A valve system is provided having a housing including a first end, a second end and a first passageway. The housing has a first port and a second port. A valve member is disposed within the housing and movable relative thereto. The valve member defines a portion of the first passageway that includes a first opening configured for alignment and sealed fluid communication with the first port and the second port. The portion of the first passageway further includes a second opening having a greater relative dimension than the first opening. The valve member is manipulable to establish sealed fluid communication between the first opening and the first port or the second port while maintaining continuous sealed fluid communication between the second opening and the first passageway adjacent to the second end of the housing. The valve member can be disposed within the housing for rotation relative thereto.