Bharathi Associates
Scroll-controlled exploded view film of diffusers equipment

Better aeration starts at the membrane.

Fine bubble discs and tubes, coarse bubble diffusers and retrievable assemblies for treatment tanks.

View diffusers & specifications Enquire

Scroll to open the product

Illustrative exploded view film. Use the specifications below for selection.

Diffusers, specified
for your application.

Compare the range below, then share your operating conditions for a matched selection. Range limits are dependent on the model and are not simultaneous duty point guarantees.

250 mm fine bubble disc diffusers

Fine bubble disc configuration
Fine bubble disc configuration

Fine bubble membrane discs for aeration grids in sewage and effluent treatment tanks. Match membrane material and diffuser loading to the actual wastewater and air supply.

Nominal size
250 mm, nominally labelled 9 inch
Membrane
EPDM or silicone
Support
ABS
Bubble size
1–1.5 mm
Airflow per diffuser
2–4 m³/h
Connection
3/4 inch BSP male thread
Listed operating temperature
35°C
Material temperature tolerance
85°C, not the continuous duty rating
Air discharge
Top discharge

Applications
STP and ETP fine bubble aeration.

Pressure, depth and membrane area must be confirmed for the chosen black or blue membrane variant.

Enquire about this range

320 mm fine bubble disc diffusers

Fine bubble disc with blue membrane
Fine bubble disc with blue membrane

A larger nominal disc option for fine bubble aeration. Use a balanced air grid and an appropriate diffuser count rather than running each membrane above its selected loading.

Nominal size
320 mm, nominally labelled 12 inch
Membrane
EPDM or silicone
Support
ABS
Bubble size
1–1.5 mm
Airflow per diffuser
4–6 m³/h
Connection
3/4 inch BSP male thread
Listed operating temperature
35°C
Material temperature tolerance
85°C
Air discharge
Top discharge

Applications
Treatment tank aeration and compatible biological processes.

The nominal inch labels are not exact conversions of the listed millimetre dimensions. Confirm physical drawing and membrane area before layout design.

Enquire about this range

90 mm × 1 m fine bubble tube diffusers

Fine bubble tube configuration
Fine bubble tube configuration

Fixed tubular membrane diffusers for distributing fine bubble air over the tank floor. The support uses PVC with ABS components.

Size
90 mm diameter × 1,000 mm length
Membrane
EPDM or silicone
Support
PVC with ABS
Airflow per diffuser
8–12 m³/h
Connection
1 inch female thread
Bubble size
1–1.5 mm
Perforations
28,000; nominal hole size 0.33 mm
Maximum allowable pressure
4 kg/cm², subject to model confirmation
Support colour
Black

Applications
STP/ETP aeration and compatible aquaculture systems.

Maximum pressure is not a normal operating setpoint. Confirm head loss, minimum airflow and continuous operating conditions.

Enquire about this range

63 mm × 1 m fine bubble tube diffusers

Fine bubble tube with blue support
Fine bubble tube with blue support

A smaller diameter fixed tube membrane option for aeration layouts. Select the material and tube spacing against the treatment duty.

Size
63 mm diameter × 1,000 mm length
Membrane
EPDM or silicone
Support
PVC with ABS
Airflow per diffuser
6–8 m³/h
Connection
3/4 inch female thread
Bubble size
1–1.5 mm
Perforations
20,000; nominal hole size 0.33 mm
Maximum allowable pressure
2.5–3 kg/cm², subject to model confirmation
Support colour
Blue

Applications
Sewage and effluent treatment aeration grids.

Pressure range and allowable service conditions are dependent on the variant and need supplier confirmation.

Enquire about this range

63 mm × 610 mm fine bubble tube diffusers

Short fine bubble tube configuration
Short fine bubble tube configuration

A shorter tube format for compact aeration arrangements. This version has a white support and a fine bubble membrane.

Size
63 mm diameter × 610 mm length
Membrane
EPDM or silicone
Support
PVC with ABS
Airflow per diffuser
6–8 m³/h
Connection
3/4 inch female thread
Bubble size
1–1.5 mm
Perforations
16,000; nominal hole size 0.33 mm
Maximum allowable pressure
1.8–2 kg/cm², subject to model confirmation
Support colour
White

Applications
Compact treatment tank aeration.

Do not apply retrievable assembly weights to this fixed tube. Confirm mounting details before installation.

Enquire about this range

Retrievable diffuser assemblies

Retrievable diffuser assembly
Retrievable diffuser assembly

A 2 m retrievable diffuser assembly with a polymer weighting box. Sand and pebble ballast provides submerged stability and an alternative to conventional concrete weights.

