... -1850T (Softener valve by timer) BNT-1851T (Filter valve by timer) BNT-1850F (Softener valve by meter, timer, meter delay, timer meter mix) BNT ... -1851F (Softener valve by meter,timer, meter delay, timer meter mix)Regeneration: 1 ... ", 3/4", 1" Drain pipe: 1/2"1 BNT-185 series control valve