Oval 50 - Operation Shutdown Precautions

B-149-4N-E
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(3) Liquids of low steam pressure
Temperature and pressure of LPG, polyvinyl chloride
monomers or anything with low viscosity and low
steam pressure that are too ready to vaporize should
strictly be controlled.
During operation, the temperature of bearings in the
meter is usually higher than that of the metered uid.
Vapors around the bearings can be causes of faulty
conditions, including generation of unusual noise
and bearing seizure.
(4) Corrosive liquids
When you make a measurement of highly corrosive
liquids, such as nitric acid and sulfuric acid,
appropriate materials should be used for tanks
and piping assembly. Heterogeneous materials
originally contained in the metered uid or corrosive
substances liquated out from tanks and pipes of
inappropriate materials may lead to costly downtime,
as a result of locked rotors, for example, when they
are allowed into the measuring chamber.
CAUTION: If it is a jacketed model, see page 15.
9.3 Precautions at Operation Shutdown
(1) Valves should be closed progressively.
Rapid valve closure could, under certain piping conditions, cause a sharp pressure rise by water hammer, or
hydraulic shock, resulting in damage to the meter.
(2) Precautions against pressure buildup on closure
Complete closure of valves upstream and downstream of the meter makes the affected section a totally
enclosed chamber and could cause a rise of internal pressure due to a rise of atmospheric temperature,
resulting in an unexpected damage to the meter.
(3) Liquids ready to adhere or gel at zero flow velocity
Liquids that tend to adhere and solidify or gel at ow velocities around zero must thoroughly be washed away
from the meter interior by running cleaning uid before shutdown. Negligence of this instruction may leave the
meter as an immovable unit when the operator attempts to resume meter operation the next time.
CAUTION
9.4 About Register Life
Due to the life expectancy of components incorporated, such as the LCD and nonvolatile memory, the internal
electronics are designed to be replaced in about 10 years. The electronics life depends on the environment in
which they are used; if any of the following operating conditions applies, we recommend you to replace them
an assembly in ve to six years:
- High temperature environment.
- High temperature process uid measurement.
- Field installation with widely varying temperatures.
- LCD counter display is directly exposed to the rays of the sun (ultraviolet rays).
- Frequent process uid ow interruptions.
TAKE PRECAUTIONS
AGAINST BEARING SEIZURE!