[shyguyshy]

Hello all,

We have a residential development with 22 independent villas. Each villa is provided with an underground tank with float arrangement for water storage. A 2 1/2 " ring main (a loop) runs in the entire plot, from which the connection to each underground tank has been tapped-off. The ring main was connected to a municipal supply main.

Due to scarcity of water in the area, the municipal connection now a days are of no use, we have dig three open wells in the compound, with good yield. The municipal connection has been blanked-off. The intent is to pump water directly from these wells to the loop, and hence supply to each villa.

We plan for water supply 2 hrs a day, one in the morning and one in the evening. We plan to initiate the pumping manually (house keeping staffs are available).

What I would like to know is how to cut off the pump automatically when all the independent tanks in the villas are filled up. (We have a float arrangement in each of these tanks). What kind of control device shall be used for the same purpose?

I assume that when all the tanks are filled up and all float valves are closed, the pressure inside the loop increases and shall reach the rated head of the pump. Any device to read this pressure and give a signal to the pump to turn off shall do the needful I suppose. Again there are 3 pumps in 3 wells, which we plan to operate in alternatively, giving each well enough time for yielding back.

We shall turn on each pump in this manner, but we need a system to put the pump off when all the villa tanks are filled up.

Kindly help.

Tankyou.

[speedball1]

What country do you live in? I'm not familiar with your set up. I hope that you're installed check valves on each pumps suction and discharge line to isolate it from the loop until it's turned on by the staff. This is important ! Each pump MUSt be isolated from the loop until it's turned on. All you want are controls that will shut the pumps off automatically when the villa tanks are pressured up and full. Correct?
A 30PSI cut in and a 50PSI cut out Square "D" Control should do the trick.
One for each pump. Outside of the wiring all you should have to do is connect a small copper tube from the control box to the loop to provide the pressure information back to the box so it knows when to shut the pump down. Let me know if you need more information. Good luck, Tom

[hkstroud]

How do you plan on getting the water from the underground villa tank to the villa?

How large are these tanks.

To use a float valve, the tanks must be vented to let air out as they are filled and let air in as they are empted.

Are all of the villa tanks at the same level of elevation? If they are, when one is filled, all will be filled. If they are not, water will flow from the upper one to the lower ones as water is being used.
Is the float valve manual or does it control an electrically operated valve. If manual, the pressure from the line will probably over ride the float valve.

How do you plan on controlling the pump that moves the water from the tank to the villa? If a float valve is used to fill the tank, a float valve will also have to be used to stop the pump to the villa when the tank is empty.

Why are you using float valves, why not pressure valves.

Why do you have 22 tanks, why not one large tank with supply lines to each villa?

How far along are you in development?

Why do you plan on manually activating the pumping and why twice a day? Why not have it be automatic when needed.

You need to re-think you system. It is far to complicated to operate reliably.

You need a single large sealed tank with your pumps controlled by tank pressure, not water level. You could manually select which well to be used but there are well pumps, which can sense low well water and automatically shut down.

You could use the existing 22 small tanks with a pressure valve on one to control the well pump. But because water, under pressure, will absorb the air in the tank, you will have to periodically have to recharge each tank with air. How often depends on the volume of water used.

Depending on water usage, you need about a 1000 gallon pressure regulated tank with a smaller control tank. You could do with out the control tank but will have to periodically recharge the pressure tank with air. Again how often depends on water usage but probably every 6 months.

[shyguyshy]

Tanks Mr. Tom for your early response. I live in India, where this kind of scenarios are common. Yes, we do have check valves on delivery sides, isolating the delivery from loop. Its like this for each pump:-

One foot valve (basically an NRV) at the end of the suction line - the submersible pump - delivery line - check valve-NRV-again check valve - connect to the loop.

The villa tanks are vented type, and the loop is expected to get pressurized to aprox. Maximum head of the pump, when all the float valves in the villa tanks get closed. If we provide an automatic cut-in, I fear the pump to have frequent on-off which I understand is not good for the pump. That is why we are planning for manual switch on and automatic cut-off for the pump. (Provision of diaphragm tank is not possible due to economic constrains)

In brief, what we are looking for is a system which turns the pump off when a set pressure is achieved in the loop. (we have pumping hours and we need the system if the tanks are filled up before the predetermined pumping time of one hr)

Thanks & regards.

[speedball1]

For your needs A 30PSI cut in and a 50PSI cut out Square "D" Control should do the trick.
One for each pump. Outside of the wiring all you should have to do is connect a small copper tube from the control box to the loop to provide the pressure information back to the box so it knows when to shut the pump down.
Each pump as it's turned on wiill pump up to 50 PSI and shut off and will operate as a individual source. Is that what you wanted? Regards, Tom

[shyguyshy]

But Mr Tom, will the pumps get cut in when the pressure drops to 30 PSI? That means, if suppose the water level in any of the villa tank reaches the minimum level, the float valve will open and water which is there in the loop will flow to this tank, resulting in reduction of pressure in the loop, right? When the pressure reaches 30 PSI, will the pumps get into operation?
'

[speedball1]

But Mr Tom, will the pumps get cut in when the pressure drops to 30 PSI? That means, if suppose the water level in any of the villa tank reaches the minimum level, the float valve will open and water which is there in the loop will flow to this tank, resulting in reduction of pressure in the loop, right? When the pressure reaches 30 PSI, will the pumps get into operation?

Correct! However, this is not necessary a bad thing. You could shut two pumps down manually and leav one on automatic and stagger the pumps by hand as you want each pump to cut in. That way only one would be working at any given time and the pressure supplied to the villas would be constant every time the loop PSI dropped to30 PSI. **OR**
You could devise some sort of a 8 hour timer that would keep each pump energized for 8 hours and that would give you 24/7 automatic service.
To reduce the cycling on and off the pumps I suggest that the loop have either a galvanized pressure tank or a bladder tank installed on the pressure lineafter the check valve. That would feed pressure to each villa as the float opened up and prevent the working pump from cycling on each time there was a pressure drop.
I'm breaking new ground here so check my recommendations over for flaws and let me know what you think. Regards, Tom