A welding procedure specification is a document. It contains a set of written instructions that welders use to make a weld. Normally, the WPS is written in compliance with a specific code, specification, or definition. Common examples include ANSI/AWS B2.1, Specification for Welding Procedure and Performance Qualification and ANSI/AWS D1.1 Structural Welding Code-Steel. A competent review of welding procedures helps to ensure that production welding is done according to the requirements of the construction code and any additional requirements imposed by a contract specification and applicable industry standards.
Unfortunately, many welding supervisors are not trained in the proper use of welding procedures. Too often, welding procedures are a form of window dressing that are pulled from files to show inspectors, or used at the beginning of contracts and never seen again.
Yet, imagine the consequences if any of the following occurred:
- Piping for critical steam service was welded with the wrong type of consumable.
- Austenitic stainless steels for corrosive service were welded using plain carbon steel welding consumables.
- Piping or vessels for cryogenic service were welded without the required Charpy impact tests.
- Gas tungsten arc welding occurred using an argon/oxygen shielding gas mixture.
- ASME code work took place using AWS D1.1 welding procedures
It’s obvious that welding procedure specifications should not only be used—they should be thoroughly reviewed as well. The examples above are just a few of the glaring errors found during welding procedure reviews. The list of mistakes and omissions goes on and on, from minor inconsequential and typographical errors to major critical miscalculations.
Moreover, just because a Welding Procedure Specification (WPS) or Procedure Qualification Record (PQR) has been “certified” by the manufacturer or contractor as being in conformance with code requirements, does not mean that is actually the case. In some instances nothing could be further from the truth.
A large percentage of errors are due to the writer of the WPS failing to do the following:
- Proofread the document
- Do a variable-by variable code check
- Ask himself if the procedure makes good sense
Most errors seem to be due to a lack of attention to detail. Therefore, the writer should always:
- Check the code.
- Check the contract.
- Check for special service requirements
As with writing any formal document, it’s advisable to draft the procedure, walk away from it for a day or two or even longer when possible, and then come back to it again and review it for technical content and accuracy. Whenever possible, ask another competent individual to review the document. Also consider asking an experienced welder to look at the procedure.
A review by independent organizations or third-party insurers who have welding experts generally helps to ensure the documents are properly written, qualified and, certified.
Source: Luke, Spencer O. (2013, Summer). Reviewing Welding Procedures. Inspection Trends, 16(3), 26-28. Inspection Trends is available for free with your AWS membership.