Coarse Bubble Diffuser – ProFlex™ Style 730CBD

What Does a Coarse Bubble Diffuser Do?

Coarse bubble diffusers aerate or mix wastewater for effluent / sewage treatment and pollution control. A coarse bubble diffuser produces bubbles which rise from the floor of a wastewater treatment plant or sewage treatment tank. They are used in grit chambers, equalization basins, primary and secondary settling ponds, and areas where sediment settling is a concern. Coarse bubble diffusers typically produce 1/4 to 1/2 inch (6.4 to 13 mm) bubbles.

Benefits of the ProFlex™ 730CBD Coarse Bubble Diffuser

Diffusion is a term used to guarantee that when sewage is put into a holding tank, it is not allowed to settle into the bottom of a tank. The ProFlex™ 730 CBD is an engineered molded valve which, when submerged and charged with air, will create a series of bubbles strong enough to capture the sewage effluent and carry it to the surface of the tank.

A diffuser system is driven by an air blower or a compressor, this ensures the volume of air is always exiting the valves outlet. A unique benefit of the ProFlex™ 730CBD is its unique elastomeric duck bill design which is always in a 100% closed position and relies on static head to open, so the instant there is an absence of inlet pressure the valve is closed bubble tight ensuring unwanted media does not flow back into the manifold as well as the blower or air compressor internals.

The ProFlex™ 730CBD is built to handle industrial applications that require effective and low maintenance wastewater treatment. With no maintenance or costly down-time this results in a coarse bubble diffuser system which provides long life features. The ProFlex™ 730CBD features a 3/4” NPT SS Hex nipple instead of a standard SS pipe nipple, this feature allows the owner / contractor a hassle-free installation, providing a positive seal on the manifold without breaking the adapter or the manifold’s inlet fitting.

EPDM or Neoprene are the most specified elastomers for this coarse bubble diffuser, and both offer superb flexibility along with long life expectancy, contact us for other available elastomers.

Application of the ProFlex™ 730CBD Coarse Bubble Diffuser

This design of the ProFlex™ coarse bubble diffuser prevents backflow of media and fluids into the diffuser and manifold piping. Exiting airflow discharges towards the floor of the chamber eliminating accumulation of solids. This in turn creates a complete overturn loop which ensures high mixing of the reservoir, once again resulting in minimal maintenance. The ProFlex™ 730CBD design provides the engineers with SCFM information for each orifice size which allows the Engineer / Municipality to design and implement their air pump / compressor flow data which in turn lowers design costs.

For more information about the features and benefits of the Proco ProFlex™ Style 730CBD rubber duckbill check valve, download our brochure.

For up-to-date pricing and availability information, contact Proco today.




Proco Products, Inc. has ANSI/NSF 61 Certification for Series 730. Elastomer: Neoprene. Sizes: 1” I.D. thru 120” I.D.

ANSI/NSF Standard 61 standards were developed by the National Sanitation Foundation (NSF), and the American National Standards Institute (ANSI) setting stringent requirements for the control of equipment that comes in contact with either potable water or products that support the production of potable water.



All Proco Series 700 ProFlex™ Rubber Check Valves including the 730 CBD Coarse Bubble Diffuser are available in a various selection of elastomers including ANSI/NSF-61 certified product under UL Certification #MH47689. The Proco Series 700 ProFlex™ Rubber Check Valves will not freeze or deform and function solely on inlet and back pressures which will be present in each unique application.

Each valve is carefully constructed using the finest of materials engineered by some of the most experienced rubber technicians in the industry. All check valves are engineered with precise detail to ensure proper operation and will provide years of unhindered operation and trouble free service.

Available Styles & Materials

For Specific Elastomer Recommendations, See: PROCO "Chemical To Elastomer Guide"
PROCO Material Code Cover Elastomer Tube Elastomer Maximum Operating Temp. °F (°C)
BB Chlorobutyl Chlorobutyl 250 °F (121°C)
EE EPDM EPDM 250 °F (121°C)
NH Neoprene CSM 212 °F (100°C)
NN Neoprene Neoprene 225 °F (107°C)
NN-NSF61 Neoprene Neoprene 225 °F (107°C)
PP Nitrile Nitrile 212 °F (100°C)
NR Neoprene Natural Rubber 180 °F (82°C)


ProFlexTM is a trademark of PROCO Products, Inc.
All products are reinforced with polyester tire cord.
1. Styles with Neoprene covers meet all requirements of U.S.C.G
2.  NN-NSF/61 UL Classified Water Quality
3.  Other Materials available. Please contact Proco Products, Inc.

Coarse Bubble Diffuser – Style 730CBD
Diameter Standard Valve Dimensions Flow  Range
Length Duckbill Height
in. mm in. mm in. mm
1.5/0.75 40/19 7.50 191 3.50 89 0-12 SCFM or 89.8 USGPM
2.0/0.75 50/19 8.70 221 4.50 114 0-18 SCFM or 134.7 USGPM
3.0/0.75 80/19 9.50 241 6.00 152 0-24 SCFM or 179.5 USGPM

Note: Length (approx.) based on standard molded valve length installed on PVC fitting with 2″ long 3/4″ nipple threaded into PVC fitting

Due to the wide array of uses for the Proco ProFlex™ Style 730CBD Coarse Bubble Diffuser, it is recommended that you download our Series 700 Brochure to review the Frequently Asked Questions. This will ensure that you choose the proper style of check valve for your specific application.

If additional information is needed, please contact us directly.