Condition responsive valve construction

A condition responsive valve construction comprising a housing means having a chamber therein and an inlet and an outlet leading to and from said chamber, a self-contained valve seat and movable valve member unit removably disposed in said chamber to control the interconnection between said inlet and said outlet, said self-contained unit comprising a retainer having a part thereof sealingly disposed in said chamber between said inlet and said outlet and having passage means therethrough spanning said part thereof and being in communication with said inlet and said outlet, said retainer having a valve seat in said passage means, said retainer having a movable valve member disposed in said passage means and being retained therein by said retainer whereby said self-contained unit of said retainer and valve seat and valve member can be removed as a unit from said chamber, and condition responsive means carried by said housing means and being operably associated with said valve member while being separate therefrom for controlling movement of said valve member relative to said valve seat in relation to the condition sensed by said condition responsive means, said self-contained unit being either a direct acting unit or a reverse acting unit while still being operated by the same condition responsive means whereby said condition responsive valve construction can be either direct acting or reverse acting depending upon the self-contained unit being removably disposed in said chamber thereof.