Loud banging noise inside pressure tank & size (gallons)needed for 4 people

[Valveman]

Would like to see the video, but I assume the loud noise is water hammer from a bad check valve slamming on pump stop. If you have an above ground check valve, remove or gut it. The check valve on the pump is the only one you need, and it may work better after removing the extra check that is not needed. The check valve on the pump may still be bad, but you will have to remove the upper check to test in anyway.

Those big and expensive tanks are a thing of the past. The most you need is a 4.5 or 10 gallon size tank if used with a Cycle Stop Valve. The CSV will solve the problems that caused the tank bladder and check valve to go bad in the first place.

 

[JenL]

Would like to see the video, but I assume the loud noise is water hammer from a bad check valve slamming on pump stop. If you have an above ground check valve, remove or gut it. The check valve on the pump is the only one you need, and it may work better after removing the extra check that is not needed. The check valve on the pump may still be bad, but you will have to remove the upper check to test in anyway.

Those big and expensive tanks are a thing of the past. The most you need is a 4.5 or 10 gallon size tank if used with a Cycle Stop Valve. The CSV will solve the problems that caused the tank bladder and check valve to go bad in the first place.

Thank you for your information. Could you give me a little more information about the CSV? I see your occupation is a Pump controls technician. Do you work with water pressure tanks? I am very curious. This evening, the banging sound was far worse than just a couple of days ago. It must have made the "bang-bang" sound about 10 times after I turned the water sprinkler off. We really need to make a decision soon. Cannot afford a $2-3 k repair with all of the medical bills we've had recently! My husband has experience with commercial plumbing, so I believe he would be able to take care of this issue without calling a plumber. Just to have someone take a look will cost a few hundred.

 

[Sponsor]

 

[Valveman]

I have also been drilling wells and fixing pumps for about 50 years. Yes I work with "water pressure tanks" as pump controls are about the only thing I do anymore. That first video is the best explanation I have for how a CSV works. But here is another on how it prevents water hammer. You will have to post a video or show some pictures so we can see where your check valves are, then we need to know about the air charge in the pressure tank.

 

[JenL]

Video of sound from this morning. Put on a half load of clothes in washer. Turned off after filling with water. This is about a minute later. This sound is what it makes after almost every water source is turned off. If only a little water is turned on, it usually doesn't make the sound. https://drive.google.com/drive/folders/1Z23IYsPZsPsks-LWbDDzsVoVYEUK2EcV?usp=sharing

 

[Valveman]

Can't get access to the video. Ahg!

 

[Bannerman]

On G-Drive, she will need to either create a Public folder so anyone can access files within without needing a PW or, a PW will need to be provided individually to anyone attempting to access the videos.

Online sites such as DropBox come pre-configured with a 'Public' folder.

 

[Valveman]

I use Vimeo. I think they have a free service?

 

[JenL]

uploaded to Vimeo. Look for keywords: pressure, tank, noise

 

[Valveman]

Can you not just post the link? I get 65 results and don't see any that look like yours.

 

[Bannerman]

Cary,

 

[Valveman]

Thanks man! I can't see the gauge or anything. So I am guessing it is just the one loud bang about a second after the pump goes off? In that case your check valve on the pump has failed. The water is having to reverse before the check valve closes, which causes the water hammer bang. Slamming the check valve closed and throwing it wide open every time the pump cycles on and off is what causes that. The fix is to replace the check valve on the pump. The long term cure is to eliminate the cycling and make it have a mechanical soft start and soft stop, which makes the check valve and everything else last much longer.

 

[Bannerman]

Cary,

JenL said a pump guy established the tank bladder has failed, which seems to be confirmed by how rapidly the system pressure rises and falls.

Perhaps with no air remaining in the pressure tank, the weight of the water falling in the drop pipe to close the check valve, may be resulting in the pressure tank oil-canning slightly which is the noise she is experiencing from the tank?

 

[WorthFlorida]

On the first post my first thought was a failed bladder. Tha pressure tank is at least 20-30 years old made by Sta-Rite. Sears changed their logo in the 1980's. Replacement air bladders are still available from Sears Parts but extremely costly, not worth it. I don't see a replacement gaskets and the stufds on the old tank maybe rusted beyond use. It'd be better to get a CSV and a smaller pressure tank.

https://www.searspartsdirect.com/model/10otjqfav0-000247/craftsman-390291701-water-pump-parts

 

[Valveman]

The bladder is most likely bad. But the pump is not clicking on/off like a jack hammer, which happens when there is no air in the tank. It seems to be taking a fairly good time reaching shut off, then one loud bang. A new bladder tank "might" help soften the blow. But it sounds like water hammer from a slamming check valve to me.

Sometimes adding a CSV will help. The CSV causes the flow to decrease to 1 GPM to fill the pressure tank. So, the sticky check valve has time to unstick. At 1 GPM the check valve should "hopefully" only be open the thickness of a piece of paper when the pump shuts off. This lets the check valve close from a small distance instead of from wide open as it does without a CSV. Unsticking before pump shut off is the key though. If the check valve is bad enough to stick in the fully open position every time the pump starts, and not unstick until the pump shuts off and the water reverses, then even adding a CSV will not keep you from having to replace the bad check valve.

 

[Reach4]

Our current water pressure tank makes a loud noise about a minute after a water source is turned off.

How long after the pressure switch clicks off does the loud bang occur?

 

[JenL]

Around 1 minute. I will need to listen again and use a timer.

 

[JenL]

Just last night, the air sounds started while using a water source. Sounds like air is being pushed through the faucet, shower, etc. I forgot about the water doing this last summer, until last night when it did. Then, I remembered. We seem to only have this problem when the air and soil become warmer. Did not have any of these issues during the winter months. The only difference this summer verses last summer is the water pressure is low. Does anyone know why these things would occur according to temperature?

 

[JenL]

Can you not just post the link? I get 65 results and don't see any that look like yours.

My apologies. I did not realize there was a link to post.

 

[JenL]

Sounds like we need to replace the check valve and pressure tank??

 

[JenL]

Cary,

Thank you for finding it and posting!