Scwd

[jsoon]

We have heard of the US power failure and then follow by other countries like UK, Malaysia and early this mornig at 2am my whole block got a power failure

Luckily I woke up in time and prevent a disaster from happening.

I use a SCWD and connect my main outlet pump to my SCWD unit to create the different wave directions.

I realise that if there is a power failure to the main pump, the high water pressure from the main tank will reserve flow back into my sump tank via the SCWD. This will result in a disaster if the water overflow the sump into my floor.

I am now thinking how to prevent this and would like to ask advice from the forum.

I though about it and if there is an inlet of air when the water flow back, it will create a air pocket and thus water will stop flowing down. This is similar to using a hose to suck out water from the main tank sitting on top of a stand to a bucket belpw. The water pressure will push down the hose into the bucket but when we introduce air into the hose, the water will stop.

The problem is how can we modify our oulet pipe to have some air hose.

Beside, this, I am thinking of investing into a UPS but am not sure what the electrical consumption will be liked as I heard that they are in KV rating which is higher than my chiller rating.

[sinner]

how about using check valves?

[planetg]

check valves need regular maintenance as it may calcify or "get dirty"

what jsoon meant earlier is a siphon break. just drill a little hole on your return line. is it over the top return (i.e. pipe runs from the back of tank) or in tank return (hidden in the overflow compartment)?

if it's over the top, just drill the hole at the safety point. any water below that level will not be drained. thus it shd be high

if it's in tank return, it's more tricky. i'm not sure about that. maybe someone else can comment.

[jsoon]

check valves need regular maintenance as it may calcify or "get dirty"

what jsoon meant earlier is a siphon break. just drill a little hole on your return line. is it over the top return (i.e. pipe runs from the back of tank) or in tank return (hidden in the overflow compartment)?

if it's over the top, just drill the hole at the safety point. any water below that level will not be drained. thus it shd be high

if it's in tank return, it's more tricky. i'm not sure about that. maybe someone else can comment.

Hi all,

Thanks for the advice. siphon break is what I looking for.

OK. My SCWD is connected at the return on top of the tank. I have 2 pipes on the left and right of the SCWD. Both pipes are above the water (acutally sitting on my tank). Where should I drill the small hole where the safety point is ?

[hoppinghippos]

If both pipes are above the water, ie the outlets are above the water then nevermind what, no back flow of water? but if the outlets are in the water then either drill a tiny hole just below the water surface, so when water backflow till the level drop below the hole, air will enter, BUT since its a tiny hole very little water will go out of the hole when there is no backflow so won't spoil your pipe water current flow. OR alternatively, you can be kiasu and drill the tiny hole above the water level but put some form of barrier loosely over the hole, like tape small piece of plastic bag like a openable flap over it, idea is that when you have power failure, immediately air will enter to break siphon, and when you don't have power failure, some water will escape thru the hole, so the physical barrier is to block the water shooting like fountain and let it dribble back down the pipe into the water. the hole should be as small as possible tho. Just my 2 rupees worth!

[jsoon]

Thanks for your advice.

I was going home to do the drilling when I realise that the area where the tank is flooded with water

My block has just got another electrical failure and the SCWD has a reverse flow....

Mop the floor for already 4 hours !!!!!!!!

Started to drill a small hole just above the outlet pipe and did a few dry runs and it works. Thank you.

[planetg]

hi jsoon.

glad u got it working.

how abt posting a pic to show all!

cheers