My wife is very much into eco solutions - we are wanting to pump gray water from our washing machine out to our garden. (Aside: We do use a plant friendly detergent.)
We are wanting to pump a length of 20 meters. The diameter of the outlet / flow pipe is 22mm, but when we tried pumping this distance (using a 20 meter length of pipe @ 22mm) - it really sounded like the pump was struggling. We then tried 34mm (which was much much better) - before finally ended up using 38mm diameter diverter.
Could someone please let me know the basic Physics involved here ? Ideally we would like to know the "optimal" diameter to use - how can you calculate it ?
P.S. If this is the wrong stack exchange to be asking in please let me know. Maybe Engineering is a better fit.
With Thanks in Advance