What is a pressure tank used for in water-based fire protection systems?

A pressure tank in water-based fire protection systems serves the crucial function of supplying water using air pressure. This is essential in ensuring that there is a reliable and consistent supply of water, especially in situations where the municipal water supply may be insufficient or slow to respond.

The way this works is that the tank is typically filled with water, and the space above the water is filled with compressed air. When a fire protection system is activated, the air pressure forces the water out of the tank and into the piping system, enabling a rapid response to a fire incident. This mechanism is especially important for maintaining adequate pressure in the system, facilitating effective water delivery to sprinklers and other fire suppression components.

In contrast, increasing the flow rate of water, maintaining temperature, or filtering contaminants are not primary functions of a pressure tank in this context, making option B the correct and suitable choice.