Online Condition Monitoring

The Environment Agency has installed an online condition monitoring system at one of its remote pumping stations near Hull, UK, to enable its engineers to make key asset management decisions regarding two critical floodwater pumps. Situated on the outskirts of the village of Patrington in the East Riding of Yorkshire, the Winestead pumping station is remotely located across the end of a drain. The station houses two 240kW vertical spindle, axial flow pumps that each transfer 3,700 litres of floodwater per second back into the river. The pumps were originally commissioned in 1976 and were designed to last for 50 years with major refurbishments in that timescale. The Environment Agency in Hull is responsible for up to 100 pumping station sites across the region. Depending on its location, each station can house from one small submersible pump up to four larger 250kW units. Historically, these pumps would have been more involved in preventing tidal flooding. However, nowadays, with the reduction in availability of undeveloped agricultural land that had originally provided better drainage and soak away facilities, they are increasingly being used to pump larger amounts of rainwater back into the surrounding rivers. As Simon Thompson, MEICA Operations Engineer based at the Environment Agency’s offices in Hull points out: “Recent flash flooding incidents have reminded us of the challenges faced in maintaining pumping units that are not in continuous operation. When floodwaters reach a certain level, the duty select pump should automatically start operating to return the water levels back to normal. However, if there is a problem with this pump, the duty assist pump will take over. Unfortunately, if weather conditions are such that these pumps have stood idle for some time, our engineers have no way of knowing if they are in good working order for the next time they are called upon.” When Thompson joined the Environment Agency from British Sugar 18 months ago, there was only limited information on the condition of all of the pumping stations under his remit. Some of the sites had been previously owned by other authorities and subsequently handed over to the Environment Agency with little or no maintenance history. "One of the major challenges for me was how to decide which pumps should be refurbished with little or no previous maintenance history to go on,” continues Thompson. Very often we would be faced with a breakdown before one of our field engineers would be required to refurbish the unit. They had no means of evaluating the condition of the pump other than running each one for periodically and reporting any unusual noises which would require further investigation.” Having initially considered an electrical-based pump efficiency monitoring system to provide data on the condition of the pump units at Winestead, this was eventually deemed useful for electrical monitoring and fault finding but could not provide the vibration data relating to the condition of the bearings inside the pump. Thompson was familiar with the benefits of vibration monitoring at British Sugar where patrol monitoring was used successfully to assess the condition of various items of critical plant. However, due to the remote location of the Winestead facility, an FAG DTECT X1 online system was recommended by Schaeffler’s maintenance and condition monitoring partner, Corus. According to Ian Taylor, Business Development Engineer, Plant Condition Monitoring at Corus, “the benefit of using vibration monitoring is that bearing defect frequencies can be used to provide reliable trend data on the state of the bearings. Condition monitoring shouldn’t be used to find faults, it should be used to prevent faults.” The DTECT X1 system has been in place on the two pumps in Winestead for two years. Asked how this online system has benefited the organisation, Thompson responds: “The system has given me the confidence that the two pumps are doing what they should be doing. Without the system we could have one pump that is an hour away from a catastrophic failure, but we wouldn’t know that. Then, when it goes down, I have to ask myself why wasn’t it being monitored.” Thompson continues: “Very often people ask me what is the point of condition monitoring when all you get back are readings that say everything is OK, and we could have saved this money in the first place? For me, these people are missing the point. We could be making maintenance and pump refurbishment decisions on equipment that is either in good working order, so we have wasted our time and money – approximately €24,000 to €30,000 to refurbish a large unit – or it is about to fail and we have no idea of knowing this.” Thompson is confident about the future of condition monitoring. He is keen to use the data from the DTECT X1 device to integrate into the company’s PLC equipment so that he can see which units are vulnerable and which are in good working order. He is also looking to extend the equipment to other critical sites within his region. “We need to be smarter in managing our assets,” he concludes. “Gone are the days when component parts, skills and resources were readily available within a week. Due to cost saving efficiencies, we don’t have things sitting on the shelf any more. With a condition monitoring system, I have the peace of mind that the decisions I make are based on hard evidence.