old vapor arco model k system - air vent needed when a condensate pump vent exists?

elfie

have an older system that has model k radiators valves  (ie. nuts on radiator valves used to control orafice and with no radiator valve)



at some point it appears a condensate pump was added (with a vent pipe)



there is below floor condensate piping connecting to the receiver/pump.



in light of this vented receiver, it there a need for a gorton air vent on the dry return? ie. the return lines below the water level may also be dry due to the pump and therefore could the vent pipe be considered the sole source for venting air from dry returns for the system?



not sure how air gets vented from condensate lines that connect to an underground condensate return pipe that may always have water in it - a mystery.



there is an old arco air eliminator that needs to be replaced (on the dry return) - would a basic f&t trap  installed  in place of air eliminator make sense (allows air to pass thru and stops steam) or should an air vent be installed? an air vent attached to a dry condensate return may not have any functional value due to vent pipe on the receiver





thanks