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Phil Burge, communication manager at SKF, has explained how the latest condition-monitoring equipment and techniques can prolong the operating life of water and wastewater pumps.

Vibration caused by the wear of components or the misalignment and balancing of rotating shafts is a common problem with water and wastewater pumps, leading to an increase in energy consumption, higher maintenance costs and, in extreme cases, to catastrophic failure.

In answer to the problem, condition-monitoring equipment, such as accelerometers, is widely used and has often proved to be the most effective method of detecting vibration and increasing temperatures.

Perhaps most importantly, these devices can form a fundamental element of holistic predictive maintenance programmes, which can then provide the early warning of a change in operating conditions, allowing remedial action to be taken before any significant damage is done.

Driven by its increasing adoption as part of plant-wide management programmes, condition-monitoring technology – including both vibration detection and thermal imaging devices – has developed steadily in recent years.

In comparison with earlier models, the latest systems now offer greater speed, simplicity and sophistication of analysis, with extremely high levels of accuracy.

Moreover, portable and handheld devices are now smaller, more powerful and feature better displays than ever, while also provided wireless connectivity to networks for remote interrogation and control, providing data than can be used for both short-term maintenance planning and long-term plant cost control.

In particular, the latest generation of sensors and accelerometers used for vibration monitoring exploit innovative piezoelectric and piezoceramic technology to deliver excellent performance.

As a result, they provide a robust and reliable method of measuring both high and low frequencies, with low hysteresis characteristics and high accuracy over a wide temperature range.

These devices can be packaged within compact stainless steel sensor housings to protect against the ingress of moisture, dust, oils and other contaminants, so often present in water and wastewater pump environments.

Mounted in a number of key locations on the equipment to be monitored, these sensors and accelerometers allow output data either to be read periodically using sophisticated handheld data collection instruments, for immediate analysis, or subsequent downloading to a PC, or being routed via switch boxes to a centralised or higher-level system for continuous monitoring.

Equally innovative is the latest generation of handheld devices that are also simplifying maintenance, ensuring that machinery continues to operate at optimum performance levels so that costs are minimised.

For example, the easy-to-read and ergonomic series of SKF Microlog portable data collectors and analysers automatically collect vibration signals and static process variables, as well as bearing assessments, from a range of sources, including handheld and magnetically mounted accelerometers, permanently mounted vibration sensors or online monitoring systems.

Temperature measurements can also be collected with non-contact infrared sensors or with a contact probe to check bearing temperatures for abnormal heat loads that could indicate lubrication problems.

The SKF Microlog Analyser AX, for example, can also be customised to meet the specific needs of individual applications, allowing the time required for equipment monitoring rounds to be cut considerably.

Users can select from a range of application modules, creating a custom device that suits their individual requirements.

Modules can be added as needs develop, keeping ongoing costs down, and can include balancing, bump analysis, recorder, frequency-response function, run up/cost down, and check to conformance.

This range of modules enables users to perform several advanced tasks with a single device, including impact tests, digital recording, modal analysis, transient phenomena analysis and quality inspections.

This device incorporates an 806MHz Xscale processor to provide real-time rate and display updates, which can be viewed clearly on the instrument’s 6.4in VGA colour display.

As with all SKF Microlog products, the Analyser AX features SKF Enveloped Acceleration technology to evaluate readings alongside established bearing vibration guidelines, while offering four-channel non-route, two-channel or simultaneous tri-axial route analysis and two-channel balancing.

Equally, the rugged IP65-rated, dust and waterproof analysers are constructed to withstand the environmental conditions common in water and wastewater applications.

In addition, the latest field-mounted, wireless condition-monitoring measuring devices, such as the SKF Multilog WMX, have been developed to form one of the key components in advanced condition-monitoring systems, collecting acceleration, velocity, displacement temperature and bearing condition data.

Typically, this is automatically uploaded for fast and simple data analysis in a condition-monitoring software suite.

Furthermore, they are suitable for monitoring hazardous, remote or hard-to-access areas, such as pump farms, as they do not rely on cables or wires.

There is also a range of software tools available that have been developed to improve data collection and analysis, helping realise the full benefits of the latest condition-monitoring instruments.

SKF’s Aptitude platform, for example, enables users to view and analyse detailed information on the condition of the equipment being monitored, as well as communicating it throughout an operation quickly and simply.

In addition, users have access to a wealth of online information and periodic results against which to compare the recorded data, resulting in improved efficiency levels as labour-intensive data analysis is replaced by an automated process that identifies the probability of specific faults within the machine before prescribing remedial action.

Once this corrective work is complete, it is then vital to continue to monitor conditions to identify areas for further improvement in terms of machine performance, energy efficiency or output.

In essence, this becomes a continuous process of machine optimisation using a database of statistics and readings gathered over time.

Accordingly, this will help to reduce overall maintenance costs and downtime, while also improving the efficiency of plant and equipment, which will ultimately boost business performance, productivity and profitability.

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