172-65639M-01 (EF200) 13 Apr 2018
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3.3.8 Other Considerations
Vibrations
The correct operation of the measuring system is not influenced by plant
vibrations up to 1 g, 10 to 500 Hz. Consequently, the sensors require no
special measures for attachment. If higher levels of vibration are expected, be
sure to secure piping before and after the flow meter.
Preventing Excessive Flow
Caution!
To ensure long service life for the flowmeter, excessive instantaneous/
periodical flow rates should be held below the flow meter’s maximum flow rate.
Failing to do so might result in damage to the sensor. Special care is
necessary for steam at startup when the pressure is low, or when a valve is
opened rapidly, such as by a solenoid valve, as excessive instantaneous flow
rates often occur.
Pulsating Influences
The ability of the flowmeter to measure correctly may be adversely affected if
there are large variations of pressure or pulsating pressure from compressors
and/or soot blowers. Use the procedures below to minimize pulsating
pressures:
•
Move the source of the pulsations to the downstream side of the flowmeter.
Alternatively, put as much distance as possible between the source and the
flowmeter.
•
Install a pulsation dampening device, such as a chamber.
•
Close the valves before and after the flowmeter when there is no flow.
(This is to prevent false non-zero readings under zero-flow conditions.)
Prevent Mixed Phase Flow
This flowmeter is designed to measure both gases and liquids. However,
accurate measurement cannot be guaranteed when gases and liquids are
mixed together (i.e. gas-liquid mixed phase flow).
Ensure Pipe is Flooded
When measuring liquids ensure that the pipe is flooded, as this will have an
influence on the accuracy of flow rate measurements.
Bypass Lines
The installation of bypass lines can facilitate maintenance and inspections.
When installing a bypass line, use upstream and downstream valves of a type
that does not disturb the flow profile, and secure sufficient length of straight pipe.
EF200
Bypass Valve
Ball Valve
Direction of
Flow
Ball Valve
Caution!
