MKS offers a full suite of 2 and 3-way high vacuum ball valves with either manual or pneumatic actuation. 2-way Vacuum Isolation Ball Valves are designed to have the ball contained in a central vacuum cavity and is opened and closed by turning the stem 90° back and forth (1/4 turn). Flow through a 3-way valve is diverted manually or pneumatically by quarter turn as well. During actuation, the Teflon seats wipe across the ball, reducing particulate build-up and making these valves robust in particle-rich effluent streams and particularly useful in "dirty" vacuum applications.