Galvanized Tank Question

First off, let me apologize in advance for the lenght of this post. Just want to make sure all of the info is here.

I Have a 82 gallon galavanized steel tank. Just recently had my 35 year old Red Jacket pump replaced and replaced all the steel piping with PVC pipe. The old system had the bleeder values on the pipe in the well which would provide the shot of air each time the pump cycled on. Also have an AVC on the tank which would bleed off excess air when necessary. This all seemed to work just fine and maintained the correct air to water ratio in the tank.

When the contractor installed the new pump and pipe, he inisited it wasn't a good idea to have the air making system since water went back down the well each time the pump shut off and that could cause problems in the future. He said the galvanized tank would be just fine as long as the correct amount of air was maintained in the tank. So he drained the tank, added 20lbs of air using an air compressor to the tank through the valve at the top of the tank. Turned the power on to the pump and it ran until it hit the 60lb limit set on the pressure switch. He than showed me by taking a tire guage to the valve on top of the tank that it registed 20lbs which was the air sitting on top. He told me to periodically check the pressure this way and it should remain around the 20lbs. He said that once a year, the tank should be drained down and 20lbs of air added to maintain things.

A couple weeks later, I checked the pressure on the top valve and it was right at 20lbs. The guage on the tank was at 60lbs as the pump just filled it up so all seemed fine. Checked just recently after the tank filled up. The guage on the tank read 60lbs. Took the tire guage to the top valve and it read 45lbs. After using some water and the tank pressure got down to 40lbs where it turns on, the guage on top read 30lbs. Since the water is so cold this time of year, just feeling the side the tank told me where the water level was and it is about 2/3 the way up.

I should also say, I haven't noticed any difference at the facuets with pressure. All seems normal.

My questions are:

Is this the start of the tank becoming waterlogged? I haven't acutally measured the drawdown but it appears to be less than normal.

Not sure how, but could there be extra air being introduced into the tank through the water coming in? I know excess air wouldn't be a problem since I have the air volume control to bleed off the excess. I haven't heard this valve open and it makes a load hissing noise I can hear even upstairs.

You and the well driller must have skipped physics class. If he put 40 pounds of air or 10 or 50 into a plain tank, when the pump shut off at 60, that AIR was at 60 also. You must have a very special and humorous chinese pressure gauge.

Well pro? I don't think so. If so, it must have been his first job.

Pressurizing the tank with a compressor to the CUT IN pressure is fine. [not so fine if he left the air release valve in] When it shuts off it will be at shut off pressure. Period.

But water loves air, and you will be doing this more like every month at the very least. You can replace an airmaker on the surface, however. The overpressure from the compressor gives you MUCH more drawdown, however.

ballvalve said:

But water loves air, and you will be doing this more like every month at the very least.

Click to expand...

At least with the AVC working, it is almost a no brainer since any surplus air volume added at low tide would be bled off. If too much air pressure is put in the tank, hopefully the PRV will pop off, assuming there is one.

The tank should have about 2/3rds air. If the gauge on top and the gauge on the line don’t read the same, then one or both gauges is bad.

Once a month is probably about right. Unless you are using sprinklers or a lot of water, then once a day may not be enough. All you have to do is forget or not be early enough to put air in the tank, and in one day your pump can cycle itself to death. Click, click, click, poof!

I would either put the bleeder orifice back in, or add a bladder tank to the system.

valveman said:

All you have to do is forget or not be early enough to put air in the tank, and in one day your pump can cycle itself to death.

Click to expand...

I think that's what pumpmen call repeat business.

In another thread Don was content with about 25% air in his tank.

Thanks Valveman. So the fact that the tank is at 2/3rds water is indicating a problem?

Also, I don't have an actual guage on the top. It's like a tire valve that I can check with a tire guage. That's the one he told me should remain around 20lbs regardless of the overall pressure of the tank shown on the guage down lower on the tank.

Brian, the water level should be as low as the AVC will allow. If you put in more air than what the AVC senses, the AVC will just let it out. There is no need to check the air pressure as it is meaningless since as valveman said, it should read the same as the water pressure. It also in no way gives any indication of the water level. A temperature gradient should show where the water level is.

Yeah, no matter how much air you put in, it will come out of the AVC. So the water level should be at the AVC during the lowest pressure. If you remove the AVC, you can keep it about 2/3rds full of air, which will give you more draw down, and more air, which will last longer, since you are now having to add air manually.

Tire gauge and system gauge should always read the same with that type tank.

