Big Mouth air vent update

crawas

What do you mean the Allan wrench goes inside the pipe? Inside the main pipe itself?

adasilva

What they are saying is the bottom of the big mouth vent has a spud that threads into the main pipe. This part has an 5/8 allen shape to it so you can use the wrench to tighten it. Then you assemble the rest of the vent after.....

KC_Jones

I'm not at home right now, but when I get home I can take a few pictures of it disassembled for you. That won't be until later this evening.

Sailah

The Big Mouth has 3 parts. Body, union nut and spud.

You want to tape/pipe dope the NPT threads on the spud only. Put on union nut. Use 5/8" allen wrench or bolt head to thread this spud/union combo onto piping.

Then attach body to spud by tightening union nut. Do not put any pipe dope or tape on the body threads. The body seals to spud because of matched tapers and does not need any extra sealing.

An alternative method is to just assemble the entire vent. Dope up NPT threads and use assembly to thread on. You're limited by friction but is likely enough to seal the threads.

But who needs an excuse to buy more tools? Not this guy...

crawas

What does NPT stand for?

Sailah

National Pipe Thread. See blue arrow

crawas

> @KC_Jones said:
> I'm not at home right now, but when I get home I can take a few pictures of it disassembled for you. That won't be until later this evening.

Thank you!!

crawas

OK so put some Teflon tape on the NPT of the spud piece and then use an Allen wrench to tighten the nut on to the spud. So I’m first screwing the spud into the pipe itself and then putting the nit over the spud and tightening that with the Allen wrench.

Once this is done, then hand tighten the valve itself onto the nut?

KC_Jones

The nut needs to be on the spud when the spud is installed, it is captured by the spud.

Found a picture that might help. There is a collar on the spud, the nut grabs that and pulls the spud and vent body together. You can also see the hex requiring the Allen wrench in this picture.

Sailah

https://www.youtube.com/watch?v=TDfL3cy55dU

crawas

Awesome video!! Thanks.

crawas

Last question, does it matter which way the valve is facing when it’s screwed on? It’s in a vertical position but just wondering if it needs to face outwards or onwards or anything. See pic of my current gorton vent installed.

Sailah

As long as it's vertical it doesn't matter. Big Mouths don't like water so if you have the space, it would help to put the tallest riser and coupling to get vent as high as possible.

crawas

There isn’t really any space to go higher there as you see in the picture. Do I need to worry about water spitting out with this vent? I’ve never had that issue with the gorton

Sailah

It's hard to tell. The Big Mouth is really a radiator steam trap that has been redesigned to work as a vent. Gortons have a float that prevents water from exiting vent. Only way to tell is install it and see if there is any water coming out.

Most installs don't seem to have an issue but if the vent is just in a wet location, it might spit. And to be clear it really needs to be quite a bit of water to subcool the thermostatic element to the point where it pulls the plug from the seat.

crawas

@Sailah, I should probably also mention that my boiler seems to have two main pipes and I’ve established with the help of Fred from this forum that the second main needs to be vented as well and being that the walls are all closed up and there’s no other access panels I have no idea if it even is vented or where the second main goes and all the routes it takes or anything like that. See pic of my NBP. The main on the right side is the one where I found the gorton and am going to change to the big mouth. The main on the left is the one that goes a different direction but unfortunately the contractor didn’t leave this main vent exposed for me.

crawas

Anyone?

ethicalpaul

I mean...it's behind the finished part or it doesn't exist, are there any other options?

crawas

Lol no. Should I start opening walls?

Gsmith

I'd suggest making a plan of the basement and upper floors showing the location of the boiler and the exposed piping and the known location of the radiators and other heat emitters on the upper floors (if any). From that you may be able to deduce pipe locations or at least limit the areas you have to expose. Doesn't need to be fancy, but should be made using measured dimensions.

JUGHNE

You have 2 main steam runs coming of off the boiler header.
But there is only 1 dry return pipe (above the boiler water line).
Typically there is a return for each steam main.
If they are tied together somewhere, that tee connection must be below the boiler water line and then the return from there is considered wet.

It is possible that your 2 mains themselves tie together and has a common return. The problem then is venting as the shorter part of the loop will close the vent before the longer part gets rid of it's air.

Or the remote possibility that the taller steam main riser is a counter flow main that would not have a separate return but would need a main air vent at the end.

So as Gary said to make a map/plan of piping and radiators you might see more.

Steamhead

crawas said:

Lol no. Should I start opening walls?

If you have or know someone who has an infrared camera, you can run the boiler and follow the heat signature of the steam main. Wherever the heat signature ends is where you open the wall.

crawas

@JUGHNE , there is a wet return that runs from where the current vent is in the back of the house all the way back to the boiler and runs underground back to the boiler. See pic.

