From Fluid Handling
While not as common as centrifugal
pumps in the CPI,
gear pumps play important
roles in handling many of
today’s more difficult-to-pump fluids.
Because they operate at lower speeds
— generally, 900 rpm or less — their
seals and bearings tend to last longer
than those of centrifugal models. In addition,
unlike centrifugal pumps, gear
pumps’ flows are independent of their
systems’ pressure curves, and they can
handle a wider range of viscosities.
Although high-flow, low-head applications remain the domain of centrifugal pumps, the use of gear pumps is increasing in the chemical process industries (CPI). While some application boundaries between gears and centrifugals are blurring, there are some crucial differences between the way the two are operated and maintained — for example, where pressure relief is concerned. This article provides a general summary of gear pump characteristics and applications, highlighting critical aspects of installation, operation and maintenance.
Generally, gear pumps are used in both metering and general fluid transfer applications. Metering units tend to be smaller and built to closer tolerance levels than general transfer pumps.
In the past, most applications ran at fixed speeds, but today, variable speed drives are gaining popularity. Standard industrial pumps are available with...
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