This month's issue of Process Heating brings articles on replacement part inventories and building a spares contingency plan, using flexible RTDs to sense fluid temperatures, a compare/contrast look at heat exchanger types, a matrix of fan maintenance and a case history on using plastic cooling towers in highly corrosive environments. While each discusses a different type of heat processing equipment, all show the effects that neglecting that equipment can have on your production.

Continuing his combustion systems series, John B. Clarke of Diamond Engineering Inc., Fort Wayne, Ind., weighs in with “Spare Parts.” In Clarke's previous articles (which you can read on, he presented methods to measure and reduce the total cost required to operate your process heating equipment. In this article, he looks at a seldom scrutinized area of equipment maintenance: spare parts. He asserts that there are opportunities to improve the way you specify, inventory and utilize replacement parts, but only if you work proactively.

In “Sensing Fluid Temperatures with Flexible RTDs,” Marty Knutson and Bruce Larson of Minneapolis-based Minco Products Inc. describe how flexible RTDs can be used to achieve accurate temperature sensing of liquids flowing in pipes. They describe the traditional approaches using probe-style sensors and thermowells inserted into the fluid stream, and then introduce flexible resistance thermometers, which are thin, bendable temperature sensors that contain flat wire-wound elements laminated between layers of electrical insulation. Could they be the sensor you need for tighter process control?

Heat exchangers are used to heat and cool products in the food, dairy, chemical and pharmaceutical industries, among others. Many different types of heat exchangers are available, and they often are interchangeable for a given application, but this does not mean that any heat exchanger can be used in any application with optimum results. In “Heat Exchanger Basics,” Alan Ferraro of Terlet, Pennsauken, N.J., explains that choosing the right heat exchanger requires some knowledge of the different heat exchanger types as well as the environment in which the unit must operate.

Also, in “Tactic: Plastic,” technology writer Ed Sullivan explains that plastic cooling towers that handle process heat must also be impervious to caustic and costly pH factors. Whether applied directly to heat exchangers, equipment jacket coolers, oil cooling, quenching baths, annealing furnaces, sterilization apparatus, pasteurization systems or air compressors, protecting expensive process equipment and maintaining cooling fluids represent an indispensable adjunct for any process operation.

Typically, fans provide years of trouble-free operation with relatively minimal maintenance. However, this high reliability can lead to a false sense of security, resulting in maintenance neglect and eventual failure. “Fan Plan” from the Department Energy's Office of Industrial Technologies Program details weekly, monthly and annual maintenance to keep your fans in tip-top order.