Coarse Bubble Diffusers

Maximum mixing, minimum maintenance.

When you need your basin to be well mixed, that’s a fine job for bubbles that are a little less, well, fine.


Optimized mixing involves applying a force in the right places with the least effort.

Coarse bubble diffuser systems offer moderate oxygen transfer efficiency and low maintenance with aggressive mixing. A very robust solution, circulation and turbulence ensures that the entire water column is mixed adequately, sludge accumulation is limited, and there are no moving parts in the water and orifices are less prone to clogging.


CoarsAir™ coarse bubble diffusers are compatible with the following configurations:

..and serve applications including:
  • Municipal Wastewater
  • Industrial Wastewater

How it works


EDI’s full spectrum of coarse bubble diffuser platforms provide advances in mechanical reliability, application flexibility, and ease of installation and maintenance.

The primary advantage of this technology is its robust design and ability to mix. First, the circulation and turbulence created by the static tube ensures that the entire water column is mixed adequately and sludge accumulation is limited. Second, the fact that there are no moving parts in the water and the orifices are less prone to clogging makes this a very robust solution.

Otherwise known as large bubble diffusers, coarse bubble diffusers get their name from the type of bubble they produce. Coarse bubble diffused systems are composed of dozens to hundreds of coarse bubble diffusers, each attached to a PVC or stainless steel air supply line fixed to the bottom of the treatment basin or tank. The most common coarse bubble aerator is known as a static tube. When large bubbles are released at the bottom of the tube, they create an effect that pulls the water from below the static tube and pushes it towards the surface.

Want to know what CoarsAir could do for your mixing?

Submit your RFP today and our on-staff professional engineers can help you size and design a coarse-bubble aeration and treatment upgrade to meet your wastewater treatment requirements.

What It Delivers


and their benefits.

CoarsAir™ HexAir

  • Economical capital cost and ease of installation.
  • Ideal for single-drop mixing applications
  • Mounts on any pip material (VC, ABS, CPVC, & SS)
  • Clog Resistant
  • Rugged Heavy-duty construction
  • 1-inch and 2 inch sizes available

CoarsAir™ Max (PVC)

  • Simplex or Duplex configuration
  • Designed for high airflow capacity
  • Available in 24-inch length (610 mm)
  • Clog resistant self-purge design
  • Full 48-inch air release perimeter (1220 mm)
  • Standard open bottom with optional closed bottom units available
  • PVC or optional CPVC construction for maximum chemical and temperature resistance
  • Three-level air discharge for wide flow range operation
  • Fully non-metallic—corrosion resistant

CoarsAir™ Wide-Band (SS)

  • 316 stainless steel construction
  • High-temperature resistance—will not fail in high-temperature settings
  • Clog resistant—designed for harsh environments
  • Highest airflow capacity for efficiency
  • Rugged heavy-duty construction for worry-free maintenance
  • Excellent for mixing and for demanding applications

CoarsAir™ FlexCap™

  • Economical capital cost and ease of installation
  • Mounts on any pipe material (PVC, ABS, CPVC, & SS)
  • No-clog design
  • Durable ABS body
  • Greatest air capacity
  • Integral check valve

CoarsAir™ PermaCap™

  • Economical capital cost and ease of installation
  • 5” diameter for greater air distribution
  • Mounts on any pipe material (PVC, ABS, CPVC, & SS)
  • Premium quality EPDM membrane with check valve
  • Rugged heavy-duty construction
  • Pre-assembled in our facilities

    CoarsAir™ AirCone

    • Non-clog design
    • Engineered orifice design for maximized air distribution
    • Turbulent mixing with contoured edge to fragment bubbles
    • Internal diaphragm check valve to prevent entry of solids
    • UV protection
    • Low capital and maintenance cost

      Recent Case Studies

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      Sanitary district upgrades lagoons for full cold weather ammonia nitrification within existing footprint.

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      Absarokee, MT

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