Some traditions never die, but sometimes even an old tradition needs a little help from something new. That was the situation for a manufacturer of a split-case gas compressor who needed an infusion of some new technology to remain profitable.
The design for this particular split-case compressor, used by the oil and gas industry to reduce the volume of material and increase product flow, has been around since the 1950s. Demand warranted continued production; however, the compressor's failure rate during pressure testing was alarmingly high because fasteners joining its top and bottom halves were not maintaining the proper tension.
It was an expensive problem.
After each completed assembly, the unit moved to quality control for pressure testing. If a unit failed, it had to be fully disassembled, remachined and then reassembled, and tested again. Unfortunately, this trial-and-error process often required as many as six complete pressure cycles before a compressor was given a green light. It was a time-consuming, costly way to make the product.
The OEM contacted Valley Forge & Bolt for help. Sales specialist Bill Denby suggested using the patented Maxbolt⢠load-indicating fastener to join the two compressor halves. These studs would replace the commodity- class product currently in use.
Maxbolt has a built-in, on-board gauge and display that continuously measures and monitors fastener tension. Shown as a percentage of minimum yield strength, Maxbolt measurements are accurate to within +/-5 percent of the fasteners' design load. Not only is this far more accurate than the +/-20 percent accuracy provided by torque measurements; it's also compliant with ASTM F2482-08 standards.
Denby specified Maxbolt knowing proper fastener tension is critical to the long-term performance of split-case gas compressors. "These compressors need to perform for decades without ever being reopened," he said. "By using the Maxbolt, the production crew can easily see and verify during assembly when proper tension has been achieved."
The proof came at the first hydraulic pressure test conducted after the OEM switched to Maxbolt. After rigorous qualification, it was evident the compressor had no leaks. Instead of having to tear it apart and start over again multiple times, workers were able to simply move on to the next compressor. Installation of the Maxbolt was also faster than that of the previously used studs, an added bonus to production.
"The mightiest system can be brought down by seemingly small but critical components. Controlled bolting with Valley Forge load-indicating fasteners has been able to save manufacturers and plant maintenance teams untold dollars by preventing lost productivity and equipment failure," said Denby.
For more information, visit www.vfbolts.com or call (602) 269-5748.
