water from loft tank is returned to main line

[Mr_David]

1)
*If I install simple air release valve , on the *top of loop* (horizontal plumbing) available at out side window, when air gets sucked from downstairs (low pressure) and pulling along the water with it passing through loop, what are the chances air will be released from valve and breaking the air pressure
which would stop water being pulled along?

Not sure why this is working. But to break a siphon you have to let air in.

but at same time I would need water from upstairs (i.e main line ) so to fill tank again.*

5) The system is working guys ,its absolutely working now

I'm glad it's working? For now. But I am still curious about your system.
It's very interesting to me. Most people around here are spoiled. If I turn off the water to a building to make repairs they come out like rats from a burning building complaining that they were not given 24 hr notice. Whaaa Whaaa Wha

[1] In your sketch you have A going into building below the window and to left. Then the line coming out of wall to the tank also label A to the right of the window just as I drew in my sketch. So It's not a straight shot through the wall. ARE Sinks and toilets on the system between A into outside wall and A out of inside wall. Is this a correct assumption. Do you have a water heater in this system as well?

[2] So If I understand, you have to manually fill your tank by opening a valve. If you leave valve open and walk away you may over fill tank. and then you have to close valves to tank once it is full. Then you use your tank water only when the main common roof tank is empty. When on reserve tank, original check valve on line outside window was to prevent water from drain down to unit below. You replaced it with a high loop, but it still siphoned down to unit below.

The vent you installed failed because the siphon does not start at the tank. The siphon actually starts at the bottom of the loop where it comes out of the wall. The tank will drain down to that point with out a siphon so the vent on the line near tank is useless. CAP IT! To break a siphon on the high loop requires an anti-siphon device on the top of the loop. Not sure why the air release valve is breaking the siphon for you. But if it fails try using a vacuum breaker. I will close when water come in from roof tank. It will open and let air in, breaking any siphon.

[3] Another observation I made is in regards to the check valve you installed on the outlet/bottom tank line.
Not sure of it's purpose. Your sketch shows direction of flow from tank. Was this valve always there or did you relocate it from line outside window. I'm thinking why have a check valve preventing water flow into tank when you have available common water. This is what I think . Please correct me if I am wrong. you manually fill tank when common water is available . then close both lines to tank when full. when no common water you open bottom line only. Tank flows into your system. If common water returns check valve prevents tank from refilling. So if your not aware of or present when common water returns you don't get flooded.

Sorry for rambling on but like I said, this simple system you have is interesting.

If I am wrong on my assumptions please tell me.

 

[kebyaa]

I'm glad it's working? For now. But I am still curious about your system.
It's very interesting to me.

Thanks on this note ,I sensed this

ARE Sinks and toilets on the system between A into outside wall and A out of inside wall.Is this a correct assumption

exactly!

Do you have a water heater in this system as well?

I have one more tank with almost same fittings in another baathroom,
so it has geyser (but not between A In & out )
I haven't installed air release valve for it yet. i thought lets test this configuration first and once there would be full proof solution,install and relax.

So If I understand, you have to manually fill your tank by opening a valve. If you leave valve open and walk away you may over fill tank. and then you have to close valves to tank once it is full. Then you use your tank water only when the main common roof tank is empty. When on reserve tank, original check valve on line outside window was to prevent water from drain down to unit below. You replaced it with a high loop, but it still siphoned down to unit below.

Yes , I didn't knew concept of siphon physics ! I was happy after learning the concept, which failed my thought

The vent you installed failed because the siphon does not start at the tank. The siphon actually starts at the bottom of the loop where it comes out of the wall. The tank will drain down to that point with out a siphon so the vent on the line near tank is useless. CAP IT!

Yes I did, I could draw the water flow traveling in pipes

To break a siphon on the high loop requires an anti-siphon device on the top of the loop. Not sure why the air release valve is breaking the siphon for you. But if it fails try using a vacuum breaker. I will close when water come in from roof tank. It will open and let air in, breaking any siphon.

Wow, I would search its availability in my area, and install may be on other tank,but I have bought air release valve for it also.

Another observation I made is in regards to the check valve you installed on the outlet/bottom tank line.
Not sure of it's purpose. Your sketch shows direction of flow from tank. Was this valve always there or did you relocate it from line outside window.

It is available earlier too,My thought was water from roof tank should go from top side and this ck would not allow water to go in tank from bottom side but damn plumber misfitted it,anyways that must have been damaged by now due to corrosion.as long as tank is getting filled i don't have concern

I'm thinking why have a check valve preventing water flow into tank when you have available common water. This is what I think . Please correct me if I am wrong.

In past , when I installed tank,I had thought water from tank would restrict water from roof tank for filling .It's out let is 1 inch as compared to inlet 1/2 inch. But it turned out my assumption was not right.
so if you see I had provision of ck to restrict water going in tank from that direction (my thought was - no clash of roof water & water coming out of tank ) & its job would be only to out the water, to fill the tank , water from would go in from top side.

you manually fill tank when common water is available . then close both lines to tank when full.

yes sadly I have to.

I have a new quetion here (suppose bottom line ck is operational ) - When tank has water ck would open and water from tank will drain. but at same time when common water is available. who will win? will ck would close due to high water pressure from roof tank or pressure from 1 inch outlet of tank would keep the ck open (and in clash roof water goes in from bottom )? ( I suspect that's why tank used to fill though I closed only the upside ball valve.)

so Yes I close ball valve available near to point A (inside ). which restricts water to go in tank or out from tank. Habitual I am , i close the upside ball valve also

when no common water you open bottom line only. Tank flows into your system. If common water returns check valve prevents tank from refilling.
( Here upside ball valve is in closed position )
So if your not aware of or present when common water returns you don't get flooded.

Yes this was my thought. but I get flooded.... Who's winning? obviously roof tank. should I try to reposition bottom line ck? but its slightly tilted, it should work though its swing check. but here pressure would win I guess.please think solution for this.

I liked your idea in previous reply, regarding level of inlet to tank from outside above window. but the gotcha was water would first come to tank & and I get water from tank with low pressure every time.
So our loop came into picture

Sorry for rambling on but like I said, this simple system you have is interesting.

yes sir, The loop made it very interesting thankfully worked anyhow.
thanks for understanding this.

If I am wrong on my assumptions please tell me.

you nailed it

 

[Mr_David]

Thanks on this note


yes sir, The loop made it very interesting thankfully worked anyhow.
thanks for understanding this.


you nailed it

Thanks for clarifying.

here's a vacuum breaker . the watts does not require flow through the valve so you can just screw it into a tee on top of loop. water positive water pressure will close. a siphon cause negative water pressure ( suction so it opens and lets air in.

The angled one you have to install at a 90 on the top of the loop. harder to replace

 

[kebyaa]

Gr8,I would try that may be, Happy new year
Thanks