Automatic foam premixing system 

Proportional proportioning for the N/NH pump series

For pumps of the N/NH series, FIXMIX, a mechanically-operated around the pump foam proportioning system that is completely integrated into the pump, is available. Rosenbauer FIXMIX works automatically and adjusts to the pump output and pump pressure. The system of this foam proportioner is completely maintenance-free.

On the normal pressure side, up to three different fixed preset proportioning rates can be selected.

Impresses with

  • High foam output
  • Best integration into the N/NH pump
  • Automatic adjustment to the water flow quantity
  • Simple design and operation


The water flow raises the water cone which in turn raises the foam cone via a control rod. By opening the drive water line, water from the normal pressure side flows back to the suction side of the pump. The corresponding ball valve is then opened for the desired proportioning rate. In this way, foam compound flows over the opening between cone and conical seat and is mixed with water on the suction side.


Choosing the proportioning rates is available both with manual (for one proportioning rate) as well as with pneumatic operation.

Technical data

  • Around-the-pump foam proportioning system
  • Water flow measuring via water cone
  • Fully automated, mechanically controlled dosing cone system
  • Measuring range of water from 180 to 5,000 l/min (depending on pump)
  • Up to three proportioning rates (choose from 0.5%, 1%, 3% and 6%)
  • Foam compound tank suction and external foam suction possible


  • Versions with 1, 2 or 3 proportioning rates (one stage per proportioning rate)
  • Manual (possible for single-stage design) or electric/pneumatic operation
  • Usage of different foam compound sources (2 foam tanks and external foam suction possible)
  • Construction of the housing in light alloy and gunmetal (depending on pump material), cone system made of brass
  • Different sizes for the various pumps of the N/NH series
  • Special cones for highy viscose foam compounds (on request)