Pressure and Vacuum Systems
Ultrasonic inspection technology really works. Consider this. Packages are moving along a 20,000-foot conveyor system operated by air. How many leaks could I possibly find and in what time frame if this were already well maintained? Five technicians walked the nearly 4 mile long system using ultrasonic technology to perform an air sur-vey. The CTRL UL101 receiver was used with the Concentrator attachments to scan the com-pressed air lines in the conveyor system. The PowerBeam 300 was used with the receiver to detect leaks in the lines up along the ceiling from distances up to 300 feet away. A laser mounted on the PowerBeam allows the technician to easily spot the components for testing and to pinpoint the source of ultrasound.
The air survey resulted in 134 leaks detected and tagged for re-pair in less than four hours. Once repairs were made, a 33% decrease in the utilization of the compressor’s capacity was realized. A significant amount of the total energy used was being wasted on a single compressor in this well maintained system. Now that’s some real money!
Hydraulic and Pneumatic Systems
Hydraulic systems are under a lot of pressure. Although the oil used is much more viscous than air, it still produces a lot of turbulence in the ultrasonic range. The lack of detectable ultrasound indicates no flow. There must be a clog. Detectable flow beyond a closed check, stop, or actuator valve indicates a leak or cavitation. Here’s an example: Lost pressure in the hydraulic system of a multi-head vertical drill press was causing variations in the cutting ability of the equipment. Variations in pressure had caused premature wear on the bits and the head unit. The UL101 was used to find the problem in both the check valve and the actuator. The coolant check valve was also found to have a defective valve seat, which was creating a potential heat buildup on the drill bits.
A good example of the inspection of mechanical systems involves a major corrugator in a packaging manufacturing facility. Random listening of ultrasound to a set of gearboxes showed that one gear-box sounded significantly louder than the other. When the suspect gearbox was replaced and sent for analysis, it was found to have a faulty bearing, which caused unwanted grinding. A failed gearbox would have caused two hours of unscheduled downtime for replacement, which translates into an approximate $6,000 pro-duction loss for the company.
So you already have vibration analysis in place for your mechanical systems or maybe you are even using thermography. Great! These are both terrific tools in which you’ve already invested a lot of time and money.
Ultrasonic technology is the cost-effective tool that verifies suspicions and even detects problems much earlier. For example, a bearing is installed without any lubrication. The motor must run for quite some time before the bearing is hot enough for detection of a problem with thermography. To detect a problem with vibration analysis, the motor must vibrate with considerable amplitude.
To detect a mechanical problem with the UL101, use the receiver with a solid probe attachment and place the tip of the attachment in contact with the casing of the mechanical component. Ultra-sound created by under-lubrication is detectable with the UL101 in the first seconds of operation. Even more, you know which bearing is dry. There is no guesswork. Other conditions indicated by the use of ultrasonic technology include over-lubrication, cracking, grinding, scratches, wear, and impact.