Iris® flow control valves are characterized by flow which is always centered. The passage can be varied continuously, similar to a camera aperture. Thus, constant flow rates may be reproduced in any position. The ideal control characteristic according to DIN EN 60534 and its low pressure losses make the Iris® control valve a reference to an energy-saving valve in many industries. Here is a small selection of typical applications.

IRIS Diapragm Sequence

Aeration in a wastewater treatment plant

Used to regulate the aeration, this valve has been proven thousands of times at wastewater treatment plants. Due to the enormous energy saving, Iris® diaphragm control valves recover cost rapidly in wastewater treatment plants. In combination with a Kurz model 410FTB Thermal Mass Flow Meters, cascade regulation with slave loop according to ATW can be assured.

  • Air for aeration in wastewater treatment plant
  • Gases
  • Municipal and industrial wastewater
  • Slurries and viscous materials
  • Paper pulp and fibrous suspensions
  • Pellets with a particle size over 0.5 mm
  • Sugar suspensions
  • Drinking water
  • Ammonia-based aeration control (ABAC)


  • Highly precise control of the flow rate through concentric Iris®
Aeration in wastewater treatment
Liquids and Gas in Chemistry

Liquids and gases in chemistry and industry

In chemistry and industry, the BSH design is used for higher system and differential pressures. It is prepared for various monitoring systems and exists as all Iris® diaphragm control valves also in Atex design. The industrial design BSH fulfills the requirements of the Technical Guidelines on Air Quality Control (TA-Luft).

Viscous fluids / Centrifuge feed

Centrifuges such as in the sugar industry or wastewater
technology, can be fed accurately by Iris® diaphragm air flow control valves.

Viscous Fluids Centrifuge Feed
Sludge Wastewater and Fiber

Sludge, wastewater and fiber

Even slurries, solid containing liquids and fibrous products can be regulated precisely. The Iris® diaphragm control valves avoids clogging due to its completely open circular-shaped passage.

ABAC / Ammonia-based aeration control

Ammonia-based aeration control (ABAC) is a cascade control concept for controlling total ammonia nitrogen (NHx-N) in the activated sludge process. The Iris valve offers a broad range of stable air flow control from 15% to 94% which makes it ideal for ammonia based aeration control.

ABAC / Ammonia-based aeration control
IRIS Air Flow Control Valve

The Best Solution For Your Application

Reducing operations cost have become the Number #1 priority for a wastewater treatment plant. Egger’s IRIS® Valve offers both high regulating accuracy and a very low pressure drop saving as much as 15 percent of your blower’s energy usage.

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