purgeur à tension de vapeur

CONT: Thermostatic traps are the most common of all types used in two-pipe steam heating systems. ... They are designed to open in response to pressure and temperature to discharge air and condensate and to close against the passage of steam. ... Balanced pressure-type thermostatic traps are those which have been described. They employ thermal elements made from metal bellows, a series of diaphragms, or special cells made from diaphragms. There are some types that employ special shapes of bimetal for the thermal elements.