July 11, 2006
Although eddy-current testing is king in the tube production industry, flux leakage is worth a look. Using a small test sample, equipment-maker InspecTech found that for 3.50-in. to 4.00-in. carbon steel tubing with wall thickness from 0.056 in. to 0.100 in., the flux leakage method found more defects and turned out fewer false alarms than the eddy-current method did.
April 11, 2006
Most manufacturers measure or test parts to verify that the parts meet quality standards. This conventional approach is time-consuming because testing adds steps and time to the production process. Furthermore, it is only as good as the sample size. A different approach to quality is to use a strain monitor to measure strain on the machine's frame. Comparing the strain with a reference (measured when the machine was known to be producing good parts) is a way to monitor the production process, and it doesn't require extra time or steps.
July 10, 2003
In May, automotive quality gurus J.D. Power & Associates released the results of its 2003 Initial Quality Study (IQS). As is the case every year, the winners will trumpet their scores while the losers will promise improvement. A closer look at the numbers, however, reveals some interesting observations.
July 10, 2003
How do you check tube fabrications to ensure they meet quality standards? Do you ship parts without checking them and hope that the next time the phone rings it isn't a prelude to a tirade from a disgruntled customer? Or do you check finished parts only to realize that your scrap rate is too high and wish you had checked them at earlier stages of the manufacturing process?
June 12, 2003
A welder's primary concern in any kind of work is ensuring his weld is sound. For this reason, it's important for an inspector examining the weld to be able to spot a variety of weld discontinuities, including:Porosity.Incomplete fusion.Incomplete joint penetration.Unacceptable weld...
December 12, 2002
Editor's Notes: In-service weld defects found in Australian refineries by an inspection team required assessment to determine the best course of action - repair, replace, or do nothing. This is the author's first-person account of the team's findings and solutions.The post-World War II period to...
October 24, 2002
Leaders who oversee weld designs, materials, methods, personnel training, and manufacturing teams should promote welding performance by addressing quality and testing issues in contracts for any work. Total quality systems and weld acceptance criteria must be specific--specified for each contract--and adherence must be enforced without wavering. Acceptance criteria for welding should be agreed to in a face-to-face meeting before fabrication begins. Before a project begins, all parties should agree on the retention time for inspection and test records—including X-rays, personnel qualifications and other project data--and the contract should state the location and description of the records storage facility.
July 25, 2002
In-process sampling and between-process checks can prevent problems at the production stage. Although using an inspection jig can be costly, some testing approaches that are not as rigorous as using an inspection jig are: stacking and blocking a sheared batch in order to scan the batch for variations; weighing castings; touring a customer's facility; and doing small batch inspections.