Inspection Trends / Summer 2013 27 or PQR was changed without updating the base material type (or vice versa). For example, a WPS might incorrectly indicate an E7018 electrode to weld an ASME P-No. 8 (stainless steel) base material. Mechanical test data on PQR forms are often inappropriately duplicated from one PQR to another. This same problem occurs when multiple references to the welding consumables are used on a WPS. For example, a WPS might indicate E7018 on the first page and E8018-B2 on the second page. Always check for multiple references to make sure the consumable classifications are consistent. Using a WPS or PQR form that specifies the consumable classification(s) in only one location on the form eliminates this type of error. Beware of Outdated or Incomplete Forms Using incorrect forms leads to errors. For example, if a form for the shielded metal arc welding (SMAW) process is used for the gas metal arc welding (GMAW) process, the writer can easily fail to address shielding gas since there isn’t a data field for that variable. Errors occur when outdated or incomplete forms, without data fields for all the required code variables, are used. It is much easier to identify any missing information when proper up-to-date forms with all the necessary fields are used. Always use the latest code edition to qualify a welding procedure unless there is a specific reason to use an earlier edition. Often the code edition year listed on PQRs is a much earlier edition than was current at the time of qualification. Laboratories performing testing should also be requested to use and identify the latest code edition on the report forms. All the pages of a WPS should have the same identification number and the same revision level, and all pages of a PQR should have the same identification number. When WPSs are revised, the revision level should be increased. When PQRs are corrected or amended, a notation and recertification signature should be added in order to document the correction or amendment. Particular attention should be made to the contractor’s document control procedures. The same errors identified and corrected on one contract sometimes resurface on submittals for a later contract. The Review Process Review of procedures is complicated when insufficient information is provided with the submittal. It’s not uncommon to be asked to review a stack of procedures without being provided much other information. It is time consuming for the reviewer to track down contract specifications, materials of construction, identify any special service requirements or applicable industry standards, etc. For professional submittals, the submitter should consider at least developing a cover page that briefly describes the contract, materials of construction, any special requirements, and the assignment of the WPSs. While the review process should ultimately result in procedures that have been accepted, the shop or field CWI should verify the procedures are implemented properly; for example, verifying that the WPS is used only within its qualified limits. Occasionally a contractor will try to sneak through a WPS to weld on base materials the WPS is not qualified for, maybe with the thinking that the WPS is “close enough.” Fabrication codes generally require contractors or fabricators responsible for welding also to be responsible for qualifying their own welding procedures. In the end, the contractor or fabricator is also technically responsible for the content and accuracy of the welding documents. For reviewers who are not employed by the contractor or fabricator, the review comments should be worded so to avoid giving final “approval” of the welding documents, in which case the reviewer might be held responsible for any consequences from oversights in review of the welding procedures. While a reviewer might not always check every variable in a welding procedure, the reviewer and especially the writer should be aware of possible consequences of any oversights. An authorized inspector, for example, might decide that welds produced with a noncompliant WPS needs to be cut out rather than accept the welds as a nonconformance. Verifying that welding procedures are properly qualified, meet contract requirements, and are properly implemented is serious business. In extreme instances, noncompliance can potentially result in loss of life, or rework costs and delays totaling hundreds of thousands if not millions of dollars. Commonly, errors are attributed to the submitter or writer of the procedures failing to pay attention to the details of the contract or the particular service requirements. The writer, submitter, and reviewer should always have a basic checklist in mind regarding how welding procedures are written and qualified for the industry they serve. That checklist would vary from industry to industry. A mental checklist might include, for example, contract specification special requirements, specific code restrictions, NACE service, cryogenic service, seismic service, etc. Specific code restrictions might include, for example, mandatory preheat or PWHT requirements found in ASME B31.1. Writing and reviewing a welding procedure based on the base code welding requirements is usually a straightforward task. Making sure requirements of all associated relevant standards are addressed can require much more diligence. When writing a procedure, it is always advisable to use the appropriate code tables and references like a checklist in order to verify that all the necessary code variables have been addressed in the WPS and PQR. How to Review Procedures Following is a suggested methodology for reviewing procedures:
Inspection Trends | Summer 2013
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