The trap contains a float valve mechanism which modulates to discharge condensate continuously at steam temperature, while non-condensable gases are released by a separate internal balanced pressure thermostatic air vent.
Spirax Sarco Float and Thermostatic Steam Trap, 3/4 in Nominal, FNPT, 4.6 in Length, 15 psi, Cast Iron, 450 deg F, 5.75 in H x 6.2 in W