Feeding Pumps - the Suction Lift in Steam Systems

The danger of impeller cavitations increases with water temperature

To avoid cavitations in a feeding pump the suction lift and pressure head should not exceed the limits below:

Temperature of Feeding Water Max Suction Lift Minimum Pressure Head
(oC) (oF) (m) (ft) (m) (ft)
55 130 3 10
65 150 2 7
77 170 0.6 2
80 175 0 0 0 0
87 190 1.5 5
95 200 3.5 10
99 210 4.5 15
100 212 5 17

For water with temperature above 80 oC (175 oF) its necessary with a positive pressure head - and the pump is located in an elevation below the water or condensate receiver.

In steam distribution systems its common with open vented condensate receivers with temperatures close to 100 oC (212 oF). This is true especially in systems where most of the steam consumed is returned as hot condensate, but also in systems where the make up water is heated to reduce the amount of air dissolved in the water.

pump suction head altitude

  • 1 ft (foot) = 0.3048 m

Search the Engineering ToolBox

Engineering ToolBox - SketchUp Edition - Online 3D modeling!

3D Engineering ToolBox - draw and model technical applications

Engineering ToolBox - SketchUp Edition - enabled for use with the amazing, fun and free Google SketchUp

Translate the Engineering ToolBox
About the EngineeringToolbox