black pipe welding vs threading

MikeMens

I have a pipefitter who wants to weld my 3&4 inch steam near boiler black pipe rather than thread.
Is this a good practice? 3" from boiler to 4" header then 3 Inch from header to main lines

Any comments?

also whats a fair labor rate for an experienced pipe fitter side work?

EzzyT

Thread the joints don't weld them.
And we don't discuss pricing here.

Fred

Definitely use threaded joints from the boiler into the header and make sure you have proper swing joints in the near boiler piping.

MikeMens

Thanks for the replies, thats about the way I see it, one question, what is a swing joint?

Fred

They are the threaded joints that allow the header to expand and shrink from side to side, alleviating any stress on the boiler block. You want 90 degree elbows at the top of your boiler risers that go into the side of the header, no configuration that would take your boiler risers into the bottom of the header. If you use a drop header, then you will use two elbows at each riser (maybe more to carry one riser over so that the risers are next to each other on the header), one that will turn towards the header and then one that will turn down into the top of the header.

MikeMens

Ok thanks thats my plan - 2 risers out of boiler 90s to horizontal then 90s down into drop header - just hadn't heard that term before and wanted to be sure I didn't miss anything

EzzyT

@MikeMens This is what your header should somewhat look like

Fred

MikeMens said:

Ok thanks thats my plan - 2 risers out of boiler 90s to horizontal then 90s down into drop header - just hadn't heard that term before and wanted to be sure I didn't miss anything

Also make sure the pipe configuration, into the header, is correct as well, riser out of the boiler, 2nd riser out of the boiler, risers to each main (piped individually, into the header) and then the equalizer at the end of the header (don't reduce the size of the equalizer until after you turn down).

MikeMens

Thanks, slightly different configuration, but functionally the same

Steamhead

EzzyT said:

@MikeMens This is what your header should somewhat look like

Nice work!

EzzyT

Thanks Frank

The Steam Whisperer

Here's how we do them... Welded from the the steam main riser to the header and over to the boiler riser takeoffs. Then a drop header configuration of boiler risers with all these joints threaded. This should allow the piping to easily move with the boiler block expansion and contraction. Threaded piping is required on cast iron boilers by Peerless, Burnham, and Smith. Weil Mclain has no requirement for threaded fitting...only swing arms between the risers and the Header.. all welded piping is deemed acceptable. I wouldn't do all welded piping , no matter who's boiler it is!

Jamie Hall

Well... not to cast the apple of discord, but if you have only one riser, then swing joints aren't really necessary, and one could weld an assembly of the riser, crossover pipe, a drop, and then the drop header and get away with it. Cedric is set up that way, and has given no trouble.

The Steam Whisperer

Yep, single risers don't have the block expansion vs. pipe expansion issue, but it is still nice to allow for some movement of the system piping so as not to put undue stress on the boiler.

Jamie Hall

The Steam Whisperer said:

Yep, single risers don't have the block expansion vs. pipe expansion issue, but it is still nice to allow for some movement of the system piping so as not to put undue stress on the boiler.

Oh quite -- and there are swing joints going to the mains. Never fear...

Gordo

@The Steam Whisperer (Formerly Boilerpro) . Hi!

You say that Peerless, Burnham, and HB Smith all require threaded headers. Please could you show where it says that in the HB Smith literature? Particularly in regards to their oh so wonderful 28A series? Our wonderfully-fantastic-extra-special-with-sugar-on-top local Smith rep knows nothing about it, and says welded headers are no problem so far as he knows. (Surprised? Don't be).

That same rep said he'd call up to Smith and get back to me if they had any information against welded header use. I'm still waiting.

Please let us know where you are getting this
information. I hope it is in writing. Please do share with us this vital information. Please!

Weil Mclain within the last two years did put out a bulletin (available on-line) in regards to hybridizing a welded header with threaded joints to allow for expansion. One assumes They got tired of dealing with leaking boiler claims by this welded header business, and wanted one more reason on record to deny compensation.

It seems, in general, that it all depends on who answers the phone as to what the policy is vis-a-vis welded headers.

From what I have been able to uncover, like it's some big secret,
is Weil Mclain, and only Weil Mclain, has any written disclaimer on welded headers.

At the same time, a customer threw in my face that he called Weil Mclain about soldered copper headers, and the person answering the phone (one hopes it was the janitor having a jape) said that soldered copper headers were just fine, thank you very much.

The Steam Whisperer

I stand corrected.....the Smith 28HE is the same boiler as the Peerless TCII. Peerless requires threaded piping.....Smith says nothing. That is really screwy....I thought the installation requirements would be the same for a boiler no matter whose name is on it.. Very Bizzarre.
I thought I heard something about threaded piping starting to be required by WM, but I didn't see anything in the series 88 manual.
This is one of the reasons I use Peerless almost exclusively....they seem to have higher standards than other brands. I've notice that across all the models of steam boilers I looked at ( 64 vs EGH, 211A vs LGB, TCII vs 88), thier boilers are about 15% heavier than the comparable WM.....I suspect due to heavier, thicker castings. It's also probably a contributing factor to the Peerless having slightly lower efficiencies too.....thicker castings, less heat transfer efficiency

ratio

Hasn't that nearly always been the case? Sacrifice something, usually longevity &| simplicity, for efficiency? I'd like to see an honest, well implemented, TCO analysis covering total $$$ & fuel used over some well agreed upon "lifetime". It's my personal opinion that $$$ will significantly favor simple & long life unless you're "very inefficient", but fuel will somewhat favor "very efficient".

