The Taco 4900 Series Air Separators are designed for the complete elimination of air from closed loop heating and cooling systems up to a maximum temperature of 240 F and a maximum pressure of 150 psi. The principle on which the Taco 4900 Series Air Separator is based is a patented and proven method of removing gases from water: the PALL ring process. Minimal pressure loss - Vent can be closed - Large surface contact area - Protective vent plate - Maximum air removal - Expansion tank connection tapping - No minimum run of pipe requirement - Bi-directional flow