BARL free flow valves  are used as closure valves under vessels or in pipes. In the open condition, the clear passage is free of impairing bottlenecks. Free-flow flaps are used for complete emptying of containers. Partial emptying is not possible, since closing is not possible while the product flows. They work with short opening and closing times. 

BARL free-flow dampers are pressure-tight and product-tight to the outside up to 0.5 bar in the standard version. They are pressure- and product-tight in the passage and their design with elastic flat seal up to 200°C and up to at least 0.2 bar depending on size. They are pressure- and product-tight in the passage and their design with elastic flat seal up to 200°C and up to at least 0.2  bar depending on size. The shaft seal by adjustable and relubricateable packing glands is part of the default as the outer roller bearing. Any inspection that may be required may be performed quickly by the default cleaning cap. 

 Two free-flow valves on top of each other may be converted to double pendulum flaps or chamber locks.