RDR - Constant Volume flow regulator

The flow regulator RDR is an element placed inside the duct in order to obtain a constant flow within a pressure range from 50 to 250 Pascals. It is used in air conditionning or ventilation systems either in extraction or blowing mode. RDR adjustable flow regulators are made from class MI plastic suitable for use at temperatures up to 60°C. Aeraulic characteristics meeting the requirements of the draft standard NF-E-51-776-2
RDR - Anjos Constant flow regulator

Some important facts about the RDR

  • Self adjusting on the pressure range 50 to 250 Pa (0.20 w.g. to 1 w.g.)
  • Easy adjustment
  • The requested air flow is fixed by a screwdriver «torx n°10»
  • Made in plastic material (classified M1) (also the sleeves) in Ø 150 to Ø 250 mm (6" to 10")      
  • Use with a maximum temperature of 60°C (140 F)

Principle of operation

In the example below with the RDR placed in a metal duct, the regulator element of the RDR (in yellow) decreases the air passage section with the increase of the pressure difference between the upstream and the downstream of the regulator, thus regulating the flow over the pressure range between 50 and 250 Pa
Principle of operation

RDR adjustment and installation


The flow regulators are simply fitted into vertical or horizontal ducts. On the horizontal duct, respect the mention «DOWN» indicated at the front of the product. A leap seal ensures the airtightness. When the flow regulator is associated with a diffuser, the minimum distance between the diffuser and the regulator is at least one diameter in extraction mode and 3 diameters in blowing mode
RDR adjustment and installation


Before setting the regulator, it’s necessary to calibrate the flow :
  • Using a T10 Torx screwdriver, loosen the screw on the adjustment module by one-quarter turn.
  • Set the cursor (on the left or right) to the desired flow rate.
  • Retighten the adjustment module locking screw.
Before setting the regulator, it’s necessary to calibrate the flow