Identify what this is?

cunninghamzach

Anyone familiar with what this is? Steam system, assuming it was a vapor system at one point in time.

Chris_L

Not familiar with it, but the first hit I get on a Google search for Kriebel steam system is this document on this HeatingHelp site: https://heatinghelp.com/assets/documents/Vapor-Vacuum-Heating-Kriebel-System-1910.pdf

Steamhead

@cunninghamzach , that's a Kriebel System main air vent. It works by differential expansion. See chapter 15 of @DanHolohan 's "The Lost Art of Steam Heating" for details.