I posted earlier about a well pump problem.I've been trying to figure why I have very little water and my pressure tank gets no water in it.my dad told me to bybass my tank to see if I had any more water coming to the sinks.there was a little more and dad being negative about everything starts saying how bad this was.I don't know anything about wells and stuff but I told him that the pressure tank probably provides the pressure for the water.is this right?I'm getting real frustrated(wife kids everybody and their brother )asking me if it's fixed.I put this tank in about 10 years ago.when I take the prime plug out there's a lot of water spraying out so I think the pump and well are fine.also is there anyway to test the tank.it has 30lbs of pressure.thanks

The purpose of the tank is two-fold.

1. It stores water.
2. More importantly, it provides pressure by having the water compress a volume of air as the tank fills. Most tanks now have a flexible membrane in them (called a bladder) which serves to keep the air separate from the water.

When you use water, the pressure in the tank begins to fall as water exits the tank, thus providing more room for the air. When the pressure drops to a certain point, a pressure switch turns the pump on. It pumps until the pressure builds back to a certain point, at which time the switch turns the pump back off.

This site explains it all pretty well:

http://soundlutherie.com/wells.html

It sound like you have a problem with your pump. Is your pump above ground or below ground, in the well itself?

The pump is above ground.it pumps water out but it doesn't go into the tank.can the tank build up sediment like a water heater and maybe it's plugged?

Mike,
When do you read 30 lbs? This sounds rather low. I would be looking for about 60 once the pump shuts off (completes cycle) Is this a bladder tank as jlisenbe mentioned ?


Robert

Mike, several things come to mind.

1. Your pump is above ground. Does it have one pipe going into the well or two?
2. Just because the pump is delivering some water does not mean it's capable of building pressure. It is possible that your wellpipe has a leak which would interfere with the pump's ability to build pressure.
3. I doubt that the tank is the problem. Tanks don't normally interfere with the system building pressure. They are more likely to cause problems with pressure being relatively steady. The tank air charge is the key here. As long as the tank has at least some measure of air, it will perform fairly well.
4. Does your tank have an air valve at the top? If so, then it is a bladder tank. It probably is, and this explains why you are getting a 30# pressure reading if you are reading from the top of the tank. But understand that this is the pressure in the top of the tank, above the bladder. If the tank is largely empty of water, you might have just a minimal amount of WATER pressure in the bottom of the tank, where water actually enters and exits the tank.

The tank has a air valve at the top and the 30 lbs is the reading whether the pump is running or not.I bought this place from my grandma and dad said the pump is over 25 years old.tomorrow I'm going to buy a new pump.I'm praying that's it.this spring we had to put in a $5000 septic system.oh yeah and it only has 1 pipe coming from the well.

More than likely, your suction leak that you had earlier, burned up the pump. Or melted something that clogged the jet.

Your 30 psi air charge in the bladder tank will need to be adjusted to the new pump. You should check to see what the inside of the pressure switch cover says for a pressure settings. If it comes from the factory with a 30/50 setting, let 2 pounds of air out of your bladder tank. In other words, the air charge of your bladder tank should be 2 pounds less than whatever pressure the pump comes on at.

Be sure to fill the pump with water when you prime, as described in my previous post.
Al

YOu have a shallow well pump. You are not pumping from more than 20 or 25 feet down. That is nice since it makes replacing the pump that much easier. However, your problem might center around low water level or a leak in your suction pipe. If you're going to replace your pump, replace the pipe as well. Check the water level as well. You might want to look at those two items before you replace the pump. ON the other hand, replacing a twenty five year old pump might not be too bad of a move.

I suspect that you have a ruptured bladder and the tank has become water logged.

First;
Go to that air valve on the tank, that tire valve stem looking thing. Press the needle valve and see if you get air or water coming out.

If you get air, OK.
If you get water you have a ruptured or leaking bladder.

Regardless;

Turn off pump, empty the tank of all water. Set the air pressure to 2 lbs less than the pump cut-in pressure. If you do not know the pump cut-in pressure, fill the tank (or let out pressure) to 20 lbs. Turn pump on and let it run until it cuts off. Open faucet and drain tank until pump comes on again. Note pressure that pump comes on.
Turn off pump and drain tank again. Set pressure to 2 lbs below pump cut-in pressure.

