Our previous article discussed the importance of having a specification for weld quality. In this article we’re talking about the importance of one of its basic components: Welding Procedure Specifications (WPSs). Many fabricators don’t have WPSs. They rely in the experience of their welders to select the right parameters. As much as we want every […]
If you have been reading our articles for some time you know how strongly we feel about having documented welding procedure specifications which have been qualified by testing or prequalified in conformance with code requirements. Yet when we recommend that these very important documents be developed and used in production we get a lot of […]
It is often incorrectly assumed that quenched and tempered (Q&T) steels are hard to weld or even completely unweldable. This assumption is inaccurate as most Q&T steels have great weldability. However, extreme care must be taken to prevent cracking or loss of certain mechanical properties. A very common quenched and tempered steel is ASTM A514. […]
Last week we had the pleasure of working with a fabricator of pressure vessels in order to help them reduce manufacturing costs. As mandated by the ASME Boiler and Pressure Vessel Code this fabricator had welding procedure specifications (WPSs) and procedure qualification records (PQRs) in place. These were properly written, tested and documented. The WPS […]
Not all weld discontinuities are weld defects, but all weld defects are discontinuities. Understanding the difference will let you know if you need to scrap a part, repair it or simply add more weld. There are many codes depending on what type of product you are welding on. The codes are used as guidelines by […]
We receive several calls about welding stainless and the beautiful rainbow colors, or lack thereof, on the weld and heat affected zone. Is the tinting an indication of quality? Are these colors acceptable? Do they show that the weld had enough heat to penetrate? Why do they need to be cleaned? The questions are endless. […]
Designing for fatigue is very different than designing for static loads. One of the biggest challenges is being able to estimate the loads, timing of the loads and duration of the loads. If you look at a bridge you have to estimate the number of vehicles going on the bridge every day, the weight of […]
The majority of industrial equipment and welded structural components are subjected to repeated fluctuating loads. These loads are typically of magnitudes that are within the elastic region of the material and well below its yield strength. This means that any deformation of the structure caused by the applied stress will then return to its normal […]
If you have taken or hope to take the CWI exam you probably have searched for some practice exam questions. In practicing for the code book portion of the test you may have come across a few questions for which you could find the answer, but didn’t really understand the importance of the question or […]
In our previous two articles we talked about categorizing cracks based on when they occur and in which direction they propagate. Today on our third and final article on understanding why your welds crack we look at the importance of location. If you want to review or if you missed our previous two articles simply […]
