Need advice on a captive air tank

[MillWeld]

I use 2 captive air tanks in my crawlspace to get enhanced drawn down between pump cycles. One is a Well Extrol WX202 which has been in use for well over 20 years and is still working well and the other was a Flotec which I removed from service after 18 years because it failed. (I don't know when it stated to fail but it certainly did not last all of those 18 years).
My dilemma is paying ~$400 for a comparably sized Well Extrol to replace the Flotec which I could get for 1/3 of that cost. I have read that Well Extrol is top-of-the-line and they have a guarantee to prove it. Advice? What would you do?

 

[Mendonsy]

It seems like you already know what the difference is from you own experience. It is just a question of whether you want to pay the extra cost for more reliability or save the money and replace more often.

 

[Valveman]

I always sound like a salesman when I chime in on one of these kinds of threads. But I really am trying to help you solve your problems. My dilemma is that solving your problem makes me a saleman, which I am not trying to be. I hope no one minds if I try to help you solve your problems?

I do say "problem(s)" because you have mentioned two outright, and there are always others that are related to those two problems.

You "need enhanced draw down between pump cycles". And you need to replace an expensive pressure tank.

First when you say you need "enhanced draw down between pump cycles", I assume you are really just trying to limit pump cycling overall. Pump/motors can only survive so many cycles per day, but they can run continuously without any damage. What it is important is that the pump runs continuously WHILE you are using water, especially during longer term uses of water like showers and garden hoses. Not that you have more draw down, or water to use from the tank(s) before the pump comes back on. In other words it is ok for the pump to come on anytime you flush a single toilet. But it is not ok for the pump to cycle on/off repeatedly every minute or so while you take a shower or run a hose on the lawn. A WX202 tank only holds about 5 gallons of water, so the pump could cycle on/off 10 times while you take a 50 gallon shower. Running a hose for a few hours can cause hundreds of pump cycles.

Not only is pump cycling bad for the pump/motor, it is bad for everything else in the pump system. Pressure switches, check valves, relays, and capacitors are all very suseptable to cycling problems. The life of a captive air tank is also realted to cycling. The bladder or diaphragm in the tank stretches up and back down with every pump cycle. This is the only moving part in a captive air tank, and the more you move it, the shorter the life of the tank. Theh Flotec tank didn't last as long because it can't handle as many cycles. The WX202 tank can survive more cycles, but cycling will still destroy it sooner or later.

Now is when I sound like a saleman. If you eliminate the pump cycling, you will solve the two problems you mentioned, and most of the other problems common to pump systems. If you install a Cycle Stop Valve (CSV) prior to the tank tee, the WX202 tank you have is really 5 times larger than needed. So you won't have to purchase another tank at all. You won't have enhanced draw down between cycles, but you will have eliminated repetative cycling. This can greatly reduce overall cycling. which is the ultimate goal.

Besides reducing the size of tank required, making the pump/motor, tank bladder, pressure switch, check valve, and everything else last longer, the CSV will also give you a steady or constant pressure in the shower or to sprinklers. Instead of the pump cycling on/off and pressure going from 40 to 60 five or ten times during a shower, the pressure will remain at a constant 50 PSI, and the pump will run continuously, no matter how long a shower is taken.

 

[MillWeld]

The CSV is a new concept to me. It seems to me to be useful for what I call a high volume user. If I understand correctly, with a CSV installed and you open the tap to rinse the sink or tub or to use a small volume of water the well pump comes on and goes off when you close the tap. That's rapid cycling for small uses. I try to conserve water so small usage is common in our household. I'm not convinced a CSV is what I want.

 

[Valveman]

You are right that if you never take a shower longer than 5 minutes, and never run a garden hose for any length of time, the CSV is less useful. But the CSV is not really for high volume users. It works best for systems with a high volume pump, that use low volumes of water for long periods of time. If you are using a high volume of water (as much as the pump can produce, as with a sprinkler system matched ot the pump) the pump will not cycle anyway, even without a CSV.

But for those who have a 10 GPM pump or larger, and use a 3 GPM hose or take long showers, the CSV will keep the pump from cycling to death and keep the pressure strong and constant.

