The purpose and extent of a WPS.

Updated: Jan 27



WPS - Welding Procedure Specification (The welders work instruction)

......................................................................................................................................................................................................................................................................................................

Unlike many other industrial professions, welding is arguably one of the most skilled crafts found in industry today...

........................................................................................................................

Where individual tasks combine to form the set procedures and process's of most trade activities, welding further demands a level of artistry that enables the crafts-person to cast a stream of molten metal to a finished quality that is both visually and mechanically acceptable, and meets ever more stringent trade and code requirements.


Welders may not have artistic skills on a par with Leonardo da Vinci or Michelangelo, but the skills and mastery of their craft, combined with the artistry of a true artisan allow them to replicate on a daily basis a specific process that had previously produced a weld deposit of known and acceptable quality.


The weld that's to be replicated will be extensively detailed in the PQR, (Procedure Qualification Record) and will contain every actual detail that the original welder used to produce the test weld and qualify the procedure. This includes every detail including the actual welding process, materials and consumables used, equipment settings and techniques, etc.


The PQR package will also include copy of the test results that were conducted by the test laboratory and which ultimately qualified the procedure.


From the actual data, (known as variables) recorded in the PQR document, the Welding Engineer will apply specific and permissible ranges to certain variables such as power settings and heat inputs, etc. These ranges will be predetermined by the relevant specification code, (or customer) and will be included in the WPS document.


The ranges allowed by code help to compensate for situational variances that may arise between the production floor and the original, controlled weld test procedure environment. These ranges will not be considered as having a detrimental effect on the finished quality of the weld provided the ranges allowed are not exceeded.

The purpose of the WPS document is to solely assist the welder in replicating the original, qualified weld. Nothing more, nothing less.


Adding any other information or comment to the WPS not directly related to assisting the welder replicate the original, qualified weld risks confusing and confounding him or her unnecessarily.


If you are a code qualified Welder, what information do YOU need to see in the WPS document in order to replicate the original test weld... and what don't you need to see?




69 views