The Steam Whisperer

This is interesting and confirms my previous suspicions that the castings are definitely not identical and some manufacturers stay with the old heavy castings.

Worth noting...........sacrifice a point or two on the AFUE and procure a much more durable boiler.

Actually the Series 63/64 are a newer design..maybe only 10 yearsold or so.

Gordo

@The Steam Whisperer (Formerly Boilerpro)

"The Smith 28HE is the same boiler as the Peerless TCII"?
Not surprising. So it seems Smith is all but gone and is now merely an outlet store for Peerless with different jacket colors.

Sic transit gloria mondi.

No question in that Peerless puts a great deal of effort in putting out information on how best to put their boilers in. Kudos to them, indeed!

Weil Mclain does not put any prohibitions against copper piping or welded headers in their assembly literature, in so far as I know, but do put out a separate bulletin on welded headers.

I suppose this allows them plausible deniability when it comes time for that warranty claim.

It follows their pattern of speaking out of both sides of their mouths during the great switch out from oil to gas.

And since it appears that Smith is not a real boiler company anymore, I suppose they simply don't care how you put in "their" boilers.

nicholas bonham-carter

Must it always be the case of of lower efficiency with thicker metal castings in the boiler sections?
Assuming the flue is properly managed, then where is the wasted heat going? I am also assuming no short-cycling, and well designed heat transfer surfaces.--NBC

The Steam Whisperer

No engineer here, but I would suspect that just increasing the heat transfer area would make up for the slightly lower heat transfer of thicker castings. In addition, more fluid "scrubbing" of the castings by the water ( lots of water movement /turbulence) and the flue gases could also help.

Fred

Seems to me that the thicker casting also means a slower cool down (greater heat retention). I don't know it it is a wash with the energy needed to heat the casting but seems like there are some "offsetting factors to the equation as well.

JUGHNE

Increasing the area of CI X thicker walls = more CI= more cost and weight. The bean counters/hackers/trimmers of quality, in the infamous "race to the bottom" as often quoted here, will do their job of increasing the bottom line.

Going back to the modulating or even 2 stage burner discussion for a steamer would cut down on the short cycling of cool down and reheat.

Some in the contractor business, (pick any trade, I have been in several and am guilty myself and have had things come back and deliver a bite in the butt), will follow this example and go for the cheapest product and get out before the taillight warranty expires. Most of my customers see me everyday so I learned early not to go for the lowest cost item. I have had to replace many items (even good quality) at my cost just to maintain a good reputation.

Now in the Metropolis areas the word does not get around as it does in the boondocks. And the customer is only looking at the low baller. But look at what sits in the driveway....it's not a Yugo is it?

ChrisJ

So what it comes down to is thinner casts = cheaper and thinner insulation = cheaper.

They could make the castings much heavier and the water content much larger if they increased the insulation. Imagine how well the typical cast iron steamer would do with 1" or 2" fiberglass instead of the pitiful 1/2" most use.

JUGHNE

It is good that it is Sunday and the factory design hacker/slasher is probably not reading this.
If we could make even yet thinner castings, and increased the insulation, (which is really cheap), then we could use the same jacket and shipping crates (which are not as dirt cheap as insulation is).

Then the advertising point added could be "better insulation and also our company has decreased the gravity footprint upon the earth.......for a greener tomorrow!!".

You could probably sell the lessor gravity footprint theory to people, just like the round & square BTU theory.....after all there are more overweight people than before and doing anything to lesson the gravity factor requirements has to be an environmental improvement, wouldn't you think?

The Steam Whisperer

Gentlemen, seems we got a little off track here...my bad. Weld vs. thread.... I think there's good reason for Thread and I am sticking with it even if all or nearly all the competition is using weld...even when it is prohibited by the manufacturer.

MikeMens

Thanks everyone for your feedback. Great help.
can anyone add to the description above of swing joint?
my plan is to come out of the 2 boiler outlets with a bushing to 3" pipe to union to 3" pipe 90 to horizontal, 90 back to vertical and down into my 4" drop header.

also, is there a rule of thumb as to how close together the risers into the header should be? or rather how much distance from the boiler risers into the header to the supply risers out of the header? I assume the more distance the better to help dry out the steam?

Dave0176

MikeMens said:

Thanks everyone for your feedback. Great help.
can anyone add to the description above of swing joint?
my plan is to come out of the 2 boiler outlets with a bushing to 3" pipe to union to 3" pipe 90 to horizontal, 90 back to vertical and down into my 4" drop header.

also, is there a rule of thumb as to how close together the risers into the header should be? or rather how much distance from the boiler risers into the header to the supply risers out of the header? I assume the more distance the better to help dry out the steam?

Mike I'm not sure what size or brand boiler your using, but to me 4" is really not hard at all, here is a job I did earlier this year with two 3" boiler risers into a 4" drop header. This particular boiler is a Weil McLain EG-55

Onepipe

All, I know this is an older post but I had a question on welding on boiler piping. I have worked as a fitter for many years so I am not concerned on the ability to weld but I am wondering if the boiler code requires any special license or inspections for welding on boiler piping (not the pressure vessel). I am looking to add some thread-o-lets to some existing 100yr old piping so that I can add some main vents. I have a 2" main and a 2 1/2" main that have no vents and I would like to drill the pipe and add some 3/4" npt tapings at the end of the run for vent installation. I know that pressure vessels need an "R" stamp but not sure about the boiler piping. This is a low pressure steam system operating at below 1lb.

EBEBRATT-Ed

@Onepipe

As far as i am aware on low pressure under 15psi no ASME stamp needed on welded pipe. But every state is different but there is no ASME regulation on the piping as far as I know.