Cycle Stop Valve

Discussion in 'Open Loop' started by ldameron, Mar 4, 2009.

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  1. ncgeo

    ncgeo Member

    No Flaming Please

    All, can we avoid the personal attacks? Nothing wrong with a difference of opinion but lets leave it at that.
     
  2. Rancher

    Rancher New Member

    Thanks Ron,

    So I would think your pressure tank will be fully re-filled during that 6 minutes off, so with the CSV the water pump will also cycle at 5X/hour. 43,800 times a year, about half what you would see without the CSV...

    Will that double the life of your water pump... only if cycling was the only wear on the pump.

    Rancher
     
  3. Tradesman

    Tradesman New Member

    CSV aka Constant pressure valve

    I came across this sometimes intellectual thread by accident. I have been considering buying one of these valves and I too had to wrap my brain around the basic operation. I would just like to throw something out there for the VSD especially Danfoss brand folks out there. They offer a similiar product through their flomatic side of the house. Their product is called Cycle Gard and it appears to provide the same benefits. I post this not in favor of one or the other just to say that there appears to be a market for this type of device and it hopefully will be able to solve my problems. Thanks for all of the humorous postings. Oh, and cant we all just get along!:)

    P.S. Cycle Gard® Pump Control Valves | CYCLE GARD® | Danfoss Flomatic Corporation
     
  4. ncgeo

    ncgeo Member

    Yeah I hear ya ... I'm not sure if my situation is typical. Because I had already invested in a large 86 gal tank (although a cheap one) I had already significantly reduced my cycling. Also I was most concerend about the cycling during the many hours of CONTINUOUS heat pump run time on winter and summer nights. Then I'll see just 1 cycle with the CSV vs. about 10 times/hour without.

    Also I have another motivating factor, my pump is stuck and I can't get it out :) Seriously. There is a torque arrestor on it and I believe is getting hung up on the bore hole. Some on the terrylove forum have asked why I would want to pull a good pump ... I would like to know it is repairable in the future and now I'm not sure it is, plus I want to install something more permanent with the discharge piping (see my thread "need 4 hole well seal"). I have not brought in a pro (yet) because of the expense, lack of accessibilty, and also the fear it may come part way but not all the way out. Then I created a bigger problem. So I'm looking to prolong the life of my pump for this reason.
     
  5. Valveman

    Valveman Guest

    Thanks Tradesman
    Actually this is not a new concept. People have been drilling holes through, or using a bypass tube around, pressure reducing valves for years. I have talked to pump installers who have been doing this for 50 years. The principle is sound. The PRV varies the flow rate to match the usage at high flow rates. Then a hole drilled in the valve body (like a Dole valve), is large enough to keep the pump cool, and also determines the rate that refills the pressure tank.

    There have been many brands of these type valves over the years. Jacuzzi made the Aqua Genie for many years. Red Jacket made the Hydroservant, Flomatic makes the Cycle Gard, and there are other brands that I will not mention. One of the main problems with any of these valves, is that the small drilled hole clogs up. Water spewing through this hole causes the minerals to build up and plug the hole, the same as holes in your shower head get plugged up. When this hole gets clogged, the flow needed to cool the pump/motor and to refill the pressure tank cannot get through, and the motor is destroyed.

    Trying this theory in the early 90's, we quickly learned about the hole clogging up. This is how we came up with the non-closing or "notched" valve seat. The "notch" in the valve seat creates a hole, when the valve and seat close together. However, when the valve opens, the two half moons of the hole split apart and self flushes any debris or mineral buildup. The non-closing or "notched" seat also eliminates water hammer from the valve opening or closing. The fact that the valve seat never completely closes, also allows for much faster valve reaction speed, which becomes more important as the size of the valve increases. We have several patents on this idea, and it is what sets the Cycle Stop Valve apart from anything that has been tried in the past. Pump installers who have been trying this method for years, are fascinated with the benefits that the simple notch has over the drilled hole idea.

    Again, this is not a new idea. The notched seat of the Cycle Stop Valve serves to eliminate the problems of the hole clogging up. Many of the older, more experienced pump installers have told me that the notched seat of the Cycle Stop Valve, has eliminated the main and really the only problem they have had with this method of pump control. This method eliminates most of the problems associated with pump systems, and anyone who tries to tell you otherwise, is showing their lack of experience and knowledge.

