45's vs 90's on Header design

AaronH

I'm about ready to rip out my copper near-boiler piping and build a new drop-header.



I'm curious about the use of 45 degree takeoffs from the header vs 90 degrees, (going straight up) to the two steam mains in the house. I see lots of people just going straight vertical on their headers, and this certainly would make it easier.



Thoughts on this from those who have built them? Is there a reason to go one way or another?

moneypitfeeder

I used both

But I think it really just matters what makes the easiest connection using the least amount of fittings. The risers to my mains, I used tees in the header with the riser vertical, and the connection off the riser top end to meet the original mains were handled with 90s. But in order to avoid repiping and relocating a strainer inline to my return trap/air eliminator, I mounted the tee in the header so that the takeoff was at a 45, allowing me to connect where I needed to.

vaporvac

Found aReference in DanH'sWritings

 I read somewhere on this forum (I've searched the library to no avail)

> that 45s were better in a perfect world as they offered less

> resistance to the steam. Obviously, this may not always be

> practicable, but I, too, would be interested to know thoughts on this.

>  Also, if anybody knows the thread or link I'm  talking about, please

> let us know.  I'm still looking! thanks.

>I found a reference to it in DHohohan's writings, but he just mentions they're more efficient.  still can't find why.



Finally found this reference as regards 1 pipe systems.



Article Categories / Systems / Steam / Steam Heating Problems (and Solutions!) / Problems that plague ONE-PIPE steam heating systems

The heat in the building is very uneven

http://www.heatinghelp.com/article/96/Problems-that-plague-ONE-PIPE-steam-heating-systems/98/The-heat-in-the-building-is-very-uneven



The take-offs from the main leave at a 90-degree angle instead of a 45-degree angle.

Unless you're dripping the riser, the condensate that returns from the radiators has to flow back into the main. It's important to make this connection to the main at a 45-degree angle so the condensate can hug the side of the horizontal main and flow immediately to the bottom of the main. If the horizontal runout to the riser leaves the main at a 90-degree angle, the condensate will splash into the flow of steam and keep it from reaching the rest of the radiators. Either get rid of the 90-degree connection, or drip the base of the riser so the condensate can't return to the main.

There are no drips on the risers.

The condensate from the radiators falls back into the main. This causes the steam to condensate before it can fill the rest of the radiators. Add drips to the risers.

If it's a gravity-return system, drip into a wet return or into a loop seal and then to a dry return.

If the job has a condensate- or boiler-feed pump, use a steam trap at the base of the riser drip and flow by gravity from the trap to the pump's receiver.

If you run the system at very low pressure, you can use the loop seals with a dry return instead of the riser traps. But if you do this, keep in mind that if someone raises the system pressure, you'll have water hammer problems and steam at your condensate- or boiler-feed pumps

crash2009

Counterflow SGO ?

There are a few different ways to pipe a counterflow. How are you planning to return the condensate?  I don't think counterflow is covered in the manual http://www.weil-mclain.com/en/assets/pdf/sgo-boiler-manual.pdf

The Steam Whisperer (Formerly Boilerpro)

90's

For a standard non-counterflow steam system, 90's off the header to the mains would be best.  They move the low pressure, high velocity point where the steam is rapidly going into the system further up and away from the water on the bottom of the header, so it won't tend to get drawn up into the mains.  45's are best when water is draining back down into the main from one pipe steam radiators.  The water can hug the bottom of the pipe and not rain down on the steam from above if the take off was at 90 degrees up.  There should be no water draining back off the main into the header.

AaronH

Drips...

Thanks for the replies guys!



Crash - I like the photo you posted with the 45 degree takeoffs and the drips. Sure looks sexy, but do those drips make a difference?



Boilerpro - Why shouldn't condensate drain back into the drop header? It seems as though the condensate would just run across the header and down the equalizer.



I ask because I'm really limited on space, and if I can go without drips and use 90's, it will be a much easier install.

crash2009

Plan this winter, start work in the spring.

The drips are there to eliminate problems before they start.  A counterflow system means steam is going one direction, and the water is going in another.  If the two collide, one of two (or both) is going to happen, your boiler will constantly run out of water or you will get constant hammering.  Not to mention "wet steam" which is not a good thing.



