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Double Venting a Rad

ER Member Posts: 27
I have a 2-family house with an apt on the 1st floor and another on the 2nd floor. Each apt has its own single pipe steam system. They work reasonably well, and right now I'm trying to improve the venting and balance the 2nd floor system.

The runouts from the main and risers up to the second floor are not vented. So several of the radiators have large amounts of piping to be vented. I am thinking that the balancing may be easier if I use two vents. LAOSH discusses 2 ways of doing this. One includes two vents on the standard side of the radiator away from the piping. A second method involves putting a vent on the top of the riser.

My radiators have a tapping for a vent on both sides of the radiator. I am thinking about putting a large gorton valve on the piping side of the rad and then using a smaller adjustable valve on the far side to control the balancing.

Since I haven't seen it discussed anywhere I am thinking this isn't a good idea, but can't figure out why.



  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    It would work

    but the first thing I'd do is vent all the steam mains properly. Then tweak the radiator/riser venting if needed.

    Measure the length and diameter of your steam mains and tell us what main vent is on each one. We can tell you what you need.

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  • gerry gill
    gerry gill Member Posts: 3,078
    yup, it would work.

    the first vent would shut first..then it would be like a standard set up as the rear air vent does its job..but steamheads right..if you can vent the mains that would make everything work better for you.

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  • Daniel_3
    Daniel_3 Member Posts: 543

    Agree and agree. Yes. =) It worked for me twice.
  • Phil_17
    Phil_17 Member Posts: 178
    Yes it wil work

    I have done this on a radiator in my house that is at the end of a long horizontal runout (well away from the main and it's vent). This part of the house always ran cold and adding the additional vent on the valve end of the radiator made a noticeable improvement
  • ER
    ER Member Posts: 27
    tapping a fitting

    Great, its unanimous that it will work. Perhaps not the best plan of attack though...

    My notes on the piping are trapped in my computer for the night. I'll get the details tomorrow.

    I've seen mention of drilling and tapping a connection for a vent into the body of a fitting. I have a couple long runouts without venting, but perhaps that's the better place to attack. If I can find a 1 1/2" elbow and drill and tap it for 3/4" then put a nipple up to a vent. Any surprises? I've done my share of drilling and tapping standard straight threads anything different with the taper?

    I'll get some details tomorrow. thanks all.
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