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Steam component question, What is this thing?
Customers just bought this 1600's house and wanted to Zone the 3 floors with a two pipe system. I went to check it out and told them that it would probably be better to just make sure everything was first in working order and then just balance each radiator. When I was in the basement I came across this (see images), not sure what it is or does. 4" header and the 3/4" pipe feeds into the top of this. Also is the asbestos insulation? She said she was living in a house that had steam and that every room had its own thermostat, i haven't seen that before and from what i have read, zoning a steam system is ideas of the devil.