2 Installation and Commissioning
Manual TRZ 03· EN08 2018 September, 10th
28
2.2. Operating data
2.2.1
Threshold
Recommended threshold values for maximum service life and maximum accuracy:
Notice
Maximum overload:
< 20% above Q
max
for a short time (< 30 sec)
Maximum flow or shock loads
< 0.01·Q
max/
sec 1% of Q
max
/sec
e.g. starting up 0 - 100%: > 100 sec
Maximum pressure change:
< 0.1 bar/sec
Maximum flow pulsation:
< 5%
Particle size in the gas flow:
< 5 µm
Lubrication of bearings
See
chapter 4.2 Lubrication
. Lubrication
intervals depend on the condition of the
gas (condensate, rust or dust)
Vibration / mechanical shock:
< 1 mm/sec (vibration velocity)
These specified data must be determined and checked during commissioning,
prior to filling and during the start-up and running-in phases of the gas meters. If
more than one threshold value occurs at the same time, appropriate action must
be taken in the station to improve the measuring conditions.
Notice
The operator must record all measuring data (gas meter and operating
data) during the whole period of operation in order to detect the causes of
a possible destruction of the gas meter at an early stage and take correc-
tive action in good time.
Corrective action or reduction of the critical operating conditions can be
achieved by the following measures for example:
•
Start-up screens (mesh width < 0.15 mm)
•
Filters
•
Perforated plates (Ø 3 - 4 mm) protecting the gas meter
•
Valves with control drive mechanism (flow variation)
•
Non-return valves (pulsation and return flow)