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Minor boiler explosion

Big Shrub
Big Shrub Member Posts: 18
I was just reading the post about a 75 psi relief installed on a 50 psi boiler and thought I would pass along a good story that could have been a disaster.

About 2 months ago a guy from out of town calls me hoping to locate a rear section for a 200 series National coal boiler. Yep - I got one, but what happened? He told me that he heard some tinkling sounds and was looking behind the boiler then a big chunk came out of the back section. It didn't hit him but he got soaked. He proceeded to explain that over the summer he had closed all his ball valves to work on his heating system. As cold weather set in he wanted to shut down his oil boiler so he built a fire in his coal boiler and forgot to open the valves. As soon as the water started to warm the back section gave out. I told him the pressure relief should have opened at 30 PSI and saved the day. He said he also forgot to open the ball valve underneath the relief. Lucky man. End of story.


  • Robert O'Brien
    Robert O'Brien Member Posts: 3,541
    "God takes care of fools”.
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • ratio
    ratio Member Posts: 3,649
    I don't think there's supposed to be a valve in front of the relief…

    I guess he missed out on a Darwin Award this time. Maybe next time!

  • Big Shrub
    Big Shrub Member Posts: 18
    The guy does not seem to understand just how lucky he was. I sold him the used rear section and advised him to install a new relief and remove the ball valve from under it. I am glad he is beyond my service area. He was installing the section himself. I figured I would hear about it leaking which always happens when it is a DYI project. Been 2 months and I haven't heard anything or saw his name on the 6 o'clock news.
  • kevink1955
    kevink1955 Member Posts: 88
    Good thing it was completely full of water as water will not compress and let go with explosive force. Thats why they fill cylinders with water when hydro testing. Still could have been hit with a chunk of iron though
  • KC_Jones
    KC_Jones Member Posts: 5,741
    A ball valve on the relief. Common sense isn’t so common. And as far as a know that’s a code violation.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Ironman
    Ironman Member Posts: 7,378
    Code and common sense dictate that NOTHING can be placed before or after a relief valve that would hinder its function.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.