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Where's my steam traps??...and other questions

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trivetman
trivetman Member Posts: 180
Hi all -

I'm a new owner of a 1912 build stone colonial with two pipe steam heat. The system is working well enough for now but it looks like we'll need to do some work soon so I'm trying to do as much research as I can. This site seems full of answers.

The system makes a fair amount of noise. Nothing that wakes us up at night but enough to try to make some improvements. Here's some things which I've gathered are probably contributing to the noise.

1) The risers are short - turning 90 degrees just above the boiler.
2) It looks like there are no steam traps. The returns are all piped directly into the radiator.
3) The main is probably not insulated well. The entire steam main is wrapped in duct tape over insulation (fiberglass I think).

Pics of everything attached.

We'll need a new boiler within a couple years as the current one (1980's install Peerless 400K BTU) shows signs of corrosion underneath but it has some life left in it. The near boiler piping will be fixed when the new boiler comes in. The steam traps and insulation are what I am wondering if I should do something about now. The more I read about steam systems, the more I realize that actions are full of unintended consequences. So in the interest of not having that happen...

1) Is it possible this system was intentionally designed without steam traps and should not have them? Or is that elbow on the radiator more than meets the eye?
2) Is there any reason not to improve the insulation on the steam main, or is it possible this duct tape/fiberglass job is doing an adequate job. The basement has been the warmest place in the house through December (no radiators down there) and the main is warm/hot to the touch through the insulation, so I think there's got to be room for improvement.

It seems like handling the insulation is a job a homeowner could DIY. What's the proper material to use and can a homeowner get access to it? I am guessing there's a better make out there than the foam jobs for water lines which I would pick up at Home Depot.

Thanks a lot in advance. Love the info I've gathered on this site.

-TM

Comments

  • JUGHNE
    JUGHNE Member Posts: 11,102
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    Do the rad return drop down to a wet return at the basement floor. I did not see any air vents on the rads so they may just go to a dry return.

    Either the steam inlet valves or the return ells may have some form of limiting orifice. If in the valve, it could be a cup orifice installed in the union of the valve/spud.

    What pressure does your boiler run at?
    What do you have for air vents in the basement?

    That looks to be a lot of boiler, do you have a large house?
    You need to do an EDR survey as it seems that might be an oversized boiler.

    Use only good grade fiberglass for steam, foam will melt.
    Usually is 1" thick though some go 2" thick.
    Your insulation looks compacted to the point where it has little R-value. Before insulating you want to install good pipe hangers as the original ones were often barely adequate.
    Also check the slope as you install hangers.
    Then you could insulate.
  • Jamie Hall
    Jamie Hall Member Posts: 23,635
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    It's quite possible that the system was built without traps. You can do that if, as @JUGHNE says, there are orifices either at the inlet or the outlet of the radiators -- and the pressure is kept low enough. On the other hand, there may be more than meets the eye in those innocent looking outlet elbows. Either way, a close up of both a typical valve and a typical outlet elbow would be helpful.

    Also, as he said, where do the outlets go? If this was built without vents and traps, it's almost a given that they go into dry return pipes in the basement, which in turn go back to the boiler and drop into it. If this is the case, there should be a vent or vents on the dry return(s) just before they drop to go into the boiler.

    So -- his questions need answers!

    And I agree -- I don't think much of the existing insulation -- but replacing it, while it will be a bit messy, is very much a do it yourself proposition.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,827
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    Need pictures of radiator piping and steam piping in the basement. I agree with @jughne. Probably some type of orifice or vapor system without steam traps
  • Alan Welch
    Alan Welch Member Posts: 270
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    You may find the duct tape is covering asbestos. It encapsulates it so it doesn't become airborne.
  • JUGHNE
    JUGHNE Member Posts: 11,102
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    Good point, the older pipes look to be thick enough to contain the 1" asbestos wrapped in duct tape.
    At the boiler the "newer piping" looks wrapped in fiberglass wrap and then wrapped with duct tape.

