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The "equalizer" is mis-named. It does nothing to equalize anything.

ethicalpaul
ethicalpaul Member Posts: 5,695
The industry and Dan (who I respect and admire) say that the "equalizer" serves to equalize the pressure between the boiler and the condensate-return inlet. See this from https://www.pmmag.com/articles/96529-top-10-facts-about-the-harford-loop (my emphasis):

1. A Hartford Loop is an arrangement of piping between a steam boiler’s header and its gravity-return piping. The end of the header drops vertically below the boiler’s water line and connects into the bottom of the boiler. We call this pipe the “equalizer” because it balances the pressure between the boiler’s steam outlet and condensate-return inlet.

The “wet” gravity return line, which returns the condensate from the system, rises up from the floor to join with the equalizer at a point about 2 in. below the boiler’s lowest operating waterline.

2. The Dead Men didn’t always use this piping arrangement. They used to bring the return directly back into the bottom of the boiler without the benefit of either a Hartford Loop or an equalizer. When they piped a boiler this way, however, the slightest steam pressure would push water out of the boiler and into the return. They solved this problem by using a check valve in the wet return (that’s the pipe below the boiler waterline).

Before long, though, they found the check valve would fill with sediment and get stuck open. That caused the water to back out of the boiler again, so they developed the equalizer pipe to replace the check valve. Whatever pressure appears inside the boiler will appear inside the equalizer pipe — if you size the pipe properly. The two forces balance each other and the water stays in the boiler.


But for a couple years I have really struggled to understand exactly what it is doing. I couldn't picture how the equalizer actually changed anything.

My proposal here is that it does absolutely nothing to equalize anything. It does do an admirable job of letting water escape the header to improve water-steam separation, but that's it. I believe that regarding pressure, having an equalizer is no different from not having one.

See my drawing from a recent discussion I posted:

https://us.v-cdn.net/cdn-cgi/image/fit=scale-down,width=1600/https://us.v-cdn.net/5021738/uploads/editor/ns/bjsfnpjxq2gk.png

In this drawing you can see the pressure at the boiler, AND at the condensation inlet is the same (if you disagree with this I would welcome to hear your thinking). So what exactly did the "equalizer" accomplish here? What else would the pressure be here, "equalizer" or not?

Now look at this drawing below showing no equalizer with the same pressures in all the same places. Do you see any flaw in this drawing? So what does the equalizer do again?



So a question: "If the 'equalizer' isn't doing anything, then why isn't the water level at the start of the wet return rising up to the main and shooting out of the main vent?"

The answer is: Because the true "equalizer" is in fact the main! It is what transmits the steam chamber's pressure to the far end of the wet return. That pressure is somewhat reduced of course by the flow of steam to the radiators, and that's why the water level at the end of the wet return rises a little, but not a lot.

Let me know if you see any errors in my thinking here, and thanks everyone (especially Dan) for teaching me about residential steam!
NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
Mad Dog_2
«13

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,160
    Well, yes and no.

    First, let's consider ONLY the steam mains in a one pipe steam system and, if it is a parallel flow system as you have drawn, the drip to the wet return at the end. In that piping, you are actually correct -- the equalizer serves to ensure that the total head at the boiler end of the wet return will be the same as the pressure in the boiler, thus allowing water to pass from the wet return through the Hartford Loop into the boiler.

    Since the flow rate in the wet return is very small -- and assuming it isn't plugged with gunk! -- the total head at the other end of the wet return, at the drip, will be the same. Water will stand in the drip at the same elevation as that in the boiler, plus a little more to account for the pressure drop in the steam main -- which isn't much, but needs to be remembered.

    Now however let us consider the situation in a two pipe system. There you have a steam main, usually with a drip at the end to a wet return -- but you also have a dry return which accepts the condensate from the radiation and the air from the radiation and, often from the steam maiins. That dry return is not subject to steam pressure anywhere -- it is at, or very very close to, atmospheric pressure. It, too, is connected to the wet return with drips as needed. Again, the equalizer ensures that the pressure in the wet return is the same as the pressure in the boiler, As in the one pipe case, this ensures that the water in the wet return can get into the Hartford Lopp and on into the boiler. The water in the dry return drips must stand high enough above the boiler water line to balance that pressure.

