Ball valves

A ball valve shuts off water with a quarter turn of the handle. When open it leaves the full bore, so it does not reduce pressure. It goes on the main inlet, before each appliance, on manifolds and around the pump.

Choose by size and thread type (F for female, M for male), handle (lever, or butterfly for tight spaces) and whether you need a union for quick removal. “How to replace a ball valve” shows how to swap one without a flood.