Home - Effluent Diffuser Systems - Backflow Prevention

Maintain Hydraulic and Dilution Efficiency

    Multiport effluent diffusers were conventionally designed with open, fixed diameter ports. The effect of currents, waves, tides, debris and ambient sediment transport of fresh and marine  waterbodies leads to the intrusion of sand, silt and sediment into the outfall through the open ports. The images to the right show a diver pulling sediment out of a completely clogged riser pipe.  Many treatment plants have a wide range of flow rates and low flows increase the risk of intrusion.  Marine outfalls also suffer from salt water intrusion at low flows since salt water is denser than the effluent.  Salt water can backflow thru the open ports even when effluent is being discharged.  

    The intrusion of sediment, debris and salt water reduces the hydraulic capacity of the outfall and compromises initial dilution.  The reduced hydraulic capacity will result in higher pumping costs, or the inability to discharge peak flows.  And, the costs to remove the sediement and restore the outfall to service can be enormous and will need to be done repetitively in the future. Compromised initial dilution can result in permit violations and public health concerns.    

    Tideflex Variable Orifice Diffuser Valves (TFD's) prevent the intrusion of sediment, debris and salt water into the outfall regardless of the plant flows or receiving waterbody conditions.  The all-rubber, ply-reinforced TFD's do not have mechanical parts, do not require maintenance, and operate solely on differential pressure, making them perfect solution for backflow prevention of multiport effluent diffusers.   TFD's have been installed on thousands of multiport effluent diffusers and have been providing reliable backflow prevention for over 20 years. 

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US Patent No. 6,367,505
Canada Patent No. 2,366,605