This 1 IN air scoop is used in commercial and residential, hydronic heating applications to separate air from water in the piping system. It consistx of a heavy, cast iron body construction with a 1/2 IN female threaded connection for an expansion tank, and a 1/8 IN female threaded connection for a float vent. It provides continuous purging and venting of air in the system when installed with Watts Model ET expansion tank and Model FV4 float-vent. Maximum pressure is 125 psi (8.6 bar).