    Is the equalizer strictly necessary? No, although it does serve an additional and vital purpose in allowing any water separated in the header to return immediately to the boiler, rather than getting carried into the steam mains. It also ensures that the pressure in the header and at the Hartford Loop is the same as the pressure in the boiler -- it might seem that it always would be, and certainly will be in most installations anyway, though.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • The Steam Whisperer
    The Steam Whisperer Member Posts: 1,215
    The equalizer works as a team with the Hartford loop. Without it, there is less pressure at the return pipe into the boiler than in the boiler, so water can back up and then over the Hartford loop. The steam header pressure pushes down on the return pipe into the boiler ensuring water doesn't back out and over into the wet returns. This helps prevent the boiler water from backing out over the loop into the wet return if there is a large leak in the wet return.
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    STEVEusaPAMad Dog_2SuperTechHot_n_Cold
  • 109A_5
    109A_5 Member Posts: 1,377
    Hello @ethicalpaul,
    I think you will find with the Equalizer included the predominant force affecting the water's level (or differential level) at points A, B and C is no longer the system pressure but just gravity. Since the pressure is almost equal at all three points. The Equalizer decouples two different sections of the system, the Boiler and the Wet Return.

    Without the Equalizer the pressure at point A will raise the water level at point C 27.68 inches per pound. The air and Steam will compress the water will not. If the water level of the Dimension "A" does not exceed the pressure by a tiny amount the condensate won't go back into the boiler.

    Refer to "The Lost Art of Steam Heating Revisited" Page 104
    "It also makes Dimension "A" independent of the boiler's pressure"






    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    Mad Dog_2ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited March 2023
    I'm seeing several different ideas about what the "equalizer" does regarding pressure, and that doesn't surprise me, since it doesn't actually do anything, people are going to have different imaginary ideas about it! I will try to address these, but Jamie started off things difficult by both saying I'm right and wrong and bringing up two pipe boilers which isn't going to help me address the issues plainly, but I will try, with respect and thanks to all respondents!! :sweat_smile:

    the equalizer serves to ensure that the total head at the boiler end of the wet return will be the same as the pressure in the boiler, thus allowing water to pass from the wet return through the Hartford Loop into the boiler.


    My drawings (which I haven't heard complaints about) show that the PSI is the same in the boiler, and at the boiler end of the wet return regardless of the existence of the "equalizer". Please explain that.

    Again, the equalizer ensures that the pressure in the wet return is the same as the pressure in the boiler, As in the one pipe case, this ensures that the water in the wet return can get into the Hartford Lopp and on into the boiler.


    The pressure is the same even if there is no "equalizer". The "equalizer" is doing nothing to the pressure. We all have seen boilers without it, and somehow the water gets back into the boiler. This is because the main delivers close to the boiler psi to the start of the wet return. It's a little less which lets the water level be higher there, as in my drawing.

    To @The Steam Whisperer

    The equalizer works as a team with the Hartford loop. Without it, there is less pressure at the return pipe into the boiler than in the boiler, so water can back up and then over the Hartford loop.


    With or without it, the boiler pressure is present at the return pipe into the boiler. Look at my second drawing in my original post. Is there anything wrong about it? The "equalizer" is just another path that delivers the same pressure. It changes nothing. No?

    To @109A_5

    The Equalizer decouples two different sections of the system, the Boiler and the Wet Return.

    Without the Equalizer the pressure at point A will raise the water level at point C 27.68 inches per pound.


    The "equalizer" does not decouple anything. In all my drawings, the pressure at the boiler and at the wet return's entry to the boiler are always the same, "equalizer" or no. Tell me where those drawings are wrong, and then tell me again what the "equalizer" is supposedly doing, thanks!

    With or without the "equalizer", the pressure (edit: I meant "water level"!!) at the far end of the wet return will raise, marked as C in your drawing, this is absolutely correct. But it will raise according to the pressure differential between the boiler, and the end of the main. Do you agree? In both of our drawings the boiler's pressure is delivered to your point C with the pressure drop of the radiators providing that differential and that water level rise. It's not very much, and soon I will measure it.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • 109A_5
    109A_5 Member Posts: 1,377
    Well... I guess you can believe anything you want. And ignore what you choose.
    de·cou·ple - separate, disengage, or dissociate (something) from something else
    It decouples the boiler's ability to push water back out into the wet return, regardless of the pressure.

