When should you switch from pressure mode to volume mode on a pump?

Switching from pressure mode to volume mode on a pump is critical in ensuring that sufficient water supply is available for firefighting operations, especially in scenarios that demand a higher flow rate. When more than half of the rated capacity will be needed, this indicates that the operational demands exceed what can be sustained in pressure mode, which is designed for maintaining a set pressure under lower flow conditions.

In volume mode, the pump is optimized to deliver a larger volume of water at the expense of maintaining high pressure, which is essential when needing to meet the demands of multiple hoselines or high flow situations. This transition ensures that firefighters can effectively suppress a fire, especially in cases where substantial water is required to combat the flames.

The other situations listed—pressure drops, tank levels, or high-rise operations—do not strictly dictate the need to shift modes. While they can influence pump performance and strategy, the decision to switch is primarily based on the anticipated water requirements that exceed the pressure capabilities.