Reddit reviews Barnes & Jones 122A Thermostatic Radiator Trap, Type A, Angle, 1/2" Size

I googled this. Anything else would be way above your paygrade.

http://www.apartmenttherapy.com/steam-hammer-se-5805

If it was me, I would try to pipe in a steam trap, and spend buku bucks dealing with the consequences.

Edit: And then I googled this.

http://www.amazon.com/Barnes-Jones-Angled-Radiator-Steam/dp/B008HQ21GK

If you want to go balls out, throw your damage deposit in the trash, face potential steam burns and other injury, and whatever happens down the line, by all means, go for it.

I've never used them in a residential capacity, so I couldn't speak to what an install would entail. Good hunting, 007.