When determining the level of a potable water hydro pneumatic header tank fitted with a tubular sight glass, what must be taken into consideration? |
A) The sight glass must be drained, blown down, and re-filled before each reading is taken. |
B) The actual water level in the hydro pneumatic header tank is somewhat higher than the level shown in the sight glass. |
C) The actual water level in the hydro pneumatic header tank is somewhat lower than the level shown in the sight glass. |
D) The actual water level in the hydro pneumatic header tank is identical to the level shown in the sight glass. |