1 or 2 risers

scott_block

Hi All,

For a Weil McLain EG 50 the manufacturers instructions state 1 2 1/2” riser and 2 1/2” header. Is thIs sufficient and is there truly added benefit to let’s say using 2 2 1/2 or 3” risers. In both cases it would be a drop header.

Does anyone have specific experience with this and is there truly a benefit?

Ironman

Absolutely! Dry steam is the goal. By slowing the exit velocity down, you're gonna get much drier steam.

Dave0176

Here are a couple pics of an EG50 I did. I use both risers and use three inch and a three inch header. The boiler is very quiet and heats very evenly.

scott_block

Thank you guys.

Joe_Dunham

Nice install. How about 2-2" risers and a 2 1/2" header? That would make your job easier and it exceeds the manufacturers recommendation.

ethicalpaul

scott_block said:

Hi All,



For a Weil McLain EG 50 the manufacturers instructions state 1 2 1/2” riser and 2 1/2” header. Is thIs sufficient and is there truly added benefit to let’s say using 2 2 1/2 or 3” risers. In both cases it would be a drop header.



Does anyone have specific experience with this and is there truly a benefit?

For all the complaints I have seen on here for bad boiler performance (and there have been dozens in just my couple years here), I have never seen a case where piping to the correct manufacturer specs was the cause of any problem. If anyone knows of any cases, please inform me.

Of course, if you slow the steam even more, you still won't have any problem (other than having spent unnecessary $$$), but my feeling is that the manufacturers aren't going to recommend/require a piping specification that is going to make their boilers perform badly.

I'm going to pipe my boiler in a way that will let me verify this via testing. Watch this space this summer.

Joe_Dunham

Think Pauls right

The Steam Whisperer

The eg50 is 175,000 input. If you use a single 3 inch riser and header, the velocity going up the riser will be lower than the maximum velocity water can be carried with the steam. The water being carried up the riser will fall back into the boiler against the steam. Going any bigger will not gain you very much... just a little drier steam if the boiler is really dirty and fouled. If the boiler is priming due to being really dirty and fouled, the nice big 3 inch header will still catch most of the water and you'll still have dry steam.
My recommendation is to use a 3 inch header a 3 inch riser. Going beyond a single 3 inch riser and header is really not cost effective if the boiler if going to be maintained at some reasonable level. If you make the riser very tall you'll improve performance when running with fouled water. In addition, when building the header, you should maintain at minimum 3 header pipe diameters between the boiler risers and the first take off ( this allows the water to settle down to the bottom of the header) , 2 pipe diameters between the last take off and the far end of the equalizer ( to help ensure that the water backing up at the equalizer will not get pulled up into the last takeoff) , and at least 2 header diameters between take offs ( each takeoff causes the water to lift off the bottom of the header and the 2 diameters allows it to settle back down before the next take off).
Also, if you can, size your take offs as big as the header and then use a reducing coupling to go down to the supply main size. This will reduce the exit velocity up the take off and allow the water to more easily stay at the bottom of the header.

If you can't maintain these minimum spacings, then you'll need a bigger header to help reduce the potential of water being lifted out of the header. I especially try to make the length of the pipe between the boiler riser and first take off as long as possible to allow the header enough space to do its works of water/ steam separation.

STEAM DOCTOR

Take a look at Burnham's 6 section boiler. They recommend 2" header and single 2" riser. If I remember correctly, exit velo is aprox 45 fps. You can't always go by manufacture

gerry gill

my opinion is the more risers the better, the bigger the header, the better. just my opinion.

scott_block

Thanks for all the input even though I am more confused now haha. I will leave it to the professional to decide what route to take but I see a lot of the header pictures on here and a lot of them have 2 risers with 2 1/2 to 3 inch piping and people say it slows down the velocity and dries the heat out more so I just don’t want to have the minimum spec of 1 2 1/2 riser and 1 2 1/2 header and the system have room for improvement or problems down the road.

EBEBRATT-Ed

I trust Weil McLain's instructions. I usually stick with the MFGs piping diagram and never had an issue but This is one case where larger can be better. For the cost of a few extra fittings and a little labor...your going to have the boiler (hopefully) for 20-30 years

Dave0176

You cannot go wrong piping by the manufacturers minimum specs, however keep this in mind, if the said boiler that’s being installed is the proper size based on a measured EDR of the current installed radiation. Meaning it’s not oversized then you will most likely get away with minimum piping specs. The minimum for that boiler is one 2-1/2” riser and a 2-1/2” header, this yields 26 feet per second of steam velocity. Much higher than the old standard in the height of the steam era of 15 feet per second. Most of us on here prefer to keep our steam velocity below 15 feet per second. My install is a bit overkill as two 3” risers provide 8.5 feet per second however that’s the way I will always install it.

scott_block

My thoughts exactly Ebebratt. For a few bucks more in piping I would rather go the larger pipe route since I am burned with taking on this house i bought 2 years ago with a System in need of redesign and replacement.

I plan on doing this now and never having to revisit it again so my thoughts were going with the larger piping and future proofing so at worst case I just need to do a boiler swamp in the far future.

