Author Topic: Can I use a Large Pressure Tank with a CSV?  (Read 15258 times)

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Can I use a Large Pressure Tank with a CSV?
« on: January 05, 2014, 06:04:27 PM »
A big pressure tank is good for lots of little intermittent uses of water like ice makers and toilet flushes as an 80 gallon size tank will deliver 25 gallons before the pump must start.  Then if you have any long term uses of water like heat pumps or sprinklers, the CSV takes over after the pump starts and delivers constant pressure without letting the pump cycle on and off.  For many years I believed that a big pressure tank with a CSV was the best of both worlds.

However, I have learned that the CSV takes out so many cycles for long-term uses of water, a small tank causing a pump cycle every time a toilet is flushed by itself, doesn’t add up to much.  If the pool is filling, a sprinkler is running, or any other water is being used when a toilet is flushed, the CSV just gives a little more water for the toilet, but there is no extra cycle.

Seldom is a toilet flushed by itself.  Usually within a minute after flushing, the shower or a sink will be turned on.  Many times there will be two or three flushes within a minute of each other, then the shower or sink.  And that is just one persons use.  Multiple people in a house use water at the same time.  Someone in the kitchen runs the sink or the dishwasher.  Maybe the cloths washer has been on the entire time all this other stuff was happening.  As long as some water is being used anywhere in or outside the house, the CSV makes the water go right past the pressure tank, straight to the faucet that is open.  So it doesn’t matter if the tank holds 1 gallon or 25 gallons.

We have found that only systems that supply between 3 and 50 houses will benefit from a larger tank with the CSV.

  Number of houses                             Size of Pressure Tank
Less than 2 Houses                                        4.5 gallon
3- 10 Houses                                                  20 gallon
11-49 Houses                                                 80 gallon
50+ Houses                                                    40 gallon

Another counter intuitive thing about a CSV is, the more water a system uses, the smaller the tank can be.  When you have less than two houses with multiple people using sinks, toilets, showers, appliances, etc., and/or a heat pump, sprinkler system, which includes garden hoses, a 4.5 gallon tank is all you need.

However, there are times when a little larger pressure tank can be beneficial.  A large CSV controlled pump system can use an 80 gallon size pressure tank to supply an entire city of 40,000 people.  So there is no reason to use a tank any larger than 4.5 gallon size for one or two home. 

But when 3 to 50 homes are using the same pump system, a little larger tank can be a benefit.  With 3 to 50 homes there are times when no one is using water, but there are enough connections that a few leaking faucets could be supplied by a pressure tank, so the pump does not have to start to supply a few leaks.  In situations like these, a 20 to 80 gallon size pressure tank that holds 5 to 25 gallons of water would be good to use with a CSV.

To see the benefits of a smaller pressure tank see, “Why a Small Pressure Tank is All You Need with a CSV”, at this link.   http://cyclestopvalves.com/smf/index.php?topic=1953.0


See this graphic;          http://www.cyclestopvalves.com/simple/home.php

The Cycle Stop Valve system is on the top.  A conventional tank system is on the bottom.  If you turn on a sprinkler and let it run for hours, the pump runs constantly for hours as well.  During this time, if you flush a toilet, take a shower, or use any other water, the pump is already running and the CSV just opens up a little to give you enough extra for the added shower.  When you turn off the shower or the toilets fill and shut off, the CSV just resets to the amount of water needed to run the sprinkler.

The same thing happens when you turn on a shower.  As long as the shower is on, the pump is also on, so even 40/11 toilet flushes don’t add a single extra cycle to the pump.  In a house where there are multiple people, and/or multiple systems using water, the pump will be running a lot of the time, which is a good thing.  As long as somebody, or something, somewhere in or around the house is using water, the pump is already running.  Anything else turned on just gets the extra water it needs, without the pump having to cycle one extra time.

If you noticed the conventional pump system at the bottom of the graphic, it is just cycling on and off continually no matter where or how much water is being used. 

The Cycle Stop Valve just lets you use as much or as little water as you want without cycling the pump.  Water just goes from the pump, right past the tank, straight to the sprinklers, showers, wherever, because the CSV gives only the exact amount of water needed.


