Which type of foam proportioning system uses a foam pump and valves to balance pressures?

The balanced pressure pump-type proportioning system is designed to maintain the proper foam concentrate and water flow ratios by utilizing a dedicated pump and valves. In this system, the foam concentrate is drawn from a storage tank and is mixed with water at a controlled ratio to create a foam solution that is then delivered to the discharge nozzle.

The key feature of this type of system is its ability to balance pressures within the system, ensuring that the foam concentrate and water are mixed effectively regardless of variations in flow rates or pressures downstream. This balancing is typically achieved through the use of pressure sensors and control valves that automatically adjust flows, allowing for consistent foam production even under varying demand conditions.

This feature is particularly important in firefighting applications, where the effective suppression of fires relies heavily on the quality and consistency of the foam produced. Proper proportions result in better coverage and more effective heat absorption, contributing to more efficient fire control.

In contrast, other types of proportioning systems, such as self-educating nozzles, rely on the flow of water to draft foam concentrate into the water stream through venturi action, which does not provide the same pressure balance. Direct injection systems inject foam concentrate directly into the water stream but may not utilize a pump to achieve balanced pressures