We are all shaped by our experiences as engineers. Our early experiences as young engineers are especially influential.
I first worked in the aerospace industry for five years and then the nuclear industry for two years. At each of these companies we relied heavily on a handbook written originally in Russian by a Russian engineer. I am talking about the Handbook of Hydraulic Resistance by I.E. Idelchik. This book is my "go to" book on any unusual pipe system configuration hydraulic calculations and, especially, with calculations at tees and wyes.