Burst bladder - can you repressurise and keep using temporarily?

[Steve IAnson]

Hi,

I've read quite a lot of different information on bladder tanks / bladderless etc. and have a basic understanding.

My parents have a well in a property in France and a pressure tank with bladder which is only used for filling toilets / watering garden etc.
We are awaiting confirmation but it appears the bladder has ruptured and the pressure is at 0 so when used the pump is constantly going on and off.
They are waiting for the local plumber to return with an air compressor as he's going to test repressurising.
They've been told if it is the bladder, that it is not replaceable and so they'll need a new tank - the same thing happened only a few years back and they were told it's because it's not used for approx 9 months of the year.

Assuming this is the case, until the new pump arrives, is there any reason they can't repressurise the tank and use until the new on arrives? Wouldn't it just act like a bladderless tank where the air would rise to the top and then compress/expand as desired? I understand the air would gradually dissolve into the water so they'd need to keep an eye on the pressure and this would only be to keep them going in the interim, but is there any reason this won't work or they shouldn't do it?

Also as I mentioned, this only happened a couple of years ago: it's a holiday home and for approx 9 months of the year it only has very occasional use which apparently is a large contributor to the cause of the failure.
Does this sound right? The only thing I could find online to back up that theory is mineral/deposit build up on the wall of the bladder making it more rigid and susceptible to splits when later used.
If that is the case then this could start getting very expensive if they keep swapping like-for-like every few years. What would people recommend? A thicker bladder? A bladderless tank that can just be periodically repressurised?

Many thanks

Steve

 

[LLigetfa]

Are you sure it is a bladder and not a diaphragm? Yes, you can air it back up but unless it has only a small leak, you cannot really monitor the pressure since it won't hold pressure. What you would need to do is turn off the pump and add air until the pressure reaches the cut-off, then drain the water and add more air. Repeat until only air comes out the drain. Close the drain and air it back up to the cut-in pressure and turn the pump back on.

Water crossing over to the air side sometimes gets contaminated since the air side was never meant to have water.

 

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[Valveman]

Sitting for long periods of time should not hurt the bladder/diaphragm. Maybe you have a leak and the system is cycling on and off for 9 months? That would be how a bladder/diaphragm gets torn.

 

[Steve IAnson]

Thanks for the replies. I'm not sure if it's bladder or diaphragm, I'm not there at the moment to check model numbers etc so can't be sure.
Don't believe there's any leak as there's no evidence of the pump running without toilets filling/outside tap being run.

I'm not at all happy with the advice their plumber has given them: They've been told the tank's purpose is only to provide pressure to feed toilets upstairs and therefore for the time being they can continue to use the hose in the garden. This tap comes from the tank and is therefore causing the pump to continually cycle on and off every few seconds when there's a draw which I've told them is going to kill the pump. My understanding is its other purpose is to act like a capacitor to stop the pump constantly switching on/off and as it's waterlogged that's exactly what happens whenever they run the hose.
I've told them to stop using it or they'll soon need a new pump as well as tank.

It's the same plumber who told them the bladder (or maybe diaphragm) had gone a couple of years back and that it couldn't be replaced and required a new tank (which they got). I know this is possible depending on tank but I'm now doubting this advice.

LLigetfa, thank you for advice - if not sorted I'm back there in a couple of weeks so will give it a go.
Slightly confused about this though: "Yes, you can air it back up but unless it has only a small leak, you cannot really monitor the pressure since it won't hold pressure." - The tank itself is sealed, so if only the bladder/diaphragm has gone surely repressurising the tank would work? The air would rise to the top (all be it outside of the bladder) so would it not then just work like an old bladderless tank? Or do you think the tank itself has a leak? Maybe I'm misunderstanding something?
Regarding contamination, the water is only used for filling cisterns and for watering the garden, they use mains supply for drinking water, so not too concerned about that.

Thanks again for your time

Steve

 

[Steve IAnson]

Thanks for the replies. I'm not sure if it's bladder or diaphragm, I'm not there at the moment to check model numbers etc so can't be sure.
Don't believe there's any leak as there's no evidence of the pump running without toilets filling/outside tap being run.

I'm not at all happy with the advice their plumber has given them: They've been told the tank's purpose is only to provide pressure to feed toilets upstairs and therefore for the time being they can continue to use the hose in the garden. This tap comes from the tank and is therefore causing the pump to continually cycle on and off every few seconds when there's a draw which I've told them is going to kill the pump. My understanding is its other purpose is to act like a capacitor to stop the pump constantly switching on/off and as it's waterlogged that's exactly what happens whenever they run the hose.
I've told them to stop using it or they'll soon need a new pump as well as tank.

It's the same plumber who told them the bladder (or maybe diaphragm) had gone a couple of years back and that it couldn't be replaced and required a new tank (which they got). I know this is possible depending on tank but I'm now doubting this advice.

