Blending Valve Autotrol 255 PN 1041195

Autotrol 255 Valves have been in use since late 1995.
They have a place built into the "top plate" to install this screw and special flat nut, allowing the "by pass" valve disc ( # 4 ) to be held slightly open, allowing blending of hard water back into the water supply coming out of the valve.
Not recommended for water supplies that contain iron in the source water, as staining will result.