Main Vent

DanversMA

I have a couple of questions regarding the main vents.  My system in brief is an oil fired weil mclain gold single pipe steam system about 15 years old.  There are two loops with a main vent and another run (not in a loop) without a main vent.  The two loops share a main feed coming from the boiler before branching off a tee.  One loop is 48 feet and is vented just before returning to the boiler, the other loop is 70 feet before returning to the boiler.  The run that isn't part of either loop is teed off the main feed and runs for 17 feet.  The two loops that are vented have the same vent but there isn't any ID to know what they are.

My intention is to replace the two main vents.  My question for these is; should I use the same size and make?  Any suggestions?  and my next question is; should I install a vent on the 17 foot run that doesn't return to the boiler nor have an existing vent?

The problem I have is the (2) radiators that are fed off the 17 foot run are the furthest from the boiler and don't heat very well, the room is always cold.

At the same time I am also considering replacing the radiator steam vents so they are all matched (they are currently all mismatched) to the Hoffman 1A and try to adjust them according to the size of the radiators (not the location).  I have 12 radiators in total.

Thoughts or suggestions greatly appreciated, Thank you

crash2009

17 Foot Counterflow Main?

Sounds like you have a nice big place over there. 48 foot loop, 70 foot loop, and a 17. 

I am going to step out on a limb, by saying that the main vents that you have are likely not big enough.  Can we see a picture of what they look like?  So that we can be sure.  Also We need the diameter of all three mains 48, 70, and 17, we could settle for the circumference and figure it out for you.  If there is no existing vent on the 17, is there at least a plugged hole to put a vent into?  Does the 17 go up hill away from the boiler?  If you are able to figure out how to vent the 17, the radiators and rooms connected to it will likely become warmer automaticly. 



Hold off for a bit before you decide on radiator vents, Lets get the mains done right first.

DanversMA

Main Vent Pictures attached

Thanks Crash,

Yes it is a fairly big old 1858 Greek Revival, 3,300 sq. ft.  Attached are photos you requested.   The photo titled 48-Vent is the main vent on the 48 foot loop, 70-Vent is the main vent on the 70 foot loop.  The piping coming out of the boiler (see BoilerPiping photo) is 3 inch and connects above the riser pipe to a 2 1/2 inch main, this 2 1/2 inch pipe runs about 17 feet where it comes to a tee, at the tee is where the 48 foot loop goes in one direction and the 70 foot loop in the other, the pipe coming off the tee is 2 inch in bother directions (see photo 48-70tee, the 70 foot run is the pipe that is uninsulated...dark in photo).  These 2 inch pipes again are reduced to 1 1/2 pipes in both loops and is 1 1/2 inch where the loops come to the main vents and before returning to the boiler.  The 17 foot straight run can be seen at the start in the 'BoilerPiping' photo (the tee) and is a 1 1/2 inch pipe the entire run, it is 'slightly' uphill going away from the boiler.  I think the 17 foot run could be re-piped to add a vent if needed although it would probably need to be added at the very end of the run, after where the radiator feeds tap off it.  Thanks again Crash for your time and assistance.

crash2009

The pictures help a lot.

Have a look at this video  http://www.youtube.com/watch?v=b1cZACaZ3Ww  You might not need this many, but this is the direction you are headed.  If the cold air can't get out, the steam can't get in.  Without doing the math, I would guess that you need three or four G2's (Gorton #2's) on the big main and two or three on the short main. 



What is that thing on top of the boiler?  It looks like a muffler.  Is that some kind of steam separator?

DanversMA

Main line with no vent

Thanks again Crash,

Do you have any suggestions on the 17 foot main line with no vent?  I'm thinking at one time this was a loop.  It looks like it was capped off when a second heating system was installed for an in-law apartment.  The other system is a gas fired forced HW system with baseboards.  You can see old holes in the sub floor where steam pipes probably once ran (best guess)  If I install a vent beyond the end of the last radiator tap at the end of the 17 foot run, will that help?  Install a number 2 there also?



I don't know what the muffler looking device is on top of the boiler.  This was all present when I bought the house 13 years ago.

crash2009

17?

