Equipment Knowledge

Equipment Knowledge

Basis for Bearing Life Calculation

Bearing life is defined as the length of time, or the number of revolutions, until a fatigue spall of a specific size develops. This spall size, regardless of the size of the bearing, is defined by an area of 0.01 inch2 (6 mm2). This life depends on many different factors such as loading, speed, lubrication, fitting, setting, operating temperature, contamination, maintenance, plus many other environmental factors. Due to all these factors, the life of an individual bearing is impossible to predict precisely.

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Equipment Knowledge

API Plans that I Use. 15-05

The American Petroleum Institute (API) issues guide lines to help petroleum people select and then pipe various types of controls for mechanical sealing applications. These piping arrangements are described in a series of plans issued by the API. Although 17 plans are described, only a few are really needed. Any time you have 17 choices there is bound to be some confusion. In the following paragraphs I will describe those API plans that I use on a regular basis, where I use these plans and, in the process, hopefully simplify your selection decisions.

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Equipment Knowledge

Adhesives Assure Fastener Reliability

Threaded fasteners set and hold tolerances on assemblies ranging from light-duty equipment to heavy machinery. Loosening is one of the major causes of industrial equipment failure, and results in millions of dollars worth of unscheduled downtime costs each year. In many cases, fasteners that self-loosen during equipment operation may contribute to wear and fatigue, and result in poor operating tolerances, misalignment and even catastrophic equipment failure. Various types of differential stresses such as vibration and shock, thermal expansion and contraction, and micro-movement reduce clamping force on the assembly and ultimately cause failure.

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Equipment Knowledge

7 Costly Causes of Nozzle Wear

Maybe you’re thinking to yourself that the waste and inefficiency caused by using worn spray nozzles just can’t be all that significant. If so, it’s time to change your thinking and determine if nozzle wear is a problem in your operations. Like many other processors, you may discover that you are wasting millions of gallons of water, thousands of gallons of chemicals and incurring many other unnecessary costs due to using worn nozzles.

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Equipment Knowledge

Writing a Set of Seal Specifications

It is extremely important for any modern process company to have a good set of seal specifications. When written properly the seal specifications will classify seals by operation condition.

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Equipment Knowledge

Adjusting Packed Centrifugal Pumps with Open Impellers

Open impellers are frequently used in centrifugal pumps which pump liquids that contain suspended solid materials (slurries, paper stock, etc). They do not plug as easily as closed impellers and usually have a simple external adjustment to maintain the correct impeller clearance as internal parts wear.

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Equipment Knowledge

Machine Alignment: Alignment Pitfalls – How to Identify and Eliminate Them

In theory, machine alignment is a straightforward process, but in real world applications, it is often compounded by structural faults such as ‘soft foot’, piping strain, induced frame distortion, excessive bearing clearance or shaft rubs. These pitfalls can turn a simple job into an all day affair – frequently with unsatisfactory results despite a conscientious effort and a considerable investment in manpower and downtime. This paper will examine how to eliminate some of the typical reasons why alignments are unsuccessful.

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Equipment Knowledge

Electrical Corona & Testing

What is electrical corona? Corona is the ionization of the nitrogen in the air, caused by an intense electrical field. Electrical corona can be distinguished from arcing in that corona starts and stops at essentially the same voltage and is invisible during the day and requires darkness to see at night. Arcing starts at a voltage and stops at a voltage about 50% lower and is visible to the naked eye day or night if the gap is large enough (about 5/8″ at 3500 volts).

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Equipment Knowledge

Dynamic Movement White Paper

Regardless of the approach taken to measure true dynamic movement, coupled machines need to be set to cold alignment targets that will reflect the actual changes in the shaft alignment. This will lead to lower vibration levels, increased Mean Time Between Failures, decreased maintenance expenditures and increases in production. Much like the philosophical change from aligning shafts with dial indicators to aligning shafts with laser based systems, these types of measurements will take some time to be generally accepted and routinely practiced.

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