I am not really sure what's going on in the counterflow header, perhaps Boilerpro can explain better.  From all the reading I have done here, it's a big mistake to drain the main into the header.  I only brought this up because it sounded like you had not considered this.



Another consideration you might want to look into is:  Is the main sized correctly, the main needs to be a certain diameter, based upon it's length, and/or the radiation installed.  These considerations will help you to determine the correct size's of header, riser, and drip.

Rod

Condensate Flow Direction

Hi Aaron - The drips are only needed on counterflow mains!  If you don't have a counterflow main, you don't use them.

You really don't want  the condensate flowing back to the dropheader as it will "re wet" the steam that the header has already dried out. On a parallel flow system since the highest point of the steam main is where the riser coming from the header connects the main, any condensate should continue down the main to the return piping and not into the riser coming from the header

- Rod

crash2009

Counterflow or not?

I was under the assumption that it was counterflow.  Has this changed between then and now?



http://www.heatinghelp.com/forum-thread/139183/Help-me-tune-up-my-single-pipe-counterflow-system

AaronH

Here's what I have...

The picture is what I have to replace - the bullhead from the riser is leaking badly. Other than that, the system actually works pretty well in that it's silent. No banging or clanging (with the exception of one radiator that the previous owners really screwed up the piping too, but I have it shut off).



There's only 252 EDR on the system, with 100 EDR going to the rear main (2") and 150 EDR to the front main, also 2". The boiler has a 2 1/2 tapping, but the copper is only 2". Currently the equalizer is 1 1/4"



Amazing that it's very quiet right now.

AaronH

Oh it's counterflow alright...

Yes... the system is very much counterflow! (Thanks for linking my previous thread into this one, Crash)



There are two 2" mains coming to boiler, one with 100 EDR and one with 150 EDR. My original plan was to build a system similar to the one in Crash's drawing, but without drips and with two takeoffs. My current plan is to build the riser and header from 2 1/2", each takeoff 2" and the equalizer 1 1/2".



So here's the $1000 question now: Am I being a fool to eliminate the drips? Or are drips total overkill if the above copper abortion works for the house?

crash2009

Wazzup Rod?

I copied that picture from Heatinghelp.  I believe Rod is the artist. 

crash2009

Any chance

of seeing a picture of the whole thing?  from farther back?

AaronH

Tentative Design...Critique me

Here's the plan. As said above, 2 1/2" for the riser & header, 2" for the takeoffs, 1 1/2" for the equalizer. The T on the equalizer is for the water feed.  

Rod

Counterflow System Configurations

I wasn't sure whether or not your system was counterflow as I didn't remember reading a previous link.   If you're not going with a single pipe classic counterflow setup, you'll need to add a drip line to each main otherwise you end up with very wet steam.

As Crash mentioned it would really help if you posted a picture of the boiler and piping taken from farther back so we can trace out the piping. We can zoom in if we need to look at the detail.

Crash- Yes I drew up the original drawings as I was trying to explain to someone the drip configuration of  a counterflow system I had seen. I'm glad they are being of use.

It's funny how this steam thing gets to you. I now find when I'm in someone's house and I notice they have a steam system, I talk them into  showing me the basement and the boiler.

- Rod

LOL-  After posting I finally noticed the gray printing at the bottom of your post where you put the info on your system.  Reminder to myself- "When in doubt- Read!"

crash2009

There you go Aaron

Its gotta be one or the other.  single pipe classic counterflow or counterflow main with drip. 

No draining the main into the header.  Back to the drawing board.  sorry!

Geeze, I didn't even know these things had names.  Here is another great diagram drawn by the world famous Rod.



Here is another little trick for drier steam.  Not 100% sure if a half inch will make a big difference for you but here it is.  When you order the T's for the system takeoff, try to afford 2.5" x 2.5" x 2.5" then use a short nipple and a reducer to go up to your 2" mains.  What this does is reduce the amount of condensate that gets sucked up with the steam.

AaronH

Well... No 90's!

