Near Boiler Piping on steam boiler

Rem77

My oil company installed a new boiler at one of my properties and used the piping from the old boiler which was
2 inch. The Boiler manufacturer called for 3 inch riser and he bushed it down to 2 inches. I decided to repipe it and cut out all the old piping because I am still having the old issues of wet steam and radiators not heating. I am installing a drop header as high as possible. my question is about fittings. what is the difference between using regular unions and a flange type union ( with bolts in it )?

Thanks
Bob

ethicalpaul

It seems like people use the flange type on the larger pipes but I'm sure a pro will give the real answer.

But I have to ask: you seem familiar with how the piping should be, so how is it that the contractor was able to give you piping that shouldn't be? Also, can we see pics?

Steamhead

@Rem77 , in those sizes we almost always use regular ground-joint unions. What make and model is the boiler?

EBEBRATT-Ed

@Rem77

I think using flange unions are probably more $$. IMHO 2 1/2 and up flange unions are a good idea...................not sayin I do it myself

HVACNUT

How long ago was the boiler installed? If recently, why isn't the oil company making the corrections? I have a lot of patience and let a lot of things slide, but that wouldn't be one of them. What's right is right.

Rem77

The boiler is a Smith 19HE 4 section boiler. I argued with the installer, but he had nothing but excuses. The boiler is 1 1/2 years old. The basement has very low ceilings and in my opinion ,
this boiler was the wrong choice for this install because of its height. My main objective in changing the size of the piping and getting it as close to the ceiling as possible is to dry the steam and solve the 50 year old problem , in this 100 year old building.
i have attached pics of the old piping after i removed the insulation. At this moment there is no piping. it was all removed and I was able to get the reducer bushings out without having to cut them.

Thanks
Bob

Rem77

Steamhead

If i were doing that job, due to the limited height above the boiler I'd use two 3-inch risers, going all the way to the ceiling and dropping into a 4-inch header. This would enhance the separation of steam and water.

Where are you located?

Rem77

I am located in New Rochelle NY.

Thx
Bob

Jamie Hall

Not sure who works in New Rochelle -- @Dave0176 ? @Danny Scully ? Maybe @JohnNY ? @EzzyT ?

In any case,. you have the opportunity -- as @Steamhead said -- to do a nice job there. It wasn't done. Go up to the overhead -- as high as you can -- with both risers. Then over. The down to a nice drop header just above the boiler jacket. The steam main takes off after the risers attach, and the equalizer is at the end of the line. That will give you drier steam -- and prevent the possible problem of differential expansion in that short low "header" prying the boiler sections apart.

pecmsg

3" Unions will need a Big Wrench and room to swing it. If you don't mind the cost nothing wrong with Flanges!

nicholas bonham-carter

Do you think the sizing of the boiler was done properly, at least?—NBC

gerry gill

In the big scheme of things, For 3”, little difference between flange union and ground joint union except as Pecmsg stated above.

Rem77

Thanks to all for the response.
Bob

retiredguy

We used to use companion flanges instead of flanged unions due to the cost.

Rem77

Thanks for that. Cost is a factor.

Bob

bleeder

big pipes