With the continuous improvement of environmental requirements, the foam concentrate also has C8 fluorocarbon surfactant development to C6 fluorocarbon surfactant, but the final development direction is completely fluoride-free foam concentrate.

Fluoride-free foam concentrate is a synthetic foam, no film, with high viscosity, usually in 4000-6000Cps, which requires a strong suction ability of the proportioners, especially for the water-turbine driven pump proportioners. Because of the needs to adapt to all types of foam concentrate, the suction design of the piston pump will have a very big challenge.

Fluoride-free foam concentrate is a Non-Newton type foam concentrate with the characteristics of shear thinning, when F+W water-turbine driven pump proportioner was used with Non-Newton fluid, the suction vacuum height could up to 6m.

When using fluoride-free foam concentrate, the suction line of the proportioner should be made  accurate hydraulic calculation to ensure the suction performance. When two or more proportioners are used in parallel, each proportioner should be equipped with separate suction line, and it is not recommended to use combined suction line.