The SURE-FLAP Check Flap is a pivoted stainless steel flap mounted over a rectangular concrete opening. In the rest position the SURE-FLAP hangs vertically, due to its own weight, thereby closing and sealing the opening. If the water level in the sewer or tank overflow rises, the hydrostatic pressure against the SURE-FLAP Check Flap causes it to open thereby allowing the water to flow over the sill. If the downstream water level rises, the SURE-FLAP is pressed against the concrete opening so that no water can flow back into the sewer system, tank or basin. The SURE-FLAP’s lightweight design makes it highly responsive to minimal water level changes while ensuring structural stability under high downstream water level conditions.
The SURE-FLAP Check Flap can be equipped with a stainless steel frame for embedding in the concrete or anchoring to the structure. This flat and smooth sealing-surface will increase the tightness of the flap and avoid the potential problems caused by irregular concrete openings and surfaces.