    So homeowner beware!!
  • Fred
    Fred Member Posts: 8,542
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    Better pictures of the piping above that boiler would help too. Is this a counter flow system? Aside from that one, fairly small pipe, that drops into the bottom of the boiler, I don't see and other returns or an equalizer or Hartford loop. I don't even see a water supply to add water to the boiler. A lot missing in the current set of pictures.
  • Steamhead
    Steamhead Member Posts: 16,996
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    It's probably some sort of orifice system, where the original radiator valves restricted the amount of steam that could enter the radiators. This kept steam from reaching the dry (overhead) return lines. The valves in the pics are newer ones without this feature. If steam gets into the returns, they'll probably bang.

    Are there any original radiator valves left? If so, let's have a look at them. Try to capture any name or trademark you find on them as this will help ID the system.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Waterbury Steam
    Waterbury Steam Member Posts: 58
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    Some of my radiators are piped like this. Looks like they don’t have traps until you look in the basement. The traps are on the radiator return just before they join the main dry return. Not sure why this was done. Might be worth checking your basement for traps.
    RomanGK_26986764589
  • trivetman
    trivetman Member Posts: 180
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    Thanks for all the feedback. Yes it is a very big house. 5000 sq ft over 3 floors. Total of 20 radiators - most of them quite a bit larger than the two I posted in pictures. We did get a quote for a replacement boiler and he recommended a boiler of similar size (400K BTU). The HVAC guy I am talking to seems to be doing things mostly right according to what I read on this site. For instance he did base the replacement boiler size on measuring all the radiators and not on a Heat Loss calc. He is also familiar with Dan Holohan's works. But he doesn't know why I don't have steam traps. Also - I've only talked to the company's sales rep at this point and real expertise I am sure is with the guys doing the work.

    The system is set to not exceed 0.5 PSI although I haven't actually monitored the pressure gauge when it's been on.

    The inlet valves I've seen are all the same. I would assume they are not original to the house as they seem a little too shiny and new. I'll take another look under all the radiator covers for any which seem older or different.

    The point where the radiator meet the dry returns appears to me to be a simple joint. No trap there.

    Good point about Asbestos. I am fairly confident it is mostly fiberglass under the tape. The duct tape isn't fresh, but it doesn't seem 40+ years old. Also I did ask that question of the inspector when we purchased the house and he pointed to some sections where material he identified as fiberglass was poking out of the tape. Of course that doesn't mean some old asbestos was fully cleaned out whenever it was replaced years ago.

    I made a diagram of the piping (just when I thought MS Powerpoint was completely useless) and took more pictures including:
    1)boiler supply piping and controls
    2) return piping
    3) close up of valves and elbows
    4) vents
    5) where radiator meets dry deturn .

    If anything else is helpful let me know.
  • trivetman
    trivetman Member Posts: 180
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    One last pic based on comments above. Piping above boiler
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    edited December 2017
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    This type of system must operate with very low pressure-less than could blow up a birthday party balloon!
    You need a low pressure gauge, (valworx.com 0-3 psi). Then you can see the pressure of the system, and it should not exceed 6 ounces per square inch. A regular pressuretrol such as is supplied with most boilers out of the box may not keep the pressure down low enough, necessitating the installation of a vaporstat.
    The boiler piping with the supplies Siamesed together will blow too much water up into the system, and should eventually be changed.
    For the moment, keep the pressure as low as possible, and increase your main venting with at least double what you have, maybe using the bigmouth vents we all love here, although as Steamhead says, they have no float to control against excessive water in the returns blowing out.
    You can tell when you have enough main venting by the readings of backpressure on the gauge, and it should be in the very low ounces-maybe 2-3–NBC
  • Steamhead
    Steamhead Member Posts: 16,996
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    You definitely need more main venting. Measure the length and diameter (outside diameter of the insulation is fine, don't disturb it) and post the results here. We can tell you what you need.

    For the vent on the dry return, use a Gorton #2, or two if need be. It has a float which will close against rising water whereas the Big Mouth does not. In this type of system, if the boiler pressure gets too high, water can back up into the dry return and will flow out of a vent that has no float to stop it.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • trivetman
    trivetman Member Posts: 180
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    I think you wanted me to measure the steam mains. They run in a perimeter around the basement. 63 feet on one side between the boiler and where it joins the wet return. 90 feet on the other for 153 feet total. I am only measuring the perimeter of the main and not including the length of any pipes branching up into the house, of which there are many.

