Most systems, handling gas, require sections to be isolated for maintenance without shutting down the complete plant, Hitherto, in sophisticated plants, this has been achieved by using gate valves. Fouress flap isolators now offer a simpler and cheaper solutions without any loss in sealing efficiency. In particular they require less external space and no special precautions against wind loading, can be supplied in modular form, allowing easy installation in large ducts, need no external supports when installed in vertical or horizontal ducts.

Most systems, handling gas, require sections to be isolated for maintenance without shutting down the complete plant, Hitherto, in sophisticated plants, this has been achieved by using gate valves. Fouress flap isolators now offer a simpler and cheaper solutions without any loss in sealing efficiency. In particular they require less external space and no special precautions against wind loading, can be supplied in modular form, allowing easy installation in large ducts, need no external supports when installed in vertical or horizontal ducts.