GNA Back Flow Preventer Allows water to flow in one direction only. Very low head (0.05 m of water) required to open flap and complete closure is assured by self adjusting hinge mechanism. Gates may be circular rectangular or square. Available in sizes ranging from 150 to 400 mm (6-16 in). Made entirely of stainless steel (304 standard). Maximum allowable water pressure 10 m of water (1 Bar).	GNA Downstream Level Control Device Throttles and adjusts inlet/outlet to limit water level to a pre-determined height. May be used to maintain water levels in a pump well or may be used as a flow regulator in conjunction with a downstream orifice. May be designed with one or two floats, depending on maximum upstream water level. Available in diameters ranging from 100 to 300 mm (4-12 in). Made entirely of stainless steel (304 standard). Maximum allowable water pressure 5 m of water (0.5 Bar).
GNA Flood Valve A safety device for foundations to prevent up-lift. Fabricated with double wall sleeves to prevent slippage and infiltration. Available in diameters ranging from 150 to 250 mm (6-10 in). Made entirely of stainless steel (304 standard) with removable cover and exchangeable seals. Maximum allowable sealing pressure 10 m of water (1 Bar). Minimum operating pressure 0.05 m of water (5 mbar).	GNA Flat Wall Gate This gate may be used to replace any standard sluice gate or knife gate valve. May be used as a by-pass in conjunction with HYDROSLIDE valves as well as for isolating the valve itself. These gates are designed to be installed flat against the chamber wall and to be watertight. Easy to install, long service life, safe and maintenance free operation. Available in diameters ranging from 150 to 600 mm (6-24 in). Made entirely of stainless steel (304 standard). Maximum allowable water pressure 10 m of water (1 Bar).