Drafting & Lift
Drafting pulls water up with atmospheric pressure, so altitude and lift height set a hard ceiling on what the pump can do before it loses prime. Higher ground, lower ceiling.
Vertical distance from the water surface up to the pump intake.
Blank means sea level.
Enter values above to see the result.
Try it live: set up a draft on the pump panel and watch what lift height does to the prime. Open the pump panel