Main air vent on small tapping

Levie

Hey I have a main air vent that is inadequate and on a 1/4 tapping I want to replace it with a Hoffman 75 but there is very little access and it is hard to remove the reducing bushing that is there.  Can I put a reducer from 1/4 to 3/4 and then connect my Hoffman 75 on top? I guess my question is if a 1/4 pipe will restrict too much air going to the Hoffman 75.
Levi

KC_Jones

1/4" pipe opening is more than adequate for a Hoffman 75 venting rate.

I would suggest if you haven't bought the Hoffman vent yet, the Gorton #2 is much better bang for the buck. It's cheaper than the Hoffman and has over double the venting rate.

JUGHNE

I have put Gorton 2's on 1/4" risers several times.

EBEBRATT-Ed

You can put the vent on the small tapping. If it prove to be too small you can struggle with the bushing during the summer

Levie

Thanks everyone! I did have some issues with the Gorton leaking steam but never had any issues with the Huffman.

JH3550

I have a similar situation with a 1/4” tap. I need to add 2 Gorton #2’s to one of my mains. Would that work with a reducer or would the 1/4” opening be too small for that much venting?

ethicalpaul

It might be a bottleneck for two #2 vents. Do you really need that much? Have you tried one?

EBEBRATT-Ed

@JH3550
what do you have to lose? it will be better than what you now have.

Levie

Sure enough my Hoffman 75 is shooting steam now the near boiler piping is incorrect but I still don't understand why when the vent reaches such a high temperature it doesn't close.
I've had this issue with Gordon in the past but when I switched to Huffman I have installed dozens of these and never had an issue.
Going to try swapping it out

ethicalpaul

Vents fail. What is your pressure control set to?

Levie

ethicalpaul said:

Vents fail. What is your pressure control set to?

Pressure tool is at the lowest possible setting 1.5 and 1/2
I try to Gordon 2 and the Hoffman both were throwing a cloud of steam I understand that my system produces wet steam but these vents were boiling hot and I imagined they should have been closed.
I ended up installing a big mouth and surprisingly it shut right away not sure if it's because the system was already hot and I wasn't producing so much steam would want to see what happens on a cold start.
Thx
Levi

ethicalpaul

How wet? Is water shooting out of your main vents ever?

Levie

ethicalpaul said:

How wet? Is water shooting out of your main vents ever?

No not water just like a cloud of steam

I do have an issue with a radiator at the end of the line that shoots water at the end of the cycle but I believe that's because I have a reducer right after that radiator on the main line and water pools behind the reducer.
I closed that radiator and never saw any water from the main vent.

EBEBRATT-Ed

@Levie you answered your own question. An air vent job is to vent air and close when steam hits it. Wet steam is cooler than dry steam and any water evaporating as it exits the vent will try and close the vent by cooling it.

In short feeding the vent with wet steam the vent can't react that fast and doesn't know what to do.
Fix the wet steam problem.

Levie

EBEBRATT-Ed said:

@Levie you answered your own question. An air vent job is to vent air and close when steam hits it. Wet steam is cooler than dry steam and any water evaporating as it exits the vent will try and close the vent by cooling it. In short feeding the vent with wet steam the vent can't react that fast and doesn't know what to do. Fix the wet steam problem.

I always had a problem with that theory because that would only explain why it releases a little bit of steam at the beginning but after the vent to reaches 200 degrees it should definitely shut unless I'm misunderstanding something.