steam vent location

wayneman

I 'm a new member that has gathered lots of good information to update a steam system. I have recently installed 1-#2 Groton on a 30' 2" main and built a antler with 2- #1 for a different 20' main. I am concerned about were I replaced older vent with the # 2 and it is on a return line near main line.Is it the most effecent location?? I would also like to add a vent on a different 2" main line and wondering if off the 2" Tee shown in second picture would be a ok spot. please share your thoughts.

JUGHNE

Is the first picture your 30' main with the old vent on it?
Is the second picture the end of your 20' main?
Was that pipe/tee previously a feed to a removed radiator above the floor, and is it tapped into the top of the steam main?

wayneman

yes 30' before I put in Gorton #2
second picture is a tee fitting coming off a2" feeding a 2nd story radiator. There is no vent on that line.The entire apartment house use to be on one huge steam boiler. We are eliminated pipes that no longer feed radiators. One apt left that we installed slant fin 120,000BTU steam furnace.

JUGHNE

I would put a Big Mouth on the 30' and the G2 on the 20'.
Assuming the pipe for the 20' is at the end of the steam run?

wayneman

I will get a couple better pictures. The first question is the vent off a return line ok. The plug in the end of 2" tee is rusted,plus after reading comments it would be in direct line of the steam racing toward vertical leg? So does the condensing line give venting to the main line above it?

wayneman

I did some remeasuring. the facts are approx 25' 2" line running from boiler tied into some originall 3" piping. At the 25' mark the line divides 3 ways. 15' more of 2" to vertical shown with gorton # 2, another 2" line 15' long to vertical with the new antler w/ #1. and a 3rd 11/2" line going 15 ' to a vertical with no venting. The questions are: 1) does our location with gorton #2 work well even though not on main 2" line? 2) do I have enough vent on the antler set up? 3) can I vent the unvented line where the old disconnected line is capped off. 4) I reduced system pressure some , but should I go even lower? I have differential set at about 1.25?

Fred

Set the Cut-In to .5 and the Differential to "1" on the Pressuretrol. A reasonable rule of thumb is One Gorton #2 for each 20 feet of 2" main or 1 Barnes and jones for each 40 to 50 feet of 2" main.
It looks like you have two Gorton #1's on that one main. How long is that main as those two Gorton 1's are about the same as a single Gorton #2.

wayneman

so you are saying lower to the .5 on right hand side of scale,correct. The run with the 2-#1Gortons is total of 35'. 20before it splits apart and then 15' after the other two horizontals split off.is the location of the Gorton #2 allowing the proper venting as it is off a return line, but not far from the main? What about the 3rd question in my post?

Fred

Correct on the Pressuretrol settings.
The horizontals that split off of the 35ft. main are branches. If each of those branches supply more than one radiator, they should also be vented.
If those horizontal splits only supply one radiator, each, they are radiator Run-Outs and don't need additional; venting but that 35 ft run should have at about 2 Gorton 2's or one Big Mouth.

The location of the vent on the return is fine.

JUGHNE

Steam main air vents ideally would be on the main just after the last active radiator is connected....just before the main turns into a return line.
But in reality, they could be anywhere on the return line, even at the boiler before the return drops down to the boiler. I would take advantage of your existing tee if it is at the end of the steam main or even if there was another radiator downstream of it.

Just some things to consider, you want to get the air out of the basement main fast so the small rad vents don't have to do all that work, the air has to be vented...or no steam will flow far enough to heat. Some repair people (aka Boneheads...not you) will raise the pressure up to compress the air so the steam will go farther, but that is not the answer.

You want the vent high as possible with additional fittings if needed to protect it from water hammer and debris......and then you want the vent to be able to drain back into the pipe as it will get condensate in its piping of attachment.

wayneman

The horizontals are not coming off 35' main, but each horizontal totals 35' . great response and I am learning. The run where i now have the #2 GORTON is feeding two radiators located on second floor apt. the run where i installed the antler set up is feeding one radiator that is very large second floor, the last # 3 line that has no vent currently is feeding one smaller bath room radiator on that same second floor.

JUGHNE

Think in terms of the pipe in the basement and not so much of the radiators connected to them.
You are venting the steam main. Any air you can remove in the basement helps the entire system, as long as that pipe is carrying steam headed towards some rads, that air is then removed.
Without having revamp piping you should utilize the taps available. IMO
2nd floor risers need more venting as possible.

wayneman

thanks, I think I have room were i installed the #2 vent to add a second. and possible change the antler to hold four # 2 instead of just two. any idea of what gas savings one might expect to see??

