| 摘要 |
A drain valve device includes a drain valve housing (40, 56, 90, 104) arranged to be located within a drain opening. The housing (40, 56, 90, 104) has a wall structure (42, 1 19) surrounding an axis (46) so as to define an internal flow passage (156) through the housing (40, 56, 90, 104) and a strut member (58, 59, 148, 166) depending radially inwardly from the wall structure (42, 1 19). The device has one or more valve members (10, 88, 138, 146, 155, 160). A gas vent passage (136) may be provided in the housing and a vent valve (146) or control member (168) may be provided to selectively prevent flow through the gas vent passage (136). |
