Fluke interviewed a manufacturer about air leaks. This manufacturer literally keeps the wheels of the industry turning. As one of the world's leading aftermarket manufacturers of wheel service equipment, the company designs, builds and sells products for trusted and leading brands.
Many of this manufacturer's processes depend on compressed air, and the 14,000 sq m factory has some 400 tools, all powered by a 200 hp compressor. “Everywhere in the plant we use compressed air - for pneumatic drives, robotic welders, laser cutting machines and powder coating equipment,” says the plant director. Compressed air usually involves noise, as well as air leaks.
Reducing energy waste
Air leaks cause compressed air-powered equipment to have to work harder, leading to energy wastage. The likelihood of air leaks in the factory is further increased by the presence of older equipment accumulated over the last few decades due to consolidation of several factories. In such a noisy environment, any leaks are difficult to hear, so most leak detections are carried out outside factory hours.
“We usually wait until it is very quiet in the building, outside working hours or during a maintenance shutdown, and try to detect air leaks by listening as closely as possible,” says the maintenance manager. “We also use bottles of soapy water to spray on an area where we think there is a leak and then see if air bubbles form.” This spray-and-see method requires members of the maintenance team to be close enough to the potential leak to hear it and then spray the soap solution on the right area.
The other method used to detect compressed air leaks is detection with ultrasonic air leak detection equipment. This method can only be carried out by a well-trained person and detecting all leaks takes quite some time. Small leaks can be very difficult to hear with the human ear and not all leaks are in easily accessible places. So detection can be a difficult task.
Make visible what you cannot hear
When Fluke approached this manufacturer about whether it would cooperate in testing the Fluke ii900 Sonic Industrial Imager, which can detect leaks up to 50 metres away in a noisy environment, this one was rather sceptical but very willing to try it.
The testing involved both the head of maintenance and the maintenance engineer, who alternately examined the entire plant for leaks for eight hours with two ii900 Sonic Industrial Imagers. The ii900 allowed them to ‘see’ sound while checking hoses, fittings and connections for leaks. The leak survey had a surprising outcome for the production team.
Within one working day, they found around 143 leaks, both large and small.
“I did have some doubts about the leaks the tool found, so I sprayed those spots with soapy water and indeed saw that there was a leak where the tool indicated there was one,” says the maintenance engineer.
The maintenance manager was particularly impressed by the ii900“s ability to find even the smallest leaks. ”Small leaks are very difficult to find,“ he says. ”I noticed there were leaks that the ii900 detected that we would never have found by spraying soapy water on them. We found one leak in an air pipe in the paint room that we could not feel by holding our hand above it or by listening, but it was clear that this leak had been there for some time."
The ii900's built-in acoustic array of sensitive microphones generates a spectrum of decibel levels for each frequency. Based on this output, an algorithm calculates a sound image called a SoundMap™ and this is projected onto a visible image. The SoundMap is automatically adjusted to the selected frequency level to filter out background noise. The SoundMap is updated 10 to 20 times per second on the screen.
Long-range air leak detection
The team quickly detected a leak at 26 feet in an upper air line.
“I was amazed at how easy it was to pick up the Fluke sound imaging camera and walk through the aisles to scan spaces overhead and still detect leaks very quickly,” says the maintenance manager.
The production team recognises that not only are very hard-to-detect leaks now easy to detect, but the ii900 can save significant time and costs. “Once we have found and fixed most of the leaks the first time, we can probably do a follow-up and scan the whole plant in one shift of about eight hours.” That way, huge savings can be made on overtime costs because they can already scan for air leaks during the normal day shift, instead of outside working hours.
It also leads to less energy wastage and wear and tear on equipment. “Air leaks also cause the company to lose a lot of money,” says the maintenance manager. “They are very hard to detect, so it is also difficult to send the maintenance team to the right place. Now we can take a picture of the leak with the Fluke sound imaging camera and send it to our maintenance teams as part of the work order, and it is much more cost-effective. We think it will save us a significant sum of money, both on labour and energy costs.”
