When Finish Thompson ETHYLENE COOL
needed a demanding site to
test its DB Series of plastic
magnet-drive centrifugal
pumps,Wright McGill,
manufacturer of the Eagle
Claw Fishing Tackle brand
was happy to oblige.

The company makes fishhooks
that require a range of
metal finishing processes.

One such process involves
concentrated nitric acid, used
as a stripping agent to remove
built-up plating materials.

The highly oxidising acid
became saturated with the
various plating products and
engineers wanted to reduce
its use.

A DB Series pump was
installed on a trial basis in a
filtration system designed to
recycle the nitric acid.

The test pump was made
from corrosion resistant
materials including precision
moulded carbon fibre filled
PVDF, PTFE bushing, high
purity ceramic and powerful
neodymium drive magnets
encapsulated in pure PVDF.

It was installed in the nitric
acid recycling system and used
to circulate 680L of acid
through a series of filters, with
each filter removing smaller
particles. The goal was to recirculate
the tank three times
per hour until the nitric acid
was clean enough for reuse.

The pump was in regular
use for six months while the
process was evaluated. Such
was its reliability,Wright
McGill has continued to use
the Finish Thompson
magnetic drive pumps for
handling corrosive and
hazardous fluids.

The pumps are available
through Michael Smith Engineers