| 摘要 |
A safety valve (1, 2) for use on an impervious sheet (23) separating two spaces (24, 25). A wall (10B) at least substantially parallel to the attachment surface (10A) and supporting an annular sleeve (16) comprises a through-hole (15) enabling means (27) to engage the bottom wall (3) of a sealing member (2) from one (25) of the two separate spaces. |