LLigetfa, thank you for advice - if not sorted I'm back there in a couple of weeks so will give it a go.
Slightly confused about this though: "Yes, you can air it back up but unless it has only a small leak, you cannot really monitor the pressure since it won't hold pressure." - The tank itself is sealed, so if only the bladder/diaphragm has gone surely repressurising the tank would work? The air would rise to the top (all be it outside of the bladder) so would it not then just work like an old bladderless tank? Or do you think the tank itself has a leak? Maybe I'm misunderstanding something?
Regarding contamination, the water is only used for filling cisterns and for watering the garden, they use mains supply for drinking water, so not too concerned about that.

Thanks again for your time

Steve

edit:
--I think understand what you mean by this now "Yes, you can air it back up but unless it has only a small leak, you cannot really monitor the pressure since it won't hold pressure." - you mean I need to follow that process to repressurise it - fair enough. Once done and I've managed to get air in it, should it function ok like a bladderless tank (contamination issues aside)?

 

[Reach4]

he tank itself is sealed, so if only the bladder/diaphragm has gone surely repressurising the tank would work? The air would rise to the top (all be it outside of the bladder) so would it not then just work like an old bladderless tank?

It would be imperfect, but you are pretty much right. There could be water trapped on the wrong side of the diaphragm. Putting in air with a compressor to maximize capacity could be overdone. A burst of air could come out.

The old galvanized tanks were really big generally which made air control precision less important.

For the uses you say, bypassing the pressure switch, or turning it high, and always having the hose open when the pump runs, could work. They would need to make sure that the pump did not deadhead. A pressure relief would be good in case somebody makes a mistake.

 

[LLigetfa]

...would it not then just work like an old bladderless tank?

Yes it would work similar to a hydro-pneumatic tank albeit at a reduced capacity.

Rather than cranking up the pressure switch so the pump runs continuously while using the hose, a safer and permanent fix would be to put in a CSV. There is a link to it in valveman's post. Since you need a tank anyway, look at the PSIde-Kick.

 

[Steve IAnson]

Yes it would work similar to a hydro-pneumatic tank albeit at a reduced capacity.

Rather than cranking up the pressure switch so the pump runs continuously while using the hose, a safer and permanent fix would be to put in a CSV. There is a link to it in valveman's post. Since you need a tank anyway, look at the PSIde-Kick.

I assume there's no issues using a CSV to pump water upstairs (currently upstairs cisterns but later desire to use for washing machine fill too)? I guess the pump must be able to produce adequate pressure, otherwise it would never have been able to repressurise the current tank?

Thanks

Steve

 

[Valveman]

Here is how it works.

 

[Steve IAnson]

Here is how it works.

Makes perfect sense, thanks

 

[Steve IAnson]

Here is how it works.

For the use of the hosepipe for long periods (sprinklers, filling the swimming pool etc.) this makes perfect sense and while they're there, this would be at least every couple of days for sustained periods.

However, for the cisterns (not sinks/showers etc. which are mains supply), this would only be a smaller draw and therefore wouldn't see the benefit. In fact I think if all they were doing was flushing toilets occasionally, they would be worse off if they had a CSV with small tank because that would only draw from the tank which would then need refilling each time.
So does it sound sensible to keep a larger tank (primarily for when only toilets are flushed) in conjunction with a CSV?

 

[Valveman]

As long as the pump doesn't cycle for the long term uses of water, it doesn't matter if it cycles for every toilet flush. However, it doesn't really cycle for every toilet flush. The CSV tank fill rate makes a mechanical timer that keeps the pump running until you have stopped using all water outlets. Flush a hundred times in a row, the pump only cycles once. I know it is counter intuitive, but we have been doing this for nearly 30 years. The CSV is nothing new, just a well kept secret. Pump and tank companies don't want you to know a CSV will make your pump last longer and work with a fraction the size of pressure tank.

 

[Steve IAnson]

As long as the pump doesn't cycle for the long term uses of water, it doesn't matter if it cycles for every toilet flush. However, it doesn't really cycle for every toilet flush. The CSV tank fill rate makes a mechanical timer that keeps the pump running until you have stopped using all water outlets. Flush a hundred times in a row, the pump only cycles once. I know it is counter intuitive, but we have been doing this for nearly 30 years. The CSV is nothing new, just a well kept secret. Pump and tank companies don't want you to know a CSV will make your pump last longer and work with a fraction the size of pressure tank.

Thanks, yes I understand, but it's not going to be flushed 100 times, it'll be flushed once and nothing else will cause a draw until someone else flushes a toilet (e.g. an hour or so later) as taps etc don't draw from the well.
But I take your point: it's a drop in the ocean for stopping the constant cycling when the hosepipe is running.

Cheers for all the advice