PD Flowmeter

For turbine types of flow meters, you get a turndown ratio (ratio of high and low flow) of about 10, thus limiting the low flow limit. It may have to do with the shift in flow regime from laminar to turbulent flow. (2D Diesel: nu = 2-6 cSt @ 40 deg C) ((http://www.engineeringtoolbox.com/kinematic-viscosity-d_397.html))

Assuming Re_turb > 2300 (circular pipe) and given Re = v x D / nu, you get the turbulent flow at about Q > 1000 L/h.

For gear types, you can reach a much lower low flow limit. (e.g. http://www.brooksinstrument.com/category13.asp). It states a range from Q = 2 - 5000 L/h.

No clear solution here, but it would be interesting to know what you found as possible solutions to you problem.

I've installed fuel flow monitoring devices in both single and twin engine aircraft and boats. Most were gasoline powered, some were diesel. Some were carbureted. Many were port or direct injected.

The average installation was about $250 per engine. The technology is simple enough consisting of a simple in-line flow meter which is little more than a small, free spinning, propeller like turbine whose blades interrupt light from an LED. The receptor sends the pulse data to a small logic circuit that converts the pulse frequency to flow rate, usually in pounds or gallons per hour. The more sophisticated units have provisions for monitoring total fuel burn and deducting that from a known supply volume. Others will tell you time to fuel exhaustion as well. Remaining distance is also calculated if there is as jack for data from a GPS unit.

Fuel induction systems which use a circulatory loop system have two turbine flow meters. The first in the supply like to measure in bound flow. The second is in the return line back to the tank which reduces the in bound value by whatever is being returned unused.

The extra cost of installing the system in a fuel injected engine will likely be about $100 more.

Most of these devices can be had for less money if purchased from a marine/boating supplier. Those units do not require any certification to strict standards as aircraft units must do to be legal. The product liability insurance associated with aircraft components for what is essentially the same device as used elsewhere is prohibitive.

http://www.floscan.com/html/blue/index.php

The units I installed were very precise measuring to within +\- 3% over a range of from 6 pounds per hour to 300 pounds per hour. They will read much higher rates but I never had occasion to install one in a high volume system.

L. J.

Hi

Emerson process have a flowmeter for this aplicatión with coriolis technology

regards

Coriolis is the better technology ofcourse! but the application is not suitable for coriolis flowmeter as the flowmeter is to be installed at the suction inlet of the pump!

regards,

Afifa

Hi there

Pipe size is 40mm less than 2 inches, the best way is using DP flow meter such as Honed flow or integral orifice meter they are suitable for pipe size less than 2inches and small flow rate.

good luck,