Fluid additive supply system for fire fighting mechanisms

摘要

An additive supply system for fire fighting mechanisms such as a fire fighting truck including an additive supply line system having a pump and a recirculation line, a balanced pressure valve metering flow in the recirculation line and in communication with the measure of additive line pressure and fire fighting fluid line pressure, and additive pump control apparatus connected to the additive pump and in communication with the measure of the degree of openness of the balanced pressure valve.