Technically I think the proper size was about 130K btu or so. One guy wanted to use an eg 40 while another an eg 50. I am going to have a tankless coil off of this with an indirect hot water tank and a couple of radiant and hot water baseboard zones which is why I think the 50 was chosen even though it may be slightly large for the steam side.

Not sure how much this plays into the piping but I guess it was go a little under or a little over so they chose to go with the ladder.

Dave0176. It seems like I get mixed signals about guys that say more more more and want 2 3 inch risers with a drop header. Others say the manufactures suggestion is never a problem.

I don’t have a lot of ceiling height so a drop header seems like the option most people suggest. Is a drop header with 2 3 inch pipes overkill or can it hurt the system in any way?

The Steam Whisperer

I calculate exit velocities at 0 psi since this is the pressure the boiler starts at and usually only operates at a few ounces pressure most of the heating season. This works out to 32 ft/sec in a single 2 1/2 inch pipe, which is higher than the maximum velocity water can fall back against in a 2 1/2 inch pipe (26 ft/sec). That's why I'd use a 3 inch riser... velocity is at 21 ft/sec at zero psi steam, well under the maximum velocity water can fall back against in a 3 inch pipe( 29 ft/sec). Using a 3 inch header will provide an additional safety factor for performance. With proper spacing between fittings on the header you should get excellent performance out of the heating plant.

Most old boilers had no headers installed, so they had to be very conservative with exit velocities to keep the water in the boiler even if it was severely fouled.

scott_block

The steam whisperer is 2 3 inch risers overkill or is the 1 3 inch riser and 3 inch header plenty?

STEAM DOCTOR

@The Steam Whisperer . Very interesting. Where do those "fall back" numbers come from? Thanks.

The Steam Whisperer

The fall back numbers are right out of "The Lost Art of Steam Heating" as are the formulas for calculating steam velocity. The quailty of the steam also depends on the boiler. The Weil Mclain EG and Peerless 63 both have big steam chambers, so they work pretty good. However, I have found that the Slantfin Galaxy produces exceptionally dry steam with just a single 2 1/2 inch tapping in the 180,000 btu/hr input models. When good and clean the equalizer stays ice cold because there is 0 carry over. The design routes the exiting steam through the large end section that appears to act as a built in steam separator and there is a baffle at the exit that probably also reduces carry over It's the only cast iron steam design I know that doesn't have the steam exit on the side where the top push nipples are located. I'd probably use more of them if they were well represented in Chicago. I have also found they back thier boilers far better than any other manufacturer.

STEAM DOCTOR

@The Steam Whisperer. Thanks. Time for some review. My lost art seems to have disappeared. I think that my wife may have stolen it. FWIW, I find that the Slantfins have a fairly short lifespan. Just my personal findings and that is based off a small sample size. They aren't many Slant Fins in my area.

Precaud

ethicalpaul said:

For all the complaints I have seen on here for bad boiler performance (and there have been dozens in just my couple years here), I have never seen a case where piping to the correct manufacturer specs was the cause of any problem. If anyone knows of any cases, please inform me.
{snip}
I'm going to pipe my boiler in a way that will let me verify this via testing. Watch this space this summer.

Oooh, a tease... I like it...

STEAM DOCTOR

Once upon a time, I had a list of exist velocity. Manufacture by manufacture. Assuming minimum specs. The contrast was stark. I don't think that one can make a blanket statement that you should or should not follow the manufacturer's minimums. Some were in the low 20 FPS range and some were close to 50 FPS ( if memory serves me correctly).

ethicalpaul

So you do think that some manufacturers publish install requirements for their own boilers that result in poor quality steam and/or carryover?

STEAM DOCTOR

Absolutely. Seen it in the flesh. Lets say manufacturer A says use 2" and manufacture B says use 3". Which manufacture will many installers choose?

STEAM DOCTOR

The manufacture wants people to buy their boiler. You can always blame problems on steam being old blah blah blah.

ethicalpaul

I can't see how it could ever be in a manufacturer's interest to instruct installers to underpipe their boiler. It would just give them a bad reputation, but I definitely can't refute your personal experience. Thanks!

If you come across your list and can share an egregious example I'd love to see it!

STEAM DOCTOR

Lost the list long ago. As soon as I get my new Lost Art, I will try to make another list.
I don't have the formula for calculating FPS

EzzyT

I personally when out to take a look at this project to present an estimate to @scott_block the homeowner. Based on the EDR numbers a Weil Mclain EG40 would work best and a EG50 would be a way oversized.
As many have said the slower steam velocity the dryer the steam which in then has an overall effect on the system efficiency along with proper steam main venting, radiator venting and all steam piping being insulated.

STEAM DOCTOR

I think that we all agree that slower=dryer=better. The unknown is when do we say overkill. I don't think that a 6" header on 65 btu boiler, is of any benefit. So where do we draw the line? Is 7 FPS drier then 15 FPS? 24" risers vs 48" risers? Lets say you are using a 3" header. Does adding a second 3" boiler riser make much of a difference? What role does header slop play? Is insulation more effective then that 2nd riser? I have been exceeding manufacturer's recommendations since forever. The real shame is that we are working with lots of anecdotal evidence. Would be nice if someone set up a lap and provided real and scientific data. Maybe plexiglass risers and/or headers should be mandatory.

ethicalpaul

I'm glad you got a chance to look at that boiler sizing @EzzyT ! I was nervous when I heard they were deciding between two of them.

