Dear Sir,
I looking a plumbing water supply pipe sizing and pump head farmula for 40 story building or genral fandamentl

Thank you

We need more details. What country are you in? How many units in the building? Wile there be a storage tank on the roof? You will need more thenone pump,(booster pump) to over come the back pressure caused by a 40 story pressure head.
We'll wait on your reply, Tom