So the 17 is 2.5".  If you poured 5 gallons of water into the 17, would that drain back to the boiler or drain to the end of the 48 or the 70?  Or do you think it may have had its own drain in the past?

MrDvorak

Yes it will help

I am not a pro, just a home owner, but I think it is safe to say you can only benefit from a vent at the end of that pipe if it is pitched right. At the moment, steam can only get into the two radiators after all the air in that big pipe gets pushed through your radiator vents. They are likely very noisy both during start and end of cycle, they also likely click a lot, and they get warm much later than the rest of the radiators. I am not sure if #2 is necessary for those 17ft but it will certainly not hurt.



Note that if you think that there was a loop there before, that pipe may be incorrectly pitched. Where is the pipe closest to the ceiling - at the tee or at the capped end?

crash2009

Two 17's?

I think I see what I was missing.  You have two 17's?  One is 17 X 2.5, and the other is 17 X 1.5.  The 17 X 2.5 will be vented by the 48 and the 70.  The 17 X 1.5 (if I am getting it correct now?) 



If so, I started a diagram.  If this is the real way it is the 17 X 1.5 is going to be a problem.  If it truly is counterflow, meaning it drains back to the boiler, it needs a drip for the condensate. 

If it drains away from the boiler, it would need a drip installed at the other end.  The other end would be where you would add the main vent.

What kind of shape is the boiler in? 

DanversMA

2 17's, yes

Pretty good Crash, that's pretty close.  Is there a suggested way to install a drip?  Or is it easier to pitch the pipe?  I suppose a vert could be installed where the pipe is capped off but I'm thinking that would be the path of least resistance and the direction the steam would want to go, which is the opposite direction of the radiator.  In that picture, you can see where the pipe is capped, going in the opposite direction about the same distance from the tee is the tap for the raidiator, which goes to the second floor.

The boiler is in pretty good shape, it's about 15 years old and I have it serviced every Spring before shutting it down for the season.  I haven't had any serious problems with it.  I try to drain out the rust about once a month during heating season.  I had a problem last season when a hot hater tank burst and the burner gun was under water, and the fire chamber had water in it as well.  This is the first use since then and it's working OK other then the two cold rooms.....but those two rooms have always been cold.

Thanks again

Rod

Which way do the mains slope?

Hi- I've been following this thread but am still completely lost as to which direction the pipes slope. I've added some letters to Crash's drawing and it would help if you could check the level of the piping and let us know what letter applies.

- Rod

crash2009

Thanks Rod

I was about to tell Danvers that I don't have enough experience to suggest how to change the slope on the 17 X 1.5  I was hoping you would jump in and help out.  You always seem to ask the right questions, and come up with the most economical solutions. 

DanversMA

Main Vents - updated drawing

I thought it might be easier to get an accurate picture.  The colored dotted lines represent the direction water would flow if poured into the pipes.  The orange dotted lines the water would flow back into where it started or back through the top/front of the boiler.  The blue dotted lines show where the water would flow to the bottom/back of the boiler.  The two main vents are located where the circles marked with 'V' are in the drawing.  The piping after both vents drop to floor level, all the other pipes are at ceiling level.  The pitch on the pipes is about 1 to 1.5 inch every 4 feet.  The pipe on the back wall (the 28 foot run) is level all the way.  Hope this helps and thanks again for the assistance.

Paul Fredricks_3

FYI

I believe the thing on top of the boiler is just a chamber. It is there to briefly slow the steam so any water being carried out of the boiler will drop out of the steam and back into the boiler.

DanversMA

Updated Drawing - Any Thoughts

Any other thoughts on my main vents or lack there of?  I updated the drawing showing the direction of the pitch and an exact location of the existing vents, note that right after the main vents, the pipes drop to floor level and enter the bottom/rear of the boiler.

Thanks again for any suggestions, advice

Rod

Main Vent Calculations

Hi-  I looked over your piping diagram and calculated the amount of air volume in the piping. I wasn’t sure where the 2 inch ended and the 1 ½ inch started so calculated it as mostly 2 inch. If this isn’t correct it won’t matter - Unlike your radiators you can’t over vent your mains !

