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Anonymous Poster

Air in Pipes

06/23/2008 9:48 PM

I have a well with a 900 gal. galv. old tank, when I turn on the bathroom facet I get a blast of air and low pressure. Then everything is fine. I can not fine a any type of bladder tank on the system. Should there be one?. How can air get in to the water lines?.

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#1

Re: Air in pipes

06/23/2008 10:50 PM

A couple of questions and some observations from my past.

I presume that the tank is used to store the water from the well and then gravity feed to the house. Is that correct?

I presume the water from the well is pumped into the tank from a bottom entry. (Below the water level.) Is that correct?

I presume that the pipes go "down" below house floor level and then rise inside the house to the various taps that you have. Is that correct?

(Nearly too many presumption, please forgive me, but these conditions set the scenario that I've seen a couple of times.)

Now, this is what I've seen happen in the past.

Water from a well was pumped using a footvalve that was around 3m below the top water level. The water was fed into the bottom of the tank (which was also around 3m deep) and then gravity fed to the house. There was constantly air in the lines.

What we "decided" was that some gas was stored in the well water at a pressure represented by the 3m depth that was sustained though the tank and other portions of the system and that this separated inside the delivery pipes to the house and accululated in one particular outlet. (Just like the bubbles in soft drink (or some alcoholic beverages) are only released when the external pressure is removed.)

Our solution was to re-direct the delivery pipe for water into the top of the tank so that any "effervesence" was able to be dispersed at that time. It seemed to work.

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#2

Re: Air in pipes

06/23/2008 10:57 PM

Congratulations, You have a leak .

Check your tank for an air valve ( it looks like a tire valve ) and if you don't have one on it, then you are most likely correct, in that you don't have a bladder tank. If you do, then check the pressure it is holding. It should be between 45 & 60 PSI of air on the bladder side for most American piping. Air is part of the system ONLY if you have a leak as you suck some air into the lines with your use or failure of the foot valve.

This leads to pollution of the water system, in the end, so do start looking for the wet spots on the lawn or water falling back into the well , if a foot valve is bad. This will require someone to pull the pipes from the wel & replace it. Look and see if you have 2 pipes, ( sending & receiving ) going down to the well water . If so, you have a foot valve about 1 foot off the bottom, of the original depth, of the well. And if the tank is old and without a bladder, you might consider turning it into your next wood stove conversion project vessel and invest in a newer type of tank anyway , as this gives you, the constant pressure you will want.

Water hammer causing this is one slim chance where this could happen, but I think you have a leak as you have air in the line over & over again. Water hammer problems arise often when pipes are not plumed with a short 6" or so expansion line , that by a tee w/a line ending in a cap , goes past the 90 Deg point of where the pipe turns toward your faucet. Lack of this, could cause you a bumping sound, of the water & air hitting ,when your water is cut off too - at least it did ours once; but check for leaks - you've got one somewhere .

Cheers

Bond

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#3
In reply to #2

Re: Air in pipes

06/23/2008 11:16 PM

Amen Jamie , Amen

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#5
In reply to #2

Re: Air in pipes

06/25/2008 8:12 AM

Well I was going to go into some detail but you beat me to it so I give you the good answer for your post. On my wells I do not have a foot valve but I have a submersable pump and I assume there is a "built in" foot valve to keep the column of water in the pipe. I have two wells on my property a 525" deep and a 325" deep. I have a air bladder tank on both of them and they work very well. I always thought you have to have an air bladder tank to keep the constant pressure on the system. On my wells the pump is well below the natural water line. I don't see how just having a faulty foot valve could introduce air into the system without a leak somewhere for it to get in there.

pipewelder

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#6
In reply to #5

Re: Air in pipes

06/25/2008 10:48 AM

Hello Pipewelder,

Thank you I'm often shot at Its good to get a 3 cheers. I think that the air in the line can develop from a faulty foot valve in that as water leaks back into the well , a strong vacuum is drawn upon that specific pipe, thereby leaving a space of no water.

The air must come from somewhere and clearly it does not come from down below the water itself. So I think the force of the vacuum has drawn it in, from the weaker places in the system, perhaps that older 900 GAL tank.

I wish I really knew, after all - It's just a guess.

Cheers,

Bond

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#4

Re: Air in Pipes

06/24/2008 5:43 PM

The others are correct if you have a pressure system installed.

In a pressure system, if the leak is "making air" then the leak will be on the suction side of the pump, or it could even be the seals at the pump drive shaft since there is negative pressure in those zones and may draw in air. Generally if the leak is on the delivery side of the pump, you will see damp spots somewhere rather than air in the lines.

If you have a "pressure system", then from your description (air in the lines) I'd suggest focus your attention on the suction side of the pump.

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#7

Re: Air in Pipes

06/25/2008 3:13 PM

Guest,

Is there a pressure gauge on the tank? If so, watch and see what pressure the pump comes on at and what pressure it goes off at and also if the pressure drops right away after the well pump shuts off. Sometimes the tank will only have an air space at the top with no bladder and it can become flooded. However, with the problem you are describing it sounds almost like there is a high water usage somewhere else in the system which causes a vacuum at the faucet sucking in air. This has happend in households that do not have a vacuum breaker installed on their outside hoses and have actually drawn poison through a hose feeder into the house plumbing causing a poisoning.

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#9
In reply to #7

Re: Air in Pipes

06/25/2008 3:42 PM

Better know as a back flow preventer.

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#8

Re: Air in Pipes

06/25/2008 3:41 PM

A check valve may be leaking allowing the water in the storage tank to very slowly syphon back into the well leaving an air filled void in the piping and storage tank. When the pump starts up to maintain the proper water level in the storage tank it'll compress the small amount of air in tank. When you open the faucet for water the first thing you get is air then water at a low pressure until the tank is full.

Maybe? I'm not a well expert...just guessing. Now I'm incognito!

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