    The company mentioned by Tradesman, is a very large company who understands the benefits of this type of pump control. However, they lack any innovation and simply copy other successful products. The name of their valve closely resembles the name of our valve. Most of their valve models are the same or closely resemble ours. Their advertisements, installation instructions, and other things are almost an exact copy of ours. They also have spies who watch every move we make, copy where we advertise, and even copy our key words and phrases on search engines. If imitation is the greatest form of flattery, then I should be extremely flattered. However, they do not use the patented non-closing or "notched" seat design, and I take offence when they say "theirs is just like a Cycle Stop Valve only cheaper". Flaws with their drilled hole design have been known for many years, and gives this method a bad reputation. The many brands of this type of control valve available, does prove there are others who understand the benefits of this type of pump control.

    I apologize for the personal remarks made by Rancher. The Mods here need to clean out the uncalled for personal remarks. In this one thread my product has been unjustly called "snake oil", "smoke and mirrors", and other things. I have personally been called a "liar", "full of BS" and he even tries to deny that he sent me the threatening message. Using misinformation to try and keep people from trying products or methods that can be of great benefit to them, is eco-terrorism, or at the very least Un-American.
     
  6. Valveman

    Valveman Guest

    Why do older threads not come up when searching?
     
  7. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    We hoped it would not come back, even in a search. I suggest starting a new and improved thread about CSV forthose truly seeking information about it.
    Eric Sackett
    weberwelldrilling.com
     
  8. Valveman

    Valveman Guest


    Now don't start! I am just waiting for Leonard to come to a conclusion. Some things you just don't know until you see it for yourself.
     
  9. Guest

    Guest Guest

    Valveman, can you post a link to a pump manufacturer's specs that show this?
     
  10. Valveman

    Valveman Guest

    Any good pump curve from any pump manufacturer will show you the horse power. Most curves for smaller pumps do not show horse power or even efficiency. If you can get the efficiency curve, you can figure the horse power. We have a calculator at this link that does the math for you.

    http://www.cyclestopvalves.com/horsepowercalc.php

    The attached curve is for a 10 HP pump. It shows 10 HP required at 200 GPM, and shows the drop in horse power to 4 HP when flow is restricted to 50 GPM. Nearly all pumps work this way regardless of size. Notice the RPM is 3450, which does not need to change to reduce the load to 4 HP. All that matters is that the flow is reduced. Even though the back pressure increases, the HP still decreases. It is very counter intuitive but, it is a fact. I have to explain this to engineers for the major pump companies all the time.
     

    Attached Files:

  11. moondawg

    moondawg Member

    Summing up:

    1. Poorly-designed water systems cycle pumps excessively.

    2. Cycling reduces the life of your pump.

    3. Cycle Stop Valves reduce the flow (and therefore cycles, and potentially efficiency) of your pump.

    Extrapolating, from the chart given:

    1. Cycle Stop Valves may require your pump to consume much more ENERGY (power applied over time) to move the same volume of water. OR less, depending on where your pump now operates on the efficiency curve.

    2. Depending on how long your pump now survives, it may cost you much MORE in the long run to run with a CSM than to replace your pump with a pump that runs a the required flow rate at the peak of the efficiency curve. Or LESS, depending on where your pump now operates on the efficiency curve

    3. Properly determining your usage rate before installing the pump is the BEST solution for the problem at hand.

    4. Doing a cost analysis and picking a CSV that reduces cycles while not completely killing efficiency is the NEXT BEST solution.

    5. Slapping a CSV on and ignoring your electric bill will keep your pump out of your mind for a while longer.
     
  12. Guest

    Guest Guest

    Thanks, it is non-intuitive until one thinks about a completely throttled pump not having any new water coming in to accelerate. Less work to do, less torque, less amps.

    Of course a pump turned off can use even less energy.
     
  13. Valveman

    Valveman Guest

    Thanks jonr, you are 100% correct.