Thanks for that diagram, crash - that made it all clear to me and answers the original question I posed in this thread about 90's on the mains and the answer is a definite NO!



SO - now I just have to figure out how to either add drips (and retain the 90's) or create a smooth path for the condensate flow back into the boiler using 45's and the like.



If I add drips, what size should they be? On page 90 of Lost Art - the chart says that for up to 700 EDR, a 1" drip/wet return is OK. Am I reading this right?

AaronH

Current System Pics

Here are two more views of what I have right now. Excuse the mess, but this re-pipe is the kick-in-the-pants to clean the basement, too! 

crash2009

We all

have inhierited one type of mess or another.  That's how we got here.  The easy part is fixing it.  The hard part is figuring out how to fix it without making it worse.  Back in Jan 2010 these are the cards I was dealt. http://www.heatinghelp.com/forum-thread/129536/The-burner-turns-on-runs-for-a-little-while-then-shuts-off-and-starts-all-over-again 

Thanks for the "farther back" picture, that explains a lot.  In the first picture, I saw those new steel fittings and couldn't figure out how they were connected.  I now realize that was your new (uninstalled) header sitting there on top of the boiler.

I understand from your previous post that you have a leak, up there, in the copper somewhere, and this explains your urgency.  Have you explored the bandaid till spring idea?  So as to give yourself more time to plan?

The SGO_3 is rated for 354 edr, your home has only 250 edr.  This means that your boiler can turn water into steam faster than your system can turn steam into water.  The boiler will run out of water and shut off often.  I am pretty sure someone around here could suggest a modification or two, to help overcome this with the new re-pipe.  One idea that just popped out of my head, is maybe using the Resovoir Tank which is shown on page 21 of the SGO manual.  Or, maybe just add a couple fittings here and there so that it will be easy to add in the future, if you need it.

On the outside, looking in,

Crash2009

  

Hap_Hazzard

Vaporstat

Short of down-firing, the solution to an oversized boiler is to keep the pressure low with a vaporstat, so as soon as the boiler gets ahead of the radiators, the vaporstat will shut down the burners. This, of course means short-cycling on pressure, but it's better than cycling on low water.

AaronH

Oversized Maybe... Out of Water? No.

We didn't have anything close to and out of water situation last year, but I do cycle pretty quickly on pressure right now. After she reaches pressure the first time, the burner "on" time is about 3 min to 2.0 psi and then it takes about 2 minutes burner "off" to fall down to 0.5psi.



The waterline (with the exception of slight surging, perhaps from the bullhead?) is pretty stable. 



We've got some warm temps starting this weekend and I've got some time - so I'm ripping into it starting Saturday morning.

Rod

Header Configuation

Thanks for posting the new pictures. I've attached one of them with a few notes. I've labelled what I'm presuming are mains with the letters "A"& "B". How far do you have to go back from the center point along each mains piping before you don't have copper pipe? (or where does the steel pie start?)

It's hard to tell in the photos though it would seem to me that using a 90 degree bend in the new header would make the positioning of where the mains connect to the header more flexible.  Keep in mind that the height of the riser is the important part. The header can go much lower (as long as the bottom of the header is above the boiler waterline)  Having a lower header often helps the riser to the main configuration. 

While it's nice to locate the drip connections on mains next to the riser coming up from the header, if position it there isn't convenient on your system, moving it up the main a bit (away from the connection of the main and the riser from the header) won't do any harm. The drip's function is to catch the condensate coming back from the radiators before it drops into the header.

- Rod

AaronH

Estimates

Rod - Here are my best estimates (I'm away from the basement right now)



Where you have label 'center point' is actually more towards the rear of the boiler.



Main 'B' is the tight one - my threaded iron to copper connection occurs right above the stack (behind the feeder supply). It's about 6 inches. I'm thinking of adding a 2"x2"x1" T here to make the drip. I may have to take it off at 45 degree to clear the stack. Then I can take a close nipple to a 90, and go down into the header, putting my union on the vertical. It just might fit!



Main 'A's connection is right where the insulation ends, so about 3 feet forward of the boiler. Lots more horizontal room. A 2x2x1 T for the drip could go straight to the floor.