Air Vent Setting

mmc239

I have this vent on a steam baseboard located in living room right above the boiler. It hisses so loud that we can’t hear each other. What setting should I have it on?

ethicalpaul

It's not the vent's fault. Do you have main venting installed? What pressure is your boiler allowed to run up to?

mmc239

I don’t believe there is a main vent installed. Would that be the same concept as the radiator ones? Just drill and yep one into pipe about the boiler?

ethicalpaul

there might already be a plugged port in the main pipe where it would go.

After the last radiator runout and before the main turns downward to the wet return is the place to look

bburd

Main vents have a faster venting rate than all but the fastest radiator vents. Their purpose is to fill the main quickly with steam so it will arrive at all radiator takeoffs at about the same time. This helps balance the system and reduces noise from the radiator vents.

mmc239

what size should the main vent be? 3/8, 1/2 inch?

bburd

If you give us the length and pipe size of your steam mains, we can tell you which main vents would work well.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1814813#Comment_1814813

Like @bburd said, we can give some suggestions when we know the size of the main. Strangely, the physical size of the main vents' threads is not necessarily an indicator of their capacity (speed).

The Gorton/Maid o Mist #1 can go on a 1/2" or 3/4" fitting where the Gorton #2 with three times the capacity has only 1/2" threads. Only history knows why

The Gorton D is the exact same capacity as the #1 and it can have I believe 1/8" or 1/4" threads.