Best Shutoff Valve for Storm Drain Lines? 1

[sportsnut44]

Local requirements make it necessary to have a shutoff valve just downstream of stormwater treatment devices such as oil/water separators in case there is a spill, etc. What is the best type of shutoff valve for stormwater piping applications for piping 12" and smaller, and for piping larger than 12"? I typically see people using gate valves, but I am concerned that a gate valve won't seal well if grit and debris from a storm drain line gets in the bottom of the valve as it does the piping. I've heard one engineer suggest plug valve because it's motion of operation will tend to sweep away the grit at the bottom of the valve and still provide a good seal, but I also hear all the horror stories of trying to operate a plug valve if they are not regularly maintained (even if it's a non-lubricated plug valve). Are ball valves an option, and if so is there a size limitation? What about globe valves? If a gate valve is the best choice, should it be a standard gate vavle, is there one type of gate valve that is better for this application than another? Your help much appreciated.

 

[cvg]

slide (sluice) gate is the typical method for stormwater

 

[bimr]

For valves smaller than 12-Inches, you should use a plug valve. Larger valves should be knife gate valves

Plug valves are perferred on wastewater applications.

Gate valves can be used. Gate valves are slow to operate and easier to sieze up.

Ball valves are never used on wastewater.

Globe valves are never used on wastewater.

See the linked article for further details.

http://www.engvalves.com/itemfiles/valveselectionessentials.pdf

 

[sportsnut44]

Looking into this a bit more it looks like a knife gate valve might be the way to go; however, all I can only seem to find them with handwheels. Do they make knife gate valves with a 2-inch operating nut for flush mounted valve box applications in traffic areas?

Also, it seems pinch valves would actually be another good alternative. Any thoughts?

Thank you.

 

[bimr]

The pinch valve is a good altenative. You will get tight shutoff and the valve will remain operational despite sitting idle for long periods.

 

[beej67]

If your application is immediately downstream of an oil-grit separator, then your grit and debris concerns should be pretty minimal.

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

http://www.campbellcivil.com