Whether you need to measure dimensions or perform some sort of flaw detection on sheet, tube, or pipe, you'll find what you need in this technology area. It discusses measuring coordinates, diameters, and hardnesses; flaw detection using eddy current, ultrasonic, radiographic, and X-ray systems; and using a few other equipment types, such as vision systems and material composition analyzers.
June 12, 2007
Conventional quality control in tube bending operations usually means detecting the number of links on a tube bending mandrel. When such a system detects that a mandrel link is missing, it shuts down the system so personnel can discard the last bent tube and replace the mandrel. Unfortunately, the broken mandrel link usually is a symptom of a larger problem—one that may have produced poor-quality parts long before the mandrel broke. br> br>Another method, process variation monitoring, measures the tension on the mandrel and alerts the equipment operator when the tension changes. This lets the manufacturing personnel know that a problem is developing while it is still small and manageable.
April 10, 2007
Good welders learn to inspect their own work, but welders are just one part in a long list of variables (and people) involved in ensuring quality welds. Thorough communication of the welding parameters, as well as proper training to carry out the design, can help welders achieve quality work and to reduce the number of rejected welds.
March 13, 2007
Manufacturing processes are prone to variances, resulting in manufactured products that do not conform to specifications. Dozens of types of electronic sensors and measurement systems are available that fabricators can use to verify that their products are not defective. Understanding what types of sensors are available and how they work are the first two steps in implementing electronic sensing devices for quality control.
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...