But don’t get me wrong.  The CSV will work with any size tank you prefer.  Some people think a larger pressure tank will give them a little stored water for times when the power is off.  This is true if you are lucky enough that the power goes off while the tank is full.  However, Murphy’s law says the 40/60 pressure switch will be at 41 PSI when the power goes off, and the largest tank available will be empty.  A couple of 5 gallon jugs in the closet is a more reliable way to have some water when the power goes off. 
« Last Edit: February 08, 2014, 02:58:29 PM by Cary Austin »

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #1 on: September 12, 2014, 10:40:16 PM »
What about pump heat dissipation if there are many very short cycles during the day?

For most single residential applications is there much difference in outcome between using a tank with a draw down of 3.2 gallons vs a tank with a draw down of 5.5 gallons?

Most of the available small 3,4,5 6 gallon tanks come with a very low preset pressure. I have one of these tanks and use it with my CSV1. I increased the preset to 45 lbs and it seemed to work well... what would you suggest I set the tank pressure to? I would like to run my system at 60psi to 80psi. Any suggestions would be welcome.

Thanks,
Leonard
Pittsburgh
« Last Edit: September 12, 2014, 11:57:30 PM by MutantMonk »

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #2 on: September 15, 2014, 07:11:20 AM »
What about pump heat dissipation if there are many very short cycles during the day?

For most single residential applications is there much difference in outcome between using a tank with a draw down of 3.2 gallons vs a tank with a draw down of 5.5 gallons?

Most of the available small 3,4,5 6 gallon tanks come with a very low preset pressure. I have one of these tanks and use it with my CSV1. I increased the preset to 45 lbs and it seemed to work well... what would you suggest I set the tank pressure to? I would like to run my system at 60psi to 80psi. Any suggestions would be welcome.

Thanks,
Leonard
Pittsburgh

It is motor heat dissipation that you are talking about.  There is usually a 1 minute minimum run time and off time for the motor to dissipate heat caused on start up.  However, with a CSV the motor is running and especially filling the tank at reduced rate and reduced amperage.  At reduced amperage the motor load is "de-rated", which means it doesn't have as much heat to dissipate and doesn't need the 1 minute minimum tank fill time.

With a 60/80 pressure switch you would want about 55 PSI air in the tank.
« Last Edit: September 16, 2014, 07:13:33 AM by Cary Austin »

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #3 on: September 15, 2014, 02:07:50 PM »
Wow!
Thanks for responding.
Not to be argumentative but since I first asked this question, I found somewhere on this forum (I think), that the tank pressure should be set 2 psi below the pressure switch cut in pressure?
So that would require the tank pressure to be set at 58 for a 60/80 system... again I am not trying to be argumentative here… just want to make sure I am understanding correctly.
I have been using a CSV1 for the last 8 years and it is truly manna from heaven. I have been running it with a tank preset at 45psi and tank draw down of 5 gallons with a pressure switch set at 50/70.
Will a CSV150 work with a 60/80 system pressure
What are the different applications for the CSV140 the CSV150 and the CSV160?
My other question was... is there a significant functional difference between a tank with a drawdown of 3.2 gal vs one with a drawdown of 5.5 gal.
Are there any, out of the ordinary, tank specifications when using tanks with a Cycle Stop Valve; i.e. using a tank that is used with a reverse osmosis system
Do you know if Cycle Stop Inc. sells their small pressure tank individually?
That’s a lot of questions sorry.
Regards,
Leonard
Pittsburgh

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #4 on: September 15, 2014, 03:40:57 PM »
Who, how and what controls the "1 minute minimum run time and off time"?

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #5 on: September 16, 2014, 07:33:58 AM »
My bad.  I corrected it.  “With a 60/80 pressure switch you would want about 55 PSI air in the tank.”  Not 45 PSI air as I first stated.  Actually 58 PSI is the perfect amount. I just use 55 PSI because of discrepancies in the gauges, and the fact that too little air is better than too much.

Lowering the air pressure in the tank is really the only way to have any water stored during a power outage.  With 58 PSI air in the tank and using a 60/80 pressure switch, the tank only has a few cups of water in it when the pump comes on at 60.  Because of Murphy’s law, the system will be at 61 PSI when the power goes off.  Therefore you won’t have 3 cups of water left in the tank, which is why pressure tanks are not good for storage to use during a power outage.

