Centrifugal pumps represent some of the most ubiquitous and versatile industrial equipment. Wherever there are liquids, there are pumps. Based on the number of sizes, variety of manufacturers and configurations, there seems to be an almost infinite number of possible combinations. Unfortunately, pumps tend to be maintenance intensive. They exhibit wear-related problems in all sorts of ways, and failures can be spectacular, but not in a good way.
In spite of these characteristics, pumps get remarkably little attention in most plant environments. The frequent practice is running them until they fail or nearly so, which forces dependence on having double or even triple installations to ensure there is always a working backup. Such redundant installations seem like a hugely expensive solution, but it is the reality in many critical applications.
Brian Joe says it doesn’t have to be this way ,and he explains a more practical approach in an article in the June issue of Power magazine: Improving Plant Efficiency with Pump Performance and Condition Monitoring. While he understands that most companies won’t give up redundant installations, running to failure is a bad idea.
Studies show pumps tend to be some of the more maintenance-intensive equipment in a plant, suffering a failure or some level of degraded operation on average every 12 months. Reactive maintenance, where it is necessary to fix something that has failed, costs 50% more than practicing predictive maintenance where problems can be detected and resolved before a failure. Pumps can be equipped with sensors to monitor condition and performance to ensure problems are detected as soon as possible so appropriate action can be taken.
To most plant managers, adding sensors sounds expensive. They may respond, “We can do a whole lot of pump maintenance for what that kind of monitoring would cost. Besides, we do manual inspections.” How is that working for you?
Given the reduced number of human operators in plants these days, the checks are probably not as regular or as frequent as they should be. Moreover, checking something like vibration with a hand-held device requires the operator to get right next to the installation, regardless of where it is located. This involves obvious safety concerns, along with the likelihood that a difficult to access installation might not receive the attention it should. All these factors taken together explain the dependence on expensive redundant installations to ensure continuous service.
Few plant managers would argue with this summary of the problem: there aren’t enough people or time to do the checking required, but automated monitoring is too expensive. But this is only half right, because it’s no longer expensive to add automated monitoring to pumps, due to the proliferation of WirelessHART networks and devices, and associated software applications.
Over the last few years, the number of devices designed for equipment monitoring capable of operating on wireless networks has grown substantially. Some communicate using a plant’s Wi-Fi network, but a larger group has been designed to communicate via WirelessHART, the same network used by many types of wireless field instruments. The variety of low-power and low-bandwidth devices designed for these networks has grown enormously, and for all practical purposes, every type of monitoring device necessary for a full pump monitoring setup is available for use with WirelessHART networks.
The list of sensors for this purpose is pretty comprehensive: bearing temperature, vibration, seal flushing system level, differential pressure, and so on. Basically, it’s possible to monitor anything from bearing condition to strainer clogging. The data collected can be processed and turned into information without bringing in a system integrator to set up a huge asset management program. The article goes into more detail on how all this can work using low-overhead apps so it’s well worth a full read. Let’s just say industrial software programmers have learned a lot from all those things on your smartphone.
You can find more information like this and meet with other people looking at the same kinds of situations in the Emerson Exchange365 community. It’s a place where you can communicate and exchange information with experts and peers in all sorts of industries around the world. Look for the WirelessHART and IIoT Groups and other specialty areas for suggestions and answers.