Our 1922 home has an original low pressure (1/2 psi) Warren Webster steam heating system. The boiler is up to date but the rest of the system is original. Since the system only runs on 1/2psi and there is no pump the steam rises to the radiators by the virtue that heat rises. As the steam enters the top of the radiator (the radiators do not bleeder valves but do have modulation valves) and the radiator is heated a sylphon (that's the correct spelling) trap, at the bottom of the radiator, closes. As the radiator cools the steam condenses at the bottom of the radiator. At temperatures cooler than the steam the sylphon trap opens and allows the condensed water to return to the boiler.
The system seems to work very efficiently except in radiators where I suspect that the sylphon trap is no longer operating. After over 80 years they've surely exceed their life expectancy.
Well Warren Webster is no longer around and finding so finding replacement traps is no easy. I'm wondering if there is anything wrong with running the system if I just take out the traps and allow the steam to flow through the system without being trapped in the radiators until it condenses? I remember my Dad doing something similar in his sports car because the thermostatic valve would always break. Quality British sports car. The only issue he had is that it took much no longer for the engine to warm up and provide heat to the passengers since the not having the value allowed the radiator fluid to constantly move through the engine.
If your interested in some more technical information about this type of system follow this link http://books.google.com/books?id=TFNDAAAAIAAJ&printsec=frontcover&dq=A+Handbook+on+Piping#PPA202,M1
to Google Books go to Google Books and search "A Handbook on Piping" by Carl Svensen and see page 211 of the book not pdf page 211.
Any advice is very much appreciated.