Siphon affect


In the following illustration we see a “down pipe” that will give the pump discharge head a siphon affect for 10 feet. It is the same principle we use to siphon gasoline from an automobile to fill a lawn mower.

  • Our discharge static head is 40 feet (11 meters) minus 10 feet (3 meters) for a total of 30 feet (8 meters).
  • The suction static head is 5 feet (2 meters)
  • The total static head is the discharge static head minus the suction static head, or 30 feet (11 meters) minus 5 feet (2 meters) for a total of 25 feet. (9 meters)

The pump will have to develop enough head to overcome the 40 feet (11 meters) inital filling of the piping, but once running the static head will drop back to 30 feet (8 meters)