Main Vent

Bob W._3

He posted the problems with the near boiler piping under a thread titled: Header Question.

Raph

So I have

another question. Hmm, looks like I'm getting a bit obsessed about my single pipe steam system! This is how my steam main looks like in my basement(pardon the lousy patching of the pictures, but it gives you a good idea of how the whole main looks, notice no main vent!!)

Right now my radiators heat good, but hissing a bit loud. I imagine the loud hissing is due to no main vent.
In the 2 radiators that are fed off the last 2 risers off of the main (the last 2 are all the way to the left, just before the drip connection to the return, the second to last one is hard to see but it is going away from you into the block wall) I get a slight hammer and gurgling(they are already pitched towards the supply valve), but it's still pretty anoying. Is this becasue they are connected to the last 2 risers off of a main with no vent, and the steam is fighting with the water trying to drip down?

Also, when the system turns on, it will go for while then stop for 5 min. and start up again for 5. I thinking this happens because there is no main vent and the pressuretrol(cut in .5, cut out 1) shuts the boiler off because the pressure is building up too fast without a main vent. Not due to low water, since it does this even when the gauge glass is half full. Does this sound right?

Regarding location of the main vent, should it go about where I put the red arrow on the main?

Again, I'm just trying to learn all I can about how to make my system run as smooth as possible.

Hey, just a side note regarding insulation....I added all of the white & silver insulation in the pic(since there was none when I bought the house). Does this look adequate, or should I go thicker??
Thanks is advance.

-Raphael

John S.

Venting

sounds to me like you're dead on with the lack of main venting being an issue. The main vent should go after the last riser, preferably back 15" from the drip down to the return.

The picture is a bit small, so I may not be seeing it correctly, however, it appears there's no equalizer or hartford loop and there are other issues with the near boiler piping. Take a few pics of the piping around the boiler.

(edit) Sorry, just read your other post regarding this issue.

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Raph

So,

is this where you recommend the main to go? I circled the area in red.

John S.

It appears

that's the return back to the boiler? It looks like the last riser is a good 10'-20' to the left of your circle, but it's hard to tell with the foil seam tape. the ideal place would be right after the last riser, raised as high as possible.

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John S.

Saw that..

after the fact. thanks Bob.

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Raph

Ok I get whay your saying,

after the last riser on the dry return but before the drip connection. So why is this the best spot for a main vent? -Raphael