Ultrasound is more than a leak detector

January 30th, 2015

A major part of utilizing predictive maintenance tools effectively is to combine different analysis techniques to provide as broad an approach as possible. Then, by tracking results over time, plant managers can see the data trends and determine where and when problems are likely to occur.

Deborah Hayes of Dmax Ltd. conducted a seminar on the advantages of using ultrasound in partnership with other predictive maintenance techniques to uncover performance trends. She discussed the ways ultrasound has helped her company save money and increase plant efficiency, using her own industry needs to demonstrate ultrasound uses that apply to manufacturing plants of any variety.

Any factory would love to be able to increase its efficiency and avoid spending a fortune on repairs. Fortunately, ultrasound has the benefit of being fast, non-intrusive and predictive. When used as a first step for predictive maintenance on all of your plant’s assets, the technology can provide valuable insight about where a problem is occurring. Then, vibration testing can give more specific information about the nature of the issue.

Not just a leak finder – but still a good one
Dmax Ltd. machines and assembles the Duramax Diesel Engine for General Motors and uses a variety of predictive maintenance tools, including an infrared camera, vibration detector, motor circuit testers and an ultrasonic probe. The plant’s investment in predictive maintenance paid itself off in a single day of leak detection. They discovered there was a 65-gallon hydraulic leak, but they couldn’t find it. After a month of losing thousands of dollars through the leak, they turned to ultrasound. One day after purchasing the system, they found the leak.

While ultrasound leak detection is an excellent way to determine where a plant is losing steam or compressed air, its ability to supply predictive maintenance is of equal value. Problems within machinery do come out of nowhere – there is usually a long period of degradation before a malfunction rears its head. As the component deteriorates, its performance declines, creating inefficiencies and unexpected costs. Therefore, it is not enough to resolve an issue once it becomes evident, because the machinery loses operating efficiency long before that.

Ultrasound probing lets the user hear inside of a machine, which provides an understanding of a piece of equipment that a visual inspection does not.

A factory-wide solution
The ultrasonic probe allows many plants to run multiple diagnostics checks per year on their entire infrastructure. Dmax Ltd. runs a check on all of its 1,500 pieces of equipment twice per year. Then, if one component indicates noise inconsistent with the norm, they can use vibration condition monitoring to determine the specific issue.

The ability to run multiple checks per year on all or most of a plant’s equipment will also let factory managers track and log trends so they can successfully predict when components will wear out, rather than reacting to issues once they’ve become evident later along the P-F curve. That also means the machinery can stay in use for longer – ultrasound is quick and non-intrusive so it doesn’t require any dismantling of machinery. Additionally, it prevents the need for big repairs, which also allows equipment to run uninterrupted year-round.

Plus, because managers will know exactly which parts are needed and when, they can keep inventory to a minimum and save money and space.

Tracking the data
Collecting data trends is an essential part of the implementation of a good predictive maintenance system. Over the course of a few years, a plant manager should have a firm grasp on some emerging patterns in their equipment. Some parts will show corrosion or damage after certain time intervals, so repairs can be made before it gets out of control.

Dmax Ltd. uses 500 ball screws throughout its production. Any one of these can require better lubrication or some other routine maintenance in order to optimize its functionality. Because a single ball screw can cost almost $18,000 it is crucial that they be adequately maintained so as to avoid replacement. Gearboxes are another ubiquitous piece of equipment at the Dmax Ltd. plant, with the price of a single unit running upwards of $7,000.

By running semi-annual diagnostics on each of these pieces, Dmax Ltd. has reduced the amount it spends on replacements and can instead make small repairs as needed. Plus, the quality of the parts manufactured using the ball screws and gear boxes is markedly higher and more consistent as the tools themselves can perform optimally.

For example, the results of one ultrasonic inspection yielded this report:

“During an ultrasonic check, we found an abnormal sound coming from CB-10 St8’s Z-axis ball screw. Recommended action: Check ball screw gearboxes for oil and inspect ball screw and nut for wear. Also inspect couplings. Drain gearbox oil and check for debris.”

Because preventative checks were performed the plant will avoid an otherwise expensive and urgent problem. When a component does require further inspection, that’s when vibration analysis and other predictive maintenance techniques should be deployed.

While building a RCM program, it is necessary for you to keep an open mind. Be willing to test different techniques on different equipment – there is rarely a one-size-fits-all solution. The important thing is that a consistent approach is in place, that information is kept and tracked over time and that they take a comprehensive approach. Understand the benefits and drawbacks of each process so that you can build an all-encompassing program.

With that said, ultrasonic inspection is a good place to start. There are training materials available for factory managers to acquaint themselves with different sounds to look out for – grinding, gravelly noises, and so on. The check itself takes no more than a few minutes and any additional maintenance can be dealt with on the third shift so production won’t take a hit.

Ultimately, the best way to keep operations running smoothly and efficiently is by taking action before a problem arises or a mechanical failure occurs. By taking a proactive approach and using some of the techniques outlined, plants can maximize their potential and minimize their maintenance expenses.

Suggested Ultraprobe Instruments for Ultrasonic Condition Monitoring: Ultraprobe 10,000; Ultraprobe 15,000
Suggested Ultraprobe for Lubricaton Monitoring: Ultraprobe 401 Digital Grease Caddy

©2017 UE Systems