Originally Posted by broodro0ster
I hear this a lot, but I've never seen test results. Do you have an article with measurements that proves this? I'd really like to know this.
If not I'll see if can test it with my spare loop.
From Sodiki and Adigio
it looks like Roberson and Crowe in 1975 and Giles in 1977 did the original research or were the first to compile other sources of head loss through fittings. Good luck tracking down those papers though. All of it has been revised and refined in the last 45 years anyways and the tables today are taken as gospel. In practice, equivalent lengths are usually calculated at worst possible loss with an added safety factor unless other factors such as volume taken up or fitting mass are needed to be considered.
Testing fitting head loss should be doable if pressure drop or flow rate can be precisely measured using a pump with a known curve. But there are a ton of variables that could complicate matters.
Last edited by PM2843; 05-17-2020 at 06:41 PM.