Operation & Installation Manual V12-V6 2010-05-31.doc
31/05/2010
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7
Maintenance
7.1 Periodic maintenance
The ALTOSONIC V12 has no moving parts that can wear and tear. No service or
maintenance is required, unless the meter gets corroded or heavily contaminated.
It is however good practice to make a log file (see par. 6.3) on regular basis. It is not to be
expected that wear or tear takes place but external influences such as an overflow in a
separator or a process failure in a gas treatment plant, may cause a fouling of the meter
which may result in a deviations. By making a log file on regular basis such a failure can be
pinpointed in time, and as such the financial consequences can be correctly adjusted. The
ALTOSONIC V12 also has on board diagnostic features which will produce warnings and or
alarms. In a log file information will be stored with much more detail.
For even closer monitoring of the ultrasonic flow meter, KROHNE can deliver the “KROHNE
CARE
System” that on a regular base automatically collects log data, alarms and captures
changes in the flow profile as a result of corrosion, contamination or operating conditions that
otherwise have been changed. If required the KROHNE CARE
organises trained process
engineers on site to schedule the required visual inspections, validation and calibration
frequency of the flow meter (see details in section 7.10).
7.2 Cleaning
In case of exceptional growth of contamination inside the meter body, that is detected using
the log file trending, on board diagnostic or KROHNE Care
system, the ultrasonic gas flow
meter may need dismantling and cleaning.
7.3 Exchange of transducers
Transducers are not likely to break down (MTBF > 300 years). In the exceptional situation a
transducer fails there are two methods to replace both transducers of an ultrasonic path:
1. Isolate the ultrasonic flow meter with failing path(s). Depressurize the corresponding
meter run to atmospheric conditions as per company procedures (continue par.7.3.1).
2. Use a transducer extraction tool to remove the broken transducer(s) under pressure
(max. 100 bar(g)). Use the same device to install a new set of transducers (see
par.7.3.2).
7.3.1. Exchange of Transducers - Depressurised Condition
DANGER!
Always read instructions for safe handling of the equipment and installations first.
Switch off the power supply to the meter and wait at least 1 minute before opening the EXd
enclosure. Advisable is also to use a gas detector in detecting possible hazardous
environmental conditions. Also during raining conditions make sure no water/rain can
penetrate in the electronic housing, same accounts for dusty environments.
It s also preferred to disconnect power supply from the equipment by unscrewing the right lid
of the electronic housing (see par 5.3.1 & Figure 5-1). After disconnecting close lid fully and
attach labels to switching gear to prevent from unwanted switching on again.
