Ever-evolving systems to reduce risk and add to the bottom line
There is little argument that intelligent pumps have significantly improved fluid handling applications in a wide variety of industries worldwide. Since their introduction several decades ago and through enhancements along the way, intelligent pumps, working in conjunction with computer and central process control data systems, have allowed users to monitor and control temperature, flow and pressure—in many cases, from hundreds of miles away.
Intelligent pumps have virtually eliminated the run-to-failure option. They have certainly also allowed users to more reliably predict the need for routine maintenance rather than a scheduled maintenance program that may have been too cautious, resulting in unneeded repair and adding overall costs.
Consider the Cost
Intelligent pumps are not a cheap investment. The cost of adding them to a system can, in some extreme cases, reach up to $50,000 per pump (including a controller). However, that initial cost is offset by the monetary savings in maintenance costs, man hours, and, in many cases, liability costs if failure occurs. In addition, most users consider that the assurance that a smart system provides is well worth the initial purchase price. The selection comes down to understanding the potential for significant downtime and liability costs that could result from system failure when intelligent pumps and systems are not used. With the potential savings, an intelligent pump system can pay for itself many times over.
The Evolution
All devices, including intelligent pumps, continue to evolve. Most people can do things on their mobile phones today that were considered impossible just five years ago. So goes the evolution of the intelligent pump. Things such as wear sensors, leak detectors and cavitation detectors are now realities that end users can add to further protect their systems. Development of new sensors such as these, all of which use controls with unique algorithms for measurement, is a significant step in the evolution of intelligent three screw and positive displacement pumps. Add to that the ability to monitor a fluid transfer system, make adjustments—even order replacement parts, all without human supervision—and end users have a powerful control tool at their fingertips that was beyond comprehension five years ago. Tying it all together in an intelligent system gives end users a powerful way to control their system and add to their bottom line.
Wear Sensors
While not all users will require such high-level detection, critical applications—such as those in the oil and gas industry—can benefit from wear sensors for three screw pumps. Lube oil systems, as an example, pump fluid that is typically clean, and a wear sensor may not be needed. But pumping crude oil, containing contaminants, could result in babbitt lining wear. Scheduled maintenance will of course help reduce problems, but varying contamination conditions could result in failure regardless of maintenance, requiring major repairs such as the replacement of rotors and housings. The immediate costs include a repair kit that can total a significant percentage of the cost of a new pump (depending on the damage incurred), plus downtime and the man hours required to repair the pump. A hidden cost might include the amount needed to cover an environmental clean-up in the event of a system failure.
A wear sensor provides a forward-looking idea of what is occurring within the pump. Ideally, the rotor should not contact the housing, thanks to a thin layer of lubricant. However, crude oil contaminants can cause premature wear. Set points can be created that measure the housing's wear depth, giving ample time to schedule downtime before failure and ensure that repair kit parts are on hand.
Leak Detection
Leak detection is being perfected to the point that it will indicate to the end user the number of drops of fluid that are being released from a seal over time. Users that see the leakage rate increase can quickly confirm that a seal is not performing as expected. What's more, an in-line, retrofittable installation that is compatible with any pump or system already in place is available for the leak detection system.
Leakage detection can be beneficial if a system experiences high vibration. The end user may set the parameters to determine what actions or adjustments are required by the system based on the rate of leakage. These range from taking no action to complete shutdown of the pump, if warranted.
Cavitation Detection
Cavitation detection monitors the pressure within the system and within the pump to determine if cavitation is occurring and can help to prevent pitting or more severe damage. Setpoints within the controller allow the system to take actions from continued monitoring, to reducing pumping speed, and to actual pump shut down, providing maintenance opportunities before catastrophic failure occurs.
Intelligent System Advantages
The overall advantage of intelligent pumps comes together, however, with the intelligent system. Many applications exist today in which available infrastructure and data can be harnessed and provide, in real time, an overall assessment of what any pump or motor is doing—from an overall workload standpoint versus what it is fully capable of doing. Based on the analysis, an operator can act upon the data to increase production or allow the system to continue operating as is. Control room personnel can oversee the process and make changes quickly, without being pump and motor experts.
This can have a direct effect on the bottom line. With preset parameters, the system can also operate on its own, adjusting to changing conditions without direct human supervision or for on-site inspection, saving costs for on-site supervision and maintenance as well as increasing personnel safety.
Based on the conditions of the pump, the system automatically makes adjustments to maximize throughput efficiency and adjusts flow rates to prescribed levels. A preventive maintenance calendar can be established and, if desired, the system can automatically issue purchase orders for repair parts. The system can also track performance trends over time by maintaining an electronic log book. Added cost benefits include the potential for reducing energy consumption and energy bills.
Back to mobile phones. Consider this. With today's smart phones, the capability exists to transmit real time information and alerts from an intelligent system to provide real time information via e-mail. Think about it. When was the last time you got a call in the middle of the night...from a pump?
Pumps & Systems, June 2011