flow meters

[acmckracken]

has anyone had a problem with turbine flow meters agitating and foaming the product?

[Andrewwe_]

Laminer flow device / or use an ultra sonic meter

I don't have experience with flow meters and beer, but do with flow meters and water. Yes turbines will create turbulence / air bubbles in water. Usually a vent is installed to allow the air to escape. Also, the meter must be installed on a straight line of pipe (i.e. no elbows or diverters before or after the meter for several feet: depending on the size of the pipe). With water you can insert a Laminar flow device after the turbine meter to smooth out the turbulence. Or, ditch the turbine meter and install an ultrasonic meter.

[BDL]

Ok, first off just no. turbine flow meters can not "create air bubbles". If you're getting bubbles its because your line isn't full of liquid, or you're breaking out CO2. Either way if thats the case no flowmeter is going to give you accurate readings. It's true that you do need to have a straight piece of hard pipe both before and after the flowmeter but that only has to due with the accuracy of the meter, reason being things like elbows can induce a vortex in the liquid which obviously spinning liquid is going to give you bad readings. Generally the pipe before the meter should be at least 10 times the diameter of the pipe and the piece after only needs to be at least 5 times the diameter of the pipe. As far as turbulence yes, anything in the pipe will induce turbulence. But a meter induces no more turbulence than an elbow, tee, valve, or reducer does. As far as laminar flow, unless your liquid velocity is under 5-6 ft/sec then you aren't going to get laminar flow in a piece of straight hard pipe anyways.

Long story short I have used them in both beer and hard cider and have never found any kind of "rough handling" to the product or any other kind of problem. If you are super concerned that you will have an issue buy a magnetic meter they are nearly just a straight piece of pipe, and cheaper than ultrasonic. I don't actually know anyone in brewing using ultrasonic, not sure why. But I wouldn't worry about it, turbine should be fine.

cheers!
Brian