For the Small loop:

10 ft. of 2 inch pipe     @ 0.023 Cu.Ft per lin. ft. =      0.230  cu ft.

12 ft. of 2 inch pipe      @ 0.023 Cu.Ft per lin. ft. =     0.276  cu ft.

1.5  ft. of 1 ½ inch pipe @ 0.014 Cu.Ft per lin. ft. =    0.021  cu ft.

2.5  ft, of 1 ½ inch pipe @ 0.014 Cu.Ft per lin. ft. =    0.035  cu ft.

                                                                                  0.562 cu.ft.



For the Large Loop ( Note that the Riser from the boiler and the 2 ½ main are included is this calculation.

2 ft of 3 inch pipe @ 0.053 Cu.Ft per lin. ft. =             0.106  cu ft.

3 ft. of 3 inch pipe @ 0.053 Cu.Ft per lin. ft. =            0.159  cu ft.

17 ft of 2 ½ inch pipe @ 0.03 Cu.Ft per lin. ft. =         0.510  cu ft.

10 ft. of 2 inch pipe @ 0.023 Cu.Ft per lin. ft. =          0.230  cu ft.

12 ½ ft. of 2 inch pipe @ 0.023 Cu.Ft per lin. ft. =      0.288  cu ft.

17 ½ ft of 1 ½ inch pipe @ 0.014 Cu.Ft per lin. ft. =   0.245 cu ft.

                                                                                  1.538 cu ft.



Second Floor Radiator Loop    

(* Allowance is an estimate for length of vertical and horizontal runs)

14 ½ ft. of 1 ½ inch Pipe @ 0.014 Cu.Ft per lin. ft. =                    0.203  cu ft.

28 ft.* Allowance of 1 ½ inch pipe @ 0.014 Cu.Ft per lin. ft. =      0.392  cu ft.

                                                                                                    0.592  cu ft.

 

Main Vents (Large & Small Loop main vents)-

From what I can see in your pictures, the vents you have now look like either Dole #4s or Hoffman #4 s.  Neither of which have a very large venting capacity.  Also both models lack a float valve to prevent water from squirting out.



On your system I think I would use a  Gorton #2 on each of  the loops (Large and Small). The Gorton #2 vents at 1.100 cu ft per min @ 2 oz. PSI.  (Gortons are available at Pex Supply  www.pexsupply.com on the internet.)  I calculated the Long Loop to include the 3 inch and 2 ½ inch feeder main but in reality the venting will probably be split between the two Gorton #2 s so they should work out well. 



Second Floor Radiator Loop -

Ideally you would put a main vent at the farthest end of the 1 ½ main pipe away from the boiler after the last radiator on this main..  2 ea  Gorton #1 on a “antler” would work well. If this configuration isn’t practical. You could try using some “C” or “D” vents on the radiators as radiator vents.  (A “D” has about the same venting capacity of a Gorton #1)

“C” and “D” size radiator vents are made by both Gorton and Jacobus ( Maid - O- Mist)   I’d get the Jacobus to experiment with ( cheaper in both  price & quality) and then get comparable Gortons if these vent sizes work out okay.    Large venting capacity radiator vents can cause problems like noise and water hammer so this may not work out but I think I would try it as it is quite simple to do.



Piping- As I’m sure you have already figured out your system  piping is rather marginal as it is now configured.  Since it seems to be working reasonably well I would at this point just increase  the main vents ( with the Gorton #2 s) and deal with the second Floor Radiator Loop. When you get ready to renew you boiler would then be the time to straighten out the piping configuration. which could be fairly easily done by adding a few drip lines. BTW the can on the boiler riser that looks like a fat car muffler, as Paul pointed out, is a steam/water separator. Here’s a link to one that is similar: http://www.unionsteam.com/separators.htm#SR2  This contraption tries to do the same function as a dropheader, that is, to dry the steam out.



