Main steam vent leaking

Marduke

I have a one pipe steam system and I just replaced the original main vent on the main header with a Gorton's#2 air eliminator. While the system was heating up the #2 was leaking a little steam and then when the system got up to about .3psi the Gorton's #2 was really spitting out steam and then a good amount of water as well. I am assuming this is not normal? When should that main vent close? The radiators upstairs were almost warm all the way through but not quite. Any thoughts?

DavidK_2

I'm no expert,

But mine make a hissing noise until the steam gets to them, then they shut off. No (visible)  steam, no water, comes out of the vents.

nicholas bonham-carter

leaking main vent

doublecheck your pressure with a good low pressure gauge [gaugestore.com]. make sure you mount the vent away from the elbow using an antler, or menorah [use the search button above].

these mainline vents become paperweights at 3 psi, and leak above 2 psi.--nbc 

Marduke

main vent leaking

I have a brand new vaporstat 1-4 psi and a brand new 0-3 psi gauge teed off of the siphon loop. The vaporstat was set at 1 psi but the boiler cut out and the pressure gauge was only reading point 2 psi. Something is not working right. The Gorton's #2 is right on the elbow at the end of the main steam header. I will try raising it up on an "antler"

Jamie Hall

Raise it

and offset it if possible.  The hissing is probably trying to tell you that adding another one wouldn't hurt -- that's the air coming out at speed.  However, that said, it shouldn't let any steam out -- when steam hits it, it should close.  You say it's on the main header?  You may have a wet steam problem... and it's just possible that it's not really steam you are seeing, but a lot of water vapour.



You can actually watch the vapourstat (at least the older ones you could!) tilt switch (maybe the newer ones you can't... hmm... mine's older) tilt to switch off; it shouldn't do that until the vent closes and pressure starts to build.  They're pretty reliable.  Is the pressure gauge on the same pigtail as the vapourstat?

Marduke

hmm

If it is water vapor and I have a wet header what is the cure for that? Yes, the pressure gauge and vaporstat are on the same pigtail. It definitely cut out while the main vent was steaming away but the gauge was only showing point 2 psi. I have a gorton's #1 on the short main and that seemed to work fine.

AlexR

make sure it rattles

A couple of us got broken Gorton #2s- mine was stuck mostly closed, so it didn't really vent right but would also leak steam after it got hot.  If you're taking it off anyway, try gently rotating it 30-50* in your hand- it should rattle.  You can also try blowing through it to see whether it feels open or closed.  There are some other threads with more details.

Patrick_North

... and if you do the "blow" test...

My apologies if this is obvious, but if you want to blow through this vent to ensure that it's not frozen closed, it needs to be upright. Pointed down or on its side the float should close and you shouldn't be able to blow through it.

Patrick

brian_44

Do this...

Mine is right on the elbow as well, and it doesn't spit any water at all.  It used to a little with the old crud vent I had...

Marduke

still leaking

I took the Gorton's #2 off and did the blow test and air comes right out the top. When I turn it upside down it closes and no air can pass through. I tried raising it up away from the elbow and now no water is coming out but plenty of steam. Is there anything else that can go wrong with these vents? Does it matter that the tee on the main header which the valve is on is only 1/4" then I use an adapter to get to 1/2" to thread on the valve?

Patrick_North

Well there's yer problem.

It's generally recommended that the tapping for a main vent be positioned on the top of the pipe, several inches before the main terminates. I'm no expert, but it looks like you're sending a slug of steam/condensate right into the vent piping.

Patrick

Marduke

picture of vent steaming

picture of vent steaming

Marduke

original piping might be wrong

Thanks for the help.

That is where the old vent was. It had a small radiator vent attached. I don't see anywhere else to attach a main vent unless I modify the piping.

brian_44

Couple of things...

1. The antler should go the other way.

2. It's hard to tell if that would be the proper place to even place a vent. Is that anyplace near the boiler? Not sure if you have multiple mains, but usually the main vent is someplace near the boiler.

Marduke

defective valve

ok. so I replaced the Gorton's #2 valve with a #1 I had and it worked fine. So, I guess the #2 which leaked steam badly is defective and I'll return it. Thanks for the help.