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Water Hammering- One Pipe Gravity Return

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Suchitapage
Suchitapage Posts: 28
in Strictly Steam

Hello,

I am working on this building which has been having water hammering issues for the last 20 years and more. It is a one pipe steam building with gravity return. Have attached the picture of the boiler specification tag

I tried to diagnose the issue as per the detailed description given in "The Lost Art of Steam Heating"; Chapter 14 (Shoutout to Dan Holohan) . I verified the near boiler piping, traced all the main steam lines, the riser connections to the apartments, main vents and condensate lines coming back to the building. I have attached the steam schematic and vent photos

I found some major issues related to hammering and venting as stated below:

Main Vents

The building doesn't have enough vents with enough capacity to vent the air out of the system. As seen from the steam schematics and photos, , they only have four (4) vents in total.

One of the G-line Riser not heating

One of the riser on the G-line (Every floor has 6 apartments with letters as suffix, for eg: for first floor its 1A,1B upto 1G) is cold all the time during boiler firing cycle. Have attached photo of the riser below. Its located in the boiler room. The temperature was around 77F-80F all the time. The riser is in bad condition and might be clogged?

image.png

Water Hammering

For water hammering, I found these issues in the building:

1.Concentric Reducers

The reducers are concentric rather than eccentric reducers as seen in the photos below

20261007_160014608_iOS.jpg 20261007_160008930_iOS.jpg 20261007_163732268_iOS.jpg

2. Not Enough A dimension

The condensate line from Loop 2 and Loop 3 (in the steam schematics) combines and comes to the boiler room as a single line. The condensate from Loop 3 comes as a standalone line. From my observations, I believe the system doesn't have enough A dimension to generate enough static pressure to push the condensate back to the boiler. I have attached an isometric drawing of the boiler room, which has boiler water line and the dry returns coming into the boiler room along with their height from the ground level. It gives a clear picture of the current "A" dimension problem.

Boiler Room-Iso view Drawing.pdf

3. Pipe Insulation

Some sections are not insulated or not properly insulated

20261007_160404871_iOS.jpg 20261007_164055877_iOS.jpg

4. Improper Condensate Pitching

Some sections of condensate piping doesn't have enough pitch or has a positive slope.

20261007_171303365_iOS.jpg

Please let me know what do you guys think? Thank you.

Regards,

Suchit S Apage

Boiler Spec.jpg
Main Vents-1.jpg
Main Vents-2.jpg
Main Vents-3.png
Main Steam Line- Schematic.PDF

Main PressureTrol.jpg
Presusretrol Reset.jpg

Comments

  • leonz
    leonz Posts: 1,957
    edited 5:09PM

    I am speaking as a layperson that grew up with steam;

    It would save you a great deal of work if you hired a mechanical engineer or licensed steam plumber to look at

    this place and then do a heat study.

    It is more important to ask if they are willing to actually spend good money to fix it by replacing any bad

    piping, adding main vents or replacing the current vents with larger vents, adding a pair of low water cut off

    switches to bring the boiler up to code, install new steam controls, shimming radiators to increase condensate

    drainage if needed, replacing old radiator vents with new ones, replacing/moving the condensate return pipes

    to create properly sloped pipes, adding a main vent menora on the top floor if possible-if needed, adding a

    double drop header on the boiler if there is enough ceiling height.

    One of the first things on the list would be to do the heat study then wand and clean the boiler if there is a

    mud leg to drain any sediment otherwise one would have to be added if there are 2 tappings in the boiler

    sump and clean the burner(s) and do a combustion test.

  • EBEBRATT-Ed
    EBEBRATT-Ed Posts: 21,100

    Lets see the boiler header and the boiler piping. Is the water line steady when it is steaming?

  • Suchitapage
    Suchitapage Posts: 28
    https://forum.heatinghelp.com/discussion/comment/1906200#Comment_1906200

    Sure. Here we go. The water line fluctuates a lot when it's steaming. I have also attached the boiler spec sheet from Rockmills

    Boiler MP-70.pdf

    website.

    20261007_135507768_iOS.jpg 20261007_135459212_iOS.jpg 20261007_135503817_iOS.jpg 20261007_141044100_iOS.jpg 20261007_141710566_iOS.jpg
  • mattmia2
    mattmia2 Posts: 18,158

    i'm not super familiar with that type of boiler but it looks like it is afire tube boiler. i'll let others comment but it looks like the interior of the boiler is completely filled with water not giving the steam any place to separate from the water.

    the rules about headers don't apply the same way to an older boiler as they do to a modern boiler, the interior of the boiler should have more space for the water and steam to separate, making it less critical that the header is set up to do that job.

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