by Todd Kierstead, Colfax Fluid Handling

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.