Posted 6/12/2019 19:34 (#7555579 - in reply to #7555506) Subject: RE: Raven Viper Pro rate hunting
Meter cal is the number on the tag of the flow meter. Valve cal is a number you plug in determined by the type of valve you have and adjustable after that.
Meter cal and valve cal are 2 separate things and Independant.
What sort of pressure you running at the point of rate flutation?
Being high flow, my guess is that you have a 3” raven flow meter. Those have a window of accuracy and you might be flirting with the bottom side of that at a “slow speed”. Those things do not want to read accurately under about 25 gallon per minute. You might look at putting a 2” flow meter on when you are running this low of a rate per minute.
We have also added a 3” valve on the back side of the flow meter and close it most of the way down, this makes the pump SHOVE it through the flow meter and with back pressure which dampens the flow so it lowers the odds of surging.