    Summing up:

    1. Even the best designed water systems, cycle pumps excessively when varied flow rates are required.

    2. Cycling greatly reduces the life of your pump.

    3. Cycle Stop Valves match the flow (and therefore reduces cycles), as the efficiency of your pump varies with the flow rate.

    Extrapolating, from the chart given:

    1. Cycle Stop Valves require your pump to consume ENERGY comparable to Variable Frequency Drives (more power applied over time) to move the same volume of water, depending on where your pump now operates on the performance curve.

    2. It may cost you MORE energy in the long run to run with a CSV, than to replace your pump with a pump that runs at the required flow rate at the peak of the efficiency curve. However, this is only possible if the pump runs at a set volume every time. So it is impossible to exactly size a pump for a 2 stage system, or one that runs a heat pump and a house at the same time. How much longer the CSV makes your pump survive, less any possible increase in energy, determines how much total energy you save.

    3. Properly determining your usage rate before installing the pump is the BEST solution for the problem at hand if the pump is dedicated for a single, unchanging flow rate.

    4. Doing a cost analysis and picking a pump that has a good brake horse power to work with the CSV efficiently, is the NEXT BEST solution.

    5. Slapping on a VFD and thinking you are saving energy and increasing the life of your pump is totally false. Using a CSV to eliminate cycling and produce variable flow rates will keep you from ever having to worry about your pump. Using a CSV to increase the life of your pump system can save more energy than spinning the meter a little slower. It takes a lot of energy to mine, manufacture, transport, install, and recycle pump systems that fail prematurely because of cycling or abuse from VFD's.

    6. Getting advice from someone who really understands pumps can help you design a reliable and efficient system when variable flow is required. There are so many people who think they understand how pumps work, but don't, that accurate information is hard to come by.
     
  14. Guest

    Guest Guest

    I would like to see more discussion of a third option which may apply to OL geothermal users who have two requirements:

    1) frequent high volume (say 15 gpm), low pressure (say 15 psi) for geothermal
    2) occasional need for higher pressure, lower volume (say 50 psi/4 gpm).

    This could be achieved with a low pressure pump in the well and then a booster pump only for domestic water.

    Also, in the case of multiple OL heat pumps running off of one pump, would it make sense to regulate (not just a fixed valve) the pressure to each heat pump so that it never exceeds the flow it requires?
     
  15. Valveman

    Valveman Guest

    As far as using a separate valve for each heat pump, as long as the supply pump system maintains a constant pressure at variable flows, all you have to do is set a flow control valve for each heat pump.

    I agree the two pump set up is much more efficient. Here is an explanation of a system for someone who was wanting to cut pumping cost. I have done others similar to this before and it works very good. This cuts the pumping cost by lowering the pressure and horse power needed for the heat pumps. Then the only time two pumps are running and using the most power, is when the house is using water. However, the house uses very little water compared to the heat pumps, so the time both pumps are running is minimal. This leaves a smaller, lower pressure pump to handle the heat pumps, which can save a lot of energy.


    Another way to cut pumping cost which would be easier to control follows. I would use a 16S05-5 pump end, remove 2 impellers, and use a 1/3 HP motor. This pump would deliver 16 GPM at 50' of lift. Control this well pump with a 20 PSI Cycle Stop Valve, a small pressure tank, and a 10/30 pressure switch. After the pressure tank, one line tees off to the heat pump, another tees off to a booster pump for the house. Use about a 3/4 HP jet pump with it's own Cycle Stop Valve set at 50 PSI, and a 40/60 pressure switch.

    When a heat pump is running, an electric discharge valve opens, the pressure tank drains from 30 to 10 PSI, and the pump starts. The 20 PSI CSV will vary the flow to match 3,6, 9, or12 GPM, for single or multiple heat pumps and maintain 20 PSI constant. This should cut your pumping cost to 1/3 of what the 3/4 HP well pump is doing now. When the heat pump shuts off, the electric discharge valve(s) close. Only when the last heat pump shuts off, will the CSV slowly fill the pressure tank to 30 PSI, and the well pump is shut off.

