The special design and internal baffles of Taco Air Scoops slow water velocity to separate the air from solution. Thanks to this design, Taco Air Scoops efficiently remove air to provide noiseless, air-free hydronic heating, cooling or combination systems. They also provide an economic way to integrate air elimination by the connection of either a plain steel or diaphragm expansion tank. Quality features include one piece, cast iron construction, and engineered baffle to separate air from water, maximum operating pressure of 125 PSI and maximum operating temperature of 300 F (135 C).