What's up with these pipes?

Hap_Hazzard

Okay, this has been bugging me for a while now, but I've had too many irons in the fire to worry about it, but I finally took camera in hand and went downstairs and snapped a picture of my near-boiler piping so I could get some informed opinions on how bad it is.



The system has always worked well, and I never had to do much to it in the 12 years I've had it until the wet return rusted out, aside from the weekly blow-down--just a low water cut-off, a thermocouple, and an air valve now and then. But thanks to the return, I've had to learn a lot more about the thing, and as I've learned more (mostly from you guys), I've started to look at things more critically.



The first thing that looks odd about the piping is the way the mains do this weird little do-si-do thing, where they go around each other and then the left one goes right and the right one goes left.



Next, and more important, is the way the two boiler risers go right through the header and on up to the system mains instead of having the supply riser coming off the header between the boiler risers and the equalizer loop.



But the weirdest thing, which isn't obvious from the picture, is that the IOM for this model (Peerless G-561) says it has only one supply outlet! I'm guessing the installer thought he could get more steam out if he took that 2" plug out and screwed another pipe into it, thinking Peerless must have plugged that hole by mistake. What do they know? They're just the manufacturer.



So this has to be putting a lot of extra water into the system, but I really haven't had any problems to speak of, and while I can see that this is pretty far from right, I don't really feel confident that I could fix it. At any rate, I'm not about to tackle now, with heating season just around the corner, but I'm planning to take the mains apart next summer, and it would be good to have a plan for redoing the near boiler piping by then.

Rod

Let Sleeping Dogs Lay

Hi- Nothing wrong with have 2 risers pipes coming out of the boiler and you're right, the boiler piping is pretty "odd" as there is no header.

I'm a homeowner so one of the pros could better tell you whether working on this boiler is really feasible. My initial thoughts are that, since it is working satisfactorily, I would just leave it alone. It's an old boiler and trying to change over the piping at this point, I would think, is very likely to break something expensive and perhaps irreplaceable. If it were me I'd be seriously planning for a new boiler sometime in the near future and wait to have the piping corrected at that time. As I remember it, Peerless puts a date code in the serial number, at least on those boilers built after1984.  What are the last four numbers of the serial number?  They tell the month and year it was built. (The newer ones also include the full year.)

Just a thought.

- Rod

Hap_Hazzard

There is a header, sort of

Technically, that horizontal 2" pipe connecting the risers to the equalizer is the header, but, since it doesn't really do what a header is supposed to do (separate water from the steam), in effect there is no header.



The serial number ends in "88," so that would make it a mere 23 years old. That's not as old as I thought. (I was thinking it was pretty old because it's a 561 instead of a 61-05, but I'm not sure when they made that change.) I recently removed the plug from the tapping for the probe-type LWCO, so I got a little peek inside, and it's not that bad in there. I'm sure it's not as efficient as it used to be, but I don't expect it to start leaking anytime soon.



Thanks for the advice!

JStar

RE:

Boilers of a certain size only require one riser off the top, so the manufacturer plugs the other tapping. Once you start getting into a larger BTU rating, you'll need to use that second tapping, as well as increase pipe sizes around the boiler. There are great advantages to using the second tapping on every size boiler, so it's actually better that it was piped in like that.



However, as you know already, the piping is a bit...off. The only problem I would predict would be uneven heating on one of the mains. And possible water hammer near the boiler.

Hap_Hazzard

I'm not convinced

that there is an advantage to using both tappings on a smaller unit, mainly because I can't imagine why Peerless wouldn't recommend that. It doesn't cost them anything to say, "stick another pipe in it." If it would allow them to get better performance out of a smaller boiler, why would they put themselves at a competitive advantage by specifying only one riser?



As it turns out, the 561 was the largest of the single-pipe boilers in that series, so it's not as bad as if it had been even smaller, but still, I'm pretty sure they chose to draw that line where they did for good reason. I'm not going to pretend that I know enough about the physics to understand exactly why a given size and number of risers is optimal for a given boiler, but I'm willing to bet that the people who designed these boilers did.



I can't recall any water hammer issues at all. When I sit in my living room I can usually hear the burners come on, then I can hear when it's making steam--especially when it needs a skim--but nothing unduly noisy. There's even an upfeed branch that's pitched the wrong way, but I never knew about it until I saw it. It must be practically full of water most of the time, but the radiator gets hot, and I've never heard it hammer.

crash2009

Me too

  I think I would just leave the piping alone until its time for a new boiler.  However if I was sleeping beside that one, I think I would find out what caused those burn marks on the boiler skin.

ChrisJ

I donno

I'm fairly knew to this but at this point I agree with Dan's comment in Greening Steam which is something along the lines of "If a boiler has 10 tappings USE ALL 10".  The slower the steam exits the boiler the dryer the steam you will have. 



At that point I believe its more about wasting energy than making noise. 



However, that being said I also agree with others.  Don't touch it if its working.

JStar

RE

There most definitely is an advantage to using both tappings. It's steam-fact. The more tappings you use, the slower the steam will exit the boiler (a good thing!). The manufacturer designates the number of risers to be use based on size so that the contractors buying them will pick their product, because it's easy to install. One pipe is easier and cheaper than two, right? I'd rather trust a century of field knowledge than a modern engineer in a test lab.

ChrisJ

Actually

I have no problem trusting the engineers.  You will notice the size of pipe and number of risers recommended ALWAYS says "MINIMUM REQUIRED".



And that setup will give you just that, minimum performance.

Techman

Hartford Loop,

Is there one lurking down there?

Hap_Hazzard

Yes. At least they got that right.

At the moment there's nothing connected to it because I'm replacing the return piping. It's been a slow process because I had to take a couple of walls down.



By the way, has anyone noticed the effect some interior paints have on steel pipe? As I've been tearing the old pipe out from behind the walls, I've noticed that the sections that had been painted have looked worse on the outside than they did on the inside. I'm wondering if only certain kinds of paints cause this or if interior paints in general are bad. I've painted the new pipes I've fit, but I used a rust-resistant paint formulated for high heat--like barbecue paint, only nicer colors.

Hap_Hazzard

Okay, okay...

I'll leave the near-boiler piping alone for now. It's not like I'm running out of stuff to do.



But not until the boiler gives out? I'll probably be dead by then.