Maintenance bearing

Pump maintenance steps were performed from memory without a checklist or independent checki ng. Two types of pumps were being maintained the other type did not require bearing maintenance. Thi.s mix up of procedures is called a "stereotype error. ... 

The steps for maintenance of the pump involved in the incident were very similar to those for other pumps that did not require bearing maintenance. These pumps were maintained much more frequently than the type requiring... 

The failure mode of an equipment item describes the reason for the failure, and is often determined by analysing what causes historic failures in the particular item. This is another good reason for keeping records of the performance of equipment. For example, if it is recognised that a pump typically fails due to worn bearings after 8,000 hours in operation, a maintenance strategy may be adopted which replaces the bearings after 7,000 hours if that pump is a critical item. If a spare pump is available as a back-up, then the policy may be to allow the pump to run to failure, but keep a stock of spare parts to allow a quick repair. 

Comparative costs for conveyor systems can be based only on studies of specific problems. For example, belt-conveyor idlers are available in a range of quahties that may make the best unit cost three times as much as the cheapest. Bearing quahty, steel thickness, and diameter of rolls all affect cost, as does design for easy maintenance and repair. Therefore, it is necessary to make cost comparisons on the basis of a specific study for each conveyor application. 

The most common maintenance problem with centrifugal pumps is with the seals. Mechanical seal problems account for most of the pump repairs in a chemical plant, with bearing failures a distant second. The absence of an external motor (on canned pumps) and a seal is appeahng to those experienced with mechanical seal pumps. 

Radial Bearings Antifriction bearings are largely unsuitable for these applications, chiefly because of the special attention and maintenance which they demand. 

Hot running Preventive maintenance bearings., Monitor bearings temperature Purging and sealing to keep solvents out, if solvent (even vapor) exposure is possible Use improved bearing lubricant CCPS G-29... 

Running unbal- Preventive maintenance and operator checklist anced, vibration inspections due to worn bear-, effective vibration monitor/shutdown device ings or other mechanical problem such as product accumulation behind filter screen. ... 

Implement preventive maintenance on bearings for rotary, autofilter, and agitated pan dryers... 

Heat build-up Ensure frequent preventive maintenance checks due to worn or on bearings overloaded, Monitor and alarm bearing temperature bearings. Ensure proper belt tension CCPS G-12 CCPS G-23 CCPS G-29... 

Hot bearings pro- Avoid by regular preventive maintenance (PM) viding a source of inspections, lubrication and belt checks Ignition., Ugg improved lubrication CCPS G-23 CCPS G-29 CCPS G-34... 

Check bearings and air gap during maintenance, at least once a year. 

Code of practice for installation and maintenance of rolling bearings... 

Installation of bearings and pulleys Important checks at the time of commissioning Maintenance of electric motors and their checks Maintenance of bearings General problems in electric motors and their remedy Winding temperature measurement at site Analysis of insulation failures of an HT motor at a thermal power station... 

As we ve di,seussed, system design is responsible for much of cavitation. Yet, the maintenanee mechanic is responsible for stopping and preventing eavitation. And certainly, it s the maintenance mechanic who has to deal with the results of cavitation, the constant changing of bearings, meehanical seals, damaged impellers, wear rings and other pump parts. 

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