Installing New WM EGH-85 Images of existing piping attached looking for comments if OK to keep as is

MikeMens

I am installing a new WMRGH 85 315000 btu gas steam boilerand would like to get your comments on if current piping layout is OK images attached
It doesnt have a "Main Header" as I have seen other boilers piped. Also, supply risers are not attached to one header, but go in oppposite directions right from riser to feed opposite sides of the house. Is this OK? These are 3" mains.

MikeMens

sorrry its the Weil McClain EGH 85

KC_Jones

Completely wrong what is in the manual is the way it should be, if a contractor is proposing to use that mess over you should immediately fire them. Also how did they size the new boiler? From the old, or did they measure all the rads and do a proper EDR calculation for sizing?

MikeMens

measured all the radiators dimensions, # of columns, # of segments etc had a couple of boiler factory reps do the calculations and contractors confirm around 760 sq ft of radiation. requires 315000 btu unit.

RE: piping manual - not it is not laid out this way, and I intended to follow the manual unless someone said this is normal when main goes in opposite directions as shown in images.

Just trying to understand what is correct and why.

will be meeting with contractor to put together piping BOM Sat and looking for info so I can be sure his plan is correct.

KC_Jones

Couple of things to make sure of. The mains must not be tied together the must come down to the header individually. They also must NOT be tied in between the risers from the boiler. Those are the 2 things I have seen done incorrectly the most often. Also keep in mind the manual is the MINIMUM and most GOOD steam guys will exceed this using either a drop header or oversized header or both. It will give a better more efficient performing boiler. Post pics when it's complete we always like to see some good piping.

KC_Jones

One other thing. Just guessing here. Based on a boiler that size hooked up to a system that big that main venting is almost certainly not adequate....not even close in all probability.

Fred

Totally piped wrong as is. At a minimum, pipe it like the installation manual shows. If at all possible, put in a drop header (that option should be shown in the manual also. You definately need more Main venting as well. Have the installer add that to your order. Main venting is calculated based on the size and length of each main and should go at the end of the mains, after the last radiator on that main (I'm assumming this is a one pipe steam system???) One pipe on each radiator with a valve on that pipe/radiator connection?? Steam is supplied and condensate returns through that single pipe?

MikeMens

Ok so installation manual shows (2) 2" risers to 90 deg bend then to 3" horizontal pipe that enters 3" header then a 3" vertical run leaving header )(to the left of the risers) to go to main(s).

I take it that since my mains go in opposite directions the system should have 2 vertical exits from main, outside the risers, on opposite ends of the header?

Should the header be 4"?

Even though manual does not show a drop header I should add this feature? If so I assume the drop header should be at a level below the top of the 2" risers? How much below? Again, should header be 4"?

KC_Jones

NO! the main connections should both be on the same end of the header and also the same end as the equalizer. The header should be laid out in this order. Boiler riser, boiler riser, main main and finally equalizer. The manual is the minimum, in all honesty how far you exceed that minimum is up to you, your installer and your pocket book (we don't discuss pricing). The more bells and whistles the more the cost. If it was mine I would do 3" risers into a 4" or 5" header. I wouldn't do 2" risers on that boiler no matter what. The WM comes with 3" tappings in the block you should use them full size. I have a much smaller WM in my house and it has 2" riser with a 3" drop header (see profile picture) and mine is 125k input boiler. The drop on the header is as much or as little as you need, generally they are used when head room is at a premium because it makes it easier to install the main takeoffs. Not sure what your head room is.

MikeMens

Gotcha Thanks a million I think you got it thru my thick head

MikeMens

Reply to Fred,
Yes its a single pipe system
What size vents are normal for a 315000 btu system with 3" mains.
One main is approx 50' the other around 75'

BobC

It would take 3 Gorton #2's on the 50 ft and 5 Gorton #2's to vent those mains quickly and completely. Are you sure the mains are 3" ID?

Bob

KC_Jones

Vents (plural) is the key here. The largest main vent is a Gorton #2 vent and the rule of thumb is one of them for every 20' of 2" pipe. With your 3" mains that would translate to about 9' for 3" pipe so 1 vent for every 9' or so. You will be looking at roughly 6-8 Gorton's on the 75' main and 4-5 on the 50' main. A good test to figure out how many you need is to run the system with the vent hole open and time the steam from a hot header to the end of the main (feel for heat, don't get burned) then use that as a baseline and put as many vents on as you need to get close to that time. What size pipe you have available for the vents can also dictate what you can do. 5 Gorton's are going to need roughly a 1" pipe to run more I think you will need a bigger pipe for the vents. There is a balancing steam book available in the book store for 10 bucks it's a huge help and also where I am looking all this info up at right now...lol. As a double check 3" pipe has an OD of 3.5".

MikeMens

Thanks Guys You have given me the outline of a good plan to discuss with my contractor on Sat

Dave0176

According to Jstars header charts you can use a 4" header but it is right on the cusp. Unfortunately a 5" header would double your cost, soooo. Definitly run two 3" boiler risers at least 30" high into a 4" drop header, take your system risers off after you bring the boiler riser into the header but before you drop for the equalizer this will help you get good dry steam.

Fred

Not much left to be said here. You do need a lot of vents to get all the air out of the mains quickly so that steam can get to the radiators as quickly as possible. Once that is done, you can adjust the size of the vents on the radiators to try and get steam to each radiator at about the same time (a balanced system). The drop header can "drop anywhere from a few inches, down to a couple inces above the top of the boiler, it really doesn't matter but the drop header will allow the water droplets to fall out of the steam giving you much dryer steam to the radiators. With this size boiler, I'd opt for a two stage gas valve, if it's an option on the boiler you select. That will allow the burner to fully fire until the piping is heated and you get to a couple ounces of pressure and then step down the burner to a lower level to maintain an even flow of steam. It will save you some money on your fuel bills. That two stage gas valve should be controlled by a couple vaporstats.

MikeMens

Thanks guys,
Question, assuming I use a 4" header, when you come out of the boiler with the 3" risers and transition to horizontal do you switch to 4" on the horizontal the rest of the way into the header or stay with 3" pipe all the way to the header

Fred

Stay with 3" into the header. You don't want to transition anywhere on the horizontal that might allow water to pool.

MikeMens

stupid question #2 - do i want to use cast iron fittings?
on both steam and gas piping?

Fred

You can use cast iron or malleable black iron fittings on the steam. I would use malleable on the gas line.