    When the house alone is using water, the house pressure tank will drop from 60 to 40 PSI and the 3/4 HP jet pump will start. The 50 PSI CSV will maintain 50 PSI to the house no mater the flow rate being used. This jet pump system is drawing water from the well pump system, so the pressure tank on the well pump system empties as the pressure drops from 30 to 10 PSI, and the well pump is started. The CSV on the well pump feeds exactly as much water to the jet pump booster as the house is using. Both pumps run as long as the house is using water. When the house stops using water, the CSV on the jet pump will slowly fill the house pressure tank to 60 PSI, and the jet pump is shut off. Then the CSV on the well pump will slowly fill it's pressure tank to 30 PSI, and the well pump is shut off.

    When the heat pump is running, the well pump/CSV is delivering 3,6,9,or 12 GPM at 20 PSI. If the house needs water at the same time, the jet booster pump comes on, and the CSV on the well pump opens up to supply both the heat pump and the jet booster pump. Depending on the water level, you should be able to get about 18 GPM total when the house and heat pump need water at the same time. When the house no longer needs water, the jet pump system will fill the house pressure tank to 60 PSI, and the jet pump is shut off. Then the CSV on the well pump reduces the flow to 3,6,9, or 12 GPM, matching the amount used by the heat pump(s). Again, when all the heat pumps are shut off, the well pump fills it's pressure tank to 30 PSI, and both pumps stay shut off until water is needed again.

    If the water level in the well pulls down to more than 20' at high flow, you will have to stay with a ½ HP well pump and not remove impellers from the 16S05-5. Even this will cut your pumping cost to half of what they are now.
     
  16. moondawg

    moondawg Member

    Here is some data I found comparing actual energy consumption on a 40hp pump assembly. Tests were done with a VFD and also a throttling valve.

    http://www.plantservices.com/articles/2 ... tml?page=2

    Their results seem to indicate that at low-to-mid flowrates, energy savings can be dramatic with a VSD over pump throttling. I linked to page two because it has a table of their results. The whole article is interesting. It's geared more for industrial customers (hence the 40hp pump!)
     
  17. Valveman

    Valveman Guest

    “Finally, if most of the energy for a centrifugal pump isn’t needed to overcome static head, using a VFD instead of a throttling valve to control flow will produce energy savings.”

    Finally, if most of the energy for a centrifugal pump is needed to overcome static head, using a VFD instead of a throttling valve to control flow will not produce energy savings.

    It all depends on how you word it. Static head rules with well pump and most booster pump applications. A VFD won’t pay off unless you can lower the head required. Most of these type systems operate at a constant head, which limits the usefulness of varying the speed.

    Energy saved is never as dramatic as they say. I can see maybe 4% to 6% difference on curves like the following, but the VFD causes 3% more energy use at high flow, which is not shown on a curve like this. So many times the VFD actually increases energy consumption when the flow only needs to be reduced a small part of the time.
     

    Attached Files:

  18. Looby

    Looby Member Forum Leader

    It's just plain ol' high school physics:

    pressure x volume = energy,

    and thus:

    head x flow rate = power

    1 horsepower = 1714 PSI-GPM (at 100% efficiency, of course)


    ...have you hugged an engineer, today?

    Looby
     
  19. Guest

    Guest Guest

    The chart at http://www.plantservices.com/articles/2 ... tml?page=2 shows energy savings using a VFD vs throttling at any head.

    Say in the case of an OL system with two HPs, when only one HP is running (50% flow needed), you may be looking at 1/3 the energy using a VFD vs. throttling.

    Rewording isn't always that simple:

    `I do,' Alice hastily replied; `at least--at least I mean what I say--that's the same thing, you know.'

    `Not the same thing a bit!' said the Hatter. `You might just as well say that "I see what I eat" is the same thing as "I eat what I see"!'
     
  20. Guest

    Guest Guest

    Maybe best to ask "what is the recommended water delivery design for the following OL system" and "what are the expected operating costs"?

    2 heat pumps, each requiring 10 gpm at 20 psi.
    domestic water requiring 10 gpm at 60 psi.
    heat pumps run about 4000 hours/year each.
    mix of when one vs two heat pumps running - estimated at 4000 hours - single HP running, 2000 hours both running.
    single well with submersible pump
    100' water level in the well
     
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