| 摘要 |
<p>An improved sewer relief valve which is vandal-proof and automatically opens responsive to a back flow of sewage and drain water within a plumbing system.</p><p>The sewer relief valve comprises a coupling member (15) adapted to connect to a sewer line and including a material flow opening (23), a lid (22) connectable to said coupling member to obstruct said material flow opening of said coupling member means (36) for locking said lid in obstruction of said material flow opening of said coupling member; float means (30) comprising a buoyant member (31) operatively disposed within said coupling; and means (40, 41, 85) for venting a build-up of air pressure within said coupling member to allow a back flow of sewage to rise within said coupling member and displace said float means, for unlocking said lid and permitting the lid to be opened so as to unblock said material flow opening.</p> |
