Look closely… and what do you see? Think about your piping RAGAGEP(s) for pressurized piping such as ASME B31.3 or .5. Answer…
What we are seeing is a piece of welded pipe that was being installed in an Ammonia Refrigeration process. As REQUIRED by ASME B31.5, Section 527.5…
527.5 Qualification Records
The employer shall maintain copies of the procedure and performance qualification records specified by ASME Section IX, which shall be available to the owner or the owner’s agent and the Inspector at the location where welding is being done.
After completing a welded joint, the welder or welding operator shall identify it as his or her work by applying his or her assigned letter, number, or symbol as a permanent record in a manner specified by his or her employer.
Thus what we are seeing in the photo is the “welders stamp” (i.e. identification symbol) at the weld.
Now this stamp (e.g. #41) will correspond with the welding documents so that this welder’s qualifications can be traced back to his/her certification. EACH WELD is supposed to have some type of “identification” so that EACH WELD can be traced back to a certified welder. Some businesses/engineers do not like “stamping” pipe so they will have some other means to identify the welder(s) and their welds on a project; however, stamping each weld is the most basic method used.
The benefit to this is that when a weld fails inspection, we know what welder did the work and we can look more closely at his/her other welds. For example, welds failing their inspection/test may be a rare occasion, but it does happen. When you have a large project where welders are making hundreds of welds and you find a pattern of a welder’s work failing at a higher frequency, one could then subject that welder’s work to more frequent inspections or remove him/her from the project.