Series TF-1


The TF-1 has become the preferred Tideflex Check Valve configuration for outfalls. Designed for in-structure and end-of-pipe installations, the TF-1 features a flat bottom and flared top. This allows the valve to be installed at a lower overall elevation than other configurations, with less bottom clearance required. This is especially important in low-lying areas where maintaining as much driving head is critical, or where silt, sand and debris might tend to collect beneath the valve.

The TF-1 is ideal for manhole applications, such as junction boxes, diversion chambers and interceptors, where the invert of the pipe is close to the floor of the vault. These vaults are designed to maximize the available gravity head, thus the invert pipe is as close to the floor as possible. The TF-1 allows installation in such structures and is easily retrofitted to existing structures, often replacing failed flapgates. There is no need to break up the concrete floor to provide bottom clearance.

The TF-1 installs by slipping over the end of an exposed piece of pipe, and is fastened with compression clamps. The inside diameter of the TF-1’s cuff is fabricated to exactly match the outside diameter of the pipe.

The original Tideflex Check Valve design, the TF-2, has a flare on the top and bottom of the valve. It has been superseded by the TF-1 and has been standardized by many consultants and owners. The patented TF-1 design is a result of 25+ years of experience, research and development and testing of elastomeric duckbill check valves. In addition to the benefits provided by a flat-bottom valve, the TF-1 also benefits from the increased angle of the upper spine. The inherent geometry and construction of the TF-1 yields a more durable check valve with greater strength to support not only the weight of the valve itself, but the weight of the water discharging from it. In large diameter valves, this weight can amount to several tons.

The TF-1 can also be installed on the O.D. of elliptical pipe and many arch pipes. Tideflex Technologies also offers a thimble plate option allowing the slip-on TF-1 to be installed directly to a headwall or seawall. For higher backpressure ratings or to lower headloss while maintaining backpressure ratings, the Saddle Support Technology (SST) can be used in conjunction with the Series TF-1.

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U.S. Patent No. 5,931,197


  • Reliable backflow prevention
  • Minimal bottom clearance required
  • 100% elastomer construction eliminates maintenance
  • Will not corrode, warp or freeze open or shut
  • 1”-2” cracking pressure, low headloss
  • Curved bill enhances sealing around debris
  • Custom built for each application based on pressure and flow conditions
  • Available in diameters from 4" (100mm) to 102” (2550mm)