    I said "The air and Steam will compress the water will not." (significant water level difference without an equalizer)

    And "Since the pressure is almost equal at all three points." (with the Equalizer)

    And Refer to "The Lost Art of Steam Heating Revisited" Page 104
    "It also makes Dimension "A" independent of the boiler's pressure"

    The Equalizer has a significant purpose besides a header drain. Maybe you should think it as 'equalizing' the water level across the wet part of the system and not think of it as a 'pressure equalizer'.


    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    Mad Dog_2
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited March 2023
    We are all free to believe anything! But I have shown that the pressure is the same at the boiler and at the wet return's entry to the boiler both with and without an "equalizer". Please tell me what you think the pressures are in those locations without an "equalizer" as shown in my second drawing.

    (in fact, the "equalizer" is just presenting the exact same pressure to the exact same points. How does delivering 5psi from the boiler to the wet return differ from the wet return connection itself giving that same delivery?)

    Page 104 is incorrect. The "bleeder" is delivering the exact same pressure that already exists in its two connection points. It is imaginary.

    The book says "Now when the steam pressure in the boiler tries to push the water out, there's an equally powerful force pushing it back in". This is wrong, sorry. The force is equal, for sure, but it isn't pushing in. It's pushing both in and out equally, at the same pressure that is already there.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    Mad Dog_2
  • Matt_67
    Matt_67 Member Posts: 284
    If you imagine the water in the boiler as a piston it makes total sense.  With the equalizer the exact same pressure is on both sides of the piston.  Without the equalizer one side of the piston has 5 psi and the other has less than 5 psi, just as you acknowledge in the drawing.  Physics says the water level must go down.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited March 2023

    @ethicalpaul in your diagram, which I have robbed to create an older system, before the Hartford loop was introduced, that may have looked like this. The way it was explained to me, back in 1974 by Mr. Spence, who was in his late 60s at the time, (he qualifies as one of the dead men) that the <5 PSI that you have provided in your drawing can only be 4 PSI or it can also be 3 PSI requiring a greater dimension "A". Some designers operated their boilers well over 5 PSI back then. This would create the potential for a 3 or 4 or even 5 PSI difference in the steam pressure at the far end where the column of water at the other end might be 9 feet.. That much pressure difference could lead to catastrophic boiler failure about 2 to 3 times a week.

    As each design change was introduced over those early years, the good ideas stuck and the bad ideas were abandoned. Today in YOUR boiler, you have the benefit of all those dead men designs. And since YOUR boiler operates at less than 2 PSI, YOU actually do NOT need the "Equalizer" in order to ensure the boiler pressure is "Equal" at both the supply and the return. That is what the "Equalizer" does. It makes the pressure at the supply and the return "Equal". Has nothing to do with the other end of the main where the pressure at the end is lower.

    But as I said, YOUR boiler does NOT need the equalizer... Until there is a malfunction and then it DOES need the equalizer. These design changes over the years have nothing to do with NORMAL operation. They were implemented to combat the times when NORMAL operation was somehow interrupted due to a blockage, malfunction, or operator error that caused a catastrophic failure. Since YOUR boiler will always be maintained by a competent person, You also do not need a low water cut off, or a safety limit, or even a water feeder. The relief pop off valve is unnecessary. YOU will never let the pressure go that high. Those features are for the rest of us that might do service on boilers that are not in our own homes. Remember those homeowners don't have Glass Pipe in order to look at the steam on their boilers.

    So the Equalizer is called the Equalizer because it ensures that the boiler supply pressure and the boiler return pressure IS Equal.

    Does that make sense Paul?

    Mr. Ed

    PS. I think your glass pipes are cool! Well actually they are pretty Hot Stuff to be literal.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    ethicalpaulttekushan_3SuperTechjohnshanahan
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    Thanks Ed! Let's say this pipe friction could possibly be high enough to noticeably change the pressure at the end of the main (I am skeptical but I'll set that aside). We both agree that the pressure is less at the end of the main than at the boiler I think.

