1 Introduction
MANUAL TME400-VCF · EN08 · July, 01
st
2021
1.4.2.5.
Threshold values
The following threshold values are recommended for maximum durability and the
highest measuring accuracy:
< 20% above Qmax, short-term (< 30
sec)
Maximum flow rate changes and/or
impact loads
< 0.01·Qmax/sec 1% of Qmax/sec e.g.
start-up 0 - 100%: > 100 sec
Particle size in the gas flow:
Refer to lubrication chapter
Intervals depend on the status of the
gas (condensate, rust, dust)
Vibration / mech. vibration:
< 1 mm/sec (vibration speed)
These measures must be determined and checked during commissioning, before fill-
ing, during the start-up and run-in phase of the meter and evaluated, in particularly
with simultaneous occurrence of multiple of these threshold values. Intervention in
the system for improvement of measuring conditions must be carried out when the
aforementioned threshold values are reached.
The operator should record the overall measurement data (meter and operat-
ing data) during the entire operation in order to be able to recognize causes
of potential damage at an early stage and to intervene in good time.
Remedy and/or relief of critical operating statuses can be achieved, for
example, with the following measures:
•
Start-up screen (MW < 0.15 mm)
•
Filter
•
Meter protection perforated plates (Ø 3 - 4 mm)
•
Valves with control drive (flow change)
•
Check valves (pulsation, backflow)