For drafting purposes, how is lift measured?

For drafting purposes, how is lift measured?

• A. From the surface of the water to the pump intake
• B. From the pump intake to the water surface
• C. From the water surface to the discharge valve
• D. From the pump to the water surface

Answer: (A)

The lift is the vertical distance the pump must raise water from the source up to its suction opening. For drafting, this is measured from the surface of the water to the pump intake, because the pump has to create enough suction to draw water up to that point. This lift directly affects suction pressure and the available Net Positive Suction Head (NPSH); the greater the lift, the more challenging the draft and the more careful the operator must be with fluid conditions and pump selection. The other options describe distances that don’t represent the suction-side height the pump must overcome.

The lift is the vertical distance the pump must raise water from the source up to its suction opening. For drafting, this is measured from the surface of the water to the pump intake, because the pump has to create enough suction to draw water up to that point. This lift directly affects suction pressure and the available Net Positive Suction Head (NPSH); the greater the lift, the more challenging the draft and the more careful the operator must be with fluid conditions and pump selection. The other options describe distances that don’t represent the suction-side height the pump must overcome.