Insulation- . You might want to check out Crash’s excellent post on insulating steam pipes.   http://www.heatinghelp.com/forum-thread/137178/Insulation   Insulating your steam pipes really makes a big difference and is probably the best “bang for the buck” improvement you can do to your steam system. Let me know if you have any questions and also let us know how the new main vents work out.

- Rod

DanversMA

Thank you

Rod,

I can tell you gave this some thought and took the time to help me get this right and corrected.  I'll get the vents you suggrested and give that a try, I'll have to take another look at the small run to see if I can get a vent after the last radiator(s).  I have started insulating the pipes and have a bulk of them done other than the risers to the radiators and the tees and elbows.  I've noticed a difference already where the basement is a lot cooler now than when there was no insulation.  I bought the insulation at Homan's Associates http://www.homans.com/ , they were pretty good at helping me out and getting me what I needed to get started.  The insulation I bought comes in 3 foot sections with 1 inch of fiberglass insulation and  have a 'peal and stick' flap on them, and Homans gave me some tape made of the same insulation jacket for the seams.  Is it neccessary to insulate the tees and elbows?



Thank you again Rod.  When it's time to replace the boiler, are you near Massachusetts?

Rod

Main Vent

Hi- The insulation will help a lot. As for insulating the tees and elbows, that's a call you'll have to make yourself. Every bit of insulation means more heat is delivered to the radiators. However the fittings are a small percentage when compared to the steam pipes so if you not inclined to insulate the fittings you are losing a little efficiency but no where near where it was with completely bare pipes.

When you get around to replacing your boiler let us know and we can probably recommend someone to you. There are a lot of good steam pros in Massachusetts. I'm a homeowner like yourself and my home is in  Maine. I had to learn steam myself as there aren't many steam pros up in our area.

- Rod

DanversMA

Alternative for Gorton#2

Rod,

I ran into a slight problem.  I didn't realize the Gorton#2 vents were so big (about 6 1/2 inches).  The space between the top of the tee and the brick ceiling above is about 7 inches total as shown in the attached picture, this vent would be for the small loop vent.

Could the smaller Gorton #1 vents in an antler configuration be used instead?  If so, how many should I use?

Thanks again-

BAB

air vents

Nothing beats those #2 Gorton vents.  I started with the #1's noticed positive results then "invested" in the #2's.  The changes were so dramatic I bought more.  Thanks to this site /chat I broke down and did the calculations & found that I still needed more #2's.  Our system has will over 10 #2's and over 20 #1's.

crash2009

3 TO 1 RATIO

CFM rating @ 2oz cfm is (1.750 G2) (.540 G1)  Its kinda expensive to use G1's.  But anything is better than what you have. 



Another suggestion for you, would be to remove the nipple from the reducing T, install a shorter nipple to fit the G2 in there.  Or leave the nipple, remove the coupler, and 90 right out of there.  Two 45's make a very flexible 90, so you can make a little slope.



Attached pic shows the 45's.  Union comes in handy at cleaning time.

MrDvorak

Removing that nipple

Are there any tricks that make the nipple removal "easy"? I would like remove a couple of vent bearing nipples plus I would like to remove some really old 3/4" plugs cemented in place but I am afraid of breaking ~80 years old pipes with too much brute force.

DanversMA

Gorton#2 horizontal install?

Thanks Crash,

That measurement of 7 inches is from the top of the reducing tee to the ceiling.  Once I add a nipple and reducing coupler, there isn't enough room to put a #2 in vertically.  Can the vent be installed horizontally?  Or does it need to be pointing vertical to work properly?  I have enough room to put a 90 in there and point a #2 horizontal.

Rod

Low Profile Antler

Hi - No! The vents must be installed in the near vertical to operate property!  They have an internal float to stop water releasing from the vent and if placed on their side, the float wouldn't be able to do its job.  Look at Crash's vent setup which is a great example of main vent "Antler". (The pigtail on the end is so a pressure gauge can be attached.)



I’ve attached a drawing of a low profile antler which might work for you.  Note the slope. Install it so the antler is uphill so that water will drain away from the vent. Water doesn’t like going around corners and doing a 180 degree turn as it runs down the steam mains really slows it up. As noted on the drawing you can lengthen the nipples if you need to place the union and vent in a more accessible area. Lenghten the first nipple next to the elbow is preferred as this puts less weight on the union.

