mounted inside the tube outlet and an internal annular ?ange
22 downstream of the ?aplike member together with an
actuating mechanism for the valve which includes a ?oat
member 23 disposed in the water W above the tube inlet 13
and a linkage assembly 24 connected between the ?oat and
valve for pivoting the ?aplike member in accordance with the
changes in the liquid level of the water W in the ditch D to
open and close the valve.