It sounds like if I don't stay on top on this on a regular basis I will have problems. I should have insisted the well guy put the bleeder valve in like the old one dispite what he told me that it wasn't a good idea. I think he was hoping to sell me a new bladder tank at the same time. Any truth to his comment that water draining back down isn't good for the well?

Sounds like changing out the bladder tank may be the best solution. I'm not great about sticking to a regular schedule on checking things. Any recommendations as to brand and size. I always liked the 82 gallon tank I have because it always had a great draw down -usually 15 gallons+.

Your well guy is missing a few spark plugs. Your tank is okay, you can add the air intake on the surface just before the tank. And no, a drip of water in a well is pretty normal. I like the air intake valves on the surface because you can monitor them and adjust the amount of air uptake by pipe length between the schrader and the valve.

I run several wells like this ( no air maker with galv. tank). Some wells "eat" the air faster....some don't. Generally speaking, every 3-4 months you need to add air to the tank to keep it going.

It should not lose the air in one month as has been suggested, unless your water really likes the air.

It is true that a bleeder makes the well very nasty at the top (air + water mixed continuously). But it really should have no detrimental effect down where the pump is.

Thanks Texas Wellman. Maybe I'm jumping the gun here. What's the best way to determine when it's time to add air? And when I do add air, do I need to drain down the tank or can I add air with some water still in the tank.

thanks

BrianP said:

do I need to drain down the tank or can I add air with some water still in the tank.

Click to expand...

Either the AVC is not working right or you seem not to understand how the AVC works. If you drained all the water from the tank, the float on the AVC should sense not enough water (assume too much air) and open to vent it. The AVC is meant to work withing the normal pressure range the pump is set to.Turn off the pump and drain just enough water to reach the kick-in pressure. Add air until it reaches the kick-out pressure. Lather, rinse, repeat. If you end up with too much air, one of two things will happen. 1. The AVC will vent it, or 2. The air will vent through the house plumbing.

BrianP said:

What's the best way to determine when it's time to add air?

Click to expand...

Determine the natural level that the AVC wants to maintain at kick-in pressure and mark it on the side of the tank. Also determine the level at kick-out and mark it as well. Then periodically check the level by observing the temperature gradient. In high humidity, it should be obvious by the sweat on the tank. In low humidity, hold you hand on the tank.

Got it. I do know how the AVC works. It worked everytime under the "old" system bleeding off the excess air put in by the air maker system each time the pump went on.

I'm just pissed now that I went from a basically maintenace free tank situation to one where I periodically have to check and add air. All because I let the "well pro" talk me out of installing the valve to make air on the new piping installed in the well. He said if it becomes a problem for me, I can always switch to the captive air tank which he was trying to convince me to buy when he put in the new pump and piping.

I know what you mean about maintenance free. Now, if you neglect it, it will start short cycling and get gradually worse.

Take note that there was some discussion of having two thirds air to emulate a bladder tank for more drawdown. Probably your AVC would not let you do that, but should your AVC fail or be too slow to vent, you could run into problems. If you have a filter or softener that backwashes, should the pressure drop (power fail or overdrawing the well) during backwash, the air could vent through the house plumbing and blow resin or filter media up through the system and clog things up. Ask me how I know!

BrianP said:

Got it. I do know how the AVC works. It worked everytime under the "old" system bleeding off the excess air put in by the air maker system each time the pump went on.

I'm just pissed now that I went from a basically maintenace free tank situation to one where I periodically have to check and add air. All because I let the "well pro" talk me out of installing the valve to make air on the new piping installed in the well. He said if it becomes a problem for me, I can always switch to the captive air tank which he was trying to convince me to buy when he put in the new pump and piping.

Click to expand...

Put your air maker right next to the tank, you really only need a few feet of pipe to get enough air, then your vent likely will not ever need to vent. Most guys blow way too much air into a plain tank.

Since the chinese are dumping air compressors on us for 39$ now, you could also put one on a timer for a minute a day.

Ja, some folk use the bleeder to prime a trap in their basement. Like ballvalve said, most often there is too much pipe between bleeder and snifter.

Whitewater even makes a compressor with probes for the tank to keep the right air level. Just make sure to use an oil free type compressor.

I like my galv. tanks. They allow a bit of sediment to settle to the bottom if you have any (I blow my tanks down once a year). They last forever if the water quality is even somewhat decent.

The last two galv. tanks I replaced had '69 and '72 scrawled on the bottom. Tanks were still good.