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Vent location ( Big mouth)

I just purchased a new Big Mouth vent for part of venting upgrade for one of my steam boiler units. I want to install correctly and Barnes says 8"-10" from end of main. I have attached two pictures of possibilities. (1) putting 90 elbow and going up 8" or extending 8-10" then install elbow. What difference does it really make. One pipe system

Comments

  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    Go with #1. It will help to keep water from spitting out of the vent before it closes.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • wayneman
    wayneman Member Posts: 29
    wouldn't the vertical riser do that without the horizontal 8-10" piece??Would just seem to look rather strange?? with the horizontal extension.
  • wayneman
    wayneman Member Posts: 29
    sorry, i misread your answer. It was recomended you the discussion group last year that with the lenth of the run from the boiler that the big mouth would do a better job. This picture shows just one leg. I have already install antler on the other leg. approx 40' from boiler.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    I guess I'm confused. I thought the horizontal extension was #2.

    Screw the elbow into the reducing coupler at the end of the main with the female tapping facing up, screw the 8–10" nipple into the top of the elbow, then use a ¾" coupler to mount the vent on top of the nipple.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • wayneman
    wayneman Member Posts: 29
    That makes more sense. Thanks. If the big mouth is elevated 8-10" would there be much spitting out of the big mouth??
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    That really depends on your system. It would be less likely with the extension than without it.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,512
    What is on the tee on the return line?? Looks like a vent to me.

    That tee is the correct location, raise it up as high as you can

  • gfrbrookline
    gfrbrookline Member Posts: 753
    @EBEBRATT-Ed I thought the same thing, looks like there is already a vent on it albeit too small. Put a shorter nipple on and you will be good to go with the big mouth.
  • wayneman
    wayneman Member Posts: 29
    so you both are correct there is a tee on the return line, but after reading to forum, felt the big mouth would be better. I also thought being at the end of the main would release more (steam) air than the current location on the return. wouldn't the path of least resistance be true? doesn't the return line have possible water in it to slow down the escape of air thru a vent?? still learning here so enjoying your wisdom!!!
  • wayneman
    wayneman Member Posts: 29
    so one of you say use current vent location and raise as high as possible. and the other member says put a shorter nipple on. Who wins the tug of war :)
  • Gsmith
    Gsmith Member Posts: 431
    Either location will work. Put as much distance and height from the end of main elbow as you physically can if you put the vent there to minimize possibility of steam pushing condensed water into the vent. If you put the vent on the old location on the return it will not change the time to vent the main by any appreciable time because the volume of the air in the short distance from the end of main elbow and the vent location on the return is so small, likely to make perhaps only 10-15 seconds difference in main air venting time.
  • ChrisJ
    ChrisJ Member Posts: 15,658
    edited January 2020
    If it was me, I'd take that bushing out and use larger pipe and raise it a decent amount after the 90 then put the bushing where the vent is. It'll keep velocity down and pull less if any water and debris with the air.

    It doesn't matter how far you go horizontally, but vertical height helps.
    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
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,512
    @wayneman
    Remove the old vent and put the big mouth in it's place. Put the big mouth as high as possible.

    If you can get the bushing out of the tee make the riser to the vent as large as the bushing and then put a reducer for the big mouth on top of the riser as @ChrisJ sad if not just extend the riser the old vent is on
    ethicalpaul
  • wayneman
    wayneman Member Posts: 29
    great responses glad to have the help.
  • wayneman
    wayneman Member Posts: 29
    I just wanted to show picture after reducing coulper was removed,larger vertical and big mouth installed
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,512
    @wayneman

    That should be fine. How is it working??
  • wayneman
    wayneman Member Posts: 29
    so far very good. I have one more vent to install on a different branch(3 main) of this boiler system that never had a vent. I will see when I get a gas and electric bill if there is savings. It certainly appears the system is heating up much faster than last year when we just had the original small vents on the 2 mains