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    where to vent the main? (10 Posts)

  • raemac raemac @ 6:57 PM
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    where to vent the main?

    I have two mains which run about 60 feet in a rectangle and risers coming off each one to 3 different floors - one pipe system. I currently have 1 main vent (ventrite # 77)  on the end of each main - see picture.   Installer says that this is enough venting.  Should I have more and are they supposed to be place at the end on a t like that?  I was reading that they should be at least 6" from the end of the main.  If I need more, where should they be placed.  Do I tell him to do the work or hire someone else?
    Thanks 
  • BobC BobC @ 7:30 PM
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    easy way

    If you come off that main with a nipple, an elbow, a 12-18" nipple and another elbow you can mound suitable vents there (all piping 3/4" and you will need to build an antler to hold the Gortons which have a 1/2" male thread). Make sure that long nipple slopes so the condensate finds it's way back towards the return. This will effectively put the vents away from the end of the main

    Those mains contain a lot of air, as I said before you will need at least 2ea Gorton #2's on each main and maybe more.

    Bob
    Smith G8-3 with EZ Gas @ 84,200 BTU, Single pipe steam

    Vaporstat with a 12oz cut-out and 4oz cut-in

    3PSI gauge
  • Steamhead Steamhead @ 11:20 PM
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    Those Vent-Rites are too small

    even assuming your mains are 2" pipe. Are they larger than this?
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  • raemac raemac @ 11:21 PM
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    switch ventrites for gortons?

    thanks bob,
    Would you recommend switching the ventrites to the gortons?  Is the current set up ok?  I know I should add more but what is the downside if I dont?  How should I get the plumber to buy into adding another vent somewhere else on the main?  I am the homeowner and he is the expert. 

       
  • BobC BobC @ 7:53 AM
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    That location invites damage

     Locating main vents at the point it drops into the wet return is bad because there can be slugs of water that will damage the vents, that is why it's recommended to put them back from the end of the main and up a bit to shield them from any water slugs.

    Earlier you said the mains were at least 4", so I assumed it was 3-1/2" pipe which has 0.07 cubic feet of air per running foot. 60 ft of 3-1/2 pipe contains 4.2 cu ft of air; the Ventrite 77 is rated for 0.2cfm, you probably need 10 times that amount of venting. 2ea Gorton #2's on each main might be a good starting point.

    It will cost a lot of money to repipe those mains so the venting is 12 to 18" bacxk from the end of the main so i suggester using 3/4" pipe to run the vents back along that main to put the vents where they should be for long life.

    The problem with using small air vents is you are paying the gas company to compress the air out of the pipes for you. Gorton #2 vents are not cheap but they save gas and they will last a long time if put in the right location.

    Once everything is working right, thee near boiler piping should be insulated with 1" fiberglass pipe insulation and you should do the same for all the piping in the basement unless you want to burn gas to keep the basement warm. I hope you installer has got the boiler working properly at this point, proper venting will help your initial problems nut it won't fix them.

    Bob
    Smith G8-3 with EZ Gas @ 84,200 BTU, Single pipe steam

    Vaporstat with a 12oz cut-out and 4oz cut-in

    3PSI gauge
    This post was edited by an admin on December 6, 2012 7:54 AM.
  • raemac raemac @ 8:37 AM
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    How do I tell him?

    the logic behind the venting sounds good.  The system is up and running and all pipes are insulated.  there still is some clanging when the system comes on but not too bad.  The installer is coming over tomorrow and wants the second 1/2 of a very large payment for labor to install the new boiler and connections.  I want it done right and not have to pay for anyone to come back and have to tap into the main and add vents in the future.  This is the hard part.  What do you recommend I do to tell him that his work is ok, or not correct, or bad, and needs to be fixed without making me sound like a jerk or homeowner know it all because I go online and asked a few questions?   I am assuming the city inspector will sign off on the work and not even question the venting?  If I push too hard I may lose the guy who will service my system and lives 3 blocks down the road.  Please Help!
  • Charlie from wmass Charlie from wmass @ 9:49 AM
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    check your contract

    If he said he would do venting as suggested on here, which I doubt, then have him install it. If on the other hand he did not have it specified you will need to pay for the additional work to be done. We do not discuss price on here as to keep the general peace we all prefer. Having said that I will say the benefits of adding the venting will in the long term pay you back well for you. Gorton #2 vents are not cheap, but are worth the price. As for clanging that is not normal and needs to be addressed. Can you post any Photos of the boiler?
    Cost is what you spend , value is what you get.

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  • BobC BobC @ 9:57 AM
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    look at previous thread

    He posted pictures in a previous thread -  http://www.heatinghelp.com/forum-thread/143775/Conversion-to-Gas-two-systems-to-one#p1281558

    It seems the installer replaced two steam boilers with one and is using zone valves to control which steam main gets steam along with a pair of traps. I have some doubts about this but don't have the experience to know if it will work correctly as it is now.

    Bob
    Smith G8-3 with EZ Gas @ 84,200 BTU, Single pipe steam

    Vaporstat with a 12oz cut-out and 4oz cut-in

    3PSI gauge
  • nicholas bonham-carter nicholas bonham-carter @ 10:33 AM
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    Piping problems

    From the other post, I would say the boiler is piped improperly, with no equalizer that I can see. Do you have the manual for the boiler? If not, then go to the mfg's website, and download it, and print it out. Then go through the piping instructions, comparing what you have with what should be there.The specifications are quite exact, as far as piping layout, and sizes. If these are not followed, then more problems will come down the road.
    Ask him to show you how to skim the boiler, which will be a whole day of trickling off the residual oils from the surface of the waterline. Dumping chemicals into the boiler is no substitute for this.
    I would remove the zone valves, and properly repipe the header, and make the system work as efficiently as possible, at the lowest pressure (ounces).
    When you order the lost art of steam heating, get the installer a copy as well!--NBC
    I forgot to answer your original question. When you put the several Gorton 2's on an antler, the twists and turns of the antler will absorb any water-hammered slugs of water coming though the dry return, and lessen their impact, so the present tapping is suitable for the antler mounting.
    This post was edited by an admin on December 6, 2012 10:42 AM.
  • BobC BobC @ 1:54 PM
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    Tell him it has to work correctly

    Charlie posted a comment to your original thread that leads me to believe this zoning attempt has some serious problems, he is a very experienced installer and i would heed his warning.

    Tell your installer that the system has to perform without banging or spurting water out of the air vents. It sounds like he convinced you to go with replacing the two boilers with one and a zoning scheme so now it's up to him to make it work. I hope the system set to operate at less than 2PSI and that it has been skimmed so the water is clean and the sight glass is not bouncing up and down more than about 1/2" .

    This boiler could last a long time and you want the system to work quietly and efficiently, I don't think that is a lot to ask for for a new install.

    Bob
    Smith G8-3 with EZ Gas @ 84,200 BTU, Single pipe steam

    Vaporstat with a 12oz cut-out and 4oz cut-in

    3PSI gauge
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