no hartford loop?

john_z

My neighbor is having a new residential steam boiler installed and there doesn't seem to be a Hartford Loop.  It's a New Yorker Model CGS-A. His house is a one pipe system. The boiler has a 2" supply and return and the angled pipe in the picture is the equalizer, I think, but there seems to be no h-loop. The black vertical pipe on the right connects to the condensate return coming off the main. Am I right to think it does not need a loop unless the returns are 'wet'?

DanHolohan

It needs a loop

and he doesn't have one. I'd start all over again. Tell him to ask the contractor to show him the installation instructions from the boiler manufacturer. Compare that to what he got. 

Unknown

WOW!!!

There are BIG TIME probs with this install!!!



Dan H. does not chime-in much unless he`s perturbed about something,,, looking at this pic I can certainly see why.

Big-Al_2

Does it Really Need A Loop?

1) If the return is overhead and dry, what is the purpose of a Hartford Loop, since the boiler can't drain up?  The return is connected well below the waterline, so it can't have access to steam.  What would the loop do to help?



2) The riser going straight up to the main looks like real trouble.



3) Where's the insulation?

john_z

Thanks Dan

I'll let my neighbor know. I've got your books and will show him your post and the relevant info.  He was wondering about the work as the contractor was measuring and fitting about one piece of pipe per day.  Winter is not far off!

Unknown

Does it Really Need A Loop?,,, HUH?

If anything, anywhere on the returns below-level should spring a leak(and go undetected tor a short time),, how would you propose any sort  of water level can be maintained to keep this from dry-firing?

Steamhead

Agreed

that's the kind of installation we rip out. Then we pipe it right. 

Big-Al_2

Wait a minute

The header piping is all wrong, that's for sure.  It definitely needs major revisions . . . but . . .



1) The only part of the piping that a Hartford loop prevents from draining the boiler is the return . . . and a dry return is above the water line.  I suppose the last couple of feet of horizontal pipe in the return could be considered wet . .  . but so could the bottom of the equalizer.  What protects the boiler if the equalizer rots out?  Only the LWCO. What if the ball valve on the boiler drain starts leaking?  What protects the boiler from that?  Only the LWCO.  It's not like there is a long length of buried  wet return that's going to rot out and go unnoticed.



2) The Hartford loop also acts as kind of a P-Trap to keep steam from getting back into the return . . . if the return enters the equalizer partway up.  It also forms a low spot that can collect sediment and plug up.  However . . .  this return meets up with the equalizer at the bottom, so the lower end of the return will always be underwater . . . unless the equalizer rots out or the drain valve leaks.. 



A Hartford loop would be the more conventional way to pipe the return, and certainly wouldn't hurt anything.  If I were piping the boiler, I'd put one in, but in this application I just can't see that its absence is a cause for great concern.  If I am wrong, please tell me why.

Unknown

Get "Bigger-Al",,,,,

No-one ever said the Hartford was perfect,, but it has been better protection than nothing for a long-time,,, have you ever checked Dan`s writings on boiler explosions?



C`mon,,, give your head a shake!

Big-Al_2

I'm thinking this one through.

I've read Dan's book and understand how the Hartford Loop saves boilers from leaky wet returns.  



Here's an excerpt from something Dan wrote:



"If the system has a dry return (as most one-pipe steam system do)

you still need a Hartford Loop. Consider a one-pipe steam system for a moment.

The main works its way from the boiler header, around the basement, and then

drops for the first time when it returns to the boiler. There are no return pipes

below the boiler water line, so there's no danger of losing the boiler

water should an above-the-water-line return pipe break.



But keep in mind that the

near-boiler piping has an equalizer that keeps the water from backing

out of the boiler when steam pressure builds. If you drop directly from

the end of your steam main (the return) into the middle of your

equalizer, you'll set up a condition where steam might have access to

the return line through the equalizer as the water line in the boiler

steams down. By bringing your return line down to the floor, and then

rising up into your equalizer (in other words, by building a Hartford

Loop), you ensure that steam in the equalizer can never enter the

return line and cause water hammer."





So far nobody has tried to explain what a Hartford loop would do to protect the system from a dry return that enters at the bottom of the boiler.  I have an open mind.  Please educate me.

nicholas bonham-carter

now now dave..

actually this is not the typical dumb question. al is right: in this case the boiler has less opportunity to spring a leak in some wet return, which would be protected by the hartford loop. if the drain valve develops a leak, the hartford loop is no help. this will remind us how important the weekly flush of the LWCO is.

so instead of shaking our heads, flush that LWCO!!--nbc

Big-Al_2

Thanks, NBC.

