My pool plumbing has (2) 2" suction side lines. One comes from the wall port for the pool cleaner (Kreepy Krauly) and the other comes from the skimmer. These meet into a three way (diverter) valve, which goes into the pump. It was an older model valve which requires lubricaton, and both the handle retaining screw and the grease cup snapped off on their threads.
I need to replace it, but first I'd like to justify it. My biggest problem with it's design is the direction of flow. One of the first things I was taught as a plumbing designer was to NEVER design the direction of flow in a tee fitting to come in at both run sides and go out the branch. I've just searched the internet to see if I could find a friction loss calculation for that scenario and I cannot. http://www.pumpfundamentals.com/pipe..._fitting3.html I understand that this is a valve and not a tee, but flow is still is not configured properly from a design standpoint.
The 3-way valve could be replaced by a Jandy 4716 (2" & 2.5" 2-Way NeverLube Valve) on the pool cleaner line and a tee fitting configured with the proper direction of flow. This would eliminate my ability to throttle the skimmer flow, but I never had to do that before aside from once while trying to calculate head.
Would this design change make any difference to my friction loss, or am I overthinking this?