Overflow Security Valve (OSV)

After 9/11, water utilities had to conduct vulnerability assessments and one area identified for potential terrorist attack was water storage tanks. An overflow pipe with a 2-foot air gap between ground level and the end of the overflow pipe, for example, was considered by many to be an easy access to the potable water in the tank. Screens, flap gates, and even Tideflex Valves installed on the end of the overflow could not stop the injection of a liquid or gas into the water volume.

Red Valve developed the Overflow Security Valve (OSV), (Figure 3), to address this concern. The OSV is an assembly that incorporates a Tideflex Series 37. The OSV is either welded or flanged into the overflow pipe with tamper-proof bolts. The OSV is installed above the end of the overflow. A potential terrorist: 1) cannot see the Tideflex Series 37 and 2) cannot get to it and therefore cannot damage it.

The OSV is customized for every tank based on the tank height, overflow pipe size and material, and peak overflow rate.