Even when using a CSV with a 4.5 gallons size tank that holds 1 gallon of water, the pump cannot rapid cycle. You would have to use the 1 gallon out of the tank before the pump starts, then the pump will stay running as long as a faucet is on or the toilet is filling, then the CSV will take another 30 seconds to fill the tank so the pressure switch can shut off the pump. So with a 2 GPM sink faucet turned on, the tank will take 30 seconds to empty and turn on the pump, the pump will run continuously until the faucet is turned off, then the pump will run for another 30 seconds before the pump is shut off. No way to cause rapid cycling.

In your case with a 20 gallon tank that holds 5 gallons of water, you would have to use all 5 gallons before the pump is started, then the pump will stay on until the faucets are turned off, and run for about 2 more minutes to top off the last 2 gallons needed to fill the tank until the pressure switch shuts off the pump. You can still conserve water and just use it in little spurts. But the CSV will make sure the pump never cycles rapidly, and you don't have to replace the extra tank.

This is unlike what you are seeing now using a 5 gallon draw down tank with a 10 GPM pump, I doubt that the pump even runs 30 seconds to refill the tank, and it continues to cycle like this over and over, which is not good for the pump. If you add another $400 tank, the run time will still only be 60 seconds, which is the bare minimum run time for a pump like this.

The CSV will reduce the pump cycling without the need to add another tank, even when you use water is random little spurts.

 

[ultrarunner]

Bookmarked...

Went to visit my brother in the city and noticed his Booster pump was on-off, on-off constantly... he said it just started doing that a few weeks back... did not know he had a booster pump and no idea why there is an extra "Water Heater" in the garage.

He is on city water right next to the large water tank... so 23 psi with no booster.

The home has a large captive air with no bladder installed in 1977... he was not aware any maintenance was required... I showed him how to drain down the tank to get air back in and all is good.

 

[Qapla]

The CSV is an excellent way to prevent cycling for small or large water users

With a direct order cost of only $63 and free shipping, it may warrant a try before spending way more on a tank you may not need

 

[Xfaxman]

Very happy with the way a CSV works for us: http://www.tractorbynet.com/forums/...ell-pump-monitor-post4258924.html#post4258924


This one is 24" underground, no heater required here in Oklahoma.

 

[MillWeld]

OK. You guys have got my attention now. I've googled CSVs and ran across this link. cycle stop valves - Plumbing Zone - Professional Plumbers Forum

Responder #7 certainly doesn't like them but I'm interested in your critique of what he has to say. I've used my present pump/tanks since 1990 so I'd say they are working pretty good so I am reluctant to go another route, but I can be convinced to change. Thanks.

 

[Valveman]

I don’t blame the guy in post #7 for thinking that. I thought the same thing 25+ years ago. I just didn’t think solving most of the problems with pump systems could be so easy, but it was. I just thought there had to be drawbacks of some kind, but there wasn’t. All I can say is you should take the advice of those who have actually tried them as opposed to those who just think they know everything. The CSV is so counter-intuitive that it is certainly a show me kind of thing. But it all makes sense when you see how it works.

On that same thread there was this from 2011.

(From October 2011) We use these valves all the time, I/we love these valves. I just know a lot about them cause I used them when I worked in the irrigation industry and now I use them with the plumbo-co I work for. Cycle Stop Valves, Inc.

It is nice to hear from people who have actual experience with CSV’s, because most of the time you never hear back, as in the following quote from 2013.

(From August 2013) I will be putting a Cycle Stop Valve after my neighbors booster pump next week.

I will let you know if/how it works.

They rarely let you know how it works. Once someone installs a CSV and all their problems go away, they never think about their water supply again. As long as a steady supply of water is coming out of their faucets at a strong constant pressure, the pump system never crosses their mind again, as there are plenty other things in this life to worry about. I am lucky if they remember what it was that solved their problems, or if the same people are even living in that house so many years later when they finally have a pump system problem.

Many times the CSV has been removed during pump system repairs, as it had been so many years nobody knew what it was. Then in a short time they figure out the new system is not working as well as the old system was. After a little research they figure out they need to put the CSV back in, and all is good again.