Bladder in a water tank for a pressurized water system

I am getting contradicting opinions whether just the bladder can be changed. Does anyone know the facts?

Good? Please let me know also.

I don't believe in bladder pressure tanks but this is what I found in seconds using google

https://www.hunker.com/13417609/how-to-replace-the-bladder-in-a-water-pressure-tank

Bear in mind it might just need re-pressurizing

http://www.wplawinc.com/FAQRetrieve.aspx?ID=49018

The plumber the bladder cannot be changed on the type of tank I have. Who knows?

I m not surprised. Most small tanks I have seen are not repairable. Now you know why I don't like bladder type pressure tanks. For the sake of about 1/2 an hour twice a year you can drain and refill a  tank without a bladder. I ran a resort with 20 cottages and 20 trailers on a large tank w/o a bladder. In fact I spent at least 20 years in Canada on well systems and never had a bladder type pressure tank. Just something else to break.

Does the plumber think the bladder is broken? If not then adding some air may solve the problem. I would certainly try that before a new tank.

If the tank has filled to the top with water then the bladder has a hole in it. You can tell by rapping on the tank. The top half should sound hollow.

Some pressure tanks have changeable bladders

CanuckBob wrote:If the tank has filled to the top with water then the bladder has a hole in it. You can tell by rapping on the tank. The top half should sound hollow.

CB: that will be the case whether or not you have a bladder water tank. Bladder tanks were invented to replace non-bladder tanks for those people who did not want (or know how) to drain their tanks a couple of times a year to refresh them. Non-bladder tanks are as efficient as bladder tanks and retain a much larger amount of water in the event of breakdown or power outage. The system has to be better as far as air infiltration and needs someone who knows what they are doing a when it comes to the plumbing joints and the elimination of air input.

I have worked with wells from 25 feet to 400 feet, 1 line systems, 2 line systems and submersible systems. Aljibe systems also. You will never convince me that bladder tank systems are the best.

It is kind of like the Car industry that introduced the front wheel drive where a bucket of parts costs 3x the price of the those for a rear wheel drive with little or no improvement in efficiency and a big loss in handling.

DaveP wrote:I m not surprised. Most small tanks I have seen are not repairable. Now you know why I don't like bladder type pressure tanks. For the sake of about 1/2 an hour twice a year you can drain and refill a  tank without a bladder. I ran a resort with 20 cottages and 20 trailers on a large tank w/o a bladder. In fact I spent at least 20 years in Canada on well systems and never had a bladder type pressure tank. Just something else to break.

Does the plumber think the bladder is broken? If not then adding some air may solve the problem. I would certainly try that before a new tank.

I don't understand how you would get pressure in a non bladder tank. Water doesn't compress to build up pressure.

ferret wrote:That is where the "diaphragm" comes in to separate the water from the air. When the diaphragm becomes waterlogged, you simply drain the tank, add air, refill the tank with water which compresses the air above the diaphragm and then you have pressure again.
But, as I said, I couldn't find one here. I'll try and find a link for you which explains it better.

Okay. I was thinking that a diaphragm and a bladder were essentially the same.

Diaphrams also rupture and need replacement.

ferret wrote:And here's more and you are correct. My original pressure tank was over 40 years old and that was in 1987 when the farmhouse was 125 years old. So it must have been the air over water pressure tank that DaveP describes. Then came diaphragms and then came bladders. Best described here...
https://www.rgwater.com/3-types-of-well-pressure-tanks.php

Thanks. Very interesting. It was time that I learned these things.

The pressure system on this house is about 10 years old. How would you know if it has diaphragm or bladder? It is a SKY Altamira, tanque precargado. Model SKY 25.

Look at the tank. If it is not able to be opened, you cannot replace anything inside.
Before the newfangled diaphragms and bladders, which only serve to keep the air and water from touching each other, we referred to “expansion tanks“. They serve to prevent pumps from coming on every time a faucet is opened. Air is much more compressible than water, so it acts as an accumulator of pressure. As such, some tanks were referred to as accumulators.
In all cases, there will be an air valve, just like on your car tires, at the top of the tank. Simply add air to about 20 psi a few times each year, and your tank will perform as it should; with or without a bladder or diaphragm, intact or not.
The pump and pressure are controlled electrically by a pressure switch, which may occasionally fail, or need adjustment. They are cheap and any plumber will know how to adjust yours, if needed. Basically, it will have an ON pressure and an OFF pressure, often set at about 20 and 40 psi for typical well or aljibe applications.

RV........
Couldn't say it better.....been with "pressure" tanks for 40 years.

RVGRINGO wrote:Look at the tank. If it is not able to be opened, you cannot replace anything inside.
Before the newfangled diaphragms and bladders, which only serve to keep the air and water from touching each other, we referred to “expansion tanks“. They serve to prevent pumps from coming on every time a faucet is opened.  Air is much more compressible than water, so it acts as an accumulator of pressure. As such, some tanks were referred to as accumulators.
In all cases, there will be an air valve, just like on your car tires, at the top of the tank.  Simply add air to about 20 psi a few times each year, and your tank will perform as it should; with or without a bladder or diaphragm, intact or not.
The pump and pressure are controlled electrically by a pressure switch, which may occasionally fail, or need adjustment.  They are cheap and any plumber will know how to adjust yours, if needed. Basically, it will have an ON pressure and an OFF pressure, often set at about 20 and 40 psi for typical well or aljibe applications.

Thanks for the information. When my plumber went to put air in that air valve some water came out so he said the bladder must be broken but the absentee house owner says not true. How would you know?

Checking out my model on the internet it says it has a membrane but the owner says he has had the bladder changed twice. Can you change a membrane?

If the tank appears to come apart then maybe. Mine is one solid unit like a giant propane tank with an air valve on the top and an inlet/outlet on the bottom.

If water comes out of the air valve, it means that there is no more air in the tank; bladder or diaphragm has failed. No big deal!  It is time to turn off your power and the water supply, let the pressure out of the tank by the air valve, and by opening a faucet to let some more water and pressure out. Then, close everything and get your air pump out there. Add air to about 20psi. Once that is stable, turn on your water supply and the power. The pump should come on and the pressure should rise to about 40 psi before it cuts off.  If that does not happen, you will need a plumber to check the pressure switch; probably replacing it, as they do fail in a matter of several years, but they are cheap, and easy to replace.
If you have success, you will have to repeat the addition of air every few months, like we did in the days before the “modern improvement“ of bladders or such. If that is not satisfactory, you may buy and instal a new pressure tank. They do save on electricity, as well as wear and tear on your pump.

Someone suggested Arturo, a plumber, would be a good person to look at this but I can't find the posting now for his number.

I installed a bladder pressure tank system in 2011 and last year I started having low pressure so my on demand water heater wouldn't kick in due to too low a flow and then the pump started running more frequently. The same plumber checked it out and found a pinhole in the bottom curved part of the metal tank, the bladder was fine, so I had to buy a new tank. I asked if that was typical that the metal would give out after only 6 years and he said "Chinese metal." I don't know how much truth there was to that. anyone else experience that?