The TRU-BEND overflow weir system is designed to maintain maximum water levels before it overflows through the upstream, allowing full utilization of all available upstream storage volume without affecting overflow weir capacity in combined sewer overflow (CSO) applications. TRU-BEND's unique and extensively tested design works by only allowing any excess water in the system to reach the receiving watercourse, but only after upstream water level has been reached. This increases the storage volume of tanks and sewers and reduces the frequency and volume of overflows, resulting in less water pollution. This enables the TRU-BEND to overcome the disadvantages inherent to fixed weirs. The TRU-BEND protects against backflow as it is normally in the closed position.

The TRU-BEND can be installed in new overflow structures or directly on existing fixed weirs. The following components are included in the TRU-BEND overflow bending weir system: bending weir flap, plain bearings, supports, guide walls, anchoring system, counterweight system and inclinometer.

-Counterweights rarely come into contact with debris

-No lower clearance required

-Maximizes on-site storage

-Constant, easily adjustable performance level

-Reduces overflow frequency

-Prevents backflows

-Improved hydraulic quality line

-Lower storage tank construction costs thanks to smaller volumes

-Easy to adapt to existing installations

-Stainless steel construction

The TRU-BEND overflow weir system ranges from the GTB-30 to the GTB-150. The GTB-30 is designed to hold 12 inches (30 cm) of water above the weir crest, and the GTB-150 holds 60 inches (150 cm) of water above the weir crest. TRU-BEND model selection is based entirely on the height of water storage required. Units are modular in design, with a single unit measuring up to 30 feet (9 m) in length. The hydraulic capacity of the TRU-BEND is at least equal to that of a standard weir.

The TRU-BEND overflow weir is installed on the downstream side and directly along the entire length of the weir opening. The TRU-BEND adapts to the overflow by pivoting at the bottom and opening at the top.

The flexible weir mechanism is entirely passive, requiring no external energy to operate. Fixed counterweights act against the weir flap to maintain a constant upstream water level for all overflows varying from 0 to the design flow rate. The TRU-BEND overflow weir will remain fully open and act as an emergency overflow to accommodate flows higher than the design flow rate, resulting in a higher water level. The operating level can easily be adjusted on site by adding or removing counterweights.

The TRU-BEND overflow weir requires no control, although its operation can be monitored by an inclinometer. Upstream and downstream water levels can also be monitored.