Welding - ASME Code Section IX
Welding Procedure Specification (WPS)
All parameters or Variables (essential-, supplementary- and non-essential variables) shall be specified in this document (see QW-200). This shall provide guidance for the welding personnel in the work area.
A WPS should specify ranges of variables in accordance with Section IX.
A WPS shall be written and qualified - by the manufacturer using it for Code production. Qualification is obtained by welding test pieces using the specified variables and proving by mechanical testing that the welding process as specified can be used to produce sound welds.
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Procedure Qualification Records (PQR)
A WPS may only be used after successful qualification. A test piece is welded using the specified variables and mechanically tested.
Both welding data and testing results are documented in the PQR. A PQR shall list all essential variables at least. However, it is recommended to list additional information during qualification.
A PQR as a record shall show actual values instead of qualified ranges, and may not be revised.A manufacturer's representative shall certify correctness of the records.
Welder's Performance Qualification (WPQ)
A welder or welding operator is qualified by the manufacturer employing him under the requirements specified in QW-300. This shall prove the manual skills of the welder to deposit sound weld metal. Criteria such as welding positions, pipe diameter, thickness of deposited weld metal, etc. are relevant for the qualified range. The WPQ is used to specify the range of the welder's qualification, but also to document his qualification tests. The test pieces may be mechanically tested or examined by radiography.
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