Flap Valve Needed

[JAS21]

Guys, I’m trying to resource a flap valve, 8” or 9” dia. would be fine. It’s for our village site drainage system.

The outlet system is very basic, a couple of pumps and a 12” dia. bypass valve. The system works fine on manual except that about about fourty five minutes of very heavy rain the village roads would start to flood if running only on the bypass valve. So someone needs to shut that valve and start the drain pumps. Under normal drainage the bypass copes very easily, it’s vastly oversized.

Now some bright spark decided to float control ‘auto start’ the drain pumps. Not realising that the Klong level rises when it rains and eventually the bypass valve has to be shut anyway, else you pump around in a circle..actually the dynamics are a little more complicated than that but it is not important to go into so much detail.

So I just want to locate a ‘free swinging’ flap valve (if there is such a thing), set it at about five degrees and it should shut when the Klong level gets above our site drain level. Plastic or iron would do I guess, we can resource a spool piece.

Yes, I know that flap valves are notoriously unreliable, but needs must……thanks

[eek]

moved to DIY forum.

[Artisi]

Any reasonable steel fabricating workshop could manufacture a swing-check valve. I could knock up a quick sketch if you need it. Let me know

[powderpuff]

With as much flood water piping & pumps as I see scattered around it should be easy.

Sometime in the future; when this flapper valve is leaking consider replacing the seal with leather. Has some advantages.

[WarpSpeed]

I'd get a ball of the necessary size and trap it between 2 fittings but with a larger pipe in the outgoing side of course and some sort of retention I.E. grate of some sort, that provides for a flow gap away from the effluent seat.. In theory back pressure should make it close and seat properly.. But not actually seeing the set up it's difficult to give any really accurate solution..

Edited June 14, 2010 by WarpSpeed

[elkangorito]

Would something like this do?

[Crossy]

Yup Elk ^^^ I reckon that's exactly what the OP needs, set to hang open by a few degrees so it lets the drainage out without restriction but slams closed on any significant back flow.

Going to need 8-12" diameter, got a local supplier (northern BKK) ?

[elkangorito]

I also thought that something like a pool skimmer flap/valve might do the trick.

You could try these 2 companies. Both have websites:

WEM COMPANY LIMITED.

314/228 Soi Rat U-tit 48, Rat U-tit Road, Sansab, Minburi, Bangkok 10510, Thailand

Tel. 66-2-9891073, 66-2-9891956

Fax. 66-2-9890663

E-mail address : wemco <at> asianet.co.th

SCIVALVE.

Domestic Sales Office: (Siam Syndicate Technology Co. Ltd.)

SST Building 999 Navamin Rd, Klongkum, Bungkum, Bangkok 10240, Thailand.

Tel : (662)733-6080 FAX : (662)375-8160

E-mail : siamsyndicate <at> sst.co.th

Edited June 14, 2010 by elkangorito

[JAS21]

I also thought that something like a pool skimmer flap/valve might do the trick.

You could try these 2 companies. Both have websites:

WEM COMPANY LIMITED.

314/228 Soi Rat U-tit 48, Rat U-tit Road, Sansab, Minburi, Bangkok 10510, Thailand

Tel. 66-2-9891073, 66-2-9891956

Fax. 66-2-9890663

E-mail address : wemco <at> asianet.co.th

SCIVALVE.

Domestic Sales Office: (Siam Syndicate Technology Co. Ltd.)

SST Building 999 Navamin Rd, Klongkum, Bungkum, Bangkok 10240, Thailand.

Tel : (662)733-6080 FAX : (662)375-8160

E-mail : siamsyndicate <at> sst.co.th

Thanks...I'll give those companies a try..just a simple flap valve is all I need..I googled and found the skimmer valve..It doesn't look robust enough..sometimes the water is a bit gritty. I attach a picture of the outlet..It's quite an impressive sight after a lot of heavy rain. You can't blame anyone for being reluctant to operate the valve when the pumps are running...one slip and gone!