    Outside diameter of the insulation on the steam main is 3.5 inches. There is a break in the insulation where it goes through a wall and I can see the pipe which looks like it is 2.5 inches outside diameter.

    So, the conversation changed pretty quickly from me asking about steam traps and insulation to hearing concern about the venting and that this system runs on unusually low pressure.
    What did you see that is unusual and does it explain why I don't have steam traps?
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,827
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    So you got 2" pipe for the mains. You have some type of orifice system. If you vent it right, keep the pressure low you won't need steam traps.

    Keep in mind this system was originally designed for a coal boiler=constant firing and =low pressure. To make it work well on oil or gas may take a little work and a few modifications....like adding venting but it can be made to work well
  • Steamhead
    Steamhead Member Posts: 16,996
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    Not so unusual, but now that we know the design of the system, we're getting into how it works without steam traps. For a system of this type to run well, you need to keep the pressure very low, and steam won't distribute well at these pressures unless there is enough venting. And if the pipes are not insulated, they will lose a lot of heat. That's why we make such a big deal out of this.

    How much height is available above the tees for the existing vents?

    Also, at Main Vent #1 it looks like the pipe coming out of the tee and going to the return is smaller than the steam main. Can you verify this?

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • trivetman
    trivetman Member Posts: 180
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    Above where the dry returns meet there is 10 inches space before the ceiling.
    Above the wet returns at the T one has 7.5 inches (the one which currently has two vents). The other T has 12.5 inches to the ceiling, but there is a water line 7.5 inches above which may be in the way of something being installed.

    The pipes coming out of both Main Vents joining to the wet return are I believe 1 inch copper pipe (around 1.2 inch outside diameter. The entire wet return is also 1 inch copper pipe until just before it meets back up with the boiler. Picture of where it joins back up attached.

    I did take a look at the pressure gage a couple times. At one point during operation the gage read 1 PSI. At another point I looked the boiler was not running but the pressure gage read 2.5 PSI. I assume in this case the boiler had shut off recently. Does the pressure typically keep increasing after shutoff as a result of carry-over? The pressuretrol is set to the lowest point at 0.5 PSI.

  • Jamie Hall
    Jamie Hall Member Posts: 23,635
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    That space above where the dry returns meet sounds like a good place for some venting. In a system like yours, it is essential that the dry returns be thoroughly vented, as vents on the dry returns are the only way that air pushed out of the radiators can escape. Poor venting = poor heating.

    I suspect the pressure gauge of lying. They do. See if you can get hold of a 0 to 3 psi gauge -- Valworks has them -- and add it to your system.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • MikeJ
    MikeJ Member Posts: 103
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    If your replacing boiler, and if you can get to all the radiators. Switch it over to hot water run pex tubing to each radiator.
    This way each radiator can be zone, have multi temp threw out the house. System would be quiet, efficient and comfortable. :)
    SteamheadMilanD1Matthias
  • Steamhead
    Steamhead Member Posts: 16,996
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    Nope. There are several problems with this:

    1- A hot-water radiator only gives off 2/3 the heat of the same size steam radiator. This means the house won't heat well, and also means that a condensing boiler won't condense much of the time- bye-bye 90%+ efficiency claims;

    2- Hot-water runs at over 10 times the pressure of steam. This will do a good job of causing leaks if the existing radiators have any weak points;

    3- The return lines in this type of system are often too small to work with hot-water. So these at least would have to be repiped.

    It's too risky and there are no real benefits. Keep the steam.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    RomanGK_26986764589MilanD
  • Jamie Hall
    Jamie Hall Member Posts: 23,635
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    Never mind the ridiculous expense of the conversion...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    CanuckerRomanGK_26986764589MilanD
  • trivetman
    trivetman Member Posts: 180
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    I thought about hot water conversion and pretty quickly ruled it out thinking about higher pressure water leaking through old steam pipes through three floors of plaster. Never really got to the question of how well the system would work if it didn’t leak.

