Plain steel water tank pressure drops quickly!

[benfons]

Hi everyone! this is my first post here in this forum, and I'm in no way an expert when it comes to water systems, but I'm in a predicament so I would really appreciate your help:

I have a plain steel water tank (no bladder) and a couple months ago, after some water leaking problems where solved around the house, I noticed that, when running water in the house -be it cleaning the dishes, taking a shower, flushing the toilet, etc.- the pump would almost instantly start to refill the tank, repeating the process a few times while water was in use in the house; otherwise, when not using water, the thank would maintain the pressure no problem whatsoever. I did not give it much thought at the time (grave error) until, while doing a check around the house 2 days ago, I noticed my steel tank was leaking. Nonetheless, I'm certain that the high frequency at which the pump turned on and off when using water inside the house before, had nothing to do with the fissure in the tank that exist right now, because this was the first time I've had seen it while doing my weekly checks around the house.

So now that you know the back story, I think that my thank had been draining to quickly (while using water) causing the pump to start to often and in turn causing great stress on the tank structure, fissuring some of the welding. Also, the pump filed the 20 psi cut-on cut-off gap, from 30 to 50 in 50 seconds or so. So my question is, what could be the cause of that and what could be the solution?

My water pressure settings are set to 30/50 (psi). The tank and well are above ground and that is pretty much all I know about the water pumping system of my house. By the way, that pressure setting is more that enough to feed water to every corner of the house (and that's how the pressure setting were set when I bought this house, so I never changed them. Also, I've already called someone to weld the fissure in the tank back again.

Thanks in advance for the replies!

 

[Sarg]

Is or was the air pressure in your pressure tank set at (approx) 28 psi ? ( Even a tank without a bladder or diaphragm requires air pressure over the water )
You don't mention it so if you have not checked it ......... Turn off your pump and open a faucet to relief the water pressure in the system ......... then with a tire gauge check the air pressure in the tank. ( Schrader valve on top ? )

I suppose all this after tank is repaired.

 

[Sponsor]

 

[benfons]

Is or was the air pressure in your pressure tank set at (approx) 28 psi ? ( Even a tank without a bladder or diaphragm requires air pressure over the water )
You don't mention it so if you have not checked it ......... Turn off your pump and open a faucet to relief the water pressure in the system ......... then with a tire gauge check the air pressure in the tank. ( Schrader valve on top ? )

I suppose all this after tank is repaired.

I'll do it once the tank is fixed and come back here.

 

[Reach4]

Normally a tank with no diaphragm has something to add air, and something to remove excess air. Air gets dissolved away in the water with time, so must be replenished. The thing to remove air is an AVC (air volume control), which uses a float to control a valve that releases the excess air.

It is possible to add air with a compressor. You don't want to overdo it, because you will get a blast of air out of faucets. You want an amount where the pump turns on to add water before the water tank is empty.

One safe way is to turn off the pump, and drain all water from the tank, so the tank is full of only air. Then turn the pump back on. This amount of air is less than optimum from a water-capacity-between-cycles point of view, but it is probably better than where you are right now.

 

[Bannerman]

As there is no diaphragm/bladder, there will be no compressed air contained in the tank if you follow the procedure Sarg provided. While compressed air will be needed, once the tank is drained of water, the compressed air will also escape so the pressure reading will be 0.

You didn't specify where the leak is located on the tank. If the leak is located halfway upwards, the air which will normally be required to push the water out from the tank will have leaked out so the tank will have become filled with too much water.

Unless Your water contains iron, manganese or sulfer, if you need to replace your current large hydropneumatic tank, you may wish to consider a pre-charged tank which utilizes a diapghram. A pressure tank will be filled approx 3/4 with air at the pressure switch cutout setting.

By using a pre-charged tank, the air chamber will be separated from the water chamber by a flexible diagphram or bladder, so the air can then be pre-compressed prior to installation. Since the water is not relied upon to compress the air, the total tank size maybe much smaller while still providing equal drawdown capacity as a much larger hydro pnumatic tank.

The best option would likely be to install a Cycle Stop Valve between the well pump and pressure tank. Because the CSV will limit the flow from the pump to exactly the flow rate being used, the pump will not cycle so a pressure tank as small as 4.4 gallons is usually all that will be needed.

https://cyclestopvalves.com/

 

[Sarg]

International shipping fees to Venezuela may be a consideration.

 

[Valveman]

Post a picture of your system. If you do not have an Air Volume Control half way up the tank to let out excess air, adding too much air can be a problem. However, your problem is the tank is completely waterlogged and you need at least 50% air in those type tanks. A leak makes the tank waterlog much faster. You will need to add air on a regular basis so put in a Schrader if there is not one already.