Device for venting and aerating closed circulatory water flow systems

Claim 1

A vent valve for use in venting devices for closed water flow systems, wherein the valve is arranged on a vent casing which defines an air collecting chamber, said vent casing being connected to a horizontal conduit of the system and extending upwardly therefrom, said valve being capable of establishing communication between said chamber and the outside, the opening and closing of the valve being float-controlled in response to the water level in the casing, said valve consisting of an exteriorly threaded cylindrical valve body with an axially extending flow passage, a first axial extension on said valve body having a smaller diameter than the valve body proper, and having a plane end surface forming a valve seat surrounding said passage, an exteriorly threaded cylindrical closure body of the same diameter as said valve body and having a second axial extension of smaller diameter than said closure body and forming a plane end surface, and a spring engaging in the threads of said exteriorly threaded valve body and closure body and urging the plane end surface of said second extension against said valve seat in a rest position of said valve, said closure body being rotatable relative to said valve body whereby tension of said spring may be adjusted and operating limits of said valve may be preset, wherein said float being connected to said closure body at a point remote from said valve seat and wherein said axially extending flow passage of said valve is arranged to release collected gases outside of said vent casing when said valve is opened.