The City of Charleston, W.V., is situated in a low-lying valley and is subject to severe spring flooding as rapid mountain snowmelts combine with excessive rain. The city depends on a combined sewer overflow (CSO) system to manage its stormwater, but this system's capacity would be exceeded each spring when rising waters rushed back through the CSO pipelines and into the wastewater treatment plant.
Charleston installed metal flapgate check valves in an attempt to prevent this backflow, but these were a constant maintenance problem as they would rust, freeze and hang open around entrapped debris.
In 1996, Charleston launched the first stage of a multi-phase upgrade to its entire CSO system that would eventually come to eliminate the annual flood disasters. Included in this phase was the installation of 12 large-diameter Tideflex® Check Valves from Red Valve. The Tideflex® Check Valve offers maintenance-free, reliable performance that cannot be achieved with the standard metal flapgate. Constructed entirely of elastomer, the Tideflex® boasts an unparalleled useful service life as it will not rust, freeze or corrode upon contact with harsh abrasives and tough solids. The unique "duckbill" design provides absolute backflow prevention – backpressure from rising water on the discharge side seals the bill drop-tight, even when large debris is trapped inside. As the valve’s bill opens and drains with as little as one inch of line pressure, the Tideflex® Check Valve effects minimal headloss to the overall discharge operation.
Approximately one year later, Charleston launched phase two of the overhaul, this time purchasing seven additional large-diameter Tideflex® Check Valves. These were installed throughout the city to prevent flooding of roadways, commercial complexes and residences.
Now, more than four years later, the City of Charleston is looking to initiate the next stage of its extensive CSO upgrade. Phase three is to include the installation of several additional Tideflex® Check Valves to protect various CSO structures. The Tideflex® InLine Check Valve is a variation of its predecessor that can be easily installed inside manholes, culverts and pipelines without damage or alteration to the infrastructure. Offering the same performance benefits as the original, the Tideflex® InLine Check Valve is custom designed to fit inside any existing structure for an easy, convenient retrofit.
"The City of Charleston is a small town with a big flooding problem, and it needed a big solution," said Red Valve President George Raftis II. "The Tideflex® Check Valve, with its proven backflow prevention technology and long-term reliable performance, was exactly what the city needed to address a stormwater management issue of such great intensity."