Which devices control the water level in the gravity tank under normal conditions?

The two ball-type floats are designed to control the water level in a gravity tank under normal conditions effectively. Each float is connected to a valve mechanism that opens or closes based on the water level fluctuations within the tank. When the water level rises to a predetermined point, one float triggers the valve to close, preventing further water from entering the tank. Conversely, if the water level drops, the floats will allow the valve to open, enabling water to refill the tank.

This system is advantageous because it provides reliable control of the water level, ensuring that the tank maintains the necessary volume for optimal performance in firefighting systems. The dual float configuration allows for redundancy, enhancing system reliability as it minimizes the risk of mechanical failure that could occur with a single float mechanism. Other devices, such as valve checks and pressure gauges, serve different purposes within the system and do not actively regulate the water level in the gravity tank.