G.E. Osmonics now offers the rugged Autotrol 256 bypass valve. 
The 256 bypass allows the control valve to be isolated from water flow, 
but still provide water to the home. 
This is helpful during the routine maintenance of the valve.
 Each 255 valve is available with the 256 bypass valve option.
 This Bypass will also retrofit to the older Model 155 Valves.
The bypass valve assembly comes with new o-rings and bolts.
It does not include the Adapter Couplers.