    How does the equalizer change the fact that x pressure is at the boiler and (x - pipe friction) is at the end of the main?

    Do you see a flaw in either of my drawings and their pressures?
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    Mad Dog_2
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    @ethicalpaul So the Equalizer is called the Equalizer because it ensures that the boiler supply pressure and the boiler return pressure IS Equal. Has nothing to do with the other end of the main where the pressure at the end is lower.

    As the steam pressure pushes down on the water in the boiler, that water will try to exit out the return. by connecting a pipe to the return from the steam main header (called the Equalizer) that downward steam pressure will act equally on the top of the boiler (Supply) and the bottom of the boiler (Return) equally. otherwise the Equalization will happen at the farther end of the main.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    johnshanahan
  • JohnNY
    JohnNY Member Posts: 3,226
    Has the Gifford Loop come up in this thread yet? It kind of seems more purposeful to me.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
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    Mad Dog_2ethicalpaul
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited March 2023

    Thanks Ed! Let's say this pipe friction could possibly be high enough to noticeably change the pressure at the end of the main (I am skeptical but I'll set that aside). We both agree that the pressure is less at the end of the main than at the boiler I think.

    Your boiler as a reference... I would also be skeptical. But if Your boiler operated at 5 times the pressure. Let's say that the friction loss would be linear. (Although I believe the faster steam velocity might act differently) The 2 PSI max would now be 10 PSI max. The pressure drop might be .5 PSI would grow to 2.5 PSI. That pressure difference would make the column of water at the other end almost 6 feet. Now look at your steam main that goes thru the basement. Is it less than 6 feet from the water line? Would that main pipe then fill up with water if the boiler steam pressure pushed the water out of the bottom? Is there enough water volume in your main pipes to hold 2 gallons of water? Would 2 gallons of water leaving your boiler make the water level drop below the water line?

    Why would all this happen to you? After you're Publishers Clearing House vacation or you were hospitalized for some unknown occurrence or disease, all of your radiator vents and main vents were to clog, and the LWCO were to fail to shut off the burner, so the water feed would not know to let more water in. You might come home to a cracked boiler.

    With an equalizer, you would have more time to come home to repair all those malfunctions. On St. Patrick's Day, everyone should realize that Murphy's law still exists. So the one time where you were unable to look at those glass pipes of yours, is the same day that all other problems were to happen.


    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited March 2023
    JohnNY said:

    Has the Gifford Loop come up in this thread yet? It kind of seems more purposeful to me.

    Wasn't Gifford a Half Back for the NY Giants? I didn't know there was a famous football play called the Gifford loop!
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    Mad Dog_2ttekushan_3
  • ChrisJ
    ChrisJ Member Posts: 15,583
    Isn't the return side of the boiler the same pressure as the supply by nature?  
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    ethicalpaul
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    ChrisJ said:

    Isn't the return side of the boiler the same pressure as the supply by nature?  

    Yes. look at my diagram a few comments back. It shows the lower water line and the higher dimension "A" that causes the boiler failure that the Equalizer and Hartford Loop fixes. The steam pressure can not force the return water out because the pressure on the return side is not offset by the Dimension "A" pressure at the far end of the system. The Pressure is equalized locally at the boiler.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • ChrisJ
    ChrisJ Member Posts: 15,583
    Isn't the return side of the boiler the same pressure as the supply by nature?  
    Yes. look at my diagram a few comments back. It shows the lower water line and the higher dimension "A" that causes the boiler failure that the Equalizer and Hartford Loop fixes. The steam pressure can not force the return water out because the pressure on the return side is not offset by the Dimension "A" pressure at the far end of the system. The Pressure is equalized locally at the boiler.
    What stops the higher pressure from the return from just pushing out to the wet return?

