A drinker for a watering system of a poultry house comprising a housing having
a side wall, a top, and a bottom defining a valve chamber having an inner surface
and a floor. A valve seat is formed in the chamber above the outlet port; and a
valve member received within the chamber to be movable between a first closed position
and a second position opened position. A trigger pin passes through the outlet
and has a head with a cavity in the top surface. The cavity has a shape different
from the shape of the valve member. The drinker elements are sized such that the
distance between the valve seat and the chamber floor is greater than the height
of the pin head. Additionally, the valve member is sized such that when the valve
member is in its closed position, the valve member is does not contact the pin head.
