing welders is the ASME Section IX.

Welder qualification to CSA W47.1

The welder qualification for this structural Standard requires the following;

1. The welder must test on a groove plus a fillet and will be covered for welding all grooves and fillet welds. There is an exception for welders to qualify for only fillet welds but, they will only be qualified for fillet welds.

2. The welder can qualify on either plate or pipe. Depending on the classification required.

3. The welder may qualify using any steel materials in groups 1,2 & 3 in tables 11.1 or 12.1 in CSA W59 Standard.

4. The welder must test for each process and position required.

5. The welder requiring an all position ticket for plate must test in following progression to achieve a transferable welder qualification ticket. Flat, Horizontal, Vertical-up (or down) and overhead. For qualifying on pipe, the welder can test in the combination 2G plus 5G or the 6G position only to achieve all position qualifications for both plate and pipe. However, fillet weld positions must be qualified separately.Welders may also qualify for only one position but will receive a non-transferable welder qualification for only that specific position.

6. Welders qualifying using the standard test assemblies in CSA W47.1 will be qualified to weld steel from 3mm to unlimited thicknesses 

7. The welder’s qualification will be in effect for two years were at that time, they must perform a check test to keep their qualifications current.

8. There are separate qualifications for open root and welds with backing, defined as T and S classification.

9. Welder test assemblies are subjected to either bend testing or radiography testing for welder test evaluations.

All welder qualification testing under CSA W47.1 shall be witnessed by the CWB representative.

Welder qualification to ASME Section IX

The welder qualifications under the ASME Section IX Standard requires the following;

1. The welder only needs to test on a groove weld and will be covered for both groove and fillet welds. There are separate fillet weld tests if that is all that is required.

2. The welder can qualify on a pipe or plate test assembly and will be qualified to weld either pipe or plate for grooves and fillets.

3. The welder may qualify using any Steel material listed in P groups 1 through 15F in ASME Section IX Code.

4. The welder must qualify for each process and position they require.

5. For welders looking to qualify for all position, the standard would be 2G, 3G and 4G on plate and 2G plus 5G or just 6G position on pipe.

6. The welder’s qualification will be in effect through a continuity clause, based on welding the previous 6 months under the supervision and control of the qualifying or participating organization. However, a regulatory authority may require annual testing in which case they must perform the same testing for each process and potions.

7. Welders are qualified under ASME section IX based on the size of pipe or plate test assembly thickness ranges.

8. Welder test assemblies are subjected to either bend test or volumetric NDE tests for welder evaluations.

Witnessing of welder testing under ASME Section IX is done under the full supervision and control of the qualifying organization.

Conclusion

There are differences between the structural and pressure qualifications required for welders qualifying in steel as laid out in the text above. Perhaps, the major difference is where pressure welder qualification is simplified and allows the welder to be qualified for grooves and fillets for all pipe and plate by testing a groove only.