Fits the Autotrol 255 valve.This new 256 ByPass is also backward compatible with the older Model 155 Valves. The bypass valve assembly comes with new o-rings ( the 3 that go between the By Pass and the Valve / Tank Adapter ), small tube of silicone, and 4 bolts with nuts. The Adapter Kit ( see related items ) that attaches the ByPass to your house pipes ( 3/4" , 1" in Copper or PVC ) is sold separately, if this is a New Installation.But if replacing an existing ByPass that already has Adapter Nut and Tubes, then you may want to include ( 2 ) of the Gaskets ( 54F ) to put inside your large adapter nuts ( reason being, the old ones may be dried out and not seal well when reconnecting your old Adapter Nut and Tubes to your new ByPass.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.And the distance between the " dead center" of each connection is 3 inches.Drain connection is 1/2 NPT ( male pipe thread ), and fittings for this connection should be available from local hardware store.Or we stock / sell an Elbow with "Barbed" end for using 1/2" I.D. x 5/8" O.D. hose.1/2"female threaded X 1/2" Barbed Elbow.Commonly used on Autotrol 1/2" male BY PASS ( 256 ) drain connection.Use with 1/2" I.D. x 5/8" O.D. tubing.Pentair short video on By Pass operation ( and Depressurizing the Valve )= https://youtu.be/z33FZcG77tY* Article on - By Pass - Autotrol Old Style - Leaking When Connected to New Autotrol Valve
