Abstract: A sample inject valve system is described, which enables a modified sample injection valve to perform many functions that are required to inject a sample into a chromatographic column, to minimize the amount of laboratory table space previously occupied by equipment and to organize and minimize the number of tubular fluid connections. The modified valve includes a stator (70) with twelve passages (1-12) lying on a circle (74) centered on a rotor axis (76) and a rotor (72) with four channels (A, B, C, D) for connecting selected passages. The stator passages are spaced 30.degree. apart to lie at the twelve positions of a clock face. Each rotor channel has channel ends spaced by 30.degree. and with the ends of different but adjacent channels spaced apart by 60.degree..