F+W Proportioner is purely mechanical system consist water motor ① and piston pump fire② , Fire water go through water motor ①, water motor①, rotating and drive the piston pump② , piston pump ② ,draws the foam concentrate and pressurized, then inject into the outlet of the water motor① . Both water motor and piston pump are positive displacement fluid machinery, In theory the flow rate is proportional to the speed, so as long as the displacement of the water motor① and piston pump② meet the requirement of the proportioning rate, then accurate proportioning rate can be achieved, the applicable flow rate range depends on the difference between the theoretical and actual displacement.

3-way Ball Valve "proportioning/Returning" is in the proportioning position under standard working Condition, when remote injection or proportioning rate testing is required, it is in the returning position,

Ball valve④ normally closed, after each use, the ball valve opened to clean the piston pump ② and related pipe components.