Flowmeters and accuracy on placement


Thread Starter


What happens to the accuracy of flowmeters if they are placed too close to obstructions in closed conduits??

We need a testreport in the above subject, proof that is.
If you want proof, your going to have to test it yourself in your configuration. There are so many variables affecting meter accuracy, you
didn't specify the obstruction, or piping configuration, or fluid, or meter type, or velocity, temperature, specific gravity, etc, etc.
Now there are some general rules:
Most flowmeters should have a straight unobstucted pipe section before and after the meter that is several pipe diameters in length. The meter manufacturers provide recommendations for this.
Bad things happen, mostly. Very bad things.

There are large numbers of studies, including a very important one done at the University of Edinburgh in the 1970s.

Walt Boyes

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Bruce Durdle

If you are looking for an "official" document to include as part of a formal case of some sort, you need to find some standards that will be
recognised by the people you are addressing your report to - and that might depend where in the world you are. In Europe, I suggest you get hold
of ISO5167 for differential pressure measurement.

It also depends what type of meter we are talking about and whether you are measuring liquids, gases or steam.

Many meters depend on a laminar type flow for their equation to work best. Turbulent and transitional flows cannot be handled by most and thats why you need special devices to condition the flow.

If you want to know a company that can give you tons of information on this, try Savant Measurement. They even have cool flow phenomena moving presentations

Hope this helps