    A pipe coming down from the top into a tee that's wide open certainly isn't going to.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    ethicalpaul
  • The Steam Whisperer
    The Steam Whisperer Member Posts: 1,215
    I agree that the equalizer doesn't do much ( if anything) during normal boiler operation in typical systems. It's when the wet return breaks open that its function of helping hold water into the boiler at the return connection comes into play. Take your second diagram and break the wet return so the water and dry return steam pressure spews out. Now that wet return is only say 2 psi, so without the equalizer, the water in the boiler will just go over the hump and out the leak.
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  • ChrisJ
    ChrisJ Member Posts: 15,583
    I agree that the equalizer doesn't do much ( if anything) during normal boiler operation in typical systems. It's when the wet return breaks open that its function of helping hold water into the boiler at the return connection comes into play. Take your second diagram and break the wet return so the water and dry return steam pressure spews out. Now that wet return is only say 2 psi, so without the equalizer, the water in the boiler will just go over the hump and out the leak.
    But how is steam keeping the water from spilling over the hump if the hump is wide open to atmosphere?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    edited March 2023
    ChrisJ said:


    But how is steam keeping the water from spilling over the hump if the hump is wide open to atmosphere?

    Gravity. Water will seek it own level. If you were to take the diagram a step further, and impose the same problem as the one I suggested before: in the top illustration there is normal operation. Middle illustration shows the problem system without the equalizer and the HL. The bottom shows the same problem with the equalizer and the HL. you can see that the 5 PSI pressure will still drive the water up the return, however the equalizer will not allow more water to be forced out the boiler. The over pressure condition may still drive the water up the return into the main, but the boiler will not empty below the HL because the pressure is "EQUALIZED" locally at the boiler return but the actual flow of water out the return is stopped by the Equal pressure at the close nipple on the HL.



    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    clammy
  • neilc
    neilc Member Posts: 2,689
    I'ld say we need the equalizer to drip the header, so keep it, or we're building a wet steam water pump,

    @ethicalpaul
    time to buy more glass pipe and show us right or wrong
    known to beat dead horses
    clammyethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited March 2023
    I have already replied to those points, and I thank you for them, but I would love it if someone would look at my two drawings (one with, one without the "equalizer) in my first post, see that all the pressures near the boiler are the same and tell me what in the heck the "equalizer" is supposedly doing.

    Without it, the pressures are 5psi at and near the boiler. With it, they are 5psi at and near the boiler.

    So what is it doing? Simple question, but no one wants to answer it. Thanks all!

    PS: Ed, you left the main out of your drawings. That is what is equalizing the pressure at the far end.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited March 2023
    neilc said:

    I'ld say we need the equalizer to drip the header, so keep it, or we're building a wet steam water pump,

    @ethicalpaul
    time to buy more glass pipe and show us right or wrong

    I agree it's a good drip for the header, I said that in my first post, thanks! But lots of headers including mine don't get any water in them but it's good for when they do.

    Regardless, "equalizer" is a weird name for something that doesn't equalize anything!
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    Paul, Do you have ancestors from Missouri?

    How easy would it be to install a valve on your equalizer in order to eliminate it during a test of your theory. And I realize I left the main out of the diagrams. I would need a longer illustration in order to keep the main on each of the 3 diagrams. Just assume the mains are the same on all three.


    So I thought the actual diagrams you provided will make it easier top see my point.

    This is the first one marked up when there is an actual problem with the pressure actually getting to 5 PSI (The reason could be a blocked main vent or the boiler is over fired or any other reason). I added some dimensions to make the 3" diameter main able to hold 3 or 4 gallons of water during this high pressure (5 PSI) event, and enough length to cause a substancial pressure drop.

    See how the poorly named Equalizer puts equal pressure on both openings of the boiler, and the close nipple 2" below the water line will stop the syphoning of boiler water over the hump. . And do you understand why YOU don't need the equalizer because you do not make 5 PSI steam. You only need it if there is a series of failures that create a higher than normal pressure in your boiler.

    If you did not have the poorly named Equalizer, then the pressure at the supply and return would also be at 5 PSI but the excess pressure would push the water up and over the hump of the Hartford loop like a syphon, allowing more boiler water to leave the boiler. The balancing point of the lower pressure would happen way out at the end of the main,80 feet away, after the water has already left the boiler.

    So to test this you need to put the valve in your equalizer and operate the boiler with the valve closed for the test. You might need to bypass your pressure control to allow the boiler to get to 5 psi and see if the water level in the sight glass drops lower than usual. If it gets to the bottom of the site glass you will see for your own eyes the benefit of the equalizer. You may also need to put some pressure gauges at different points throughout your system. I believe you will be able to see it on the gauges if you can't see it in your minds eye.

