Helle every one
I’m looking for guidance on selecting an appropriate Coriolis flow transmitter for my process application. My operating parameters are:
nominal flow rate of 60 ml/min,
maximum flow rate of 100 ml/min,
1/4" NPT process connections
and currently using DN4 tubing.
I have three Coriolis transmitters options with different DN sizes and characteristics:
DN01:
Pressure drop of 170 mbar at nominal flow
and 381 mbar at maximum flow,
with 0.1% measurement accuracy.
DN02: Pressure drop of 8.31 mbar at nominal flow
and 1.19 mbar at maximum flow,
with 0.1% measurement accuracy.
DN04: Pressure drop of 1.3 mbar at nominal flow
and 2.31 mbar at maximum flow,
with measurement accuracy of 0.28% at nominal flow and 0.17% at maximum flow.
My main concern is that my system has a maximum allowable pressure drop constraint of 5 mbar. Additionally, I’m wondering about the impact of transitioning from my current DN4 tubing to a smaller DN2 Coriolis transmitter - will this tubing size reduction significantly affect the actual pressure drop in the system?
Based on these constraints and the need to minimize pressure drop while maintaining reasonable accuracy, which transmitter would you recommend? Any insights on the tubing size transition effects would also be greatly appreciated.
The DN04 Coriolis meter appears to be the best option because:
Pressure drop remains well below your 5 mbar limit at both operating points.
It matches your existing DN4 tubing, eliminating additional reducers and expanders.
No flow disturbances caused by sudden contraction and expansion.
Lower risk of clogging or fouling if the process fluid contains particulates or has higher viscosity.
Although the accuracy is slightly lower than DN01/DN02 an accuracy of 0.17–0.28% is still excellent for most industrial applications.
About the DN4 → DN2 Transition
Reducing from DN4 tubing to a DN2 meter will increase the fluid velocity via the meter. The resulting pressure loss consists of:
Meter internal pressure drop
Contraction loss (DN4 → DN2)
Expansion loss (DN2 → DN4)
Even if the meter specified pressure drop is around 8.31 mbar the actual installed pressure loss can be slightly higher due to these transition losses.
For low flow rates such as 60–100 ml/min and the additional losses cannot be enormous yet they will not help you meet a strict 5 mbar system limit.
