GRAPHALLOY
®
When The Competition Said "No", GRAPHALLOY
®
Said "Yes"
A chemical plant in Tennessee was experiencing rapid bushing failure in their gear
pumps. These bushings were failing after only a few weeks of operation.
When plant representatives contacted this carbon bushing manufacturer about the
problem, they were told that therewas "no solution". The bushing manufacturer - our competitor -
claimed that the viscosity of the polymer being pumped was simply too thick.  Unhappy with this response, the chemical plant engineers contacted Graphite Metallizing
for assistance. After studying the problem, our engineers promptly responded by saying "yes, we
can help" and that GRAPHALLOY bushings were the solution.
The pump that was failing was a positive displacement, herringbone-type
gear pump with internal bushings lubricated by the pumped liquid. The pumpage is a polymer with
heavy viscosity (150 -10,000 CPS) similar to a thick latex paint. The temperature can range from 80
degrees to 140 degrees F with a speed of 520 -1,750 RPMs and a load of 155 - 1,980 pounds. This
pump has very high bushing loads because of the meshing gear forces. The calculated PV values were
up to 500,000 - over four times the maximum recommended level for GRAPHALLOY in submerged services.
The GRAPHALLOY engineers provided a solution designed for applications involving the transfer of
viscous liquids. Grade GM 119.3 bushings were recommended because of their load-bearing and
corrosion-resistant capabilities. GRAPHALLOY engineers also recommended slight design changes to
improve reliability.
The initial order was shipped to the customer and immediately installed.
The pumps fitted with GRAPHALLOY bushings have been operating for over one
year without failure...six times the life of the competitor's bushings.
The success of these GRAPHALLOY bearings demonstrates the potential for GRAPHALLOY
upgrades in chemical plants. 
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