Diffuser size
90 mm diameter × 2,000 mm length
Assembly airflow
10–20 m³/h
Connection
1 inch
Bubble size
1–1.5 mm
Maximum allowable pressure
4 kg/cm²
Perforations
28,000 × 2; nominal hole size 0.33 mm
Box height
300 mm
Box uplift resistance
25 kg, as stated by supplier

Applications
Treatment tanks where retrieval and maintenance access are important.

Lifting arrangement, ballast quantity, stability and safe retrieval procedure must be agreed for the specific tank.

Enquire about this range

80 mm coarse bubble diffusers

Top discharge coarse bubble diffuser
Top discharge coarse bubble diffuser

A coarse bubble option for vigorous local mixing and air distribution. Coarse bubbles favour mixing over the oxygen transfer characteristics of fine bubble membranes.

Size
80 mm
Membrane
EPDM
Bubble size
3–4 mm, subject to model confirmation
Support
ABS
Airflow per diffuser
4–6 m³/h
Connection
3/4 inch BSP male
Air discharge
Top discharge
Operating temperature
40°C
Material temperature tolerance
85°C
Support colour
Black

Applications
Collection and equalisation tanks, and duty approved aeration tanks.

Confirm minimum airflow, head loss and chemical compatibility for the selected tank duty.

Enquire about this range

150 mm coarse bubble diffusers

Peripheral discharge coarse bubble diffuser
Peripheral discharge coarse bubble diffuser

A coarse bubble disc with peripheral air discharge for tank mixing. Confirm distribution coverage and airflow against the selected layout.

Size
150 mm
Membrane
EPDM
Support
ABS
Bubble size
3–4 mm, subject to model confirmation
Airflow per diffuser
6–8 m³/h
Connection
3/4 inch BSP male
Air discharge
Peripheral discharge
Operating temperature
40°C
Material temperature tolerance
85°C

Applications
Collection tank mixing and compatible aeration duties.

Flow and bubble size vary by configuration. Confirm the exact variant and its ratings in the quotation.

Enquire about this range

90 mm × 800 mm coarse bubble diffusers

A tubular coarse bubble format for radial air discharge and mixing focused duties. Confirm dimensions and mounting against the selected layout.

Size
90 mm diameter × 800 mm length
Membrane material
Supplier confirmation required
Support
ABS
Bubble size
4–6 mm
Airflow per diffuser
8–15 m³/h
Connection
3/4 inch BSP male
Air discharge
Radial discharge
Operating temperature
40°C
Material temperature tolerance
85°C

Applications
Equalisation, collection and suitable industrial mixing tanks.

Membrane material remains subject to confirmation. Confirm material, physical drawing and mounting before pipe grid fabrication.

Enquire about this range

Related treatment media.

MBBR biological media

STEP-MBBR-1522: polypropylene, 15 mm height × 22 mm diameter, surface area 340 m²/m³, voidage 90–92%.

Tube settler media

PVC, 1.0 mm thickness, tongue-and-groove fit, 44 × 120 mm cross section, 750/1,000 mm media height, listed continuous temperature 55°C.

Pall rings

STEP-PAL-35X35: polypropylene, cylindrical, 35 mm height × 35 mm diameter, listed weight 4.34 g/piece, black/white options.

The right details.
A better selection.

Bring us the duty, not just a motor rating or a nominal size.

For help with your duty, see our selection and site support or read the equipment FAQs.

  1. Tank dimensions, water depth and treatment process
  2. Required airflow and diffuser loading
  3. Wastewater chemistry and membrane compatibility
  4. Pipe grid layout and maintenance access
  5. For a replacement: diffuser dimensions, connection thread, quantity and photographs

Diffusers: common questions.

Can I replace only a few diffusers?

Yes, you can enquire about individual replacements or a complete air grid. Share the existing size, connection, membrane type, tank depth and airflow. Similar appearance alone does not establish compatibility.

What is the difference between fine and coarse bubbles?

Fine bubble diffusers are used where oxygen transfer performance is important. Coarse bubble diffusers provide stronger local mixing and are often considered for collection or equalisation tanks. The correct choice depends on the process.

Can I replace discs with tubes without redesigning the grid?

Not automatically. Connection sizes, airflow per unit, head loss, spacing and mounting differ. Check the complete aeration grid and blower operating point before changing the format.

Does the 85°C material tolerance mean continuous operation at 85°C?

No. The listed operating temperatures are lower than the material tolerance. The continuous service temperature and chemical compatibility must be confirmed for the selected membrane and support.

Tell us what
your site needs.

Share the duty, the equipment and the site conditions. A useful selection starts with the right details.

This form opens your email application with an enquiry addressed to info@bharathi-associates.com. Review it and send it there. No form details are uploaded to this website.

Explore the rest
of the treatment line.

Pumps Blowers