October 9, 2007 | By Lewis Warren
Statistical process control (SPC) often is used to reduce the number of manufacturing defects. However, it has other uses also. It can serve to increase productivity and therefore improve a company's profitability. Statistical tools and Pareto diagrams can help you to track manufacturing problems and put you on the trail to finding their causes.
September 11, 2007 | By Kristi Nelson
A welding shop specializing in aerospace systems and parts adds nondestructive testing to its in-house capabilities to keep pace with inspection requirements and speed up part turnaround.
July 10, 2007 | By Tony Anderson
To ensure quality welds, it is important to have a quality weld inspection program in place. In order to do so, a company must understand how to evaluate weld characteristics, determine weld quality, and have a welding inspector capable of performing a number of different testing methods.
June 12, 2007 | By Paul Hogendoorn
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.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 | By Dr. Jesse A. Grantham
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 | By Dave Bird
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.
October 3, 2006 | By Michael Moles
Reliable and consistent weld inspection is a significant part of any weld quality assurance program. One type of weld inspection used over the last several decades employs ultrasonics.
July 11, 2006 | By A.C. Richardson
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.
Five types of nondestructive testing are common for tube and pipe weld inspection, and each has advantages and disadvantages that may make one more suitable than another for your inspections.
April 11, 2006 | By Paul Cameron
Although it takes effort and time, procedure qualification testing can help you standardize your welding procedures and know what to expect when it comes to the quality of your manufactured parts.
April 11, 2006 | By Paul Hogendoorn
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.
Portable technology is available that can help fabricators positively identify the alloys used in a weldment. This is especially critical when a fabricator is trying to match a filler alloy to a base alloy and application.
July 12, 2005 | By Walter Sperko, P.E.
Fabricators and contractors always should check to be sure that the extent of nondestructive examination and the acceptance criteria required are understood clearly by all parties and documented in writing.
June 14, 2005 | By Elia Levi
Fatigue causes the majority of mechanical element failures in structures and machinery. It is important to understand the causes of the failure and how to prevent or repair it.
July 10, 2003 | By Dave Petrack
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?