| 摘要 |
The present invention provides a one-way drain valve comprising a fitting and a duckbill valve, wherein the fitting comprises one or more formations that prevent inward folding of the duckbill membrane upon reverse flow conditions without constituting an obstruction to the normal drain flow where entrained solids could form a plug and thus, prevent adequate drainage. The formations extend parallel to or divergent from a fitting longitudinal axis. The fitting may comprise a recess or other suitable feature adapted to facilitate engagement with the duckbill valve. |
