To provide a check valve without making its opening-closing function insufficient by a dust, and without depositing the dust in a header pipe, in the check valve arranged in a riser (a discharge pipe).
This self-closing check valve is arranged in the riser 102 of a drain facility, with a structure for opening by the inflow of discharge water by pump operation and closing by stopping of the discharge water by pump stopping, by arranging a freely rotatable valve element 21 in a valve casing 20, and is formed by arranging a dust deposit space 26 outside a rotary range of the valve casing 20 and the valve element 21, and is provided with a drain pipe 29 communicating with an opening 27 communicating with this dust deposit space, and is also provided with a cover 28 for closing the opening 27 and an opening valve 30 for opening or closing the drain pipe so that the dust G slips down on the dust deposit space 26 when closing the valve element 21.
MIYAMOTO MASAKI
MIYASAKI ATSUSHI
YOSHIMOTO MASAHITO
Yu Takagi
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