System piping

KC_Jones

So I finished reading Dan's books last night (We Got Steam Heat, TLAOSH, and Greening Steam) and tonight I decided to take a quick look around my basement.  What I am now seeing are a bunch of potential piping issues.

1. All the radiator takeoffs from the main are coming off the top at 90° when it should be 45°

2. My mains slope in 2 different directions, the first 10' of each slopes towards the boiler.  After that both mains make a 90° turn to run across the front and back of the house.  From that point on they slope towards the end of the main and the return pipe.

3. One of my returns (short one for back of house) comes all the way to the boiler as a dry return and then drops down to the boiler piping.  The other return is a bit odd at the boiler it also drops straight down, but is already below the water level and from that point has a gradual slope around the basement to the end of the main.  When I measure for the 28" "A" dimension this return doesn't get to that until it has run 20' around the basement.  Almost like it's a wet and dry return at the same time.



I have been living with this system for over 10 years now and until the boiler started leaking recently I don't really have any major complaints about it.  Now that I am more educated I do know the hissing vents and occasional spitting and uneven heat aren't normal.  I am looking for some opinions about my piping situation.  What should be fixed and what could I get away with and not have any major problems.  Since I am replacing the boiler and fixing the near boiler pipe work I don't want that to create a problem and since I will have a lot torn apart I figure I should try and fix what I can. The pipe slope would be relatively easy with the way the piping is laid out.  Oh and one thing I have discovered reading this wall....there doesn't seem to be anything typical about these steam systems!  And here is a link to a previous post showing some pics of my boiler, you can see some of the slope issues I mentioned above.



<a href="http://www.heatinghelp.com/forum-thread/149803/Pictures-of-existing-system-that-needs-replacement">http://www.heatinghelp.com/forum-thread/149803/Pictures-of-existing-system-that-needs-replacement</a>

Jamie Hall

There are a number of considerations...

but one of the more important is going to be to make sure that you don't change the level of the boiler water line when you install the new boiler.  That may take some thought!



Can you make a diagram of the existing system piping?  It would help understand it better...

KC_Jones

Yes I can

I am a draftsman/Designer by trade!  I will work on this during my lunch break tomorrow and see if I can clear it up.  Until I found this site and read Dan's books I didn't realize any of this.  Ignorance has been bliss for a while.  lol  Seriously I am happy for all the education I have been getting lately.  As far as the boiler water level changing, shouldn't be a problem because my current plan is to replace with another Weil Mclain with similar dimension, just lower output since I am over sized currently.

KC_Jones

Here is the layout

I came into work early to do this real quick.  Let me know if anything isn't clear.  I have the mentality of fix all errors I come across.  My basic reasoning for posting this is to get a bit of advice/reality check as to if this is a good or bad idea.  I know the minute I disrupt the system (new boiler) things will change so I want to cover all my bases.  All input is welcome!

nicholas bonham-carter

Wet-dry return?

Do I understand that the dry return gradually slopes down, until, at the waterline height, it becomes wet?

It would be better to have a definite change, with a vertical drop from dry, to wet.

The reason for this is, as the pressure rises in the boiler, the waterline in the wet returns is pushed up to a new level. This rise in height will be 1.75 inches, for every OUNCE of pressure. This means more water will have left the boiler to temporarily fill up a longer length of pipe (think hypotenuse length, instead of vertical length). A situation like this can cause a very unsteady waterline, with shortened life.

Definitely readjust the slope of the supplies so they start high, and slope steadily downward to the final vertical drop. Piping as a drop header is better for drying out the steam, as well as making the final connections from boiler to header (for the novice). In addition, the drop header will trap any oils which have not been able to be skimmed off, and at least keep them from interfering with the boiling. A tee on the equalizer at just below waterline height wit a ball valve will enable draining off this oily residue.

Make sure that any wet returns are well below the waterline, by raising the new boiler, or lowering the returns.

Get a 0-3 psi gauge so you know when to stop adding main vents to the dry return. If you size the boiler right, you probably will not be building too much pressure except when it is really cold out.

A wet-base boiler with a burner whose firing rate can be adjusted would enable you to dial in the firing rate to accommodate any changes in radiation EDR (extra rads later etc.)--NBC

KC_Jones

Yes

The return at the front of the house has no definitive change it's just a gradual slope through the transition from wet to dry.  In studying the layout in my basement This should be easily corrected, of course it's old black pipe so who knows what surprises I have waiting.  I appreciate the input you pretty much confirm what I think I should do.  Many have suggested the wet based boiler, but I think I am sticking with the atmospheric.  I appreciate peoples reasoning for the wet based, I just think that route might be a bit outside my comfort zone and they are a lot heavier.  If you saw my basement stairs inside the house you would understand my concerns about weight and maneuvering.  Thanks for the input!

nicholas bonham-carter

Basement stairs

Maybe 2 smaller boilers would be easier to man oeuvre, than one larger.-NBC

KC_Jones

LOL

I only have 265 sq ft of connected rads, my house isn't big enough to need 2 boilers.  Honestly looking at the wet based even the smallest is bigger than I need.  The weight of the smallest wet based boiler is a concern to me.  Also it's a comfort thing...I know and understand the atmospheric more than the wet based with gas gun.  I look at it this way, some people like Ford some Chevy some Toyota etc.  I am comfortable with the atmospheric so I am going that route.  Again thanks for all the input! 

ChrisJ

Size

Have you made a decision on what size to go with and what did you decide on the pickup factor?

KC_Jones

I have been thinking very carefully about that!

At this point I am going for the EG-40 which is a bit over sized for what I currently have, but smaller than the current boiler.  I am going to finish off the attic and add at least 2 small rads up there and obviously a ton of new piping.  Also our laundry room off the kitchen has no heat and I would like to add a small one under the window in that room.  That room gets cold in the winter like 55°, if I hadn't remodeled and insulated the whole room I can only imagine how cold it would be!  So because of the future additional load I want to give myself some cushion.  Also I am probably going to put a 2-stage valve on the burner so I can do the lo and hi fire setup.  I think Gerry Gill is a fan of this?  I think I mentioned before I work for an industrial refrigeration/HVAC company.  We have millions upon millions of BTU's worth of boilers in our test labs so I know multiple people who will be able to come over and tune the system for me!  It's not what you know it's who you know...lol.  With a setup like that I should be able to fire the system to fairly closely match my load.  Now I just have to finish all the planning and spend a ton of money, oh and probably ask a million more questions on here.  This forum has been so educational!