Rehashing the old Williamson vs Weil McLain comparison, and new boiler specs

What size are we talking about?

If it's an EG45 or smaller a single 3" is far more than enough. Not sure about the larger ones.

I like to explain boiler choices to customers in terms of cars. (seems to work here in the motor city). You have GM the parent company of Chevy and GMC. They both have similar models One tends to be basic and one's got a little fancier trim. Both get the job done or in the case of boilers installed right will work.

I would agree drop headers are nice, and if you install them like the directions they usually will work. The only manufacture that I'm not crazy about their install instructions would be the Utica / Dunkirk branded steam boilers with the side tappings. These boilers installed without a drop header seem to carry more water off into the system. The few of these that have been installed with a drop header don't have the issues.

GSA-125 definitely does not need more than one tapping. If you want to max out, you can use a single 3 inch boiler riser. More than enough.

@dabrakeman

maybe i've got the wrong table. i'm getting like 96 ft/s at about 386 lbs per hour (i.e. 93,000 btu net/240) and 1 psi in 2 1/2 inch pipe which is on high side but still fits in desired range for heating systems (and 2" does show over the green range although not precipitously which is why I reckon the setup with the burnham fired at 1.05 through single 2" riser still worked OK.)

@dabrakeman

hmmm. thanks for pointer to those deadmen tables by Ted Parreco (look like pdfs from maybe an excel built calculator where you could input different pressures) and the TSV calculator give identical results so I think I was maybe misreading the table I grabbed.

so while 1 psi might be normal running I think 0 is the startup steamup conditions so maybe that is why those tables use 0. so if you don't want water at startup then the 0 design and as low as possible velocity (is it dan's venerable 15 fps??) maybe calls for less extensive near boiler piping to mitigate wet steam.

Using the existing 2" riser, the table for 108 output on the williamson GSA-125 shows 34.5 fps which is outside the williamson recommendation (although they greenlight 33.9 fps on GSA 175 with a single 2.5 inch riser. The new GSA125 specs actually reduce the output to 103 bringing my velocity down to 32.9 fps if i kept existing riser so maybe within manufacturers spec although they don't give the nominal limit that informs the colors in the table so i'm guessing it is kind of under 34 fps. so maybe an updated table would greenlight a 2 inch riser). All that said going to 3" (which I think is the tapping size on the GSA125?) would get me below Dan's deadmen's magic 15 fps target at 0 psi. The manufacturers seem comfortable with the idea that the near boiler piping will wring out the steam since they allow for exit velocities in the 20s and even 30s but I really like the idea of keeping it relatively dry to start.

Coming out of this burnham with a 2" single riser this system did not carry a lot of water and it does not have a drop header but it is easy enough and not too expensive with a single riser to provide some large near boiler piping.

looking at some of @ChrisJ thoughts on another great steam velocity thread - in particular hindsight he reckoned that instead of bushing the tappings he could have used a 12" nipple of 3" and then reduced. this seems really sensible as it reduces the velocity at the steam chest exit. @KC_Jones was about going back up to 3" in the drop header with, i impute, the notion of reducing velocity to allow for dropping droplets, as it were (although I think part of the idea is to avoid picking up in the first place ;- ) and also they were talking double risers so 3" header would keep the flow about rate once joined about the same.

So from experiential or theoretical perspective, is a 12" nipple enough to limit the effect of increased velocity where the riser reduces or should i try to stick to 3" for full height or riser and use a reducing L? I can get 2 foot 2.5 or 3 inch nipples without too much trouble and then I could use a reducer L and start threading a drop down to the existing 2" header which is maybe 20 inches above the boiler. i can't thread anything above 2"–as I imagine is true for many here –so getting back to 2" is handy for finishing the connections and the velocities involved are well below long term erosive potential. I understand most festidious and maybe elegant practice is to retain larger diameter and lower velocity in header so any wet steam into the header is more easily dried by gravity before the system take off and returning to the drip leg; but, unless the williamson has a reputation for pushing water droplets, this having done fine on single 2" riser from a burnham all these years it seems a bit like overkill to take the header up at this point, especially if reduction of velocity immediately adjacent to the boiler steam chest is acheived.

final thought, akin to the 3" boiler take off riser and then reducing, what if I add a short (6-12") upsized nipple at the system takeoff which is vertical so the slower velocity exit would discourage carrying droplets??? this is speculative but partakes of the same general theory. ideally like a 2x3 or 2x21/2 bullhead tee but those don't look easy to come by so that's a case for just replacing the run of the drop header with larger pipe but more of a PIA since i cant thread that size. I suppose I could use a cross at the take off and tie the bottom outlet into the drip and then I wouldn't get a puddle as i would using a tee for the take off. probably overthinking, but i'd rather over think and underdo as the overthinking allows :-). i'm really hip to not bother with this or maybe try it with the 3" up leg and existing 2" and only mess with it if it manifests wet steam problems.

and in the trying to prevent problems motif, where I do thread, I've been wiping well and then using the green automotive brake cleaner to try to reduce any oil from getting into the system although muc hlighter and seemingly evaporating don't know if i'm solving or introducing problems. and i wonder if there is any thread paste that is better or worse for creating slippery water quality in steam system?

thanks to the deadmen and their live counterparts.

brian

@dabrakeman

The closer the top of the water is to the steam tappings, the more likely it'll be to pull water up into them.

I could only guess the larger boilers have more distance between the top of the block and the normal water level.

My advice is forget about the concern of "droplets" or so-called "wet steam". All the steam our boilers make is Wet Steam, meaning it is at the verge of turning back into water.

The droplets fall out of the steam very quickly and hit the interior walls of the pipes. You all know that I've seen it.

What most people are calling "wet steam" is what I call "the boiler throwing gallons of water into the mains"

I suggest dropping the term "wet steam" and replace it with "surging" "priming" or "boiler vomiting water into the main"

It has lots of names, I'm just trying to get rid of the one that is fuzzy, misleading, and misunderstood

@dabrakeman sorry, i posted a sample pic of a double header . . . eer riser . . . williamson that i think you mistook for the job i'm working on. I didn't have an pictures but when I was over there today building a derrick in the stairs to hoist the new one in and the old one out i grabbed a couple snaps and took a longer look. i'm going to definitely do a 3x24 inch riser to a drop header. its just a question of where i downsize. it's big money to stay in 3" and this setup worked fine. If I'm doing the 3" at the boiler exit, I'm thinkin i'm likely to just hit a reducing el top of the riser and build the drop header of 2" cause I can thread it or use nipples i normally stock.

and you notice in the back shot there is drop to the harford loop which isn't even all of a couple feet long. unless the weight of the water in that 'trap' is some utility for stable operation, why would there be a drop loop, why not just a return without a trap is high in the boiler water line so it wouldn't drain the boiler if it failed.