Help Me Vent My Non-Vented Mains.....

AdmiralYoda

Hello there! I have a single pipe steam system that is about 120 years old. The boiler is 30-35 years old and everything is functional. But I just learned that I HAVE NO MAIN VENTS!

You guys have helped me out quite a bit so far! A little bit more about my system here:
forum.heatinghelp.com/discussion/152380/check-out-my-steam-system-need-some-advice-pictures

So at the end of each main is a cap on a T. Perfect! Looks like someone just removed the main vents and just capped them. But I have three problems:

Problem 1:
I just need help sizing my vents. I'm not sure if I need multiple Gorton #1's or a single Gorton #2 on each main. Main 1 has 1.312 cubic feet of piping. Main 2 has 0.750 cubic feet.
Problem 2:
The end of Main 2 is near impossible to access easily to install a vent. Its in a crawlspace with little clearance. There is only one radiator at the end of Main 2.....can I just install the main vent between the radiator valve and the radiator itself? This would make life ALOT easier.
Problem 3:
There is a single run off of Main 2 that is quite long as it goes to an upstairs radiator. The run is about 33 feet long overall and holds 0.537 cubic feet of air. Should this leg have its own vent? Or should I just rely on the vent on the radiator to make up the volume?

Thanks everyone!

nicholas bonham-carter

I think it would be possible to take off the packing nut on the valve, and remove the stem. Then drill out and tap the packing nut for the main vent threads. Use a slower Hoffman 40 on the rad itself.--NBC

AdmiralYoda

Thank you for the advice! I assume you are talking about Problem 2 correct? Which main vent should I go with?

Fred

If you can get a Gorton #2 on Main one, that will work great. You say it is "Near" impossible to get to the end of Main #2. Does "near" mean you don't want to go into the crawl space? I'd rather see the vent, probably a Gorton #1 will suffice on that small line, at the end of the main but it certainly can go anywhere before the radiator to vent the pipe and keep the radiator vent on the radiator to vent the radiator. For issue #3, if you can get a Gorton #1 on the top of that long run, it will help move the steam along that supply a lot faster but using a vari-vent like the Hoffman 1A on the radiator may be sufficient. You can adjust it to vent a little faster than the other radiators.

AdmiralYoda

Thank you! When I say near impossible....I mostly mean I really don't want to crawl into a nasty crawlspace with little room and fight with a 100 year old capped T. The radiator right above it is much easier to work on.

What is the rule of thumb for pipe volume for Gorton #1's and Gorton #2's? Or is it just more is better?

Fred

The Gorton #1 will vent .33 CFM at 1 OZ. of pressure and the Gorton #2 will vent 1.1 CFM at 1 OZ. of pressure. The rule of thumb here is typically the equalivant of one Gorton #2 for every 20 ft. of 2" main. Maybe 2 Gorton #1's on Main #2 will allow both mains to vent at about the same time.

AdmiralYoda

Great info! So if I have 38' of 2.5" pipe on Main 1....Two #2's?

And 30' of either 1.75" or 2" (don't remember)...One #2?

Fred

Those would be the minimum I'd put on. Three #2's on Main 1 and 2 #2's on main 2 would be better. You can't over vent mains but you do get to a point of deminishing returns. Also be aware that 3 Gorton #2's will require a 3/4" pipe for the antler. 1/2" is fine for two Gorton #2's

AdmiralYoda

Awesome....wish they weren't so expensive... Talking $370 plus fittings! I wonder how long it will take for them to pay me back?

Fred

I know they are expensive. I don't know where the breakeven might be. You can start out with 2 Gorton 2's on main #1 and one Gorton #2 on Main #2 and see how quickly those mains vent. As I said earlier, there is a point of deminishing return and getting those vents on will be a huge improvement over having no vents at all and forcing all the air out through those small radiator vents.

AdmiralYoda

Thank you everyone for your help. Last question. On my long leg that goes off of main #1 (33ft of 1.5" pipe), I'd like to install a Gorton #1 right before the radiator.

Can I unscrew the top of the radiator valve and install a plug with a 3/4" or 3/8" fitting?

My radiator valve looks like this:


I haven't taken it apart but it appears that the valve portion comes out.....is it as simple as that?

Fred

It might take a little effort to get it apart but it can be done. I am always reluctant to tamper with those valves for anythhing other than repacking them. Once you screw it up/strip the threads, you not only have to replace the valve but also the spud, in the radiator that irt is matched to. Not a fun job. If you do use that as a vent location, be sure to match the threads on the plug. If I remember correctly, that cap has a slight bevel on the edge that mates with the valve body too. You may be able to take an old valve apart, remove the valve stem and tap the opening that the valve stem is in to adapt it for a vent. Save the valve/cap you remove so you can put it back if you decide to at some point.