I've actually been thinking about this for a couple of years.  If I paid for the boiler installation, I'd insist on a Hartford loop, even if it was just for the sake of conventionality.  On my own single pipe system though, the dry return drops directly down next to the equalizer and joins it at the bottom, right where it enters the mud leg of the boiler . . . no Hartford loop.  It was like that for five years before I bought the place, so I can't just call the fitter up and demand a proper remake.  After careful analysis, I  concluded that it only gave me about a foot more of vulnerable pipe . . . right in plain sight . . . right next to the LWCO that I flush and test weekly.  I'm not about to pay a fitter hundreds of dollars to re-pipe it for no appreciable benefit. I'll fall asleep just fine tonight . . . but if tomorrow you read in the newspaper about some fat old Wisconsin dude who took a boiler ride . . . I probably won't be back.

john_z

Thanks again

Thanks to everyone.

I've sent my neighbor a link to this thread so he can read it himself and I'll post later with his decision just to wrap things up.



I'm a school maintenance person whose duties include operating and maintaining our low pressure boilers. I enjoy reading the opinion of folks who get to master the trade. Thanks, too, Dan for your site and books.



John

Unknown

I'd fire that "installer"

I'd fire the installer and hire a REAL steam boiler pro to redo the job and then bill the 1st installer for a real lesson of not opening/reading the installation manual.

Paul Fredricks_3

I'm agreeing with Al on this one

I've said this before. If you put in a Hartford loop you actually end up with more piping below the water line that can leak. Look at a counter flow system; No Hartford loop. o, it can't hurt to have one, so how about two of them, just to be safe.



Now maybe there is another good reason to have one, like if it's not there the inspector will fail the job because all he knows is there has to be one, though he doesn't know why. ( No offense to any inspector out there who does know).



The rest is definitely wrong and needs to be redone, per the manufacturers instructions. It's in the book that came with the boiler, show the installer.

Ron Jr._3

I agree with Big Al and Paul

For dry return steamers , the Hatford Loop is of little value . What exactly are you protecting if the return pipe hold very little water ?

 

But to be honest , we pipe in the loop on everything . I don't want that to bite us in the **** in the long run -------  by an overzealous inspector , or a premature problem with the boiler ( which would have nothing to to with the lack of a loop ) .

I also agree with everyone on the need to repipe the header . It was a good try but the equalizer is oriented dead wrong .  

DanHolohan

Good words, Ron.

And if there's ever a problem with the boiler, the manufacturer can look at their drawing and look at the installation and ask where the loop is, and then the homeowner is in a fight with the installer, and both are holding the bag. And then, as you say, there's the inspector.



I think every steam boiler is better with a Hartford Loop. I'm funny that way.

gerry gill

Al is correct regarding

the purely ''physics'' of it...but like the others i'd put it in anyways just to satisfy the powers to be.

EEngineer

No! - no hartford loop

I just recently replaced an 80-year-old steam plant with a newer one of my own design.



Designed in 1927, my original steam plant did not have a Hartford loop. I went through the same reasoning that Big Al did; since there are no buried or long wet returns, what does a Hartford loop buy you? Nothing!



The steam loop in my basement follows a lot of old coal designs, i.e. a long loop that only drops to a wet return at the boiler. The original was piped directly to the return of the boiler; no equalization loop. For a coal-fired furnace with a long cycle (8+ hours each day), this probably made a lot of sense. The norm is steady state steam pressure throughout the system with few equalization or start-up air purge issues. This system didn't even have a main vent!



When I designed the replacement, I went with a large main vent and a Hartford loop. Dan's comments made a lot of sense to me:

"But keep in mind that the near-boiler piping has an equalizer that keeps the water from backing out of the boiler when steam pressure builds. If you drop directly from



the end of your steam main (the return) into the middle of your equalizer, you'll set up a condition where steam might have access to the return line through the equalizer as the water line in the boiler steams down. By bringing your return line down to the floor, and then rising up into your equalizer (in other words, by building a Hartford Loop), you ensure that steam in the equalizer can never enter the return line and cause water hammer."



I put in a Hartford loop that dropped to about 4" (so I would still have room for a "crap-trap") from the floor for just this reason. The Hartford loop doesn't provide much protection from leaks in a long wet return; instead it provides isolation between the equalization loop and the return. It is a nice quiet system with no water hammer. BTW, the main vent ended up at the lowest point of the loop which happens to be just above the boiler. Since steam tends to rise, it purges the entire loop before closing the vent.