AS/NZS 3992 Undergoes Major Changes

AS 3992 Pressure equipment - Welding and brazing qualification recently underwent a major update. The 2020 revision corrected identified errors and anomalies in the 2015 edition, addressed issues not covered in the 2015 update, and harmonised the Australian Standard with international standards (specifically ISO 15614-1 and ASME IX) to reflect the changes in the local pressure equipment industry. As such, Weld Australia recently facilitated an interactive online workshop to provide attendees with an update on these changes, highlighting the effect on welder, procedure and repair qualifications.

Most pressure equipment is manufactured off-shore to other standards, which impacts their maintenance and repair. The 2020 update of AS 3992 addresses this reality by adopting changes to accommodate the different fabrication routes, particularly with respect to welder and welding procedure qualifications. Weld procedure qualifications have been modified for specific applications, with some testing formalised, and changes were made to clarify welder qualifications. This update also completely revamped Section 8: Procedure qualification for special welds, providing a recommended approach on how to deal with welding repairs on service exposed welds. This was inadequately described in the previous editions. Therefore, the 2020 edition of AS 3992 has moved closer to international standards, while addressing the unique challenges that exist in the Australian pressure equipment industry.

Louise Petrick (Senior Welding Engineer, Weld Australia) hosted the webinar, highlighting to attendees the importance of the changes. “This was a major update,” Petrick said. “It illustrates why we have Standards and why they must be kept up-todate,” she added.

Section Five Petrick shared the major changes to Section Five of the Standard, including the newly added clauses 5.1, 5.2, 5.3 and 5.4. These new clauses focus on general advice, materials grouping, welding energy input and preheating materials, and post weld heat treatment (PWHT) respectively.

Under 5.1, three items were added: additional materials combinations; welding consumables; and heat input information. These changes focus on the essential variables for welding procedure qualifications.

There were also updates to table 5.2, which expanded materials groupings and granted extended qualifications. Similarly, there were alterations made to table 5.3 for the range of qualification of materials for nickel alloy and steel groups. It also touches on toughness testing for thickness limitation and clarifies details on plate and pipe positions.

Section Six Section Six of the updated Standard hones in on test pieces and testing requirements. This updated section also considers requirements to qualify load bearing fillet welds, and hardness testing (where applicable), as presented in table 6.1. There were no changes to the number of tests required in this update. However, under section 6.4, the PWHT were amended to accommodate new materials groupings, and the requirement to conduct NDT before PWHT.

Section Seven “Section 7.2, that dealt with mechanical testing, has been removed, changing responsibility for testing,” Petrick said. “It clearly places the onus on the purchaser or asset owner. Tests should still follow AS 2205 - Methods of destructive testing of welds in metal.”

Changes were also made to Clauses 7.1, 7.2 and 7.4. Importantly, in Clause 7.8, the changes introduced requirements for the weld joint hardness test, when required.

Section Eight Section Eight was discussed at length during the webinar. Previous editions of the Standard did not provide a recommended approach on how to deal with repairs on service exposed welds. The update has provided clarity on how to qualify for these weld types.

Petrick shared the changes on the special welds and how they will affect repairs and all other surfacing welds. The Standard made changes to build up, buttering, overlays and clad materials, and also incorporates new information about corrosion, heat-resistant overlays and hard surfacing overlays.

Tables 8.2 and 8.3 provide information about the qualification range for parent material groups for overlay welding, and the range for the thickness of test pieces.

Section 8.3 also sheds light on temper-bead during manufacturing. This is a process where the heat input is adjusted in the second layer to ensure the first layer is tempered.

Under the changes to the Standard, welders must complete a proficiency demonstration, shown in Table 9.3, for each of the weld types.

Section Nine There were changes made to Welder Qualification in Section Nine of the Standard, specifically in reference to Clause 9.1. Under this clause, there were classifications for parent materials, welding consumable ‘F’ numbers, weld deposit thickness and weld joint detailing.

Furthermore, parts one to five of ISO 9606 were accepted as alternative qualification standard, and ASME IX with AS 3992 production tests were also deemed acceptable.

Table 9.3 of the Standard also features new information about the number of test specimens required for welder’s qualifications, specifically the special welds from Section 8.

The webinar was well attended by both members and non-members of Weld Australia, with attendees given the opportunity to interact with Petrick and gain practical examples of where and how the changes will have an impact.

“Section 7.2, that dealt with mechanical testing, has been removed, changing responsibility for testing. It clearly places the onus on the purchaser or asset owner. Tests should still follow AS 2205 - Methods of destructive testing of welds in metal.”