PM Task Report 6/21/2010

Component Type: Pump - Vacuum - Liquid RingTask Name: Borescope Inspection

Criticality Critical MinorDuty Cycle High Low High Low High Low High Low

Service Conditions Severe Mild Severe MildCHS CLS CHM CLM MHS MLS MHM MLMAR NA AR NA AR AR AR AR

Task ObjectiveThis task determines the condition of pump internals and suction and discharge flanges that might suffer erosion or corrosion. Both plant conditions and equipment age are needed to determine if this task should be stand alone or combined with another task such as an overhaul, older pumps that have not been previously overhauled could benefit from this task.

Task ContentBorescope should include:- Inspection of all pump internals (i.e. casing, rotor, cone, and lobe) and inlet and outlet piping for evidence of erosion, corrosion, wear, and damage.

Principle Failure Location And Causes:This task is focused on determining the condition of pump internals that might suffer erosion or corrosion. It should be possible to use a borescope to examine the rotor, cone, lobe, internal casing, and inlet and outlet flanges. The various causes for erosion and corrosion in these locations include material incompatibility issues and contaminants in the pumping fluid and seal water.- Corrosion and erosion become dominant failure mechanisms for this kind of equipment at extreme temperatures or if the quality of the pumping fluid is poor or corrosive.

Progression Of Degradation In Time:Erosion is usually a long-term acting failure mechanism and under ideal operating conditions may not cause problems for 20 years. However, this time is significantly decreased when operating under severe conditions including poor fluid quality. Corrosion degradation resulting from material incompatibility is much more of a random occurrence unless it is piqued by temperature which acts as a multiplier to its propagation.

Support For The Task Interval And Relation To Other Tasks:No interval has been assigned for this task because it is most effective when used in conjunction with other condition monitoring techniques such as performance monitoring which would give an initial indication of a problem.

The borescope is a key inspection device for older pumps that have not been refurbished for 20 years. In these cases it may be prudent to perform a borescope inspection every 2 years as wear on pump internals becomes a dominant failure cause.

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