On Tue, 01 Sep 2009 15:14:36 -0500, Jules
wrote:

I think they're more like the following:

from
gutter

| |
--+ |
barrel | |
--+ | | | 'cup'
+--| |--+
| |
| |

to drain

... there's a narrower small piece of vertical pipe in the middle. The
rain mostly runs down the inside edges of the downspout and collects in
the 'cup' section, where it's free to exit via the side pipe to the rain
barrel.

So long as the top of the barrel is at the same level as the 'cup'
then once the barrel's full, the 'cup' will also fill up, and
excess water then spills through the narrow central pipe and from there to
the drain.


How tall is the "cup" section in most diverters? I would have expected
the top of the narrow piece of pipe to be level with the top of the
pipe to the barrel, which is roughly what your sketch shows. This
would allow the whole bore of the pipe to the barrel to be used to
carry water.

But the diverter I have seen in the shop today has the cup only half
the height of the barrel outlet, which means the pipe can only ever be
half full. Surely this is a wasted opportunity as the pipe can only
ever carry water at half its capacity?