Turbine Meter without Straightening Vanes Upstream

[EmmanuelTop]

In AFC drawings we spotted a turbine flow meter without flow straightener upstream. Straight piping run upstream of the meter is 10D, downstream of the meter is 5D.

The fluid measured is wet Natural gas, almost pure Methane, water-saturated, at 15 barg and 50 degC.

I'm afraid it is too late for any design changes and installation of a straightening vanes, so my question is how bad the measurement accuracy will be affected in absence of the vanes? Measurement is quite important and it will serve as one of the key parameters for acceptance of the compressor (discharge flow). Contractual tolerance is +/- 5% on flow.

Thank you in advance,

http://antwrp.gsfc.nasa.gov/apod/astropix.html

 

[pennpiper]

How bad the measurement accuracy will be affected in absence of the vanes?

This is an inappropriate question to be asking on an open forum. We cannot see the configuration and we have no information about the capabilities or limits of the flow meter.
If you really need to have an answer to this, you need to contact the manufacturer of the meter and have a Technical Rep visit the site to evaluate the installation.

prognosis: Lead or Lag

 

[bimr]

You probably should not have any problem if all you are looking for is +/- 5% on flow.

However, you will have to contact the manufacturer for his specific requirements.

 

[TD2K]

I'm with the other comments but I'm surprised your instrumentation engineers didn't flag this earlier with piping for L/D requirements upstream and downstream of the meter.