The use of cooling water is prevalent in many manufacturing industries, whether to chill plastic following heat treating or to cool down vats during chemical processing.
As anyone involved in procuring water for these processes knows, the precious liquid is not inexpensive, particularly for those using as much as several thousand gallons per minute. More costly than the water, however, is the cost of not having the water.
The most probable situation in which a company would not have water is if the firm’s process cooling system fails to operate properly or shuts down altogether. Don Rivard, an electrical engineer for Process Cooling Systems Inc. in Leominister, Mass., is painfully aware of the consequences of this scenario. About 12 years ago, Process Cooling customers were, on occasion, actually living that industrial nightmare.
“The transducers we were using in our cooling solutions were not particularly reliable,” says Rivard, who handles all aspects of design for the power and control systems of his company’s equipment, including component specification and vendor selection. “Many of them were failing completely or just losing calibration. Either way, it often left our customers in a tough spot.
“The transducers were failing for any number of reasons: excess vibration, water-pressure fluctuation, voltage tolerances, you name it,” Rivard says. “As a result, they either prohibited our cooling units from delivering proper performance or stopped them from performing completely.”
Given the importance of transducers to the overall function of the cooling systems, which can represent a capital investment as high as $1.5 million, the situation demanded remediation. Depending on their design and specific application, more than 60 percent of the systems designed by Process Cooling Systems require a pressure transducer for maintaining constant machine speed and regulating water pressure and flow, all while conserving energy.
What is more, the vast majority of these transducers are not positioned directly on the equipment where they can be safely contained and monitored. Instead, they are mounted on the process piping, where they are exposed to myriad harsh ambient conditions.
Non-negotiable ReliabilityBased on the non-negotiable need for superior transducer performance, particularly in severe environments, Rivard knew a switch was absolutely necessary. After being dissatisfied with the offerings of other transducer producers, Rivard turned to Setra Systems Inc., Boxborough, Mass., a designer and manufacturer of pressure-, acceleration- and weight-sensing devices.
“The primary reason we chose Setra is that their products are reliable, accurate and cost-effective,” Rivard notes. “In truth, while the reliability and accuracy are the most critical considerations, they mean nothing without cost efficiency.”
While other transducers were available that delivered similar performance, they had a higher price tag, he says. “We’re in a field that is very cost-competitive, where the profit margins are already razor-thin. To protect those margins, and to keep the cost of the systems reasonable for our customers, we need products that are cost-effective. Setra’s ratio of cost to reliability is phenomenal.”
When Process Cooling began using Setra products about a dozen years ago, it started with the Model 206 gauge pressure transducer. The company soon moved to Model 256 when it became available. The 256 and 206 are similar, but the 256 is used in more rugged conditions.
Packaged in a die-cast aluminum enclosure designed for NEMA4/IP65 service, the heavy-duty transducer incorporates Setra’s patented capacitive design. Coupled with the company’s proprietary circuitry, it produces a strong signal that assures customers of mechanical and thermal stability as well as accurate output, even through many years of pressure cycling.
The transducer accommodates a range of pressures. “Most of our customers’ needs fall within a PSI pressure of 0 to 500,” Rivard says. “That’s almost smack in the middle of the model 256 pressure range, although it can handle ranges of 0 to 2 on the low end, all the way up 0 to 10,000 on the high side.”
The transducer’s environmental data also benefits customers because the unit retains its accuracy in temperatures as low as -40°F (-40°C) and as high as 260°F (127°C), which is critical for Rivard. He says that ambient temperatures at his customers’ plants vary greatly, not only from plant to plant but even within the same plant. “And the transducer housing makes it durable against dust, vapor and just about anything our customers can throw at it.”
The units designed and created by Process Cooling Systems do not come in a standard size or configuration; instead, they are application-dependent. According to Rivard, they can be small enough to fit into a 4 x 4' space or large enough to require several tractor trailers to move. Yet the Setra devices can be incorporated easily into any of the systems, regardless of size or shape.
“We’ve found that Setra transducers engineer well into any system,” Rivard says. “Of course, since the bulk of the transducers are mounted on outside piping, this is generally a moot point. But even when they are mounted in or on the machine, which is sometimes the case in smaller units, their compact dimensions make it a simple process.”
Currently, Process Cooling purchases about 200 of the Model 256 transducers annually.
“These things are no longer a problem for us or our customers,” Rivard says. “Neither is production downtime. Setra solved our reliability issues, and allowed us to do it without having to shoulder a huge financial burden.”
Setra Systems, Boxborough, Mass., designs and manufactures electronic instrumentation for measuring pressure, acceleration and weight. For more information, call (800) 257-3872; e-mail email@example.com or visit www.setra.com.
Process Cooling Systems Inc., Leominster, Mass., provides process water solutions, including cooling towers, chillers, and pump tanks and skids, for industrial manufacturing operations. For more information, call (800) 696-2665; e-mail firstname.lastname@example.org or visit www.processcooling.net.