JUGHNE

Are you talking about Gorton 2 main air vents?
The Big Mouth gets you twice the venting for the same money.
You could put the Big Mouth on your longest run (or 2 runs) and use the smaller vents for the shortest run(s).
It is based on the volume of air contained in the piping from the boiler to where the vents are located.
Typically a Gorton 2 does 20' of 2" pipe
A Big Mouth would do about 50' of 2" pipe
More venting than that helps, but you enter into the realm of diminishing returns on your investment.

As far as gas savings go, it is hard to say.
But from looking at your first picture with the old vent, if that was the only vent type you had then you had very little venting capacity.
Some have noticed almost a 1/3 reduction in gas......but there are many variables to consider. You would need history of gas consumption for at least a season and then factor the heating degree days for each period.
Most enjoy better heat balance in the house etc.

But in any case please report back with results, we all enjoy feedback which does not always show up here.....it is our only profit as we have no dog in the fight!

wayneman

so the tenant had mentioned radiators not heating very much( maybe 1/3) PRIOR to all of our adding vents and reducing pressure setting and differential. Do you think this will help heat more of the radiator to help "radiate" more continual heat ?

Fred

wayneman said:

so the tenant had mentioned radiators not heating very much( maybe 1/3) PRIOR to all of our adding vents and reducing pressure setting and differential. Do you think this will help heat more of the radiator to help "radiate" more continual heat ?

One of the big misunderstandings that people have is that they expect the radiator to heat all the way across. The whole purpose of radiator vents is to set the flow of steam to a level that makes the room comfortable. That may be 1/3 of the radiator, it may be 1/2 of the radiator or some other portion. Rarely, exception a Design Day will the radiator be 100% hot and depending on how over-sized the radiator is, it may not heat all the way across even on a design day.
Ask you tenant if he/she is comfortable, not if the radiator is hot all the way across.

wayneman

Will do.i appreciate your input.

wayneman

Foolish question,but why don't we find a way to vent verticals right before the line goes into radiator?

Fred

wayneman said:

Foolish question,but why don't we find a way to vent verticals right before the line goes into radiator?

Not a foolish question. It is done all the time, especially when the radiators on that vertical are slow to heat. A vertical is typically vented on the same principle as the horizontal main, after the last radiator run-out or, if more convenient, at the last Radiator run-out anywhere before the radiator. a smaller vent still remains on the radiator to vent the radiator slowly. That removes all the air from that vertical so the radiator vents don't have to do that work and they heat sooner.

nicholas bonham-carter

I have never tried this, but I see no reason why the bonnet, and spindle of the inlet valve could not be removed, then the bonnet tapped out to 1/2 inch for threading in a big mouth.
For good balance, this would have to be done for all the risers in the building, on the top floor. In some tall buildings, this would still not be enough main venting to achieve the necessary one to two ounce backpressure, and so the ends of the dry returns would still need some venting.—NBC

wayneman

after reading thru some older discussions we are told not to partially close the radiator vale to control heat. Could we not remove or adapt the valve stem cover to accept a vent of some kind? you all mention how impress you are with the looks and actions of the big mouth. could we put one there??

wayneman

There appears to be unnoticeable movement in the pressure gauge, as you would expect running 1-2PSI with a 30 lb negative and positive gauge,should I bother to change to 15 PSI gauge?

Gsmith

If you want to know the pressure the system is operating at you will have to put on a more sensitive gauge (0-3 psi, 0-5 psi).

wayneman

i think nick(NBC) has a shark tank idea. build a vented bonnet and take it to the Bank. Does anyone know if the thread pitch on those bonnets is pipe or otherwise??

nicholas bonham-carter

Each bonnet will have a thread proprietary to the valve body.
The hole for the stem should be tapped out to standard pipe threads-probably a max of 1/2 inch.—NBC

wayneman

how about you try this first and let us know. It could be a real winner 0:)

Fred

I'd be afraid that that method might cause steam to go that direction before filling the main. I suppose, like anything else, it will also become a balancing act. It will be interesting to see how it works out.

wayneman

On this system there are a couple 1' dead headed old lines capped off. is it worth the work to remove and cap at the main line??

Fred

wayneman said:

On this system there are a couple 1' dead headed old lines capped off. is it worth the work to remove and cap at the main line??

If they are capped, they are just filled with air. Won't make any difference. Depending on where they are they may be a good site for a main vent.