Float Valve Balls

float valve
A valve which is mechanically actuated by a float. Utilized on many cooling towers to control make-up water supply.
A ballcock (also balltap or float valve) is a mechanism, or machine for filling water tanks, such as those found in flush toilets, while avoiding overflow. The modern ballcock was invented by Joseph Bramah and Thomas Twyford.
A mechanism that regulates fluid level by using a float to control the filling of water in the water tank; used in swamp coolers to regulate water levels.

balls
Clench or screw up (one's fist) tightly
musket ball: a solid projectile that is shot by a musket; "they had to carry a ramrod as well as powder and ball"
(ball) round object that is hit or thrown or kicked in games; "the ball travelled 90 mph on his serve"; "the mayor threw out the first ball"; "the ball rolled into the corner pocket"
Squeeze or form (something) into a rounded shape
Form a round shape
(ball) form into a ball by winding or rolling; "ball wool"