The Steam Whisperer

Yep, that's the question, where is the "knee" in the curve. I suspect the knee in the curve ( performance versus first cost) is somewhere around the manufacturer's piping. Most manufacturer's want to keep their piping as cheap as possible so they can sell more boilers ( of course, that is assuming anyone even pays attention to the directions in the first place.) That's why you can have two identical boilers with different names on them and one manufacturer allows welded piping, while the other manufacturer prohibits its use. I look at it this way, once you get a boiler riser big enough to allow the water to drop back down against the rising steam, how much lower velocity do you need? Bump up the header size a little and that will give you an additional safety factor for foaming caused by very fouled water. Oh course, if the boiler is that dirty, it needs to be cleaned. Getting two risers on a small boiler can end up pushing the piping too close together to allow proper operation of the header, which then means you need that bigger header. In can end of being a circular logic problem at that point.

STEAM DOCTOR

Found my book. Yay. Lets compare Burnham In6 and Weil Mclain Eg50. Output is almost exactly the same. Lets assume 1 Psi. Follow manufacturer's specs. Burnham will give you 44.6 FPS. WM will give you 31.59 FPS.

scott_block

At what pipe setup, the manufacturer minimum spec?

scott_block

Guys just to fact check and make sure if I should go with an eg 40 or 50 prior to work starting can someone verify my edr. I know the hydronic zones are not supposed to really be factored into the equation but I will have a tankless coil with a 45 gallon indirect tank probably set to 150-160 degrees with a mixing valve as well as 2 baseboard zones and 2 radiant zones.

I also want to make sure I am not going to have a crappy DHW recovery etc..

Master bedroom
12 sections 3 column 26 high and 28 wide

Second bedroom
10 section 2 column 38 high and 24 wide

Small bedroom
8 section 3 column 26 high and 20 wide

Living room
8 section 2 column 38 high and 20 wide
14 section 3 column 38 high and 34 wide

Foyer
8 section 2 column 38 high and 20 wide

Dining room
10 section 3 column 38 high and 24 wide

Dave0176

@scott_block keep in mind the tankless coils provide about 35,000-40,000 Btu.

Dave0176

scott_block said:

Guys just to fact check and make sure if I should go with an eg 40 or 50 prior to work starting can someone verify my edr. I know the hydronic zones are not supposed to really be factored into the equation but I will have a tankless coil with a 45 gallon indirect tank probably set to 150-160 degrees with a mixing valve as well as 2 baseboard zones and 2 radiant zones.



I also want to make sure I am not going to have a crappy DHW recovery etc..



Master bedroom

12 sections 3 column 26 high and 28 wide



Second bedroom

10 section 2 column 38 high and 24 wide



Small bedroom

8 section 3 column 26 high and 20 wide



Living room

8 section 2 column 38 high and 20 wide

14 section 3 column 38 high and 34 wide



Foyer

8 section 2 column 38 high and 20 wide



Dining room

10 section 3 column 38 high and 24 wide

Based on the radiator info you’ve given I came up with 306 EDR so Ezzy is right in suggesting an EG40, which provides 325 EDR net.

KC_Jones

If @EzzyT came out and sized for an EG-40 that’s the correct size.

Keep in mind he is one of the top steam installers around.

If I was in NJ and didn’t do my own work, he would be one of a very short list of people I would call.

If someone else is recommending a 50, when a 40 is needed, that’s insanity. Run away from that.

I took a look at your numbers anyway. I’m getting 299. 40 is rated for 325, but you also have the pickup factor to work with. So you have ~32,000 BTU’s to play with for the water zones.

Read your other post and states the water zone is 700sq ft, what you have available will easily cover that unless you are keeping the windows open. I’m guessing the indirect will be wired with priority so I don’t see any issues with the 40, and again the 50 is insane.

My $0.02 worth.

ChrisJ

I don't know the details of what @EzzyT quoted you.

I do know he does good work and I'm betting his size is correct.

I'm running an EG-40 with 392sqft of radiation. It used to be an EG-45 but I felt it was oversized so I spent time downsizing it. Goodluck with a 50.

dopey27177

This a small boiler and Wiel McClain is giving you theminimum requirement.

Your boiler is a long time investment and your system is older. To play the safe card I would install the two risers and a 3" header. The slower the steam leaves the boiler the better.

You do not need a drop header unless you have a height problem.

Make sure that the contractor installs the system according to the diagram shown with the larger pipe and the equalizer is in the right part of the header.

Ignore the piping sizes on the simplified sketch of the near boiler piping. The sketch is the way the piping needs to be installed.

Jake

scott_block

I wound up using @JohnNY gateway plumbing and they did a great job. Very professional and very good at what they do.

Here are some pics of the job.

scott_block

One more pic

scott_block

2 inch risers and 3 inch header on eg45