If you lower the air pressure in the tank to say 40 PSI, when the power goes off while the system is at 61 PSI, there will still be a few gallons stored in the tank.  When the pressure drops to 40 PSI, the tank will be completely empty.  With lower air pressure the tank will not be as efficient, will not deliver as much draw down on each cycle, and the bladder is continually over-stretched.  But that is the only way to be able to count on a few gallons of storage from a bladder tank during a power outage.

Unless you know it is coming and go out and top off the pressure tank before a power outage, you have no way of making sure there is any water stored in the tank.  If the pressure happened to be at or close to 80 PSI, you would have a tank full of water. (WX350 would have 30 gallons)  But if the pressure is close to 61 PSI, there is basically no water left in the tank.  (with 58 PSI air and a 60/80 switch a WX350 would only have 3 gallons left)

Pressure tanks are only designed to reduce the number of pump cycles, and with a CSV you don’t have to worry about that.  If you want to make sure you have some water stored for power outages, put a few 5 gallon jugs in a closet somewhere.

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #6 on: September 16, 2014, 07:40:03 AM »
Who, how and what controls the "1 minute minimum run time and off time"?

In the old days you would get 1 minute of pump run time by using a tank large enough to hold 1 minute of what the pump can produce.  In other words, a 25 GPM pump would require an 80 gallon tank that actually holds about 25 gallons of water.

With a CSV the tank is filled at 1 GPM, so you only need a 4.5 gallon tank that holds 1 gallon of water, to get 1 minute of pump run time.  But as I explained, the CSV makes the pump/motor run cooler by pulling reduced amperage, so you don’t really need 1 minute of run time to dissipate the heat, because there is very little heat produced.

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #7 on: September 16, 2014, 01:34:05 PM »
Thanks again for all your help,
I don't know how it got into ether but I am not particularly concerned about residual water being left in the tank. If I did I didn't mean to imply that... sorry.
I am considering purchasing a CSV1W to replace my CSV1. What are the benefits of using the CSV1W instead of the CSV1 in a 60/80 system?
What are the different applications for the CSV140 the CSV150 and the CSV160, and which one would be needed in a 60/80 system?
Also… is there a significant functional difference between a tank with a drawdown of 3.2 gal vs one with a drawdown of 5.5 gal, other than the residual water in case of power failure thing (witch I don’t care about)?
« Last Edit: September 16, 2014, 05:55:56 PM by MutantMonk »

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #8 on: September 17, 2014, 07:08:32 AM »
With a 60/80 pressure switch you will want the CSV set at about 70 PSI.  The only valve we have that will do that is the CSV1A.  All our valves do the same thing, it is just a matter of how much pressure you want, where you need to install the CSV, and what size pump you have.  Again for that size pump, set at 70 PSI, and installing the CSV in the house, I would only recommend the CSV1A.

With this valve you only need a 4.5 gallon size tank with 1 gallon of draw.  A larger tank with 3 or 5 gallon of draw is not going to hurt anything except to lighten your pocket book.

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #9 on: September 17, 2014, 11:09:07 AM »
My new pump is a 1.5hp Goulds, that can pump up to 18gpm.
I only have a about a 45’ static head but it is in an 8” pipe, which gives me about 100 gallons of water in the column above the pump.

The well has a tremendous recovery rate so I’m pretty sure we will be ok with a pump this big. (If not then I will install a CSV CS1PH1-2HP230V pump sensor).
The reason I went this bit is that we have a lot of back pressure coming from the house; i.e. three and a half bathrooms, with 3 deep soaker jetted tubs, a Rheem tankless water heater and a tandem “Big Blue” filter system, hosting a 5 micron and then a 1 micron filter (I may also add a carbon filter in a third big blue housing). I ran 1” copper feed lines and ¾” branch lines throughout.   

As of right now I will be installing a CSV1A, a 6 gallon pressure tank with a 5.5 gallon draw down and a 60/80 pressure switch. If I have any problems with water supply I will install a CSV CS1PH1-2HP230V pump sensor.

Do you see and holes in my planned installation?

Thanks,

Leonard

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #10 on: September 17, 2014, 11:48:55 AM »
Looks good except that a 6 gallon size tank only has about 1 gallon of draw down at 60/80.

