The TF-1 slip on duckbill check valve has a 100% rubber construction that is available in several classes of elastomers for various temperature and chemical combinations. The TF-1 duckbill check valve is designed for end-of-pipe outfall and manhole installations. As a result, the TF-1 duckbill check valve's versatility makes it a popular Tideflex product, suited for backflow prevention and flow control alike.


  • 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)

Materials of Construction

  • Elastomer
  • ANSI Class 125/150#, DIN PN6, PN10, PN16, or custom drilling patterns
  • Compression Clamps
    • 304 Stainless Steel (Std.)
    • 316 Stainless Steel
    • Special Alloys Available


The TF-1 has become the preferred Tideflex 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 maximise the available gravity head; thus, the invert pipe is as close to the floor as possible.

The TF-1 allows installations in such structures and are easily retrofit to existing structures, often replacing failed flap gates, without the need for breaking up the concrete floor to provide bottom clearance.

The Tideflex Duckbill Check Valve is a revolutionary design for backflow prevention. Tideflex Valves are a one-piece rubber matrix of numerous natural and synthetic elastomers and ply reinforcement, similar in construction to a truck tire.

Tideflex are cost-effective because they do not need periodic maintenance or repair to keep them operational and they have a 30 year operational life span. Tideflex operate using line pressure and back pressure to open and close so no outside energy source is required.

The valve has an extremely low cracking pressure so the valve self-draining which eliminates standing water and maximises storage volume in the upstream pipe. Tideflex Valves have low headloss, they do not rust or corrode and are not affected by UV so performance and reliability is constant thru the life of the valve.

The flexibility of the Tideflex allows the valve to compress around trapped solids providing a much better seal than flap gates, as confirmed by the USEPA. With the development of the patented curved bill, sealing capabilities are even further improved because the curve bill is more flexible than the rest of the valve and therefore compress more around solids.

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 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 standardised by many consultants and owners.

The patented TF-1 design is a product of 25 years of experience, research and development and testing 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 OD 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 back pressure ratings or to lower headloss while maintaining back pressure ratings, the Saddle Support Technology (SST) can be used in conjunction with the Series TF-1.

US Patent No. 5,931,197

If you require any assistance or more information please contact us by phone on 01603 488700 or by email sales@althon.co.uk

Tideflex Check Valve Series TF-1

    Brochures, Datasheets and Installation Instructions for Tideflex Check Valve Series TF-1