Instruments Enable Multiparameter Monitoring

Today's maintenance engineer is a far cry from that of a spanner-wielding repairman called in when something has broken down. The role of the modern maintenance department is to prevent the equipment failing in the first place. Predictive and preventive maintenance strategies, for example, have moved the engineer's focus away from the repair shop and on to the day-to-day operation of machinery, with the aim of uncovering potential problems before they can take hold. Underlying this change in emphasis are the increasingly sophisticated condition monitoring procedures now available for most types of plant equipment. Even at the basic level, there are kits available from the likes of SKF that include a range of portable instruments to enable a multiparameter approach to monitoring. The collection and correlation of data on parameters such as vibration, oil condition, temperature, speed and the like helps ensure an accurate and reliable assessment of a machine's condition. On a wider level this approach can be extended to networked monitoring systems that provide online information. These allow maintenance personnel to focus on diagnosing and correcting equipment problems, rather than spending their time on collecting the condition monitoring data. In many cases, however, equipment problems, such as premature bearing failure for example, are not the result of the normal wear and tear associated with plant operation. Far too often, they can be directly attributed to a combination of poor installation and maintenance procedures. Misaligned shafts, for example, are estimated by SKF to be responsible for up to a half of all costs related to rotating machinery breakdowns. Poorly specified lubrication also contributes to a situation in which it's estimated that 36% of all bearing failures are due to incorrect specification and inadequate application of the lubricant. Getting these basics right from the start, in plant design and construction and in the setting up the correct maintenance procedures, leads to extended machinery operating life and improved plant reliability - and is easy to do using the appropriate tools. Accurate shaft alignment, for example, was once a highly skilled operation best left to experienced engineers with their dial indicators and other specialist equipment. That experience is thin on the ground these days, but the latest generation of laser alignment tools can offer quicker and more accurate results than the traditional methods. SKF's shaft alignment TMEA series of instruments, for example, are easy to set up and use. They consist of two self-contained units, mounted opposite each other on the two shafts to be checked. Laser beams are transmitted from one to the other, with a handheld LCD display unit showing the actual alignment status. As adjustments are made, normally by inserting shims under the machinery feet, the display counts down to zero, indicating the correct alignment. The process is a simple three-stage operation - measuring, aligning and documenting. The latter is particularly important in today's plant environment, where records of a machine's condition over its working life are of great benefit to the maintenance engineer. This applies equally to keeping records of a machine's lubrication. It might be self-evident, but any bearing will fail prematurely without proper lubrication. Even if the correct lubricant is being used, too much or too little can be a major cause of bearing failure. With that axiom in mind, SKF developed System 24 - a range of automatic lubricators that does away with the need to keep a wide inventory in stock. Mounted in seconds at the point of lubrication, these units automatically generate the pressure to dispense the lubricant, reliably and consistently at an easily adjusted flow rate. System 24 provides a reliable alternative to traditional manual maintenance procedures, but for automatically lubricating multiple grease points there is the System MultiPoint, capable of delivering up to 10ml of grease per outlet per day. Automatic lubricators such as these do away with the expensive and time-consuming task of manual lubrication, with all its inherent dangers of under- or over-greasing. In combination with accessories such as the DialSet programme to calculate the dispense rate, the accuracy of lubrication can be electronically controlled. As with the benefits of correct machine installation offered by laser shaft alignment tools, the result is a 'fit and forget' system that enables the maintenance engineer to concentrate on the job in hand - keeping the plant running, and not fighting fires set by poor installation and maintenance.