Service manager

JohnH

I have a potential job to replace an existing steam boiler.  After measuring the square footage of radiation I arrived with approximately 615 square feet of steam radiation, replacing boiler with a Weil Mclain steam boil equivalent to 658 square feet of steam.  The existing system is a one pipe system with 2 three inch verticle risers reduced to 2" horizontal loops, one going in one direction, one going in the opposite direction around the perimeter of the house.  At the point where the verticle steam riser pipes stop coming off of the main loops, the pipes are pitched back to the boiler for condensation return entering the boiler at the bottom with no Hartford loop, or pipe insulation on all of the piping. Do you see a potential problem leaving this system as is, replacing with a new boiler? Naturally the new boiler is a third of the physical size of the existing boiler.

Thank you 

Anne_6

hartford loop

I am no expert, just an owner of a boiler. A hartford loop is needed for a steam boiler. The old one probably doesn't have it because either it was not installed by a steam expert or it is very old and has the hartford loop inside the unit.



May I suggest you read up on the books mentioned on this site by Holohan.

crash2009

new boiler or re-pipe

The new system should be piped as per the manufacturers instructions.  A lot of times an upgrade of the existing piping using the existing boiler can be rewarded with an excellent functioning system.  Most of today's boilers need to have a header, equaliser, and a Hartford.  Along with that, the wet returns should be replaced.  The main vents usually need an upgrade, etc.  Have a look at the following links, that suggest some things for consideration.



1-The first thing is the main vent.  You will need 3-5 on each side, yes three to five, depending on how many lineal feet of main you have.  They need to be 15" before the drop down to the wet return.  Here is how they do it http://www.heatinghelp.com/images/posts/4848/resize_MAINVENT_ANTLER.jpg



2-Shut off (king valves) They sure make things easier for maintenence.  Here is the link to the video. Now is the time to think about it.   http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping

3-The drop header further helps to dry the steam.  It also aids in assembly to get the slope correct.  The drop header exceeds manufacturers specs.   http://www.heatinghelp.com/search/results/drop-header/1

4-Insulation is a good thing, here are 2 examples, do it yourself and professional, can and should be done later http://www.heatinghelp.com/forum-thread/132995/What-type-of-pipe-insulation-should-be-used-on-the-near-boiler-piping#p1206961

Steamhead

You definitely need a Hartford Loop

and main vents. Which W-M are you using- the SGO? Also, do the two returns drop to the boiler's return connections individually, or do they tee together above the waterline? How long is each steam main (boiler to last radiator takeoff), and what pipe size?

JohnH

Service manager

With 2 separate main steam lines, is it ok to install an equalizer pipe on one

without the other?

Rod

Need Some Info

Hi - I'm not quite sure what your line of thought is with this question:  " With 2 separate main steam lines, is it ok to install an equalizer pipe on one without the other?  -  The basic answer is that both risers for the steam mains need to come off the header.



I might mention that Steamhead is a very experienced steam pro so I would highly recommend you follow his advice. If you will provide answers to his questions I'm sure he can help you out.

- Rod

Dave in QCA

Look at the pictures...

You cannont install a new boiler the way the old one was piped. 



Look at some of the links posted above and study the piping arrangments.  Here is another one.  http://www.heatinghelp.com/forum-thread/132474/Oil-vs-Natural-Gas            

In this installation, the boiler has 2 risers, they lead to a drop header, then to the equalizer with hartford loop connection.  On the header, between the last boiler riser connection and before the equalizer drop is where the 2 steam mains should connect.  There is no alternative if you want the system to comply with the boiler manufacturer's requiarements, and if you want the boiler to work well and last for your customer.

I concur with all that has been said on this thread so far.  You can't hook the new boiler up the same as the old...

What boiler model are you considering?

I was just looking at the installation manual for the EG/EGH models.  The piping requirement for the close boiler piping is perfectly clear.  You cannot improvise.  Instead of one steam connection to the header as shown, you will have 2 steam connections to the header.

Dave in QCA

SGO-6 ?

The only boiler by WM that is 658 sq ft of steam, that I can find is the SGO-6.



They give very clear instructions on the piping.   See the manual  http://www.weil-mclain.com/en/multimedia-library/pdf/weil-mclain-pdf/products/boilers/oil-boilers/sgo/sgo-boiler-manual.pdf.pdf  

Look at page 16.  The only difference your installation will have is that you will have 2 connections from the building piping to the header instead of one.