While you don’t have to use a union, using one makes it much easier to connect the vent and also to remove it if maintenance is required. Use a plugged tee under the vent rather than an elbow as this allows you to easily add more venting if needed. With some street elbows the clearance between the main and the union might be tight so check this before installing the antler. The Low Profile Antler drawing is an eample of what can be done. You may need to modify it to suit the individual installation.



To remove the old nipple -  I would suggest using a penetrating oil such as Kano Labs “Kroil” or PB Blaster. A good auto parts store should carry them. I recently tried Kroil and seems superior to other penetrating oils I've used.  I get mine from Amazon.  A lot of people use WD 40 but it is useless as a penetrating oil. Its use is for water protection. Wipe any excess penetrating oil away before removing the old nipple as you don’t want it falling into the steam main.

- Rod

MrDvorak

Vertically only

Unfortunately, you cannot install them horizontally. They have a float that closes the vent should water or too high pressure reach it. I have similar problems - not enough vertical clearance makes my venting efforts difficult.

nicholas bonham-carter

mounting main vents

the main vents can be mounted on the vertical part of the dry return where it drops down to become wet. if doing this, then they should be mounted as high as possible. somewhere here is a picture of prof. steamhead's which shows just such an installation, but i can't find it.--nbc

nicholas bonham-carter

removing stuck nipples

they have to be cut off about 1/4 inch from the "t". then cuts are made along the pipe axis almost to the thread, in a couple of spots about 45 degrees apart. the small strip of pipe can be hammered in towards the center; then the remaining 315 degrees of pipe should come out easily.

for removal of the plugs, follow the advice of the former governor of the state of alaska, "drill baby, drill!" this is easier said than done as she found out.

if you have a hole to stop up, then using a nipple and cap will allow you to open it up later if needed.--nbc

DanversMA

Is this an option?

In your picture, what is that piece in between the tee and the vent?  Does that have an outside and inside thread?  Is that something I could use in my situation?  If I remove everything above the reducer tee, I could probably get the #2 in there, but would still need to reduce the thread size to 1/2 inch.

Rod

The Tee in the Picture

In the picture the tee directly under the vent is a reducer tee.  Reducer tees (3/4 x1/2x3/4) are available though you would probably have to go to a plumbing store (not Home Depot ) to get one. The second option is to use a regular 3/4x3/4x3/4 tee with a reducer bushing (3/4 MPT x 1/2 FPT) so you can attach the 1/2 MPT vent into it

- Rod

Edit: Hmm....Not sure if you were referring to my drawing or Crash's picture, In this post I was referring to my drawing but it could also apply to Crash's antler, If you need to reduce the pipe sizing you can do it with either a reducer tee or a reducer bushing.

crash2009

On my photo

the piece in between the T and the vent is a 3/4 to 1/2 reducer.  The reducer is gonna take 1/4 or 3/8 away from the 7 inch clearance you have.  I think, if you still want to go with the G2 (6 and 3/8" tall) you might be best to come out of the main, 90, union, then get out of the arch, so you have the overhead clearance to do what you want.  Too bad though, it would look cool if you had room under the arch.

DanversMA

Reducer Bushing

That's what I'm looking at in Crash's picture....the reducer bushing.  My thought is to install a 3/4x1/2 reducer bushing on top of my existing tee (1 1/2 x 3/4 x 1 1/2), then install the #2 vent into that.  It will be tight but might work, once everything is tightened up it should have about an inch of clearance above the vent top.  Is black iron good or should I get a different material?

Rod

Use Black Iron Fittings

Use black iron pipe/ fittings The steam can cause the zinc in the galvanizing to flake off and plug the vent holes

DanversMA

Antler where there is no venting

Rod,

I think I'm going to install the antler system as in your scetch on the leg that has no venting at all (from previous posted pictures).  I was going to add this after the last radiator rise.  My question is because there is no wet return at the end of this run, is it OK to just slope it back to the same direction as the dry steam?  Would it be better to add a downward facing pipe like it was going to a wet return and just let it drip on the basement floor or into a bucket?

