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1925 Flame two pipe wet return issue

ccampo00
ccampo00 Member Posts: 7
edited September 27 in THE MAIN WALL
We have an new Weil MacLean Boiler attached to original 1925 two pipe Flame Vacumn system in our historic 1925 3 floor tudor. The return runs from the steam trap back to the boiler and is sloped downward sitting on Iron pegs in the walls. The returns run along inside foundation walls and thru one wall in the middle of the house.

One of the return pipes is leaking on the basement floor. It is directly underneath the metal peg and it seems to have rusted out from inside. 100 year old pipe. Original cast iron or steel.

Should the entire 70 ft length be replaced now due to likely sludge in pipe to improve efficiency of water return to boiler? Does it make sense to epoxy the leak? Replace just one section?

What materials should be used? Will it create an issue going to copper and mixing in with original? Should the bad section just be replaced at the elbows? It maybe has been leaking for a while as there is a water replacement system in the boiler but never this bad. Seems a little difficult to understand as water seems to just keep coming out of the foundation peg/bottom of the pipe, more than the 5-6 gallons that are in the entire boiler system and the boiler is not running. Could it just be leaching thru the wall?

Galvanized? Cast Iron? What to use? How to do it to make sure we don't have noise/water hammer issues. Replace like for like? replace the whole system. Thanks. This is strictly a wet return and there is no steam in the pipe. Just returning condensate from the 17 radiators back into the boiler.

Comments

  • JUGHNE
    JUGHNE Member Posts: 8,680
    To confirm that the pipe is actually leaking, you could fashion a small gutter/trough out of a milk jug and place it between the pipe and peg.

    If the water drains out of the gutter then you know it is the pipe.
    If the peg still drips it is ground water.

    Are you sure this is a wet return....usually the return after a trap is considered a dry return.

    Pictures of the trap and air vents would help.
    Also pictures of the the boiler piping and especially where the return connects to the boiler.
    ccampo00
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 9,678
    If it is a true wet return (all the pipe is below the boiler water line) then I would replace it all. Pipe above the water line usually lasts almost forever below the water line is usually the issue.

    You can use copper with no issues (only use copper below the boiler water line)

    Or you can use steel with either cast iron or malleable iron fittings

    The copper could use press fittings if you have access to a pressing machine or it can be soldered.

    Likewise the steel pipe can use press fittings

    You will know more about the pipes condition when you cut it apart as to how much to replace, I would probably do the whole thing
  • Jamie Hall
    Jamie Hall Member Posts: 16,591
    As the folks above have said or implied -- I'd be almost certain that that's a dry return, and indeed there should be no steam in it. But there will be condensate. And yes, dry returns do eventually decide to leak, or at least some of them do (I've replaced a couple).

    If it were mine to do, I'd probably replace the section which is leaking, like for like (probably black iron). Do NOT use steel pipe. . Easiest way to do that is going to be to take out the section which is leaking -- I'll be there aren't any handy unions, so sawzall time...), put unions on the remaining pipe ends and put the new section in.

    Since it is most likely a dry return, there is no concern about water hammer. It does carry condensate back to the boiler -- but there's very little of that.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Steamhead
    Steamhead Member Posts: 14,760
    edited September 21
    "Flame Vacuum" system? That's a new one on us....... Please, post some pics.

    If the leaky pipe is on the wall below the boiler's water line, it's a wet return.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • mattmia2
    mattmia2 Member Posts: 3,668
    Add some fittings and caps or valves at the ends to flush it out if you replace the whole thing.
  • ccampo00
    ccampo00 Member Posts: 7










  • ccampo00
    ccampo00 Member Posts: 7
    Per those who asked for pictures, it does appear that the condensate pipe is above the boiler water line so it does appear to be a dry return. Including main traps and picture coming out of boiler for those who asked. It is original pipe and you can see how it appears rusted out where it sits on the peg. Whole 21 ft section from corner behind washing machine is bad. Rest is not as bad. Most likely thinking of replacing the whole thing. OD diameter pipe looks to be 2.5 inches. So Confirmation that original 2.5 inch black pipe is the correct replacement or could we do 2 inch? Thanks all for those who took the time to respond. What is typical cost for a 10 ft section of black pipe? Schedule 40 or Schedule 80? This last pipe lasted 100 yrs so thinking we don't need to go galvanized or copper.
  • ccampo00
    ccampo00 Member Posts: 7
    70 total ft of 2.5 inch. The smaller line behind the wooden shelf in the laundry room is 2 inch OD. What would be a reasonable cost to replace. I'm thinking maybe between 7-10$ ft for the pipe. Is this reasonable?
  • ccampo00
    ccampo00 Member Posts: 7
    More information-