    This is my last attempt to tell you what I see in my minds eye. Good Night Paul.

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    Mad Dog_2ethicalpauldennis53
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    I don't know what I can do except to repeat this simple question. Your modification of my drawing shows all the same pressures, so what is the equalizer supposedly doing?

    Without it, the pressures are 5psi at and near the boiler. With it, they are 5psi at and near the boiler.

    So what is it doing? Simple question, but no one wants to answer it.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    Mad Dog_2
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,713
    How about if we look at the portion of the HL that has a boiler balancer pipe (better name for equalizer) and one without a boiler balancer pipe. since the higher in the column you measure the wqter pressure, the lower the pressure will be, the few inches of elevation above the bottom of the boiler you have illustrated in the HL without the boiler balancer pipe. Since there is no vent at the top of the syphon, the pressure will be slightly lower than the pressure at the bottom of the boiler. This non vented Non-Hartford Loop will just allow the boiler to empty water to the supply main based on the friction pressure drop of the main. When the top of the boiler is connected to the bottom of the boiler with the boiler balancer pipe there is a vent to break the syphon, stopping the water evacuation of the boiler because the steam pressure at the close nipple will be equal to the steam pressure inside the boiler.

    Also if you look closely at the steam main, there is less water backed up at the end of the main, even though the pressures are the same. I did that to illustrate the fact that less water left the boiler.



    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • PMJ
    PMJ Member Posts: 1,265
    edited March 2023
    SInce I don't have an equalizer I have never given it much thought. But I can confirm that at ultra low pressures - where these systems are supposed to be running - one isn't needed for normal operation.

    I agree with @ethicalpaul that there will be a column of water somewhere in the wet return to match the pressure at the boiler whatever it is equalizer or not. The water in that column comes from the boiler and lowers the water line some amount (also equalizer or not) though the volume in say a 2 inch pipe column isn't much.

    @EdTheHeaterMan has suggested then that really the equalizer is a safety device which prevents water from leaving the boiler at la la land kind of pressures so high that the connection just below the water line uncovers and condensate has already pushed passed the A dimension and is filling the dry return. In this rather extreme condition while the equalizer prevents more water from leaving it also prevents it from returning does it not? It seems to me the control should be such that getting this out of focus really isn't possible. But I guess we are agreening then with @ethicalpaul then that in normal operation the equalizer doesn't do anything.

    I will also take the opportunity to suggest all to consider the possible benefit of introducing some timing capabilities to the standard platform. My worst case long burn from dead cold everything to fill level is 25 minutes. I have programmed in a hard game over stop in the PLC for any burn that reaches 30 minutes. If that ever happens I will get a call from my wife that the boiler is off and there is a warning message on the touch screen. My boiler has 33 gallons in it give or take which isn't going to go dry in 30 minutes. To be honest the delay to disaster the Hartford loop or equalizer provides doesn't give me much comfort.
    1926 1000EDR Mouat 2 pipe vapor system,1957 Bryant Boiler 463,000 BTU input, Natural vacuum operation with single solenoid vent, Custom PLC control
    ethicalpaul
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    Surprised Dan hasn't weighed in.
    @ethicalpaul up at 12:30am, then 5:30am, Ed up until 1am. Drawing diagrams, debating...get some sleep.

    BTW, are all these drawings, with all these psi marks, actual readings and/or accurate?
    steve
    Rich_49
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited March 2023
    Hi Steve--

    Don't worry I'm awake at odd hours :sweat_smile:

    No, these weren't read, they are proposed. Do you see anything that could make any of the ones marked "5 psi" not be 5 psi on either drawing? Honestly asking, not provoking :smile:

    I'm working on getting a meter on my far main and a valve on my "equalizer"

    And I believe these values could be any given pressure instead of "5". My proposal is not dependent on ultra low pressures or ultra high pressures. At all pressures, all those indications should hold.

