Prevent Flow Back to return pump

[euphoria]

Hi guys,

Is there a valve or any apparatus that i can fit on the return line from the return pump to prevent water from flowing back to the pump when power is switched off?

what is the name and where can i purchase it.

Jimmy

[strat]

I think Tanggy has one in his return pipe.

Can check in his 5 ft tank thread.

[Yellow Tang]

you can try using a PVC check valve, its a one way flow ball valve. you can get it at Hong Seng, Lavender street, opposite the S-11 coffee shop, behind lavender food court. Its a big PVC shop.

but using the ball check valve will reduce the flow rate. Is your water back flow to your return pump causing overflow at your sump? You can solve this problem by adjusting the outlet pipe slightly higher (if its an elbow, try to adjust it slightly below water surface), so when the pump is switch off, not so much water will back flow down once air is vented into the return pipe. This is how I do it for my tank.

[davwong]

Just drill a little hole on your return pipe just below the water surface and when the pump fail, the water will back flow and the water level will lower to the hole which will break the siphon action.

[niggy]

Alternatively, u can also drill a small hole on the return pvc pipe, just below the water line so that if water starts siphoning back, the hole when reaches above water line will break the siphon. Note that the hole needs to be big enough to break the siphon. Test it before relying on it.

This will eliminate the need for a check valve and thus won't slow down your flow rate.

Hope this helps...

[Nic a Jon]

Sorry to hijack...how far shud the drilled hole be below the water surface ..5mm? and the elbow about 25 mm..is this good enu?

[islander]

Hi guys,

Is there a valve or any apparatus that i can fit on the return line from the return pump to prevent water from flowing back to the pump when power is switched off?

what is the name and where can i purchase it.

Jimmy

one important thing to take while fixing the check valve.

always get the right specification.meaning the desired flow rate,right pressure as the check valve has a flapper inside which permits only a single directional flow.if ur intention is to protect the pump's impeller theres no need to install the check valve as most pumps deltec,eheim and etc are centrifugal pump so the sudden back flow of the water which hits the impeller is of a considerable pressure and it wun spoil ur pump.but wat u can try is to install a t-joint(with another ball valve) after ur pump ball valve outlet to act as bleeder to remove the remaning water or pressure.and remember to install lots of union joint for ease of maintenance...

[euphoria]

one important thing to take while fixing the check valve.

always get the right specification.meaning the desired flow rate,right pressure as the check valve has a flapper inside which permits only a single directional flow.if ur intention is to protect the pump's impeller theres no need to install the check valve as most pumps deltec,eheim and etc are centrifugal pump so the sudden back flow of the water which hits the impeller is of a considerable pressure and it wun spoil ur pump.but wat u can try is to install a t-joint(with another ball valve) after ur pump ball valve outlet to act as bleeder to remove the remaning water or pressure.and remember to install lots of union joint for ease of maintenance...

do u know where to get check valve?

[RockyBoy]

Get your checkvalve at Hai Cheong Plastics

53 Ubi Ave 1

#01-27 Paya Ubi Industrial Park.

or

Blk 11 Kallang Place #01-11 JTC Flatted Factory

16mm (min size) ones at less than $25 ea

[Nautical]

Euphoria, why spend the money and unsightly apparatus like the check valve ?

Just drill the hole as suggested by friends here.

I have the same .... that is, puncture a hole. Just use a small screw driver, heat it over a burner and then pierce the pvc pipe.

Only thing that I cannot remember now (as in the office) is whether the hole is above the water line or below the water line.

I have tested it by switching off the electric power and observe the back flow. Once air got sucked into the pipe, it stops the siphon.

[Nautical]

This is confirmation ... pierce hole about one centimetre below water level.

[sunnymau]

Just drill the hole as suggested by friends here. 

I have the same .... that is, puncture a hole. Just use a small screw driver, heat it over a burner and then pierce the pvc pipe. 

alright men i m using the same mathod too and it serve me well u should try and save up $$.

[FuEl]

The distance of the hole below the water surface depends on the individual. You gotta consider how much extra water your sump can contain...if it can contain more backflow water, you can easily drill the hole further down from the water surface.

If your sump is already very full and cannot hold too much extra water...best to drill the hole as near to the water surface as possible.

[euphoria]

Hi friends.....thank for all the suggestions.

Have not been here lately, busy in my new job

Now selling cars, not forklifts