The Hutchison Vapor Heating System is very simple once you know how it works. There is no trap at the individual radiators. The returns are trapped at the boiler by means of the Hutchison trap-receiver and damper regulator combination. Here is a diagram from a 1923 edition of The Heating and Ventilating Magazine.
The Improved Webster Type "R" System of Steam Heating is a service bulletin from Warren Webster and Company (The Pioneers of Vacuum Steam Heating), established in 1888.
This manual was created by O-E Specialty Manufacturing Co. and outlines how to install the "O-E" Perfect System, which is a Vapor Vacuum heating system.
Here is the original Installation and Operating Instructions and Parts List for The H.B. Smith Company's Oil Fired Cast Iron Hot Water Boilers (No. OHB-13W). This is esti...