10" Backflow Device Available?

[esass13]

I have a sump pump pit with pumps to pump water from a bldg. off the site. I also have a 10" gravity drain from the pit to a stormwater basin. The pumps run only when the gravity pipe can't get rid of all the water coming in the pit. The problem now is that we've actually seen water flowing into the pit from the gravity pipe - the stormwater basin must be over capacity at this point. Is there a device available that I can put on the 10" gravity pipe that will allow small amounts of flow to pass under normal conditions but will prevent water from flowing backward into the pump pit?

I've seen a few backflow devices but they appear to not allow small flows to go through. they seems as though some head would be needed to open the backflow "flap" or whatever prevents the reverse flow. Any manufacture names or models would be helpful.

thanks

 

[LittleInch]

I assume you're refereeing to non return valves of which there are many types. For this application, a butterfly wafer check valve would seem to be a good choice. Any nrv will need a small pressure in the right direction of flow to open, but the butterfly wafer type of valve are very small as the spring which closes them is normally very small.

They usually fit between flanges, but can come as a valve body.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Twinkie]

Look at the TideFlex - CheckMate valve

 

[beej67]

Simple flapper valve down on the stormwater basin side should do the trick.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[dhengr]

Can you raise the outflow elev. of the sump pit or lower the outflow elev. of the storm water basin? It sounds like someone forgot to consider the relative water elevs. of the storm water basin outflow and the sump pit outflow. Alternatively, if the water level in the sump pit could raise a few feet without the pumps going on, gravity flow would resume. Or, your storm water basin is too small for the elev. at which you are trying to operate it. I don’t have a manuf’er., but there used to be a back flow device consisting of a light wt. ball in a vert. chamber, and when the water in the chamber raised (caused by the pond water level) it finally seated the ball on a partial hemispheric ring seat matching the ball dia. at about 45̊ latitude. This acted as a back flow stop, but you could still pump into the chamber below the ball.