The water motor driven proportioner can beapplied to the low-expansion foam fire extinguishing system in petrochemical,wharf, hangar and other industries and fields. As the low-expansion foam systemis usually a dry system (air control after the proportional mixing device), thereis a process of system pressure establishment when starting, in which thesystem flow rate may exceed the release flow rate. At this time, the mechanicalpump type proportional mixer will overspeed, so it is required that themechanical pump type proportional mixer has a certain overflow capacity, andthe overflow calculation of the system.

The F+W proportioner can run for more than5 minutes at 15% overload flow rate to ensure that the ratio mixer cannot workdue to starting overflow in the multiple foam system.