Valve for a HDPE storm drain

[Trackfiend]

I am trying to find a valve that will work with my particular situation. I have an 18" HDPE storm pipe that is located under a levee/berm for an industrial facility. I have proposed to use a valve on both the inlet and outlet of the culvert (for redundancy). The intent is to close up the culvert if flood waters rise on the discharge end (unprotected side of levee).

I have considered sluice/knife gates but these would require a concrete headwall and/or structure and as of right now, the client would prefer a simpler (less construction) approach. I've proposed a "duckbill" valve for the discharge end of the culvert, but I don't know what type of valve would be ideal for the inlet. The current plans have rip rap lined around an open-ended 18" HDPE. Are there any manually operated valves that can be installed on the end of this plastic pipe and have a watertight seal? I feel as though my limited experience is telling me that there are several options, but the only other type of valve I've ever seen in the field was the sluice/knife gate. Any suggestions?

 

[TerryScan]

I would consider a Tide-flex valve on the downstream end.

http://www.tideflex.com

 

[Trackfiend]

It seems that we think alike. I've already called for them, specifically the TideFlex TF-1.

I don't, however, have anything for the upstream end. I'm considering a manually operated gate valve to be installed on the end of the pipe.

 

[psmart]

Why not use a TideFlex on the inlet at well? This avoids the flooding potential if/when someone forgets to open a manual valve.


Peter Smart
HydroCAD Software

http://www.hydrocad.net

 

[Hoagie]

The flap-valve at the end of the pipe is enough. Don't over-do-it by trying to isolate the line. Remember, it's a storm drain and not a water line, so the upstream valve would be superfluous...and besides, flap-valves are expensive.

 

[civilperson]

Dual valves are a bad idea. Use only one at the outlet or your storm drain will not function when the other valve is closed.

 

[Drew08]

If only one valve is used, install one on the upstream end. A closed valve on the downstream end will build up water pressure in the middle of the embankment if there are any leaks. This could cause instabilities in the embankment and possible failure.

 

[Trackfiend]

psmart -

I'm weary of using a tideflex valve on both ends (or even one end for that matter) since I need to ensure that a fairly tight seal can be obtained on the upstream end. The worry about Tideflex valves on the downstream end is what if a piece of debris were to get lodged in the valve and it doesn't seal properly. If flood waters were to arrive at this facility, then the facility will be evacuated for a minimum of seven days with no maintenance or oversight in that timeframe. As far as installing it on the upstream end, how would I get a proper seal if the water level is high enough to provide the pressure to seal it off? Remember, the intent of this gravity line is merely for overflow during a normal rainfall event. The pumping station will still run during this time. In the event of a storm/hurricane surge, the gravity line needs to be closed off to prevent any water from entering the facility via the gravity line.

civilperson -

The idea behind using a dual valve system is simply for the "what if" factor. What if a runaway barge (or other debris) were to impact the valve on the downstream end? If I were to only put a valve on the upstream end, then depending on the head, the pressure built up in the pipe could cause seepage at the joints (if not fused) or at the unseated portion of the valve. I've seen this happen on a recent job were there were knife gates on the upstream end but no valves on the downstream end. A total of 17' of head was generated on the downstream end resulting in joints opening up and cracks forming in the pipe (HDPE).

It seems as though I will probably go with a canal gate by Waterman on both the upstream and downstream ends of pipe. They are rated for 32' seated head and 10' unseated head. Thanks for all of the suggestions. It has been extremely helpful.