Rod

Attaching Vent to Main

You always want to install the piping/vents so that water will drain away from the vents.

Don't install the vents at the very end of the pipe because any water being carried along by the steam will slam into the end of the pipe.   Use a !/2 pipe tap and thread a hole in the top of the steam main. I would use a 1/2 pipe for venting (1/2 inch pipe will support up to 2 Gorton #2s venting wise)  If for any reason the pipe to main connection is weak you can always put a filet of JB Weld around the joint.

- Rod

DanversMA

Kroil

Rod,

They have a deal going on their web site where you can buy two cans of the AeroKroil for $12 (13oz cans) which is less than half of the usual price for one can.  I just bought two and getting ready to start this work on the vents.  Thanks for all the advice.

BAB

making the #2 Gorton work

DanversMA

Main Vent Update - New Pictures

Hello Rod and Crash,

I hope you both had a nice Christmas and Ney Year.  I wanted to thank you both again for all your help and input.  I used the extra time off from my regular job to get the main vents squared away as you suggested.  I installed the Gorton #2's on the two loops as suggested. I also did some re-piping on the run that had no venting and no return; on that leg  I capped the tee that led to no-where then after the last radiator feed I installed a tee and off the tee an antler with (2) Gorton #1's.  As a result (and the last two nights were a good test as it was COLD); the radiators off the leg that had no venting are getting hot now (before they would only get warm).  And the radiators off the two loops are behaving a bit different than before where some are getting heat faster than the others. On one of those radiators there was an adjustible vent that I opened a bit more and that one seems fine now, the others I can live with but will try to balance them with new vents in the near future.  Do you guys have any suggestions for radiator vents?  I was thinking of the Hoffman 1A's because they are adjustible.  Thanks again (see attached updated photos)

crash2009

Venting

Christmas and New Years were just a minor inconvienence this year.  Thank-you, same to you. 

Looks like your venting job turned out well.  Somehow you managed to get the G2 stuffed into that little cubbyhole.  The pair of G1's fit nicely as well.  I am sure you have noticed some big changes in your response time.

Get yourself a copy of Steve and Gerry's Balancing Handbook.  Steve and Gerry have forgotten more about steam in the last 5 minutes than I have learned in a lifetime.  http://www.heatinghelp.com/products/Steam-Heating-Books/25/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek

Hoffman #1 is a good quality vent.  Unfortunately I have heard a couple complaints.  First of all they CLINK when the steam gets to them.  This can be annoying in the middle of the night.  Secondly they are difficult to adjust.  The Hoffman is pictured to the left.  To adjust this one you have to loosen the set screw on the top, then dial in the adjustment band, then tighten the set screw.  Maybe I'm just lazy but the set screw just drives me nuts when I have to open and close it 10 or 15 times to get the vent just right.

Ventrite #1 is adjustable without the additional steps of opening and closing the set screw.  The indicator is clear and presise.  They work just as good if not better.  They have saved my hide many times.  Ventrite #1 might cost a little more, depending on your location, but I really beleive they are worth the extra $$.  

DanversMA

Vent-rite #1

I couldn't find any Vent-Rite #1 vents on the web for sale.  PexSupply doesn't carry them (or at least they don't list them).  Is this something carried at local suppliers or big box stores?

Rod

Vent-Rite #1

Hi- Thanks for the update on your system. Nice job on the your main vents!  I agree with Crash that the Vent-Rite #1 s are great radiator vents,  I use them on most of my radiators, However, as Crash mentioned, they are more expensive  I get mine from FW Webb (which has outlets all over New England)  The Vent-Rites are listed on page 54 of the Webb Heating catalog and the Webb part # 496. I've attached a Vent-Rite  brochure below as you might want to contact the factory and they could give you the names of sources close to you.

- Rod

crash2009

Also

http://www.emersonswan.com//vent-rite.html



http://www.partsguy.com/cgi-bin/PartsGuy/1.html