19.1 History of Inspecting Welds
David Colameco, M.Ed.
Protecting public safety
Unfortunately accidents happen that result in the loss of life, permanent disfigurement, and/or loss of quality of life to both fabricators and the public at large. The Welding Codes chapter of this book discusses that laws, regulations, and codes are written after serious injuries or fatalities have occurred. That chapter of this book discusses how codes are typically written by groups of experts from industry, government, and research institutions. Due to this expertise contained within the welding codes, many state and federal lawmakers have mandated the use of welding codes to ensure a minimum level of workmanship in fabrications that could kill or injure the public.
As part of each welding code, inspection requirements are included to provide inspectors the means to determine if the quality requirements have been met. While meeting these requirements will not prevent all in-service fabrication failures, they will help prevent them because these codes contain rules based upon lessons learned from failures.
Enhancing fabrication quality
Welding codes provide the minimum standards for fabrications. Many companies will fabricate to higher standards for increased durability and quality to meet customer expectations. Truck companies may test their trucks in scenarios where the fabricated parts are exercised to simulate years or decades of use. When failures occur during testing, manufacturers may improve the design to avoid costly warranty claims and/or to advertise an expected lifetime that is longer than their competitors.
Failures can also be identified when a customer returns a product, or with today’s social media, when customers post about failures online. Companies can then request the failed product for inspection and interview the customer to determine what in-service conditions the part encountered. If inspection of the product finds that a particular weld is repeatedly failing for example, then the company may tighten inspection criteria on that weld if it is found that fabrications with undersized welds were sent to customers. Inspection serves as a great way to quantitatively measure and determine causes of failure.
Welding steps to enable successful inspection
As a welder and fabricator it is important to know how the inspection will be carried out and if the inspection requires a certain level of workmanship. A great example of this is the need to remove spatter from the surface of the base metal for magnetic particle testing. If pieces of metal in the form of spatter are on the surface, they will interfere with the test. It is important that the transducer sends ultrasonic waves at specified angles into the material being inspected. If spatter exists on the surface of the weldment, the transducer may not be able to be placed properly.
When reading a blueprint, the inspection method will usually be placed in the tail of the welding symbol. If you are no