weil mclain 980

Paul S_3

im starting an install this spring and were using a weil mclain 980 steam boiler..... there is no room for multiple boilers....boiler manual states 6 inch header.... i was thinking using 8 inch screwed.....im a crazy? or should i just spend the money to get the header welded, with threaded outlets for the boiler drops 4inch....and the 3 mains?(2) 4inch (1) 3inch main).... what would you guys do? im just throwing it out there

northernboiler

If you are going on to install an 8" header, I would defently use a welded header.

njtommy

It's probably faster to weld the header then to thread it all. Price is the biggest question and if you allowed room in the job for a welder.

JohnNY

I'll never use 8" threaded fittings again.

Paul S_3

I do have enough for a welder on the job....I will have it welded thanks guys.....and @JohnNY why wouldn't you use threaded 8 inch fittings again? Did they leak? I know there very pricey

northernboiler

Have you ever threaded 6" pipe.
Meaning, fit the cast iron fittings onto pipe??

Much less 8"??

After attempting to install a header, as referenced by you previously, I think my arms would fall off.

And I'm fairly certain I'm not alone there...

New England SteamWorks

> @JohnNY said:
> I'll never use 8" threaded fittings again.

@JohnNY , would you use 6" screwed fittings again? I have a job coming up for 6", and I remember you did one not too long ago.

Didn't even think they made 8" screwed fittings...

northernboiler

Anything over 4", I have it welded.
Period. No if ands or buts.

Also if you compare the two, material cost, available-ability, it's almost negiable.
The time it takes to install a large diameter header is where it makes sense for a welded header.

However IMHO, it's the physical labor factor that outweighs using threaded fittings.

And I don't even know if anyone stocks 8" ci fittings anymore.
I would even doubt that Ward or Anvil even manufactures 8" ci threaded fittings anymore.
Or they may only on a special order.
Which would certainly raise the cost factor significantly.

Abracadabra

another vote for welded headers. I weld myself, so no need to have an outside welder, but anything 4" and up I'll weld as necessary with appropriate threading for swing joints.

JohnNY

RI_SteamWorks said:

> @JohnNY said:

> I'll never use 8" threaded fittings again.



@JohnNY , would you use 6" screwed fittings again? I have a job coming up for 6", and I remember you did one not too long ago.



Didn't even think they made 8" screwed fittings...

I'd make another 6" header if I had to, I guess, but there would have to be some compelling reason not to have it welded. The job you're referring to worked out great despite having it explained to me here that I didn't know what I was doing by people who don't do this professionally, but I also did another job several years ago that required about 50' of 6" piping for which time constraints forced me to use threaded fittings and flanges. That job was a headache and I'll never do that again.
Too much expansion when it all heated up. The flanges and gaskets were stressed to their limits. Too much effort turning 48" big wrenches. My guys were exhausted by the afternoon.
No good. Wound up dropping a section, having it welded and reinstalled it. All in, it cost me about $4,000 to learn that lesson.

Jamie Hall

I'm not a pro -- as you all know. But... I can't think of a good reason not to weld a header, or at least a goodly chunk of it, even in smaller sizes -- the limit being what you can handle in terms of weight and fitting. You do need to provide thread or flange joints somewhere, to allow for expansion, but otherwise... why not? For what it's worth, @Charlie from wmass welded up a beautiful if somewhat complicated header for Cedric, and it works just fine.

Charlie from wmass

Wow, you guys are soft. Lol. Seriously though welded is fine for any size if done properly. The issue I run into this welded headers are seldom installed with swing joints, flanges, or other Provisions for expansion

EBEBRATT-Ed

I agree. Not a thing wrong with welded if done correctly. Build some flexability in by making the risers as long as possible. Most boiler risers are 5" or smaller so threaded fittings can be used with threadolets in the header. Care must be taken not to warp the header when welding in the threadolets.

Most come out of the boiler with a nipple to a threaded flange with a welded flange on the top.

as long as the risers and the horizontal to the header are long enough it will have enough flex

nicholas bonham-carter

Why not weld nipples, cut in half, to the welded header, instead of Threadolets-then unions threaded onto the nipples, and on from there to a nice double header with it enormous capacity for relieving expansion and contraction.--NBC

Charlie from wmass

Cost and head room is why.

nicholas bonham-carter

Just fab the header outside, and carry it in, and hang it up.
Is a threadolet really cheaper than one 12 inch nipple cut in half?--NBC

Abracadabra

Threadolet gives you a threaded connection in less that 6 inches, just a couple of inches in fact. Also time is money. Trying to properly cut a nipple so that it properly follows the contour of a 6" header pipe for welding is time consuming. I'll always use a threadolet (and sometimes even a weldolet)

Charlie from wmass

Now we get to the other reason why threadlets and weldlets are better than using nipples. It seems most welders I come across on jobs have forgotten the proper way to install a welded nipple onto a main pipe. Most of the time when I come across them they've gotten a large whole and just shove the square cut pipe through the hole. On the top of the header this wouldn't be such a bad thing but usually I find that they've done it for drips or coming off the bottom of the header for The Equalizer.

EBEBRATT-Ed

@Charlie from wmass is 100% correct (I confess to having done it myself)

They don't know how to "fishmouth" anymore

Paul S_3

i have installed 6inch threaded once and 5inch three times....i actually found cutting and threading four inch was alot tougher than the six inch and five inch...my plumbing supply can definitely get 8 inch threaded anvil fittings....but i dont want to open a can of worms getting 8 inch screwed... i only have one 60" inch wrench and a 36" inch chain wrench that i used to turn the six inch header....i think ill have the 8"inch welded with thread o lets 4 inch... i was thinking of buying the largest ridgid compound leveverage wrench to turn the eight inch....but that seems too much labor....and im scared of a leak thanks guys for all the insight .... @JohnNY @EBEBRATT-Ed @Charlie from wmass definitely would like to see the 8 "inch threaded header and thanks @Abracadabra .....PaulS