Boiler re-pipe input

northernboiler

We are currently planning/ bidding for a re-pipe of a Weil-McLain 680.
The current near boiler piping is so incorrect that it just makes your jaw drop, to say the least.
Suffice to say it is a textbook example of how NOT to be done.

Here is where some input and advice from fellow steamers is requested.
Boiler Ratings: 1983 sqft. 476 mbh

Boiler Supply Tappings: 2 at 3"

We have 2 system supply mains, each are 5" each.

We are debating the size of the main boiler header.

Now of course we will be installing it in a dropped header configuration,
we are thinking that the main header should be at least 6" but we are considering
using a 8" to properly supply slower, drier steam to both of the 5" system supplies.

OK everyone any and all comments and advice are requested and welcomed.

nicholas bonham-carter

Is this one-pipe or two-pipe? Have you correctly sized the new boiler for the EDR of the system?
The drop header piping is to be preferred as it makes the fitting in of the piping easier, and enables the larger header to be used. This will really help produce dryer steam especially in the first month or so as the oils are working loose from the new piping down into the boiler.
Use a gravity return, and check to make sure there are no close or distant wet returns close to the waterline height, left over from some previous ancient installation. These will hide large amounts of water when firing, only to have the water mysteriously reappear when the system is off.
More main venting will surely be needed, and this could add up.
A steam trap may be the less expensive way to allow the air to escape with 2 ounce resistance, (back-pressure), verified by a low-pressure gauge.
Supply a copy of "The Lost Art of Steam Heating" to the customer so they can realize that this replacement is a job requiring forethought, and skill (not to be done by knuckleheads!).--NBC

Fred

nicholas bonham-carter said:

Is this one-pipe or two-pipe? Have you correctly sized the new boiler for the EDR of the system?
The drop header piping is to be preferred as it makes the fitting in of the piping easier, and enables the larger header to be used. This will really help produce dryer steam especially in the first month or so as the oils are working loose from the new piping down into the boiler.
Use a gravity return, and check to make sure there are no close or distant wet returns close to the waterline height, left over from some previous ancient installation. These will hide large amounts of water when firing, only to mysteriously reappear when the system is off.
More main venting will surely be needed, and this could add up.
A steam trap may be the less expensive way to allow the air to escape with 2 ounce resistance, (back-pressure), verified by a low-pressure gauge.
Supply a copy of "The Lost Art of Steam Heating" to the customer so they can realize that this replacement is a job requiring forethought, and skill (not to be done by knuckleheads!).--NBC

@nicholas bonham-carter, I just looked at this post and I so, so apologize for it somehow being tagged by me as "Off Topic". I don't even remember seeing this particular tag and since you were the only comment to the OP, I'm not sure anyone else reviewed it either. I simply do not know how I could have tagged it and clearly had no reason to view it as Off Topic. Slight of hand, maybe but certainly not intended. Again My apologies.

gerry gill

When all else fails, and you want a rule of thumb that will always work and probably overkill the sizing of the header, many old timers would use aggregate cross sectional area of the takeoffs, and the header had to exceed that in cross sectional area.

SWEI

Fred said:

I just looked at this post and I so, so apologize for it somehow being tagged by me as "Off Topic". I don't even remember seeing this particular tag and since you were the only comment to the OP, I'm not sure anyone else reviewed it either. I simply do not know how I could have tagged it and clearly had no reason to view it as Off Topic. Slight of hand, maybe but certainly not intended. Again My apologies.

Just push the 'Off Topic' button again and it will go away.

nicholas bonham-carter

Such a lot of buttons to push here now-just like a Space Shuttle!--NBC

Fred

Thanks @SWEI I was afraid to click it again for fear it would show 2 "Off Topics" LOL!

nicholas bonham-carter

Why even bother with these buttons? What's wrong with saying it in the old fashioned way, using English?
Or am I just behind the times?--NBC

Steamhead

Same reason people text instead of calling.....

nicholas bonham-carter

I do think texting is a benefit. You can compose your words, and when finished, off it goes.
As the message does not need an instant reply, as with voice, the recipient can give what you say some thought, before he replies.--NBC

Fred

nicholas bonham-carter said:

Why even bother with these buttons? What's wrong with saying it in the old fashioned way, using English?
Or am I just behind the times?--NBC

I agree @nicholas bonham-carter , You tagged a comment of mine on this thread: http://forum.heatinghelp.com/discussion/153091/balancing-my-heating-system-help#latest but didn't follow up with a post to let me know what you didn't like about the comment. I thought maybe it is to pay me back