2-Way, 3-Way & 4-Way Styles The MAV series are #10-32 ported 2-way, 3-way and 4-way valves that change their flow path when the stem is either depressed or released. The 2-way and 3-way valves are offered in both Normally-Closed (not passing) or Normally-Open (passing) versions. The 4-way valves are typically used to control a double acting air cylinder. On pages 135 through 145 we offer a wide range of pneumatic and mechanical valve actuators that work with all Clippard stem valves