Tiny Orifice Plate Sizing
Tiny Orifice Plate Sizing
(OP)
I'm sizing an orifice plate for flow reduction, as the upstream (on/off) dump valve has a very large CV and we're concerned about emptying the tank before the operator can close the valve.
Using equations from McCabe, Smith, & Harriott I solve directly for the beta ratio, which comes out to be 0.06 for the desired flow. The pipe size is 0.5" tubing, and the orifice hole, therefore, is 0.03". This gives me a Reynolds number of 8566 in the upstream pipe, which, according to the literature, should cause me to look closely to the value for C that I am using.
Since I am not measuring flow, but simply trying to reduce the rate, is this anything to be concerned about?
Thanks for the help!
Using equations from McCabe, Smith, & Harriott I solve directly for the beta ratio, which comes out to be 0.06 for the desired flow. The pipe size is 0.5" tubing, and the orifice hole, therefore, is 0.03". This gives me a Reynolds number of 8566 in the upstream pipe, which, according to the literature, should cause me to look closely to the value for C that I am using.
Since I am not measuring flow, but simply trying to reduce the rate, is this anything to be concerned about?
Thanks for the help!
Onwards,
Matt





RE: Tiny Orifice Plate Sizing
RE: Tiny Orifice Plate Sizing
Thanks for the advice. There are no options for this; it's my own spreadsheet using an equation from the literature.
I ran a couple demo programs over the weekend and I'm spot on with FE-Sizer, so I figure I'm OK. Since we're just trying to slow the flow, this should suffice.
Onwards,
Matt
RE: Tiny Orifice Plate Sizing
Begs the question: why are you using 1/2" tubing if you can tolerate that much pressure drop? Why not a smaller valve and 1/4" heavy wall tubing?
RE: Tiny Orifice Plate Sizing
I think the metering valve is a great suggestion; I wasn't familiar with those previous to your post.
Probably could go with 1/4" tubing all the way to the downstream drum, but it's already installed and replacing that tubing, and the associated heat trace, would be expensive and delay things.
I like the metering valve option. Have a star!
Onwards,
Matt