Here is a wonderful little book from Hoffman Specialty from 1927 called How To Lock Out Air: The Heat Thief. It includes some great pictures. It makes the case for steam heating systems, shares how a one-pipe steam heating system operates, how to vacuumize a one-pipe steam heating system, why Hoffman No. 2 vacuum valves save one-third of your fuel, how Hoffman No. 2 vacuum valves pay for themselves in less than 2 years, as well as some customer testimonials. Special thanks to Alex Marx for doing the scan.
This document contains the manufacturer's instructions for the HB Smith Series M450L Mills Water-Tube Boiler for automatic firing with oil or gas (Steam, Vapor, or Water ...
This document contains the jacket assembly instructions for the HB Smith Series 45 Mills Boiler (circa 1979).
This document contains the combustion chamber assembly instructions for the HB Smith Series 45 Mills Water-Tube Boiler for automatic firing with oil or gas (Steam, Vapor,...