Discharge valve for tanks used for transportation of liquid harmful substances

摘要

The invention relates to a dump valve (100) for containers provided for transporting liquid dangerous materials. The dump valve is connected to the container by the valve body (10) through which a valve opening (11) leads. The valve opening can be closed by a valve plate (15). The valve plate lies on the rim of the valve opening (11) in a closed position such that it seals. The aim of the invention is to provide a dump valve which guarantees passive security during accidents and also during long maintenance intervals while simultaneously simplifying and lightening the maintenance. To this end, the invention provides that the dump valve (100) has an encapsulated spiral spring (21) for returning and holding the valve plate (15) in a closed position. The spiral spring (21) is located inside the conical valve plate (15), and supports on the lower part (19) of the valve plate (15) and on the end of a guiding rod (13) which is provided for vertically guiding the valve plate (15) and which is guided through a continuous hole located inside the valve plate (15). The guiding rod is fixed on the valve body (10) and is arranged in the dead center of the valve opening (11).