flow transmitter with conditional orifice plate as element

Hello Everyone,

I am seeking your support and attention towards frequent wrong reading for flow transmitter. i have conditional orifice plate connect with 4 flow transmitter 1 for controlling and 3 for trip all the 4 transmitter give wrong reading, while both pump in stop condition the flow reading keeps showing even if the pump start reading not matching with operation parameter. by the way all basic maintenance been conducted but still reading not match. kindly look to the existing parameter transmitter calibration range 0 to 6 mbar. full scale 0 to 623 mbar. pressure drop 283 mbar flow rang 3100 KG/H.

please what could the possible causes?
 
What is a conditional orifice plate? flow conditioner upstream of an orifice plate?

Four DP transmitters connected to a single orifice plate?

How do you know the reading is wrong? What is your standard for the correct flow reading?

How much error are you see at what flow rates? For instance, -7% at full flow, -9% at half flow
 
What is a conditional orifice plate? flow conditioner upstream of an orifice plate? patented 4-hole design yes upstream.

Four DP transmitters connected to a single orifice plate? yes 4 of the transmitters

How do you know the reading is wrong? as per operation calculation.

What is your standard for the correct flow reading? give a reading as design pressure in this case the calibration range from 0 to 6 mbar even when the pump off reading still showing high flow

How much error are you see at what flow rates?
around -10% at full flow
For instance, -7% at full flow, -9% at half flow
 
What is a conditional orifice plate? flow conditioner upstream of an orifice plate?

Four DP transmitters connected to a single orifice plate?

How do you know the reading is wrong? What is your standard for the correct flow reading?

How much error are you see at what flow rates? For instance, -7% at full flow, -9% at half flow
What is a conditional orifice plate? flow conditioner upstream of an orifice plate? patented 4-hole design yes upstream.

Four DP transmitters connected to a single orifice plate? yes 4 of the transmitters

How do you know the reading is wrong? as per operation calculation. while both pump in stop condition the flow reading keeps showing flow range 3200 KG/Hr

What is your standard for the correct flow reading? give a reading as design pressure in this case the calibration range from 0 to 6 mbar even when the pump off reading still showing high flow

How much error are you see at what flow rates?
around -10% at full flow
For instance, -7% at full flow, -9% at half flow
 
Hello 123,
what's the pipe i.d., upstream distance to you flow conditioner, nominal fluid(liquid,air,steam), pressure, temperature, etc. Meter bore, if you have it.
 
Hello 123,
what's the pipe i.d., upstream distance to you flow conditioner, nominal fluid(liquid,air,steam), pressure, temperature, etc. Meter bore, if you have it.
the media is liquid
pressure 59 to 64 bar-g
temperature 40 to 90 C
element : conditional orifice with patented 4-hole design
 
Okay, you've provided
Fluid Liquid
Stated Flow 3200 Kg/hr (suggest small piping not normally measured with orifices)
Press 59-64 Barg
Temp 40-90 DegC
Trans Span 0-6 mBar (Please Explain the discrepancy with you indicated readings)
Full Scale 0-623 mBar
Press Drop 283 mBar
Pipe ID Not Available

Calibrated range of 0-6 mBar seems to be in conflict with you indication of 0-623 mBar
It is not clear what your term pressure drop refers to? Meter loss or current reading?

Since you have a patented design, the manufacturers will have documentation and model numbers to go by, and they will be able to help you.

Good luck
 
Okay, you've provided
Fluid Liquid
Stated Flow 3200 Kg/hr (suggest small piping not normally measured with orifices)
Press 59-64 Barg
Temp 40-90 DegC
Trans Span 0-6 mBar (Please Explain the discrepancy with you indicated readings)
Full Scale 0-623 mBar
Press Drop 283 mBar
Pipe ID Not Available

Calibrated range of 0-6 mBar seems to be in conflict with you indication of 0-623 mBar
It is not clear what your term pressure drop refers to? Meter loss or current reading?

Since you have a patented design, the manufacturers will have documentation and model numbers to go by, and they will be able to help you.

Good luck

thanks Dave for your prompt response. however, 283 mbar DP after max flow and pressure loss 440 mmh2o. calibration range 0 to 6 mbar and transmitter range 623 mbar. line size 3 inch pipe speci FAA1 and Pipe Schedule: 80
 
Most orifice style measurements are useful for higher fluid velocities, your flow is well below 1 meter/sec in 3 in piping.

You might have to consider an alternate flow element and 1 inch piping.
 
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