110mm non return valve fact or fiction???

[Kevin]

do any non return valves exist that are fit and forget and could these be buried underground? I have had lots of problems when the local main sewer backs up & it flows out from the drain in the garden, I usually can block this with a towel and bricks, but if we are not there the garden/garage fills up with raw sewage this can happen if the local river rises or after heavy rain or the local sewer pump fails, our drain seems to be the lowest open point this drain only serves 1 sink and a dishwasher

[Uno-Hoo!]

A quick Google on 'sewer pipe non return valves' brought up this:

I think it may be what you are looking for!

Kev

[Kevin]

might need to look into that a bit more