Boiler Piping seems wrong

Steamhead

the one on the slow branch could be too small for that branch. Measure the length and diameter of each branch and tell us what vent is on it, we can advise you once we know.

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Paul Lemaire

Heating is very uneven

I recently had a new steam boiler installed. I have a one-pipe system (the steam flows in loops from the boiler to the returns, there is one connection to each radiator). The header from the boiler is a 2.5" pipe. It was installed with TWO 2" supplys going to two main loops in my system. Each main loop has a branch loop off of it for a total of 4 loops. The loop that is furthest from the riser does not seem to be getting as much steam as the loop that is close to the riser (duh!). I have pictures of this but there is no way to post them here. The system worked fine with the old boiler but it did not occur to me to take a picture of the old piping to see how it was done. I am pretty sure that what needs to be done is to have a single supply coming off the header. Can anyone confirm this? From there, can I go to a 2x2x2.5 bullhead tee (should the run into this tee be at an angle?) and then have an elbow into each riser?

JM_2

venting

you probably need to address your venting of the system. It sounds like it is piped right. Get "The lost art of steam heating"

Paul Lemaire

I checked the venting

John,
Thanks for your response. I checked the vents in the basement. They are all new (4 of them). The piping at one of the vents is noticeably cooler than at the other three. I swapped that vent with another and it made no difference. The radiator vents are all in good condition and I have been experimenting with the settings on these.
I still think it's the piping (I ordered the book, by the way. In fact, I ordered the three book package). Consider the way a radiator heats up: one section at a time. Feel the bottom of the radiator, the next section does not begin to heat appreciably until the first one is full of steam. The steam rises into the first section until it can't anymore. I think something similar is happening at my boiler. It is as if the boiler is feeding a radiator with two sections. The first section is getting more than half the steam. I hope this picture works...it took me a long time to compose it:

                   |   |      |   |
                   | S |      | S |
                   | U |      | U |
                   | P |      | P |
                   | P |      | P |
                   | L |      | L |
                   | Y |      | Y |
                   |   |      |   |
                   | 1 |      | 2 |
                   |   |      |   |
            ------------------------------
           /                               &#92
          /            HEADER               &#92
         /      --------------------------   &#92
        |     /                           &#92  |
        |  R |                             | |
        |  I |                             | |
        |  S |                             | |
        |  E |                             | |
        |  R |                             |E|
        |    |                             |Q|
        |    |                             |U|
     -----------------------------------   |A|
     |                                 |   |L|
     |                                 |   |I|
     |                                 |   |Z|
     |          BOILER                 |   |E|
     |                                 |   |R|
     |                                 |   | |

Paul Lemaire

Vent/Pipe Size data

All the vents are, indeed, the same size: Vent-Rite No.75


The system has 2 main loops (SUPPLY 1 and SUPPLY 2). Each main loop has a branch loop off of it:

Loop 1: 5' of 2" pipe from header to tee where branch 1B takes off. Then 19' more of 2" pipe with radiator take-offs at 3.5, 15.5 and 18.5 feet. The return from there to the vent is 18' of 1.25" pipe (then down from the vent to the waterline).

Loop 1B: 21' of 2" pipe. Radiator at 17', VENT at 20'. The return from there is 16' of 1.25" pipe (then down).

Loop 2: 5.5' of 2" pipe from header to tee where branch 2B takes off. Then 18' more of 2" pipe with radiators at 6' and 18'. The return from there to the vent is 18.5' of 1.25" pipe (then down).

Loop 2B: 14' of 1.5" pipe. Radiators at 8.5' and 12'. The return from there to the vent is 11' of 1" pipe (then down).

Steamhead

There's your problem

The only main with a vent sized properly is 2B. Mains 1A, 1B and 2A need more venting.

Use a Gorton #1 or Hoffman #75 vent on each of those three mains. Leave the Vent-Rite on 2B. This should result in steam reaching the end of each main at about the same time. Note that Vent-Rite's #75 vent has a much lower capacity then Hoffman's #75.

Incidentally, the ideal placement of a vent is the one used on 1B. This way, you don't have to fill the return line with steam before the vent closes, therefore the system will heat up a bit faster.

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