The dry return you see in the pic is tied into the second main coming from the boiler and someone on the forum mentioned to me that’s its in fact not a dry return but just a pipe to collect any leftover condensate to prevent water hammer. See pics of how the pipes tie in to each other.

I’m also leaning to believe that the 2 mains tie in to the same return because if there was a separate return for each main then wouldn’t I see another pipe coming to the boiler from underground?

KC_Jones

The single return pipe is anecdotal for the venting situation. If those pipes are tied together and done properly, they are tied below the water line. This, from a venting standpoint, effectively isolates them from one another due to there being a water seal.

In the picture, it's finding out where that pipe circled in red goes to, and finding the end after last radiator takeoff or drops to the wet return.


Also given you have wet returns, I would suggest you want to keep a close eye on water usage. If an underground wet return starts leaking many times your only clue is water loss, so you want to know when that's happening and address it as soon as possible. It appears you don't have a water meter on the feeder, you might want to add that to a list of things to have done at some point. Either add a meter or change to a Hydrolevel VXT water feeder that utilizes a built in meter. You shouldn't use more than a few gallons per year.

brandonf

Just bought a big mouth on Amazon if anyone's interested. They are back in stock.

crawas

I actually had to change a few of the return pipes due to leaks about 12 years ago. We were pleasantly surprised when we saw dirty rusty water all over the basement floor

crawas

As for where the pipe circled in red goes to, I know it directly goes to the next room under the basement ceiling but the only way to know I guess which radiators it feeds would be to open up the ceiling. I can’t think of any other way

crawas

@KC_Jones are you in the NY area? I know the exact wet return run and where it comes from and goes to. The only way that second main ties into the same common wet return would be along the ceiling because there is only one wet return pipe coming into the boiler. The dry return pipe you see, is it in fact a dry return?

KC_Jones

There is a high likelihood it ties together underground where you can't see it.

I am in PA and just a homeowner like you.

JUGHNE

Can you see the other end of the wet return?
The 2 main returns could be tied together inside a wall and be below the water line.
At your access door for your existing vent, can you look left & right with a mirror and good flashlight? That steam main should have a slope towards the wet return. We assume the vent is after the last radiator connection.

That other return looks to be a drip pipe for that main. Do you have a second floor? Has an addition been done that the steam system could have been extended to, years ago?

crawas

The system was changed from oil to gas when I bought the house 15 years ago. When I look inside the access panel I know exactly where the pipe is coming from and where it’s going

crawas

@KC_Jones wow, you’re very knowledgeable!!

So I’m thinking that there is no second vent needed since they most likely tie into each other and changing the gorton that’s there to the big mouth should help in getting heat to the tads much wuicker

crawas

@JUGHNE , I wouldn’t know if anything was added to the system after I bought it and what was done. All I know for sure is I see the one wet return coming out of the floor draining into the boiler and I know exactly where the wet return comes from. Whether the second main ties in to the first main inside the walls and goes to that common return is I think really possible but Fred had mentioned that it didn’t make sense to have the second main tied in because then steam is going in 2 different directions and what’s the point. But if we assume that there is only one wet return then that would mean that only one main vent is needed right?

KC_Jones

crawas said:

@KC_Jones wow, you’re very knowledgeable!!



So I’m thinking that there is no second vent needed since they most likely tie into each other and changing the gorton that’s there to the big mouth should help in getting heat to the tads much wuicker

As I said in an earlier post, if they are tied below the water line, then the vents are isolated from one main to the other. In other words you are still in the same boat as before, find the end of the other main.

No matter how many ways this is looked at I don't see a way around finding that other main.

Fred

@crawas , my comment to you was in response to your comment that the main was a single main that looped around the basement. If that was the case, as I noted, that would cause steam to feed in two different directions and that is a problem. I also noted that while someone may have done that, it should be changed in one of two ways, 1) separate the one main into two with each having its own dry/wet return or 2) take the second riser off of the header and treat it as a single main that loops around the basement. Either option still requires that you know and understand your piping.

crawas

Ok I think I’m at my end here. I ordered the big mouth and will change it when I get it tomorrow. I reached out to the steam doctor who I got from this forum and hopefully he will come out to me next week to evaluate the system and we’ll go from there.

crawas

Just got my big mouth vent but for the life of me I can’t seem to get the gorton #1 vent off!! I should be trying to loosen the nut right? Any tips on loosening it up?

KC_Jones

What type of wrench are you using?

crawas

Basic channel lok

KC_Jones

You need either the proper open end wrench to fit the hex or a decent sized pipe wrench that will fit. My preference is the wrench.

I use channel locks on occasion, but, for me, they are usually more trouble than they are worth. This is most true when trying to apply serious torque, I find the slip long before enough force can be applied.