Regular monitoring and maintenance are vital for continuous and proper pump performance.
by Samuel Munn
April 26, 2013

In today’s uncertain economy, keeping pumping systems and stations operating at their optimum capability is vital. However, many organizations responsible for this crucial task do not perform regular health checks on their pump systems.

Most people would not run their car or home heating units until they break down or stop working. Similarly, most people maintain their health with visits to the doctor or dentist.

The same principles apply to pump systems. They require the same level of preventive care and maintenance so that operators and end users benefit the most from their investments. Preventive maintenance and monitoring provide a clear picture of the pump system’s performance, save end users money and reduce environmental impact by improving energy usage.

Regular Monitoring
The maintenance of a pumping station should not be a one-time event. A robust monitoring system along with regular health checks will deliver an accurate understanding of how a pump system is performing.

When end users consider the different options for monitoring performance, they should look for a system that monitors energy use, the whole life-cycle cost of the equipment and how the pump performs against its most efficient duty point. Also, maintenance records can reveal any fault trends that will help predict or diagnose pump failure, regular breakdowns or loss of performance. This information can assist the operator in planning maintenance and controlling the budget.

Continuously-improving technology has resulted in the increased accuracy of system variable measurements. Monitoring equipment can measure pressure, flow, depth, energy consumption, vibration and temperature, without the need to drastically modify the pump station layout.

A modern monitoring system can accurately obtain and record precise data, including trends of all the hydraulic and power inputs, which display in real time as the pump operates. A visual display such as this is more informative than basic numerical data logging and can be invaluable in providing information for system troubleshooting.

Specific Requirements
Having access to the data obtained from a monitoring system is particularly important because each system or station has a different set of requirements. In general, pumps are selected based on the most efficient duty point designated by the manufacturer. Selections are most often made from desktop designs and drawings.

However, even in the best circumstances, installation of a pump system/station rarely occurs exactly according to plan. This means that the pump will probably operate outside its best efficiency point. Once installed, its performance can be monitored and adjustments can be made, such as an impeller trim or speed change on the variable frequency drive. For pump upgrades and replacements, knowing the precise pumping station system data makes accurate and efficient pump selection easier.

One example of the importance of understanding a station’s requirements occurred at a station in Pembrokeshire, West Wales. An original pump had not met the required capacity. The operator, not understanding his pump system, installed an identical pump system adjacent to the original one, and this station included very large pumps. Nothing was physically wrong with the pumps, apart from being incorrectly selected. By chance, someone involved with the station called a pump system engineering firm, and the installation of a third identical system was avoided.

This firm carried out a full health check and system analysis and suggested that a different pump should be selected. As a result, the operator saved thousands in construction, plant and wasted energy costs.

Adjusting the System Over Time
As time passes, conditions change. Components wear. Parts may be added or removed, and these changes can completely alter the system’s operation. More often than not, particularly if there is no health check in place, these changes are not taken into account. However, they have altered the footprint of the originally installed system.

Over time, pipes can become partially obstructed because of silt and debris build up, or local damage may occur in which pressure from the surface has damaged or misshaped a buried pipe. Unlike our bodies, which provide signals such as pain when they are damaged, the only signals a faulty pipe will give are problems, such as flooding or a reduction in output. In most instances, pump station operators can only see the external picture. They know that the system is not working as it should, but they have no data to support their concerns.

Many common pump station issues do not show up immediately. For example, the poor design of wet well benching or in-flow paths can lead to cavitation, pump wear and reduced performance. Analysis of the pump system throughout operation will indicate the telltale signs of performance deterioration.

In an ideal world, and particularly when it comes to large pump systems or stations that use a lot of energy, the operator should perform regular health checks through a robust and reliable monitoring system that considers all aspects of the process. This includes a software system that runs seamlessly with the pumping equipment and records data, which can be viewed remotely at any given time for a performance analysis.

Key Elements of Analysis
Products are available that can show end users how the key elements of their pumping system are operating. These elements include pressure, flow, vibration and temperature. These parameters, combined with audio monitoring, provide operators with the big picture and many small problems before they become big issues.