A client recently asked me to advise them on the possibility of repairing a large hydraulic valve off a 400 ton excavator, used in open-cut mining. The valve in question was a spool-type directional control. It had been badly damaged as a result of cavitation, which had occurred over a long period in service.

Given that particle contamination of hydraulic fluid reduces the service life of hydraulic components, it would seem logical that a system can never have too many hydraulic filters. Well… not exactly. Some hydraulic filters can actually do more harm than good and therefore their inclusion in a hydraulic system is sometimes misguided.

Most of us who have spent time in the lubrication field have been told that it takes only a small amount of water (less than 500 ppm) to substantially shorten the service life of rolling element bearings. There is indeed a vast amount of research that supports these assertions. Being a career-long crusader of clean and dry oil, I will certainly not argue the contrary. In fact, water’s destructive effects on bearings can easily reach or exceed that of particle contamination, depending on the conditions. Water can even cause bearing failure.

Expansion joints for pipework are often made from corrugated metal, especially when handling liquids or for operating pressures significantly above atmospheric. Metal expansion joints are outside the scope of the ESA guide.

Seal companies purchase carbon/graphite seal faces from one of several carbon manufacturers. The seal companies pay for the necessary molds and then retain the exclusive use of them. A good seal face would be a mixture of carbon, graphite and nothing else. The carbon is purchased as a byproduct of a manufacturing process while the graphite is mined with the main sources being in Canada and Madagascar.

In today’s global environment, the “one size fits all” approach is used for so many products that we expect it to apply to just about everything. In the mechanical seal industry, one problem with that philosophy is the definition of the word all. Mechanical seals must live in literally every environment under the sun-from extreme hot to extreme cold, wet to dry, solid to gas, acidic to caustic and so on. Until relatively recently, a vast variety of cartridge mechanical seals were needed to accommodate these pump applications.

Use the proper tools and a good pair of eyes to eliminate almost all your belt drive problems. Did you know that premature belt drive failures can be attributed to just a half-dozen commonly encountered problems? Or that all it takes to solve these problems is just a few tools and using your head? Other than normal wear and use, the most common sources of belt drive failures are 1) improper tension, 2) misalignment, 3) handling, 4) hardware, 5) environmental factors, and 6) design factors.

The cost of replacement parts, labor, standby inventory, and downtime can have a devastating effect on a plant’s bottom line. Eliminating even one of them by drying a compressed air system will offset the cost of installing and operating the equipment. When pneumatic components wear or become corroded as a result of moisture, they consume more compressed air – and lose energy efficiency. When this wear or corrosion becomes great enough, components must be repaired or replaced – increasing operating expense.

My interest in writing this article was to explore one way to reduce the cost of manufacturing and installing new boilers: improved insulation practices within the boiler island. It is my opinion that the power industry requires a smarter and more economical insulation design on steam-generating boiler walls, especially when considering the rising cost and reduced availability of qualified field labor. Yes, the potential cost savings with improved insulation practices is small compared to the total plant cost, but every dollar saved is important.