Softener Media Tank Collapsed, why?

[Diane Barr]

I had a water softener system installed (3 mo ago) at my well house. The media fiberglass tank collapsed today when I shut my well power off at the panel, and drained my main line to do some water line work at the house. I contacted the water softener installer, and he's of the belief that the system malfunction lies in my well pump with a faulty check valve. I believe its the vacuum that was created when I shut off the well and drained the line that leads from the system. The pressure gauge on the line immediately below the pressure tank held steady pressure when the well power was off. To me this means my check valve was working fine. What do you think? Important features to know about my system:
Well house and softener system are located 40' of elevation greater than the house, run distance +/- 400'.
Well depth, 120'. New well pump 3 years ago. New pressure tank 4 years ago.
Order of installation of equipment: well pump, pressure tank, pressure gauge, shut valve (brass), media tank/softener equipment housed together in a 4x3 well house (1" PVC), 3/4" PVC main line to house 400' away with drop of +/- 40 feet.
Prior to installation of the softener system, my method of shutting off the water to the house was to turn the pump off at the panel, and then open a water line below the house elevation and drain the system. This is what I did in this occasion, and then said..."ahh, I have a shut off valve now I can use, and I am likely draining out my media tank, and that may not be a good thing". I hiked my way up to the well, opened my pump house door, and found my media tank collapsed, and said...OHHHH SHEESSSHHH!!!!".
What was the cause?
What sort of vacuum release or fix can be installed to prevent such an event in the future? Given the elevation difference in my source water and my point of use, this scenario could happen anytime I loose power and I have a sprinkler going.

Thanks!

 

[Reach4]

What was the cause?
What sort of vacuum release or fix can be installed to prevent such an event in the future? Given the elevation difference in my source water and my point of use, this scenario could happen anytime I loose power and I have a sprinkler going.

Wow. In retrospect the need is clear.

You would want a vacuum relief valve (vacuum breaker) at the softener. http://www.watts.com/pages/_products_sub.asp?catId=64&parCat=295 would be examples. These are often put on second story water heaters. I don't know if there is a sizing factor that you should consider, but you would not want one built for hose spigots or irrigation systems.

If you open a faucet 30 ft lower than the bottom of the media tank, that will give a really strong vacuum-- as strong as it gets. The temporary work around would be to open a faucet at the softener level once the water was turned off. That would admit air.

 

[Sponsor]

 

[Smooky]

Something like this should do it:

http://www.zoro.com/watts-vacuum-re...gclid=CMuuzqf20cgCFU-QHwod4q8JyA&gclsrc=aw.ds

http://www.supplyhouse.com/Zurn-34-VR10XL-3-4-VR10-Vacuum-Relief-Valve-MNPT-Lead-Free

 

[Diane Barr]

Wow. In retrospect the need is clear.

You would want a vacuum relief valve (vacuum breaker) at the softener. http://www.watts.com/pages/_products_sub.asp?catId=64&parCat=295 would be examples. These are often put on second story water heaters. I don't know if there is a sizing factor that you should consider, but you would not want one built for hose spigots or irrigation systems.

If you open a faucet 30 ft lower than the bottom of the media tank, that will give a really strong vacuum-- as strong as it gets. The temporary work around would be to open a faucet at the softener level once the water was turned off. That would admit air.

Thank you so for the quick reply. I will reach out to the irrigation community locally, and see what they have built. Clearly, such a valve is the solution, as if I were to loose power while a sprinkler is running, then this would happen again.

 

[Reach4]

I see Lowes lists the first one on Smooky's list: http://www.lowes.com/pd_368041-18701-LFN36M1+3/4___?productId=3503158

 

[Jadnashua]

Water pressure is a bit over 0.43#/foot of elevation change, so 40# above, or fall, would be about 17psi. Most of those tanks are designed for internal pressure, not vacuum.

 

[hj]

I have seen city water tanks, and tanker trucks, collapsed when their contents were pumped out before their caps were removed to prevent vacuums.

 

[Diane Barr]

Thanks you guys!! I am still discussing this issue with the installer. If you have a diagram that shows a typical install with a vacuum relief valve, it would be greatly appreciated. DB

 

[Jadnashua]

I think it would be the same idea as when you have a water heater. Watts makes vacuum relief valves as do others. A quick search on their site will show you a typical install when used on a WH.

 

[Reach4]

Thanks you guys!! I am still discussing this issue with the installer. If you have a diagram that shows a typical install with a vacuum relief valve, it would be greatly appreciated. DB

For this particular vacuum breaker, it must be mounted vertically. This could just require adding a tee on a horizontal (shown in brown) line, or a tee and an elbow on a vertical (shown in blue) line.

I was thinking that this would be better on the output when I made the diagram, but now I am not sure which is best. Thoughts?

I think the valve should be at the level of the tank or above. The valve should be where the a valve could not be closed to kill the effectiveness.

 

[Diane Barr]

For this particular vacuum breaker, it must be mounted vertically. This could just require adding a tee on a horizontal (shown in brown) line, or a tee and an elbow on a vertical (shown in blue) line.

I was thinking that this would be better on the output when I made the diagram, but now I am not sure which is best. Thoughts?

I think the valve should be at the level of the tank or above. The valve should be where the a valve could not be closed to kill the effectiveness.

Thanks for the diagram. This is where I pictured it in the system, for best results. I have also seen them located just downstream of the well head, but thought this could be less effective.

 

[hj]

You want it on the pipe that drains, which would be the outlet of a water softener and the inlet of a water heater.

 

[Reach4]

You want it on the pipe that drains, which would be the outlet of a water softener and the inlet of a water heater.

I was thinking that way too. Yet if there is a non-softened line running down, perhaps for lawn watering or stock watering, there is another way the draining could happen.

If you consider a well check valve failure (rare I hope), that could be another potential cause of vacuum it would seem-- even for my softener in the basement. Scary.

 

[Smooky]

Here was a similar problem:
http://www.purewatergazette.net/blog/implosion-of-water-treatment-tanks-march-9-2014/