Turn on pump.

If you have a ruptured bladder, replace tank. Old tank should work until you can replace. Water may have an odor.

The tank does two things, it stores water so that the pump does not have to come on each time you use water, and it provides the pressure to push the water to where you use it. You can not compress water. You can compress air. By adding water to a tank that has air in it, you compress the air. The compressed air is what creates the water pressure.

Here is my explanation of how a well tank functions. There are two types, a regular tank, called a pressure and a bladder tank. The pressure tank is the basic principal of how things function. Maybe it will help.


If you take a sealed tank, full of air, not pressurized, just full of air, and pump in water, when you have filled it 1/3 full of water it will have a pressure of 40 lbs. If you fill it 2/3 full of water it will have a pressure of 60 lbs. That gives you a usable volume of water 1/3 of the size of the tank, at pressures ranging between 40 and 60 lbs. This is the way a regular well pressure tank works. However, water absorbs air. As you use water it is replaced with additional water which absorbs more air. Eventually all of the air in the tank is absorbed. You tank is then "water logged". Water cannot be compressed. Only the air is compressed. Since you have less air to compress, it takes less makeup water to reach the cut off pressure. This makes your pump cycle on and off more often. This is not good for the pump. When you tank becomes water logged you must drain the tank, let it fill with air and start over again. How often your tank becomes water logged depends on the size of the tank and volume of water used. Draining about once a year is usually sufficient.

A bladder tank (which you have) has an expandable membrane on the inside to keep the air and the water separate. Thus eliminating "water logging". If you pressurize the tank to the pump cut-in pressure, that is equivalent to filling it to the 1/3 mark with water. You then have 1/2 of the tank volume to store water before you reach the 60 lb cut off point. Note that filling the regular pressure tank from the 1/3 to 2/3, is compressing the already compressed air to 1/2 its volume when the tank was 1/3 full of water. So if you fill the bladder tank, with the air already compressed to the cut-in pressure, to 1/2 its volume, you will have 60 lbs. of pressure. (One day I'll figure out a better way of saying all that).

With a regular pressure tank you have a usable volume of 1/3 of the tank size. With a bladder tank, because you have pressurized it, you have a usable volume 1/2 the tank size. That is the primary advantage of the bladder tank.

MIke, you stated in your first post that your pressure tank does not fill with water. If that is the case, then a waterlogged tank is out of the question. A waterlogged tank would be completely filled with water, not empty of water. I might add that a waterlogged tank will generally build up to cut off pressure. The problem is that it will cut on and off many times a minute. I just don't think that is your problem, but it certainly won't hurt to check it in the manner HK described. It would be nice if that is the case, since that is an easier fix than replacing the pump.

jlisenbe, I think HK missed that in the first post. It was still useful information to help him adjust the air in the bladder tank, and better understand how it works. However, if it is holding 30 psi of air charge, the tank is unlikely to be defective.

I think you are on-track with the pump, and or suction pipe is bad.
Al

You are correct Al, I didn't associate with previous post. Was thinking tank may have been over charged.

Well guys the new pump worked.had to adjust the cutoff screw because it kept shutting off and on when the tank got full.I had some pink and some white pipe tape.every place I used the pink tape it leaked.threw that stuff away.thanks for all the help from everyone.I learned something new.thanks!

Hey Mike,
Glad we were able to help. It sounds like you still may need to adjust the air in the bladder tank. You said that you have 30 psi air in the bladder tank. That means you should have been able to tighten the tall screw by about 2 psi, so that your pump comes on before the bladder tank collapses.

Watch your pump pressure gauge during a cycle. It should fall slowly until the pump comes on, it should build up over about a minute, and then shut off. If it falls slowly, then suddenly drops and the pump comes on, you need to adjust.

Also, if it chatters on and off, like it sounds like it was doing, it needs to be adjusted or it will ruin your new pump and pressure switch. If neither of those conditions exist, you are done.

Glad we were able to help!
Al

Mike, Al is entirely correct. Set up your tank correctly.

No offense intended to HK. I've missed things myself so I know how easy it is to get confused when trying to pick through so many posts.