So terrible it seems to work...

Patrick_North

Trying to lend a hand with assessing our church rectory's steam system (I'm not a pro). It's seen its share of knuckleheads over the years, one of whom split the smallish (2") single main with a bullheaded T to service the two sides of the building. Total EDR is about 350. The system is eesentially a two-pipe with radiator vents system. Distribution problems you ask? Crazy brain-jangling water hammer? Nope. You see, there's also no main vents. I'm guessing <em>this</em> problem is preventing the other by keeping the flow sloooow.

So while I'd love to add fittings to be able to add the main vents (a relatively inexpensive option) should we expect that doing so will exacerbate the bullheaded main (a relatively EXPENSIVE fix)? Thoughts?

Thanks,

Patrick

Jamie Hall

Why is it...

that churches seem to have the oddest systems (rhetorical question).



If I understand your description, you have steam coming into that T from the leg, and going out both ends of the crossbar?  That's not really a bullheaded T -- at least not what I mean by one (what I mean by one is steam coming in both sides of the crossbar and going out the leg).  If I am right, that T isn't going to cause any problems at all.



Is this a conventional or vapour two pipe system?  That is, from the diagnostic point of view, is there some means to keep steam from getting into the returns, such as traps, orifices, or something along those lines?  If so, while the vents on the radiators probably won't hurt anything, they probably don't help much either.  And the second question is, are there crossover traps between the steam mains and the dry returns?  If so, then main vents on the steam mains aren't needed, either, in my view.



Note that if there are no dry returns, then vents on the radiators -- or individual return lines above the boiler water line plus the B dimension -- are needed.  These systems aren't that common.



However, one or two decent sized vents on the dry returns (assuming that there are dry returns) at the point(s) where they drop to a wet return and to the boiler might help a lot.



For a much more longer winded commentary on vents, you might want to look at my comments under sreja's thread "no main vents on two pipe condensate system"...

Patrick_North

Encouraging!

Yes, steam exits the header from a single main, travels about 10', then splits in a T feeding two mains, left and right. Bullheaded or not, it would be a relief to know that this shouldn't cause problems!

The system is a bit of an oddball. Hard to tell from the rough "patina' left by several generations of knuckleheads, but it may have been a vapor system originally. There is no dry return. A couple of rads are piped as one-pipe, but most are two pipe with all the returns dripped into the wet return. No condensate pump.

This maps nicely to the (rare) two-pipe system illustrated in LAOSH that does utilize main vents. But maybe I'm missing something?

Thanks,

Patrick

Jamie Hall

doesn't sound

as though you're missing anything, Patrick!

Patrick_North

Now _that's_ a rarity!

Thanks for the help!

Patrick