Wrong Main Vent

Aberagejoemn

Hello, I have a one pipe steam system. I believe children installed the boiler back in 2003 before I bought the house, they put a Hoffman 40 as the near pipe vent, I bought a Gorton D to replace it. Does that sound right? Right now the boiler fires, stops, fires, stops, fires and that vent is blowing hot air out. A Hoffman 40 can't be the right vent for the return line correct?

nicholas bonham-carter

Main vent misselection

Most 1-pipe systems will need a much bigger vent, and you can never have one which is too big.

Why not post a picture of your boiler piping, and a drawing of the piping layout throughout the house, and we can advise on the size of main vent you need.

When the radiators hiss, and the boiler starts and stops endlessly, it's a sign that the main (not rad)venting needs enlarging.--NBC

Rod

Main Venting

Hi- As NBC said it would appear that you need more main venting.  Do you have only one steam main? If you give us the size of the main, the pipe size and length, we can determine how much venting capacity you need. I 've attached a chart below. Measure the circumference of the pipe and consult the chart to determine the pipe size.  We don't need an exact length of the main. If it is within a foot or two that is okay. 

You also might want to check out this website.  http://www.gwgillplumbingandheating.com/webapp/GetPage?pid=415   It belongs to Gerry Gill, who is a expert steam pro in Cleveland. Look around his site as it has a lot of good information on steam heating.

- Rod

Aberagejoemn

k

Might take me a while with the holiday weekend but I'll post an update on the dimensions. I did swap out the Hoffman for a Gorton D, fired the system up but couldn't stick around to completely monitor it.

Aberagejoemn

Followup

Ok, so attached is a rough drawing of my piping in the basement as well as a couple of photos of the near boiler piping and a list of my radiators.

Aberagejoemn

Here's the rad list

See list

gerry gill

i would feel that if you

dont at least have a Gorton #2 for a main vent that you are just wasting money. Picture yourself as the steam and you go down the main, if that main vent doesn't look as big as all outdoors to you, you'll easily take a detour and head for a radiator vent.

Aberagejoemn

So...

The way they tapped the main brings the vent out at a 90 degree angle just like the radiators. The gorton you mentioned is threaded vertically. Any easy way around this?



Any other feedback on the other vents?

Hap_Hazzard

Vents

Assuming you mean a horizontal 1/8" NPT tapping, you could either use a high-capacity radiator vent, like a Gorton or Maid-O-Mist #D, or you could use some combination of elbows and reducing couplers (or a reducing elbow, if you can find one the right size) to go from 1/8" to 1/2" and end up vertical so you can put a Gorton #2 on it. A #D vent has the same venting capacity as a #1, which is an adequate size for a short main, but the #2 is recommended for longer mains. Unfortunately, you won't be able to really get your money's worth out of a #2 on a 1/8 tapping because the ID of a 1/8" pipe nipple is .27". I'm not positive, but I think that's a little smaller than the vent port on a #2 vent, so your third option would be to drill and tap that 1/8" tapping to 1/4" or 1/2" NPT.



Regarding your other vents, you don't say what size those Maid-O-Mist vents are. They make them in all the same sizes as the Gortons except for the #2. They're not as expensive, but they tend not to last as long. Some people like the fact that the vent ports can be removed.



A hissing or squealing vent is a leaky vent. Usually they leak because of scale deposits, and soaking them in vinegar or dilute acid for a few days can sometimes bring them back, but you need something to stick in the radiator in the meantime anyway, so you're going to need to buy some new vents.



You generally want the most venting on the radiators with the longest runs from the main, and you want to make sure the radiators closest to the thermostat don't get hot before the others do, because they are going to determine when the boiler shuts down.

Rod

Main Vent Location

Hi-  A lot depends on how much vertical clearance you have between the top of the pipe and obstructions above (floor, floor joists, water piping  etc.) as the Gorton #2 is a big vent.   If you have vertical room, it is pretty easy to drill and tap a hole for 1/2 pipe. If you aren't familiar with pipe tapping, you might want to have a pro do this for you.  You can then just screw the # 2 vent straight into the taped hole.  (With any of these options always check whether you have enough vertical clearance).

Another option is to drill a hole in the pipe and weld on a "weldolet" . Your local

industrial hardware should have these or you can go to McMaster Carr 

www.mcmaster.com/



In the Search window type in "steel pipe branch connections"  or Part # 4587K53   (for 1/2 inch pipe)  

   If the tapping and just screwing in the vent doesn't work out successfully. (Joint is loose or weak due to thin wall of main pipe), you may want to further reinforce the joint between the main pipe and the 1/2 pipe using JB Weld, which is a high temperature epoxy available in most auto parts stores. I've used a close nipple screwed into a 1/2 pipe coupling. I sanded both the connecting face of the coupling and the main pipe around the hole and then screwed close nipple /coupling into the tapped hole. I then filleted in the area between the coupling and the main with the JB Weld.   Keep in mind that this tapping only has to support a max of 3 PSI so it isn't like it was high pressure.



Venting capacity wise -  1ea. Gorton # 2 is equal to 3 to 4 Gorton #1s. A Gorton # D is equal to a Gorton #1   You can get Gortons from your local heating supplier or on the Internet from Pex Supply.. You can get radiator vents from the same sources. radiator I would recommend that you get your main venting increased first before you tackle your radiator venting.

     Radiator Vents -  Gerry Gill and Steve Pajek have written a book on venting which I would highly recommend. It is available in the " Store" section of this website as a downloadable  e-book

http://www.heatinghelp.com/products/Steam-Heating-Books/25/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek

and is also included in Dan's book "Greening Steam"

http://www.heatinghelp.com/products/Steam-Heating-Books/25/158/Greening-Steam-br-How-to-Bring-19th-Century-Heating-Systems-into-the-21st-Century-i-and-save-lots-of-green-i

The venting book takes a lot of the guess work out of trying to balance your steam system.  On the non operating radiator - Check that the inlet valve is working (fully open) and check the radiator with a carpenter's bubble level. All one pipe radiator should be shimmed so that they have a slight slope towards the intake pipe so as to "encourage" the condensate (water) to flow out of the radiator and back to the boiler. 

- Rod