Which brand of captive air tank is best?

sheenashirley said:

They refuse to come to the 21st century and realize that big pressure tanks are a thing of the past. Constant pressure systems like the Cycle Stop Valve do a better job with a 4.4 gallon tank, than the old style system with an 86 gallon tank.

Plumbing service

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My cycle stop valve is a tank at 50-85 psi and a pressure reducing valve at the house. This gives me big water for roof sprinklers for wildfire which has saved the house once already. I do think about the csv for some rentals and vacation homes I have, but would like to see some side by side comps on KW use from standard to CSV at the same household.

ballvalve said:

My cycle stop valve is a tank at 50-85 psi and a pressure reducing valve at the house. This gives me big water for roof sprinklers for wildfire which has saved the house once already. I do think about the csv for some rentals and vacation homes I have, but would like to see some side by side comps on KW use from standard to CSV at the same household.

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Then the pressure reducing valve is giving you constant pressure at the house, while your pump is cycling itself to death between 50 and 85 PSI. This is also wearing out the bladder in your tank. Not only from the constant cycling, which will burst a bladder like bending a wire back and forth multiple times but, also from the wide bandwidth of 50/85, which will overstretch your bladder ever time the pump cycles on and off.

If it has already saved your house one time, then the most important thing would be to make sure the pump and tank are still in good shape, the next time you have a fire. Letting the pump cycle on and off now, means it may be broke when you really need it later. Over-stretching and cycling the bladder tank multiple times, will burst the bladder, which will also help destroy the pump. Then you will be standing there watching your house burn, because the pump quit when it was needed most, which is when they always quit, and no water is coming out of the hose.

As for the energy use, there have been several "studies" published. Amtrol, who makes pressure tanks, produced the most one sided study available, to try and prove that big pressure tanks are superior to a CSV. Their study, as obviously one sided as it was, could only show .5 Kilowatt per day more energy used with the CSV. So if you pay 10 cents per kw, that would be an extra nickel per day, which adds up to a whopping $18.25 per year. That was just for inside the house use only. If you have irrigation or a heat pump that can cause your pump to cycle excessively, then a CSV will actually decrease the energy consumption. But even if you do not have irrigation or a heat pump and you actually use 18 bucks a year more energy with the CSV, that is very cheap insurance to make your pump and tank last three times longer than usual. Not to mention how much it would be worth to have a pump system that has not been cycling itself to death, and is already on it's last leg, when you have a fire and really need it.

Lastly, the way you are using the pressure reducing valve, your house always has the lowest pressure available from your pump. 50/85 pressure switch, with the PRV set at 50 PSI, means you only have 50 PSI to the house. Using a CSV instead, which is placed before the pressure tank, could deliver a constant 80 PSI to the house, eliminate the cycling you are seeing now, make the pump and tank last longer, which saves you a lot of money, and makes sure the pump isn't completely worn out on the day you have a fire.

Thanks, all pretty well understood and good points for the average system. I pump from the 60' well [@60gpm] with a 1.5 hp submersible into a 3500 gallon tank on a long stroke float. That gravity feeds a centrifical pump which pressurizes a PLAIN tank that I precharge with compressed air from an oiless compressor. With the high shutoff point, most irrigation and especially the roof sprinklers do not allow the pump to cycle. As for the house, I am set at below 50 and its fine due to good pipe sizing and protects a radiant system from excessive pressure.

Finally, I have a large three way valve that bypasses the storage tank, centrifical pump and plain tank. In case of fire or problems with the downhill system, I can instantly run right off the well that has a small Amtrol tank. [and a generator] That is the submersible pump that runs constantly perhaps 3 times a week to keep the cistern full, so its life span should be quite long. Probably a CSV would be appropriate at that small Amtrol tank system for those times when I bypass the other components.

So I think I have mitigated your points, but they are very relevant in most "normal" systems. Not many people would take the time to build and manage my system.

Sounds like and excellent system with lots of storage, and I love a generator backup. A CSV would help if you have to run the well straight to the house service but, just for temporary use it should be fine. And I would just run the pump straight off the generator without a pressure switch in case of a fire. A 1.5 HP 60 GPM pump won’t build enough pressure to hurt anything, and then there would be nothing to mess you up if you have to fight a fire.

Thanks for the reply. Just to clarify, the pump puts out about 25- 30 gpm, but that still leaves pretty small down pipe pressure. The well was rated 60gpm.

Pretty interesting feeling to be drinking a beer under an umbrella while 4 or 5 neighbors houses burn in the distance. Our county passed a big tax to buy fire engines - [I am one of the few to know they took off when the fire came this way, and its not politically correct to say that around here.] I got quite a kick seeing all the "thank you" firefighter signs on standing houses, when they were simply the result of chance and luck.

If we took the fire engine taxes and bought chain saws for the creation of local prisoner chain gangs to cut brush around houses, That would be money well spent.