old bottom nipple connected (one pipe steam style) radiator holding condensate

in a building with steam supplied from a utilities connection , i have an old radiator (see pics). with a TRV installed.
it is collecting condensate (and therefore hammering). i assume it is from the trv closing , then the radiator forming a vacuum, then the radiator sucking in its own condensate and more condensate from an end of main drip trap that runs right under it (see pic).
My thought was to use another thermostatic trap as an equalizer . i was going to connect a half inch pipe from the elbow after the valve to the condensate line just before the wall. i was hoping this would equalize the ends of the radiator and allow the condensate to flow out./// This idea comes from the piping scheme that one might see on an air handler coil, to allow it to drain once the control valve has shut. This perimeter heat system is on a vacuum pump, so i can't just add a vacuum breaker.//// Does this seem like a good idea, only option, better suggestions from the gallery????????????? thanks.