If you are commissioning welded fabrication in Japan and your inspection body or client requires a qualified welding procedure specification, the process can seem opaque the first time. This article explains how procedure qualification works under JIS Z 3040, what the testing involves, and what a completed WPS package should contain.
What JIS Z 3040 covers ¶
JIS Z 3040 is the Japanese Industrial Standard for qualification of welding procedures for metallic materials. It covers the essential variables. Base material group, filler metal, welding process, joint type, position, preheat, and post-weld heat treatment. And defines which changes to those variables require a new qualification test. The standard applies to most structural and pressure-containing applications in Japan, though some sectors (nuclear, for example) have additional requirements.
The test piece and what happens to it ¶
Qualification starts with welding a test piece under the proposed procedure conditions. The test piece dimensions and joint configuration are specified in the standard. Once welded, the piece goes to an accredited testing laboratory for destructive testing: tensile testing across the weld, face and root bend tests, and, for thicker materials, Charpy impact testing. For pressure equipment under JIS B 8265, additional requirements apply, including hardness testing and, in some cases, macro examination.
Who witnesses the test weld ¶
In Japan, the test weld is typically witnessed by a third-party inspection body. Organisations such as the Japan Boiler Association or a registered inspection agency under the Industrial Safety and Health Act. The witnessing inspector confirms that the welding conditions during the test match the proposed WPS. Without a witnessed test, the qualification is not accepted by most inspection bodies for pressure equipment work.
What the completed WPS package contains ¶
A complete WPS package includes the welding procedure specification document itself, the procedure qualification record (PQR) with the actual welding parameters recorded during the test, the laboratory test report with all test results and acceptance criteria, and the inspector's witness certificate. Some clients also request welder qualification records for the welders who will perform the production welding. The package is submitted to the inspection body before production welding begins.
How long the process takes ¶
From the decision to qualify a new procedure to receiving the completed package, the typical timeline is three to five weeks. Test piece welding takes one day. Laboratory testing takes seven to ten working days. Inspection body review adds another week in most cases. Planning the qualification well before the production start date avoids the most common problem: a project delayed because the procedure was not ready in time.
If you need a welding procedure qualified for a project in the Kanto region, contact Weld Blend Vault. We prepare the WPS, weld the test pieces, and coordinate laboratory and inspection body involvement from start to finish.