    Steam report- This system is heated by a two-pipe steam system which uses cast-iron radiators distributed throughout the three stories of the house. The system is a Trane Vapor/Vacuum system original to the house, which was constructed in the 1920's. The boiler is only a few years old. Two steam mains originate at the boiler room and follow the perimeter of the basement in opposing directions. Dry return mains parallel the steam mains and a wet return follows the perimeter back to the boiler. The steam supply and dry returns each were terminated with vents before dropping to the wet return. The Steam lines are equipped with a float vacuum vent and the dry return with a vacuum quick ventThe piping system appears to be sound and intact. The original magnesia/asbestos pipe insulation is also essentially intact. The two air vents on the steam main and return are original, but the two vents at the terminus of the second set of mains have been removed and the connections plugged. It is unclear whether the original vents are working. There is a Maid-O-Mist vent located at one end of the dry return, but this location is probably not original. It appears to be the only venting available for one half of the system. The boiler is recent and appears to be in good condition, but the installation is not perfect, as the steam, equalizer, and Hartford loop piping are not as recommended by the manufacturer. The pressure switch is a standard Honeywell with a scale ranging between .5 and 9 psi (set to 1.5 psi), and the gauge is a standard 0-30 psi. There is a McDonnell Miller water feeder and a probe-type low water cutoff. There are no reports of consequent problems, although there were reports of possibly high makeup water usage. This may have been temporary and its cause was unclear. One of the radiator valves is original, but the balance are replacements. Many of the traps are original and some are certainly bad, although with the system operating only briefly it was impossible to test them. A radiator on third floor was reported to have stopped working as soon as it received a new trap. A radiator in the first-floor sunroom will not heat, and there are reports of general unevenness in heating throughout the home.The system was designed as a Vacuum-Vapor system, able to operate at pressures from about 8 ounces to well below atmospheric. Its current venting and controls do not allow this.
    AnalysisControls: Although the system is in generally good condition, it has some issues. It's currently impossible to know what the operational pressure range is, due to the current gauge and inappropriate pressure switch. Because the system was built as a vapor/vacuum system, operation within the prescribed pressure range of vacuum to 8 oz.'s necessitates controls and instrumentation appropriate to that range. It will still operate at higher pressures, but with unnecessarily high fuel consumption and greater inefficiency. A lower pressure “Vaporstat” could better control the boiler's positive pressure operation and a new compound gauge monitor it. Vents: Of the two extant original vents, both show evidence of past leakage. At the least, they should be taken down and cleaned. If proper operation cannot be assured, then they would haveto be replaced with new equivalents. The other two vents are missing entirely and need to be replaced. The current Maid-O-Mist (or Gorton) vent can be removed and its connection plugged.Radiators: Most of the radiators have their original Trane traps. Many of them are likely in poor condition, although some may still function passably well despite the fact that they are over 90 years old. In the short term, those known to have failed should be rebuilt. As part of a long-term renovation plan, eventually they should all be rebuilt. Modifications: The radiator in the sunroom most likely doesn't heat because the room's settlement has defeated the original slope of the supply pipe, flooding it. Possible remedies mayinclude shortening the valve and trap pipes, raising the radiator slightly, or repiping the runs.It is apparent that the garage was originally heated from the main system, but that the lines were later abandoned and capped. Consideration should be given to eventually reinstating the system; installing two radiators in the library, one or two in the garage, and reconnecting the lines. The steam supply is almost certainly intact, as it comes from an upper elevation of the house, while the buried return may or may not be intact. If leaking it would need to be replaced. If there is any unaccounted for loss of water from the system, it could be from the buried line, if it now leaks.If, after the other repairs described have been executed, there are still concerns about distant portions of the structure not heating rapidly enough, orifice plates could be installed at all of theradiator valves. This would result in simultaneous heating of all radiators
  • Jamie Hall
    Jamie Hall Member Posts: 16,591
    If nothing else, you need more and bigger vents. The vents on the steam mains are less critical -- although without adequate ones distribution will be slow and probably uneven. Since you mention that there are concerns about the distant sections not heating fast enough, my guess is that all the mains do need more and bigger venting at the ends. Probably a Gorton #2 on each. That will help a lot. Adding orifices on nearer radiators will not result in simultaneous delivery; if the air can't get out of the main fast enough, those distant radiators will still be slow. The vents on the dry returns are absolutely critical, and I'd like to see at least a Gorton #2 on each dry return. However... oddly enough, those vents should never close. There should never, ever be any steam in the dry returns!

    You need a decent low pressure gauge. Further, the system cutout pressure should be no more than 2 psi, and if this really was a vapour system -- which it may have been -- probably should be no more than 1 psi or maybe even less. This will require a vapourstat in addition to (and in series with) the pressuretrol.

    If the radiator traps have not been abused, they may still be alright. It would not be a bit surprising if some, at least, weren't, though, and this needs to be checked and evaluated. A trap which is failed closed will result in no heat in that radiator. A trap failed open, though, will often result in no or poor heat in all the radiators on that return. Check them all.

    The radiator in the sun room which you mention may well not operate because of changed pitch on either the supply or return -- or both. That needs to be attended to.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ccampo00
  • ccampo00
    ccampo00 Member Posts: 7
    Thanks Jamie. For your insightful comments. We are talking about replacing the whole return around the basement permiter wall. The pipe is 2 inch and we are considering taking it to 1.5 inch. Black pipe for black pipe. A large original section of the house garage and room above it are not being utilized by radiators and are capped off. We will consider putting gorton #2 on the ends of the steam lines. There are no radiators not heating. All work now with exception to one on porch. We will have all 17 investigated. We replaced all the valves on all the radiators and now will do the traps too if necessary.
  • ccampo00
    ccampo00 Member Posts: 7
    So what we do notice is any room close to the boiler on the 2nd or 3rd floor heat really fast and are sometimes actually too hot. The ends of the house while they heat well , are not as hot. I'm not sure if this is really common for a big 5500 square ft house or just that venting the ends of the steam lines might help to even out the heat distribution of the system.
  • Jamie Hall
    Jamie Hall Member Posts: 16,591
    The unevenness between the nearby radiators and the ones at the ends of the mains may be correctable by venting the ends of the mains If there is no venting -- or minimal -- on the ends, it certainly will help a lot. I don't recall, however, whether you had determined whether or not there were crossover traps from the ends of the steam mains to the adjacent dry returns. If there, additional venting on the mains won't help if they are working -- but additional venting on the dry returns will. So if there are crossover traps, it's essential that you check them!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ccampo00