Most GuvNu valves are essentially a TF-1 duckbill valve pre-attached to a back plate. However, custom shapes and arrays using CheckMate valves are also used. The GuvNu is delivered to site as a one-piece unit for ease of installation to a wall (headwall, manhole wall, box culvert, quay wall etc.), or in pre-fabricated pieces for installation in non-standard outfalls, like round or egg-shaped Victorian sewers.
The TF-1 has become the preferred Tideflex configuration for outfalls. 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. Tideflex Valves have low headloss, they do not rust or corrode and are not affected by UV so performance and reliability is constant throughout the life of the valve.
The CheckMate inline valve can also be fabricated with a flanged end and this is what is often used in the GuvNu valve as well. The CheckMate valve is a heavy duty, fabric ply-reinforced, vulcanized elastomer unibody product (larger sizes have integral wire reinforcement in the body as well). This makes it tough and durable, but flexible and easy to install. It also has a very low cracking pressure - upstream flows with as little as 1" (one inch) differential pressure across the valve will break the saddle seal and allow the system to drain.
MeasurIT works with customers to determine the most appropriate valve design for their needs and delivers a pre-fabricated GuvNu valve product to site. We can also offer site installation advice and/or supervision.