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #11 on: September 17, 2014, 12:39:24 PM »
Thanks,

The tank I am getting says it has a capacity of 6 gallons with a 5.5 gallon draw down. From your comments then, I should assume that this 5.5 gal draw down, that they advertise, is calculated at only one atmosphere?

The one gallon draw down will be fine. If we ever get to a situation where we have no power for an extended period of time, I will just pull the well and drop a bucket down on a rope. ?

What would be the consequences of installing a 60/80 pressure switch with a CVS150?
« Last Edit: September 17, 2014, 01:24:09 PM by MutantMonk »

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #12 on: September 17, 2014, 01:41:08 PM »
I am still somewhat confused about heat dissipation at the pump.

When the pump has cycled of (60/80 sys with CSV1A) and the pressure is around 80 t 85 psi. A 6 gal tank should be holding about 1 gallon?

If someone, a child for instance, turns on a faucet for only a few seconds, just enough time to kick on the pump, the pump will only stay on for the time it takes to replenish. Now the child decides to do that over and over and over again… doesn’t that pose a risk of overheating of the pump?

It seems as if you could turn the pump on and off at any faucet location, just by running the water a few seconds at a time?
« Last Edit: September 17, 2014, 02:13:34 PM by MutantMonk »

Cary Austin

  • Inventor, Owner, Chief Cook and Bottle Washer
  • Administrator
  • Newbie
  • *****
  • Posts: 876
    • View Profile
    • http://www.cyclestopvalves.com
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #13 on: September 18, 2014, 08:17:25 AM »
It doesn’t do any good to have a 60/80 pressure switch with the CSV set at 50 PSI.  You would only get the one gallon from the tank as the pressure drops from 80 to 60 PSI.  As soon as the pump comes on at 60, the CSV will pull the pressure down and you will only have 50 PSI for as long as you are using water.

Now if you have 6 gallon size tank, it will only have 1 gallon of draw down between 80 and 60 PSI.  But if you set the CSV at 60 you will have 60 PSI for as long as you use water.  Then when you are no longer using water the CSV will refill the 1 gallon in the tank at 1 GPM, which will take 1 minute to fill and shut off the pump.

During this 1 minute it takes to refill the tank, if the kids use water again, the pump does not shut off, but rather the whole 1 minute fill time starts all over again.  If the water is used to flush a toilet, it takes 1 minute for the toilet to fill before the 1 minute tank fill time starts.  So if a toilet is flushed every two minutes, the pump just keeps running continuously.

Now if the kids wait 3 minutes between flushes, it will take about a minute before the pump is restarted as the 1 gallon in the tank is being used (toilet fill rate is about 1 GPM).
After the pump is started it will run for about a minute to refill the toilet.  Then it will run for another minute to refill the pressure tank before the pump shuts off. 

So even if a kid is standing at the toilet with a stopwatch and flushes every 3 minutes, it is not going to hurt the pump.  The pump will always have at least 1 minute of run time, which isn’t really needed since the CSV makes it pull reduced amperage (de-rating the motor).  The pump will always have 1 minute of off time as the water in the tank is used first, which also isn’t really needed because the pump/motor had already cooled down before it shut off from the reduced amperage caused by the CSV.

Kids turning the water on and off is really not a problem.  Usually the problem is the kids forget to giggle the handle on the old toilet, and it just keeps running.  Or they turn on the sink faucet and forget to turn it off.  With the old pressure tank only method this would kill the pump, as it would just keep cycling on/off until someone finds the problem and giggles the handle.  When this happens on a system with a CSV, the pump stays on continuously and is not hurt at all, even if you come back from vacation and realize the toilet has been running all this time.

I know it seems strange that a little tank that only holds 1 gallon of water is all you need.  But our water comes from the pump, not the tank.  And as long as a CSV controls the amount coming from the pump to exactly match the amount being used, the water goes right past the tank, straight to the faucets.  So it doesn’t matter if you have a 1 gallon or a million gallon tank, except that the larger tank will lighten your wallet.

MutantMonk

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: Can I use a Large Pressure Tank with a CSV?
« Reply #14 on: September 18, 2014, 11:12:13 AM »
WOW!!!!!

That was fantastic... I think I am starting to see the light.

You know your stuff man. WOW again.

Regards,
Leonard
Pittsburgh