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pipe insulation & traps

1. I have a 2 pipe steam system. Maybe a dumb question, but.....should both feed pipes & return pipes be insulated ? All feeds are insulated, but only some of the returns are.

2. Is there a "sure-fire" test that a homeowner can use to check the steam traps ? Does the auto thermostat "test" work where you dunk the thermostat in a pot of boiling water to check its operation ? (all my traps are at least 30 years old, so I think it's a fair guess that they should be replaced!)


  • Brian_74
    Brian_74 Member Posts: 237
    amateur's answers

    I'm not a pro, just a homeowner who also has a 2 pipe system.

    I believe the answer to #1 is that it's not worth insulating the returns. If your traps are working, the condensate should have given up most of its heat in the radiators so what heat you are conserving is minimal. Some of the heat saved will be lost once the boiler turns off anyway, making it even less of a savings.

    I'm not sure about the boiling water test, although I've also asked about it. Some people will tell you that you can measure the temperature before and after the trap to see if it's working. Others will tell you that this is not accurate. I think that the only certain way to test the traps is to make a testing port in your system so that you can see whether the traps allow steam to pass. Here's one document that describes testing. http://www.swagelok.com/downloads/webcatalogs/EN/Best-Practices-16.pdf

    I hope this helps.
    1929 Ideal Heating vapor system.
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