Page 6 / 32
www.mecon.de
BA / RE 250 / EN / V17-11
Start-up
2 Start-up
2.1 Standard device
When starting up the device, the following points must be observed:
● Ensure that the actual operation conditions (pressure, temperature) do not exceed the limits
which are given on the nameplate of the device
● Avoid float impacts!
Therefore it is recommended to start up with a closed shut-off valve to be opened slowly. The use
of solenoid valves is not recommended.
● When measuring liquids, the pipes must be vented slowly to prevent shock pressure due to gas
bubbles.
● When measuring gases, the pressure must be increased slowly in order to prevent high shock
pressure.
● During start-up of new systems, residual materials may be carried in the medium and could
adhere to the float. In such cases it is recommended to clean the instrument after a relatively
short period of operation.
● When operating the flowmeter at low flowrates, the device has to start-up with a high flowrate to
allow the float to level out. This will ensure measurements within the specified accuracy class.
Special issues for measuring gas flow:
● Valves have to be installed downstream of the device if p
abs
>1.013 bar and upstream of the
device if p
abs
=1.013 bar (free outflow).
● Install a throttle just downstream of the device to prevent compression oscillations during
measurement.
● Ensure that the operating pressure for the flowmeter corresponds to the calibration reference
pressure to avoid erroneous measurements.
Float damping
A float damping is recommended
● in general for measuring gases
● where piping vibrations can not be avoided
It is also strongly recommended in the case of:
● applications where air bubbles in the medium cannot be avoided
● possibility of shock pressure in the piping, e.g. due to rapid throttling or process shut-off
● turbulence, pulsations, etc. which could lead to vibrations of the flowmeter
● rapid pressure build-up in the piping