    It is the MAIN that equalizes the pressure at the far end of the wet return. At that far end:

    • At the boiler's water level (the dotted line), the pressure will be nearly identical to the boiler's pressure. It must be.
    • At the actual water level of the wet return drip, the pressure will be nearly identical to the main's pressure measured anywhere after the last radiator runout (as long as the main vent is closed). It must be.

    The difference between those two values (in inches of water column of course) is how much higher the water level in that drip will be compared to the boiler water level. It just can't be anything else--it just goes where the pressure tells it. It's just a manometer.

    And the "equalizer" still isn't doing anything to change any of those values that are marked on either of my two drawings, no one address this question (except now @PMJ!): What is the "equalizer" supposedly doing? Mysterious action at a distance, reaching out through the ether to the far end of the main?

    For @EdTheHeaterMan I want to state if I never have before that I greatly respect you, don't take anything in this or any thread in any other framing than that. But I don't agree with some of your statements here about where the water goes and why. But that's OK, one of us might convince the other after some more thought, or maybe not :smile:

    I think I see an error in your drawing below, but I'm not sure it really affects what I'm trying to say. For your drawing below, I would say that 5psi would be measured at the water line and below the water line would be slightly higher due to the additional weight of the water. But again, I'm not sure it's relevant. Thanks for your continued conversation!




    Thanks @PMJ for your input! Oh and reading back I think that @The Steam Whisperer also agrees that the equalizer does not equalize pressure, but does bring up that it provides some safety in the case of a wet return leak. I am purposely trying to keep the hartford loop out of this discussion for simplicity (I already shared my feelings about that plenty before), but I will say that the equalizer will still push on the water with the same pressure as the steam chamber in the case of a wet return leak, which will not help hold water in the boiler (just like it doesn't help hold water in the boiler during normal operation)
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • neilc
    neilc Member Posts: 2,689
    I wanna see the video with gages hanging at all these therorized pressure points,
    gonna cost more than all the glass pipe,
    #goofing around
    known to beat dead horses
    ethicalpaul
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,506
    @ethicalpaul I'm not worried...well maybe for different reasons.
    I'm just chomping on popcorn, reading along. This is quite interesting. Although if there's an actual conclusion, I'm wondering if it's going to just be a matter of semantics.
    steve
    SuperTechethicalpaul
  • neilc
    neilc Member Posts: 2,689
    I noticed those time stamps also,
    sleep people
    known to beat dead horses
    SuperTechethicalpaul
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,272
    Hi, FIY, "Semantics began its life in the late 19th century as a technical word in the field of semiotics, referring to such topics as the relation between signs and the things to which they refer." I've been wondering as @STEVEusaPA pointed out, if this discussion is largely about semantics. What does the equalizer equalize? Would the problem be solved by renaming it "safety pipe configuration? All things being equal, that might be a nice approach we could all be happy with, though the history and story of why it's called an equalizer might be interesting! o:)

    Yours, Larry
    STEVEusaPAEdTheHeaterManSuperTech
  • neilc
    neilc Member Posts: 2,689
    edited March 2023
    yeah,
    but,
    and,
    equalizer is SOOOO easy to say
    known to beat dead horses
    dennis53
  • neilc
    neilc Member Posts: 2,689
    "vertical header drip, boiler main and return , , , "
    ah, nevermind
    known to beat dead horses
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    Header Drip or Header Drain

    I don’t think it’s just semantics though. People think it is affecting the pressure of the system
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • neilc
    neilc Member Posts: 2,689
    come on Paul,
    glass pipe and gages galore,
    show the math
    #giggleing
    known to beat dead horses
    EdTheHeaterManethicalpaulRich_49
  • Chris_L
    Chris_L Member Posts: 336
    neilc said:

    come on Paul,
    glass pipe and gages galore,
    show the math
    #giggleing

    Yes, and how about a valve before the "equalizer" so we can see what happens when you remove it from operation. I'd like the to see what happens to the boiler water line on a cold startup with no equalizer.
    ethicalpauljpm659er
  • neilc
    neilc Member Posts: 2,689
    I keep forgetting that valve,
    yes, that valve too
    known to beat dead horses
  • Matt_67
    Matt_67 Member Posts: 284
    @ethicalpaul - Would you agree that the equalizer has a function once the water level is below the weir of the Hartford loop?