Double drain system for roof of building has side entrance leading to outer vertical pipe leading to first drain pipe and has additional entrance leading to inner pipe leading to second drain

摘要

The second pipe (2) fits concentrically inside the first pipe (1). A side entrance (5) leads to the first vertical pipe. An angled pipe (7) at the bottom fits into the first drainpipe (3). The entrance for the second emergency drain (6) faces upwards and is higher up than the first entrance. It feeds through a funnel-shaped region (18) into the second vertical pipe which leads to the second drainpipe (4).