Flow meter

Dear All,

As part of Oil plant automation, I am looking for Flow meter.

One of the factors in selecting a flow meter is the required accuracy. What amount of error can you tolerate? You could use a mag meter, a vortex meter, a mass meter, or perhaps a Dp, it all depends.

If you are measuring the same product properties all the time (stable viscosity, density, etc.) you may find a mag meter that will work. The only time I have ever measured oil flow, we were burning waste oil. Since the physical properites of the oil were varied (differtent oils/sources of the oil), we had to use coriolis flow meters. The only way to be certain is to speak to some instrument reps; they should either ask questions about the process or have you fill out an application data sheet. Then they can tell you what will or won't work. You can also find this info yourself by looking at the specs for the brands/types of instruments you are looking at. The coriolis meters will give you the highest accuracy and repeatablility, along with the capability of measuring multiple variables (volumetric flow, mass flow, density, viscosity, temp. and total flow) but they will also cost more than a typical magnetic flowmeter.

Do NOT use a magmeter.

Magnetic flowmeters require conductive solutions and oil is generally not conductive enough for reliable use in a magmeter. Magmeters are great for water, acids and caustics. Not good on oils.

Turbine meters work great in clean fluids like oil (it's what they were originally designed for), have great turndown (which can measure low flows as well as high flows), are on the high end of the accuracy scale, and the pressure drop is not excessive. I've used Hoffer brand.

There are relatively inexpensive paddle wheels (Kobold DF) that some mistakenly call turbine meters, but I don't think they are in the 13 Lps (approx 200 gpm) range, and the pressure drops are fairly high for an in-line meter (much higher than a turbine meter).

There are thermal dispersion meters that produce very low pressure drops and provide an inferred mass measurement, as opposed to volumetric flow.

IFM Efector and Kobold both have a thermal flow meter. Kobold calibrates to thermal characteristics of water and I've had difficulties getting a correct compensating value for oils though.

Ken mentioned vortex and differential pressure, either of which would work. Vortex has greater turndown of the two and less plumbing when you install it.

Dan

Good results with an Endress-Hauser Promass , available with simple analogue or a variety of other interfaces .

Correollis Meters

We have had good success using Micro Motion Correollis meters.
Series 1000 and 2000 transmitters. We put them on the Profibus DP/PA and recieve Temperature, Density, Flow, Totals in what ever units you setup. The mass flow meters are extremly accurate.

We dispense 20,0000lbs with +/-2lb accuracy.

Thankyou very much for ur support.