EDIT: @AdmiralYoda Actually, if you take the packing nut off and remove the valve stem, you may be able to use the threads that the packing nut is screwed onto and put an adapter on it to accept a vent. That would simplify things a lot.

Paul48

Do you have any toolmaker or machinist friends? They could make you an adapter to go from machine screw threads to pipe threads.

RobG

Just put on a pair of coveralls and go into the crawlspace. Trying turn the valve into a vent will be opening a can of worms.

Abracadabra

Some radiators have a location to install a vent on the side closest to the shutoff. You can install a Gorton D on that side which is equivalent to a Gorton #1

Fred

Abracadabra said:

Some radiators have a location to install a vent on the side closest to the shutoff. You can install a Gorton D on that side which is equivalent to a Gorton #1

That's a better idea, yet!

JUGHNE

And if you drilled out that 1/8" opening and tapped it for 1/4" it would handle a Gorton #2. A 90 with a union would give you a pretty compact installation, as that is a quite large vent to rotate into place.

Steamhead

Fred said:

Abracadabra said:

Some radiators have a location to install a vent on the side closest to the shutoff. You can install a Gorton D on that side which is equivalent to a Gorton #1

That's a better idea, yet!

I wouldn't do that. If you vent a rad too fast, steam will come up the riser so fast it'll bang.

I'd start with a Gorton #2 and a Gorton #1 on the longer main, and a single #2 on the shorter one. Both would use 1/2" tappings.

For the long runout, drill and tap 1/8" and install a Gorton #D.

See how it does with these, and you can tweak later if needed.

Abracadabra

Steamhead said:

Fred said:

Abracadabra said:

Some radiators have a location to install a vent on the side closest to the shutoff. You can install a Gorton D on that side which is equivalent to a Gorton #1

That's a better idea, yet!

I wouldn't do that. If you vent a rad too fast, steam will come up the riser so fast it'll bang.

I've never had that issue when I've vented a long runout like that. D on the supply side and a 4 on the normal far side to vent the radiator. I'll have to keep that in mind.

ChrisJ

Replacing a radiator valve isn't all that difficult.

To remove the valve off of the pipe cut into the valve across where the threads are but stop before you go through the brass. Go as far as you can, but keep checking to make sure you haven't gone through. Once you're sure that cut has no more than paper thin brass left start hitting it with a cold chisel to spin it off. Before you know it your cut will crack and the valve will spin right off.

To remove the spud cut the nut off with a hacksaw and put a wrench right on the spud. It's brass into a cast iron radiator so it will usually spin out without too much effort.

After finally doing one my self I'm not so sure why many are afraid of them.

Here's a video someone made of removing a valve.

https://youtu.be/3u1J0hDWJJo



That said,
You can try drilling out the boss on the pipe side of the radiator and venting it with a Gorton D.

Personally, I'd get in that crawlspace and get to work.

Charlie from wmass

Chris I have split radiators in half trying to change spuds and removing air vents. It is a matter of volume exposure. Doing 20 with no issue is not a problem. When you get hundreds under your belt the odds catch up. Of course one could say the radiators that broke were on their way out anyways due to years of neglectic. I will be trying tapping a valve stem with an old valve to see how is works. If 1/4" is all I need I may even tap the body of the valve and use a 90. I can say Gorton D vents have not given be banging radiators yet. It is usually the Varivalves I have that problem with.

Fred

Steamhead said:

Fred said:

Abracadabra said:

Some radiators have a location to install a vent on the side closest to the shutoff. You can install a Gorton D on that side which is equivalent to a Gorton #1

That's a better idea, yet!

I wouldn't do that. If you vent a rad too fast, steam will come up the riser so fast it'll bang.

Well, initially it sounded like a better idea.

ChrisJ

Charlie from wmass said:

Chris I have split radiators in half trying to change spuds and removing air vents. It is a matter of volume exposure. Doing 20 with no issue is not a problem. When you get hundreds under your belt the odds catch up. Of course one could say the radiators that broke were on their way out anyways due to years of neglectic. I will be trying tapping a valve stem with an old valve to see how is works. If 1/4" is all I need I may even tap the body of the valve and use a 90. I can say Gorton D vents have not given be banging radiators yet. It is usually the Varivalves I have that problem with.

Yeah, if you can't remove a brass spud from a cast iron radiator without the radiator being damaged it was time anyway.