Welding

The most obvious difference between ASME Section IX and AWS D1.1 is that D1.1 addresses fabrication, erection, inspection, and welder and welding procedure qualification. ASME is specifically for welder and welding procedure qualification. A "code of construction," such as ASME Section VIII, Division I, must be used in conjunction with Section IX for fabrication.

Some work contracts require that a specific code be used for qualifying the welders, but in many cases either code is sufficient. If the job consists totally of structural welding and the contract specifies the AWS Structural Code, then that is the code that must be used for all aspects of the job.

If the job entails pressure vessels or piping, the ASME Boiler and Pressure Vessel Code must be used.

If the job is related to ductwork associated with a boiler, the contract usually allows qualification with either code. Choosing a specific code when one is not specified in the contract often involves a fine line.

 

Qualification Basics

The basic contents of a procedure qualification are the same in both programs.

The welding procedure specification (WPS) is a document that is intended to provide direction for the welder. It also depicts the joint design and welding materials, parameters, and technique and code requirements.

The Procedure Qualification Record (PQR) is a record of test results for the welds made in accordance with the WPS. Destructive testing (tensile pulls, bends, etc.) is required for PQRs in all codes. AWS D1.1 also requires Non Destructive Testing for procedure qualification. 

ASME Section IX does not.

The Welder Qualification Test Record (WQTR) comprises the results of a test to prove that a welder is qualified to weld to a certain WPS. It includes qualification of the range of base materials, weld materials, positions, and so forth. These tests consist of guided bends, breaking of fillet welds, and macroetching. In some cases, the test coupons may be radiographed in lieu of destructive testing.

AWS D1.1 Specifics 

The AWS D1.1 code qualification is specifically for carbon and low-alloy metals. The minimum thickness addressed is 1/8 in. The maximum yield strength addressed is 100 KSI.

This code, generally used for buildings and support structures, is useful for fabricating and erecting any welded structure.

Materials for Pre Qualification by AWS D1.1

The prequalification Section 3 of AWS D1.1 lists materials for prequalifying the WPS. These materials are listed in groups that are assigned Roman numerals. Although the groups reflect a somewhat ascending alignment as to the yield strength, there are instances of overlapping within three of the four groups.