Badger Meter Positive Displacement - Manual (Page 6)

6
Maintenance Guides are provided with the meter and are also
available from the factory. These should always be reviewed by
personnel prior to attempting any maintenance work. The
overwhelming majority of downtime and repairs are the result of
breakages due to improper maintenance actions, lack of training
or rough handling.
Never run the meter dry or spin with air only. Gear flow meters
are precision engineered flow devices and should always be
maintained in a clean, lubricated condition with the internals wet
at all times. Air and water should not be allowed in contact with
the internal parts except in short (1-2 second) cycles as part of an
automated flush.
Do not use water for flow testing. The viscosity of water is too
low to produce accurate results unless the flow rate is elevated,
and the internals would then have to be dried and lubricated to
avoid corrosion or scaling. Using a fluid with a viscosity of
approximately 30 cSt, such as mineral oil or thinned glycerin, is
recommended if calibration of the system is necessary. The
preferred calibration fluid would be the actual fluid to be metered.
Do not ramp-up flow to a full flow condition instantaneously.
Gear flow meters are rugged, yet precise instruments which will
respond almost instantaneously to changes in fluid flow. Normal
pulsating flows will not damage the meter and will merely cause
the output to be unsteady. However, if flow is repeatedly cycled
from zero to full flow instantaneously, fluid shock forces may be
significant and may produce premature damage or wear over
time. To avoid damage to the system, ramp-up to maximum flow
over a few seconds rather than instantaneously and do not inject
high flow speeds into an empty meter.
Filtration is recommended to prevent contaminants from entering
the meter. Should the meter become plugged, a reduced flow
may still be observed from the outlet as fluid pressure will
squeeze fluid through the meter. Visual flow does not necessarily
mean that the meter’s gears are turning. If plugging is caused by