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As was examined in the "Restriction of Flow of Hypochlorinators" experiment, if there is a solid material present like plastic or metal when the Ca(ClO)2 solution comes into contact with the atmosphere, the precipitate will form on the surface of the plastic or metal (Figure 32).
Figure 32. The percipitant that formed on a plastic surface after the solution of Ca(ClO)2 was leaking out of the bottle.
If precipitation forms in the stock tank or at the surface of the constant head bottle over time after the initial settlement, it would flow out of the tanks with the rest of solution or settle out at the bottom of the containers, as was observed in the Final Restriction of Flow of Hypochlorinators experiment. If it continued through the system with the flow of solution we are confident that this small amount of precipitate would not build up, or impede flow at any point in the system. This leaves us with the float valve orifice. Every instance where we were able to restrict flow from the orifice in the float valve there was a buildup of precipitate all over the surface of the float and the arm holding the float to the rest of the valve. It appears that precipitate is slowly forming in the orifice where the solution first comes into contact with the atmosphere after leaving the tube that flows from the stock tank, eventually restricting flow (Figure 43).
Figure 43. Restriction of flow through an orifice over time by the formation of a precipitant of CaCO3.
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