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No Steam Trap?

Hi Guys,

I have a building I just took over, and I was examing the system.

This is a two pipe system

The main comes from the boiler(header,etc) and goes towards the end of the building. At the end of the main it dumps into a wet return no stem trap, vent, etc. The radiators returns into a dry return higher than the steam mains and pitches down towards the boiler it. The dry return heads into what looks like a very large steam trap which has a main steam vent on it, and dumps into the return at the boiler.

What confuses me is that at the end of the steam main where it dumps into the wet return there is a tee. The steam main goes into the branch of the tee, and on the run of the tee there is hoffman 17c facing up. The last radiator which is above this main comes down there is a tee the pipes down to this inverted 17c trap, and then it continues down the dry return.

FYI each radiator has a hoffman 17c trap installed

My questions are:

1-Whay are the no steam traps at the end of the main (4 end of steam lines)

2- Why is it piped this way? There are 3 mains piped this way

Any help would be appreciated.



  • Steamhead
    Steamhead Member Posts: 15,262
    edited February 2010
    If the steam mains

    drip into a wet return, no trap is needed on the drip since the water standing in the return will contain the steam.

    The 17C is probably serving as an air vent, routing air from the steam main into the dry return. Not the best use for a 17C since other models will vent air more quickly, like the Barnes & Jones 122 or MEPCO 1E traps.

    The "trap" near the boiler is probably a "vent trap" whose purpose was to close against water.

    This is a Vapor system. Post some pics if you can.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • sevenkillers
    sevenkillers Member Posts: 2

    I was looking thru my Lost Art of Steam heating, and could not find anything that made sense that way is was piped in the TWO PIPE STEAM SECTION. However since you mentioned vapor, I check towards the back of the book, and THERE IT WAS!!!!!

    It all makes sense now.

    I will post some pics in the next few days.
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