Preventive Maintenance Archives

Preventive Maintenance

How Green is Green When it Comes to Using Everyday Industrial Cleaning Products for Plant Maintenance?

The answer is, it depends. For example, a traditional cleaner/degreaser, of which there are literally hundreds on the market, generally does an adequate job of cleaning. However – and this is an ongoing problem – the majority of them basically move the contamination from one location to another. The result? This cost of hydrocarbon removal is added to the clean-up process, plus your employees could be at risk of additional from toxins in the cleaner. So, how do you clean, provide a safe product for your employees and contribute to an active pollution prevention program?

Preventive Maintenance

What is Vibration? Linear and Non-Linear Systems

To assist in understanding the transmission of vibration through a machine, it is instructive to investigate the concept of linearity and what is meant by linear and non-linear systems.

Preventive Maintenance

Carbon Brushes for DC Motors and Generators

Carbon brush grades are usually classified according to the manufacturing processes and the types of carbons, graphites, and other ingredients used. The 4 main brush grade families are carbon-graphites, electrographitics, graphites, and metal-graphites.

Preventive Maintenance

Brinelling of Bearings

Drop a bearing (oops!), impact an interference fit hub, coupling etc., that seized onto a shaft (hammer time oops!), beat a bearing onto a shaft or into an housing, hit the machine with the big hammer to move it (no jacking bolts oops!), let that spare machine sit on the warehouse shelf or in the field for months or even years with no rotation (oops!)? And the list could go on and on…we’ve all probably been guilty of at least one or more of these infractions at some point. “What’s the big deal anyway?”

Lubrication

Lube Routes vs. Combo PMs: What’s Best? What are the Issues?

In an ideal world, the lube route is the perfect answer. Group activities based on commonality of frequency, task type (e.g. motor regreasing) or area of the plant and execute in one block. It’s efficient, effective and cuts down on paperwork by having just one work order for tens or even hundreds of tasks. The key here is “ideal world” – few if any of us live in this utopia, which causes some very real problems when it comes to executing what I tend to call “macro” lube routes.

Equipment Knowledge

The 7 Secrets of Pump Reliability

Contrary to popular opinion, a centrifugal pump is not designed to develop a specific head at a certain capacity as requested by the pump purchaser. In fact a pump is designed and built to produce a whole range of head-capacity conditions as identified by it’s performance curve. The pump will operate on that curve if it is driven at the designated speed.

Preventive Maintenance

The Role of Fireside Corrosion on Boiler Tube Failures: Part 2

One of the primary challenges of reliably burning coal is managing the corrosion experienced by the furnace heat transfer surfaces. Fireside corrosion remains a leading cause of failure in boiler tube, in both superheater and reheater tubes. Boiler tubes affected by fireside corrosion also may lose 15 mils per year (mpy), or more in extreme cases

Preventive Maintenance

The Role of Fireside Corrosion on Boiler Tube Failures

One of the primary challenges of reliably burning coal is managing the corrosion experienced by the furnace heat transfer surfaces. Fireside corrosion remains a leading cause of failure in superheater and reheater tubes. Also, tubes affected by the fireside corrosion mechanism may lose 15 mils per year (mpy) and more in extreme cases. Five case studies (three presented here in Part 1) examine the different failure modes experienced by tubes located throughout the furnace.

Equipment Knowledge

The Affinity Laws for Rotary, Positive Displacement Pumps 13-6

The affinity laws accurately predict the affect of changing the speed of a centrifugal or rotary pump, and they also do a fairly good job of predicting the affect of changing the diameter of a centrifugal pump. In another paper (02-01) we discussed the affinity laws as they apply to centrifugal pumps, but in this paper we will look at their use with rotary pumps.