Steam Valves

lolo

Hi,
I leave in a building(5 floors) with an old 2 pipe steam system. Most of the radiators are missing the steam valves, plkus the system works on vacuum. A disaster. No hope that the land lord will fix the whole system. So forget about that.
My radiators don't get full because I have too many floors on top of me, so I get air presure comming into my radiators from the return pipe (steam cannot come in). I've add regular steam valves (hoffman 41) to some of them and now they get full. After a while the steam stops comming and a little later the vaccum starts pulling empty the radiators through the return pipe. The problem whith these valves is that they are loud. So I am replacing it with a custom build exit for the air on top of the radiator with a hoffman 17 C and a backflow valve (to stop vacuum) after it. This way I can run it outside the window and not hear the noise.
THE QUESTION: which valve will close 100% when the steam comes?
I've tried: hoffman 17C and Barnes&Jones 122N
Both of them close a litle when the steams comes but none of the close completly. Is this normal?
Could you recommend me another one (preferibly straight)?
thanks in advance!

Big Ed

The problem is that a vacuum system does not use radiator steam vents.Adding valves on a vacuum system causes problems for the rest of the building. The whole system will need a good going over to make it heat the way it was designed. No help from the landlord is like spitting in the wind....... Sorry.

lolo

thanks,
I confused when I wrote steam vents. I was talking about steam traps. Every trap I have open in this building has the guts missing, so steam goes down through the return pipes, etc...
I live in the second floor of six. Since the whole system is so screwup already. I don't really care about the rest of the building ( the return pipe has a water leg that drains into a sewer Hot water!).
I have manage to build my own "venting device", and it works like a charm. Let me explain you: I have a very long radiator in a 2 pipe system that didn't get full because the air couldn't come out. So I have added a te at the end of the radiator with the usual steam trap at the bottom (so the steam doesn't go into the return), and another steam trap to the right (this one works as an air vent an vent through a 1/2" copper into the street). I had tried before all kind of air vents (the long ones and the round ones), even the bigger sizes (N1 hoffman). None of them lets enough air go through, so I built my own one with an steam trap. This way I get increidable throughput ( my radiator gets heat 3 minutes earlier than the rest), and I am able to direct this "vent" out the window so I dont hear any noise. I've added a "check valve" (called backflow in my earlier posting) in this "home made vent" to prevent the vacuum from pulling back from my "home made vent"
The question was: is it normal that steam traps don't close 100%????
Thanks a lot,
as you said: don't spitt in the wind,..just trying to turn around to spitt with the wind!