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Main line vent

after the last 8 years, i think i will take anything from the government with a grain of salt!


  • Pin
    Pin Member Posts: 61
    Main line vent

    I am replacing this old main line vent I have and need opinions on what I should do. I am confined to a very small space of 3 inches wide so Gordon #1 will fit in there i believe. Do I have room to install a menorah?

    Do you think its possible to make a bigger hole in the ceiling to fit Gordon #2?

    Take a look at the attached pictures and let me know what you guys think.

  • A Sawzall can enlarge that hole

    no problem. But that copper piping and concentric reducer after the vent tee worries me- is the entire system piped that way?

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  • Pin
    Pin Member Posts: 61

    Sorry but im not sure which copper piping you are referring to and also what is concentric reducer?
  • Brad White_191
    Brad White_191 Member Posts: 252

    of that piping seems to be copper...

    A concentric reducer has equal shoulders on each side which in your case, forms a "shelf" against which condensate can build.

    Properly, an "eccentric reducer" is used, flat on bottom, to allow condensate to pass.

    The "eccentric reducer" could also be used to describe Richard Simmons, so do not make that mistake when you go to the supply house.
  • Pin
    Pin Member Posts: 61

    The house was bought with the piping like that. If its not supposed to be copper piping then what should it be? The initial pipe that leads out of the burner is black color and then after two feet of it, all the rest are as you identified, copper piping. Is it a big problem to have copper piping?

    Also do I have to do something with the concentric reducer? or is that not a big problem?

  • installing vents

    is there even enough height there for a good vent under the floor?
    is this the end of the main in the dry return? if not, then maybe a better location would be where the return tips down on its way back to the boiler.
    as far as the copper lines are concerned, they are very non-standard, but if they don't leak for the moment.......... nbc
  • Pin
    Pin Member Posts: 61

    I'm not sure if there is enough height but that is how it was installed. I believe the main vent is at the end of the supply line.

    This pipes don't leak at all so does that mean i'm okay to use it? what is the rationale behind not using copper pipes?

    Also, back to the original question, what should I replace for the main vent considering the amount of space I have currently?

  • Copper pipe has a large expansion coefficient. The constant expansion/contraction of the joints over time leads to "work hardening" and the joints have a tendency to crack and leak so it is considered a "no-no" to use copper on the steam side of the system. (I have copper just on my wet return and it seems to keep a lot cleaner)

    As to the vent placement- Even with the pictures, we really have no way of telling what your space situation actually is. As Steamhead suggested, you'll just have to enlarge the hole to fit the "menorah". In another post Brad`suggested connecting the vents ("menorah" -an apt description BTW) using a pipe union which makes a lot of sense in that you can then take it on and off to work on it. With just a few pipe fittings you could put together a practice "menorah" mockup and see if it will fit. Use nipples the same height as the vents to mock up for the vents. If you can fit a satisfactory configuration in place you can then buy the vents and install the "menorah" permanently.
  • Pin
    Pin Member Posts: 61

    According to this PDF file from a government study, it says that quick vents do not reduce fuel consumption but does reduce the temperature differences between rooms. It also suggest installing a vent on each riser. What do you guys think? Vent on riser necessary?


  • LOL...I wonder how much money was wasted on this study?
    The phrase.. "can't see the forest for the trees" comes to mind.

    You really don't need a 47 page study to figure this out. This is "count on your fingers" engineering problem.
    Air = Bad; Steam = Good. With just a quick read, I didn't see anything relating to system pressure. Compressing air uses fuel. With No main vents and small radiator vents, you build up compressed air, pressure rises, system shuts off without steam reaching the radiators, room cold, wife complains, husband sleeps on cold couch.

    Basically venting as I see it comes down two separate areas. Venting the pipes and venting the radiators. (Not including mains as I think it's a given that this needs to be done) Ideally each riser to the radiator would have it's own thermal vent which would allow steam to reach the radiator in the quickest time period. From a practical economic stand point we combine this vent and the one on the radiator and let the radiator's vent do the job. If the vertical riser is long it (large volume of air) it is more likely to need its own vent. (Be sure to take a look at the diagrams at the end of the report. It has "menorahs" and other vent configurations)
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