    So forget about hot water conversion. Ive heard a couple things I should do. 1) replace my existing vents presumably with something bigger. Steamhead said maybe a Gorton #2 where the dry vents come together. 2) Install a 3 PSI gauge so its easier to diagnose some issues. Anything else? Do both off the bat or install the gauge first to better diagnose the system?

    Seems I can do this myself if its as easy as removing the old vent and gauge and putting in the new pieces. Any reason it might be trickier? Can I expect screw threads to be compatible? Does the low pressure gauge need any protection against pressures getting too high?
  • trivetman
    trivetman Member Posts: 180
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    And does the low pressure gauge replace the existing gauge or need to be installed alongside it?
  • Leon82
    Leon82 Member Posts: 684
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    The pipe threads will be the same, though there may be a reducing bushing in there as well
  • Jamie Hall
    Jamie Hall Member Posts: 23,635
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    trivetman said:

    And does the low pressure gauge replace the existing gauge or need to be installed alongside it?

    Needs to go alongside it -- a T, couple of nipples, couple of elbows -- 10 minutes.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • trivetman
    trivetman Member Posts: 180
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    All right. Looks like I got a project to take care of after Christmas. Thanks a lot for the advice!
  • trivetman
    trivetman Member Posts: 180
    edited January 2018
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    Hi all. Did you miss me? I know you've just been waiting to see my next steps...

    The way we left this....I've got a two pipe system with no apparent steam traps on the radiators. The system has run well enough through the winter (i.e. I'm not freezing) but it does makes some noise which I'd love to get rid of. You all told me to get a 0-3 psi gauge to see better how it is running and then probably install some more venting on the dry returns. Lots of pictures are earlier in this post for you to catch up on the details!

    So I got the low pressure gauge and sat in the basement through a couple of heating cycles. The system runs at a consistent 0.5 psi for about 25 minutes. After 25 minutes the vent on the dry returns (Hoffman #75) closes up. The pressure rises over the next few minutes to 2.5 psi at which point the pressuretrol shuts it down. If the thermostat is still calling for heat it starts back up in a few minutes after the pressure drops, but reaches the 2.5 psi mark again quickly. I think this is what's called a short cycle and is generally not what you want.

    So what's going on here? Does the vent on the dry returns closing up indicate that I have steam in the returns? Do you still think I need more venting (Gorton #2?) on the dry return in place of the Hoffman? It ran at 0.5 psi until the vent closed up. Is that low enough pressure??
  • trivetman
    trivetman Member Posts: 180
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    ?
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,827
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    25 min is a little long but the fact that the pressure doesn't build quickly is a good sign. I would add more venting. You wan't to move the steam in the mains as quickly as possible. 2 1/2 psi isn't awful but you might lower that a little.

    Short cycling is frowned upon, but an occasional short cycle like 2 /hour isn't objectional
  • trivetman
    trivetman Member Posts: 180
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    More venting at the end of the mains or the dry return (or both)?
  • Jamie Hall
    Jamie Hall Member Posts: 23,635
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    I don't recall your mentioning it, but it is an important question: are there crossover traps from the ends of the steam mains to the corresponding dry returns? They would look like radiator traps, but be piped up from the steam main, then over to the trap and down to the dry return.

    If you have crossover traps, then you do not need -- not want -- vents on the steam mains themselves. That's what the crossover traps are for. If you do not have them, then you do need vents on the mains.

    In either case, you must have adequate venting on the dry returns at the point where they drop down -- usually right near the boiler. That Hoffman 75 is almost certainly not adequate -- you should add a Gorton #2, unless your system is very very large.

    Now. That Gorton #75 on the dry return should, in general, never close. There are certain types of vapour system (notably Hoffman Equipped) where, under certain circumstances, it will close -- but in general it should never close. The most likely cause for it closing is that somewhere in the system there is a steam trap which has failed open. This needs to be found and fixed. Both of the major exceptions to that have to do with the pressure being much too high; if the system still has the vapour steam equipment, then you need to run a cutoff pressure of no more than 8 to 12 ounces per square inch -- possibly less -- with a cutin of no more than 3 to 4 ounces. In any case, your cutout pressure for a system of that type should certainly be less than 1.5 psi and better around 1 psi -- which means a vapourstat.

