Steam Boiler Header

Steve_211

My boiler is a Dunkirk ESC3100, installed October, 2010. Both 2 inch supply take-offs are used to a 2 inch header with one take-off to the steam main on a one-pipe system. After this heating season, I want to remove this header and put in a drop header. What size should it be, 2 inch...2 1/2 inch...3 inch...4 inch? Is bigger better? If not, why not? What would be an ideal size?

Jamie Hall

Bigger is better. But... it gets unreasonable beyond a certain point. So I'll ask -- how big are you comfortable threading? I'd go at least 2 1/2, 3 would be better -- but if you can't thread it...

JUGHNE

Can you down load the Installation guide for this. It would have minimal piping sizes.

Is this a side outlet boiler and are the outlets reduced from 2 1/2".

Intplm.

@Steve_211

If your header isn't of great length and Im guessing it's probably not, you can purchase nipple lengths in different dimensions as large as four inch inside diameter ( ID ).
Four inch ID makes a great header off of your currently installed 2" pipe.
Three inch is fine too.

109A_5

Hello @Steve_211,



INSTALLATION, OPERATION & MAINTENANCE MANUAL
https://dunkirk.com/wp-content/uploads/2022/03/2296_0.pdf

TonKa

What do you hope to achieve by changing only the header now after 13 years of operation?

Steve_211

To Jamie Hall: I’d be getting a contractor to do the job, so, it’s how comfortable the contractor feels on threading the black pipe. I’m inclined to go with Intplm’s suggestion and use 4 inch pipe.

To JUGHNE: 109A_5 posted a diagram of my boiler. It’s a top outlet boiler utilizing both outlets with minimum 2 inch pipe as per the manufacturer.

To TonKa: I hope to achieve, from what I’ve read on this site and Dan Holohan’s knowledge, a dry steam.

Mad Dog_2

Get the Wallet out...4" is a fortune today.  Mad Dog 

LRCCBJ

Steve_211 said:

To Jamie Hall: I’d be getting a contractor to do the job, so, it’s how comfortable the contractor feels on threading the black pipe. I’m inclined to go with Intplm’s suggestion and use 4 inch pipe.

The ESC3100 is a very small boiler. You have a net output of 116 KBTU giving 119 lb/hr steam. A 3" header results in a steam velocity of 16 feet/sec. This is perfect.

Going down to 9 ft/sec with 4" is only going to accomplish a severe lightening of your wallet without any significant benefit. You are at a point of diminishing returns.

One point of note. The longer the steam remains in the header, the more water it will drop. Therefore pipe it so the first main is at least 15" away from the T from the last riser. This is frequently ignored due to the logistics of a boiler. You'll see the second riser within three inches of the first main. If the steam is moving at 16 ft/sec, you can imagine how difficult it is to drop water in just three inches.

Long Beach Ed

I have to second Mad Dog and LRCCBJ. Last time I bought one Ward 4" steam elbow, it cost more than a February supply of New York oil. Consider your cost/benefit here. Don't even think of a drop header if you're buying 4" pipe; you'll need a mortgage.

Do you know you have a problem with wet steam? If not, your piping can cost you as much as a new boiler, with no benefit.

Danny Scully

The velocity if both risers are used is 20.83. 

2” can handle 23. 

A 2” drop header with use of both risers could work fine. 

Proper skim and pressuretrol calibration of course…

RTW

Here is link to Supplyhouse 4 inch cast iron elbow - so cost is not lost on me

https://www.supplyhouse.com/Ward-FCI90-4-4-Black-Cast-Iron-Steam-90-Elbow-428000-p?utm_source=bingad&utm_medium=shopping&msclkid=340aab54a9131d6284d7cd4560f93b37

Regards
RTW

rbeck53

You will not see any benefit to changing your piping to a dropped header. As long as your piping is correct you won't gain much dryer steam. Boilers even 13 years ago is manufactured 98% dry.

STEAM DOCTOR

RTW said:

Here is link to Supplyhouse 4 inch cast iron elbow - so cost is not lost on me https://www.supplyhouse.com/Ward-FCI90-4-4-Black-Cast-Iron-Steam-90-Elbow-428000-p?utm_source=bingad&utm_medium=shopping&msclkid=340aab54a9131d6284d7cd4560f93b37 Regards RTW

You can always get an imported 4" black elbow for 1/3 of the price. But agree that 4" is probably overkill. 

STEAM DOCTOR

Steve_211 said:

My boiler is a Dunkirk ESC3100, installed October, 2010. Both 2 inch supply take-offs are used to a 2 inch header with one take-off to the steam main on a one-pipe system. After this heating season, I want to remove this header and put in a drop header. What size should it be, 2 inch...2 1/2 inch...3 inch...4 inch? Is bigger better? If not, why not? What would be an ideal size?

How does system run? From cold start, how long does it take header to get hot? How long from hot header to hot end of main? From hot header to hot radiators? As much as I love bigger headers, not always worth the ROI.

ethicalpaul

To add to @rbeck53 's and @STEAM DOCTOR 's reasonable questions and statements, I would say that unless you have solid evidence that your boiler is surging, and that the surging is caused by your existing near-boiler piping, this proposed change is likely to result in no change to your boiler's operation and a large change to your wallet.

Do you see your water level in the boiler drop dramatically (more than 1" in the gauge glass) at any time?

Mad Dog_2

The last Steamax I installed cost almost 5 K on just the header and near boiler piping.  Mad Dog