– Anti-flood valves as solution for sewer backwater flood
– Types anti-flood valves
– Sewer anti-flood practices
Purpose of anti-flood valves
Preventing sewer backwater is one of the most challenging demands for the building drainage. The backflow stop valve (anti-flood valve) automatically closes when water or sewage flows back through the drain system during flood conditions. Anti-flood valve allows normal sewage flow from the inlet to the outlet side of the valve with absolutely no flow restriction. Flood from a sewer water can occur in a household due weather conditions (e.g. heavy rain downfall), for such reasons installation of anti-flood or non-return valves is recommended. Anti-flood valves are not a new concept, but they are becoming more common these days.
Types anti-flood valves
There are many types of valve available, single flap, double flap, stainless steel flap, manual or automatic and the above is just a selection. Anti-flood valves should be chosen specifically to suit each case and requirement and we can advise based on circumstances.
Sewer anti-flood practices
Valves are generally fitted below ground on an outgoing pipe from a property usually within the last manhole chamber prior to the main sewer. The valve will shut in case that sewer back pressure occur and prevent flooding upstream through the connecting line.
Valves can be fitted to lines entering a main sewer at a low invert level. Non-return valves can also be fitted to above ground pipework and branches preventing similar situations from occurring in communal stacks. They can basically be fitted anywhere, as long as there is easy access to them for servicing. Ranging from size, operational characteristics and required load.