Procedure Qualification Record (PQR)
A PQR is a document that proves by mechanical testing that a WPS is capable of producing acceptable weld quality, thereby “qualifying” the WPS. For a PQR, a welder completes a weld on a coupon of the material specified by the WPS. All essential variables (type of filler metal, welding process, etc.) specified by the WPS must be used. Any welding parameters which are not specified by the WPS may be set at the welder’s discretion. Upon completion of welding, the weldment is subjected to tension tests, guided bend tests (and fillet weld tests if applicable), as required by Section IX. (See Section QW-450 of Section IX for mechanical testing requirements for PQR test specimens.) Impact testing of PQR test specimens may also be required if minimum impact toughness properties are specified.
The welding variables that were used for the weld and the mechanical test results are recorded on the PQR document. The welder’s name and the mechanical testing company must also be recorded on the PQR document. The PQR must be certified by the vessel manufacturer or contractor as a true record of the welding variables and mechanical test results. Changes to certified PQRs are not permitted, except that editorial changes may be made with recertification of the PQR.
A separate PQR is required for each combination of essential variables specified by the WPS. More than one PQR may therefore be required to qualify a WPS. For example: A WPS may specify a base metal thickness range of 1/16 inch to 1 inch, which is too large a range to be qualified by a single PQR. The WPS may therefore be qualified by two PQRs: one PQR with a 1/8-inch thick test coupon (T) which qualifies the WPS for thicknesses of 1/16 inch to 1/4 inch (2T), and a separate PQR with a 1/2-inch thick test coupon (T) which qualifies the WPS for thicknesses of 3/16 inch to 1 inch (2T).
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