Maintenance Equipment: Basic of Centrifugal Pumps

How long should a vertical pump's suction bell last? That was a question a plant manager asked me during a recent consulting assignment for a power plant. A pump manufacturer's typical response to such a question is, "it depends." So what does it depend on?

Martin Sprocket & Gear Inc's Maintenance and Troubleshooting Guide. This guide covers chain drives, gear drives, chain couplings, jaw couplings, quadra-flex couplings, synchronous drives, v-belt drives, and screw conveyors.

There has always been a debate on whether jack screws should remain tight against the side of the machine case after the machine has been moved into position or to back off the screws, so they do not touch. Should jack screws be tight or backed off? The answer is yes and no. In some situations you should leave the bolts tight against the machine and in other situations, it may be better to back off the jack screws.

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.

Magnetic drive pumps (also called magdrive pumps) come in three varieties – canned motor pumps, all metal pumps, and plastic lined metal pumps. They are sealless and cannot leak into the environment. Long, repair-free service life depends on recognizing the limitations of these pumps. This article covers issues with using direct mounted, lined magdrive pumps experienced ‘in the field’. 

This article covers the two main plant numbering systems that together form the framework on which all maintenance programmes are based and describes the value that can be created by integrating these identification systems. These two systems are: Equipment Numbers, or more accurately, Equipment Location Numbers Stock-Keeping Unit (SKU) numbers or, preferably, Material Catalogue Numbers. A third, less critical but still important numbering system for Stores location (or “bin”) numbers, is also included.

Cavitation means that cavities are forming in the liquid that we are pumping. When these cavities form at the suction of the pump several things happen all at once. The cavities form for five basic reasons and it is common practice to lump all of them into the general classification of cavitation. This is an error because we will learn that to correct each of these conditions we must understand why they occur and how to fix them.