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Two pipe steam

1) can a small one family two pipe upfeed steam system operate without thermostatic traps?
2) system has radiators and cast iron baseboard with air vents and main steam air vents.
3) It has one f & t trap that instead of dropping into a wet return makes a U bend above the water line of the boiler and returns just below the ceiling of the basement when it enters the boiler room only then does it drop below the water line of the boiler and never goes to the floor before the Hartford loop.
4) The contractor had pressuretrol set at 10 psi and the near boiler piping does not meet manufacturers specs.
5) New boiler lasted one week before it cracked and overheated section melted spark ignitor control.
6) Contractor claims there was no water hammer.
7) All insulation was removed from all steam pipes.
8) Contractor had removed skim plug but with the pressure and header the carry over must have been very great.
9) No water meter on the make up water feeder.
10) Contractor says the system worked for years, I insist he must make a loop seal and wet return to the boiler and correct near boiler piping.
Can I have your thoughts, thanks chappy


  • SteamheadSteamhead Posts: 13,578Member
    Let's answer the first question- YES! These systems don't necessarily need traps to work. There are other ways of doing the same thing.

    How about taking some pics of radiators with their original valves on them, also focus on the rad return connections. Sometimes innocent-looking return elbows have stuff in them.

    Also let's see the boiler and the piping around it, and the same for the ends of the steam mains.

    This system could be several different things, and being able to see it would help us ID it.

    Where are you located?
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Some old 2-pipe systems were designed to use radiator vents, instead of having steam traps at the outlet of the radiator. These systems were designed to operate with a couple of ounces of pressure.
    Setting the pressuretrol so high, (up to 10 psi), must have allowed all the water to have been pushed out, and up into the wet returns, emptying the water from the boiler. If the installer had no knowlege about steam systems in general, then why was he even chosen to do the replacement? Hopefully, he will return any money you have laid out, and you can find someone more knowledgeable, to complete this project.
    Have a look here in the museum/library, and somewhere there will be an explanation as to how this system should work, (and very well).--NBC
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