    You mention that the system runs at about 0.5 psi for about 25 minutes. Good, but a little high; the extra dry return vent may help that. That plateau, though, also indicates where the system is balanced to run -- and all the more reason to set the cutoff at less than 1 psi (but perhaps more than 0.5 -- say around 12 ounces).

    When you reach cutoff, start timing the cycle -- so many seconds before it cuts back in, then so many seconds until it cuts out again. Do this after you get the vapourstat. The ratio of off time to total cycle time is a very good indication of how much too big, if at all, your boiler is in relation to the system demand.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • trivetman
    trivetman Member Posts: 180
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    No on the crossover traps. I do have vents on the steam mains. I don't have steam traps on any of the radiators, which was one of my original questions in this post. Sounds like it was designed to be an orifice system, though we don't know whether the orifices are still in place. My thought was also that the vent on the dry returns is closing up when the radiators have filled and steam is going through to the return pipe. But given that there are no traps, I'm not sure if there is a solution.

    Sounds like more venting in all areas is called for. Most radiators are heating up fully but not all. A couple of radiators on the third floor furthest from the boiler only get about halfway hot by the time the pressure starts to build. My thought is that some extra venting on the mains will hopefully even that out. And from what I am hearing putting the Gorton #2 on the dry returns will help as well.

  • Jamie Hall
    Jamie Hall Member Posts: 23,635
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    OK. Probably orifices -- and with any kind of luck, they are still there. All the more reason to keep that pressure down. Orifice systems are dismayingly sensitive to pressure. It is quite possible that your thought about the trap closing when steam makes it past the radiators is quite correct.

    Now. Suppose that the orifices have been removed from some -- or even a large number -- of the radiators. Is there a solution? Yes there is, and it may well help those two radiators which don't heat all the way. But it will require some patience. You can use the inlet valves on the radiators as throttles. What you want to do is to close the valve on each radiator to the point where each one gets hot almost all the way across and down to the outlet. Almost. But not quite. Mark that location on the valve; you can go below that, if some room or other is overenthusiastic -- but not above it. That point is the point at which exactly the same amount of steam is getting into the radiator as it can condense. If there are no orifices in some of the radiators, you may find that the valve will be quite nearly closed -- particularly on smaller radiators -- but if the radiator is hot across and almost down to the bottom, that's all it will ever put out anyway.

    This is very pressure sensitive! Given your system pressure -- and put in that Gorton #2 on the dry return before you start playing; the vents on the mains will speed things up, but not change the plateau pressure which is where you want to be working -- and then make sure that the boiler doesn't go over twice that plateau pressure, and preferably not over 1.5 times the plateau.

    Have fun!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • trivetman
    trivetman Member Posts: 180
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    Any ideas about specific vents I should add to the mains? I currently have a Dole #5 on one and two Gorton #1 on the other.
  • Steamhead
    Steamhead Member Posts: 16,996
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    How long are the mains, and what pipe size?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Steamhead
    Steamhead Member Posts: 16,996
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    How long are the mains, and what pipe size?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • trivetman
    trivetman Member Posts: 180
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    2 inch diameter mains. The one with 2 Gorton #1's is 63 feet long. The one with the Dole #5 is 90 feet.
  • Steamhead
    Steamhead Member Posts: 16,996
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    I'd put a Gorton #2 on the shorter main. Keep the two #1s and put them on the longer main together with a Gorton #2. See how that does, then make adjustments as needed.

    The Dole #5 is little more than decoration on mains that long.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • trivetman
    trivetman Member Posts: 180
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    I have very limited space between the pipe and ceiling on the short main. How many gorton #1’s or something of similar size?

    I also have available the hoffman #75 i am removing from the dry return, but only on the longer main
  • Steamhead
    Steamhead Member Posts: 16,996
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    Four Gorton #1 vents equal one #2.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • trivetman
    trivetman Member Posts: 180
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    Thanks all.