On 17/01/2013 20:42, Dave Liquorice wrote:
On Thu, 17 Jan 2013 17:09:33 +0000, Nightjar wrote:

A length of steel pipe, larger ID than the OD of the drain, with a
flange on the bottom and a flexible seal on the flange? The weight of
the pipe should hold it in place while the water simply rises inside
it.

Might depends how much higher up the water is getting into the drains.
Remeber that hefty great cast iron road strength manhole covers can be
tossed aside by flooded drains...

Which is why I was thinking of an open topped pipe, rather than trying
to seal the drain. I take your point about how much higher the water is
getting into the drains, but in my house the foul water drain is
connected to an open gulley outside the kitchen, so it wouldn't rise in
the pipe any higher than the water outside.

Colin Bignell