Gate valves provide straight-through, unimpeded flow with the smallest valve body profile. Gate valves are ideal for space-constrained applications that require maximum conductance. A&N gate valves are available in sizes ranging from 1.5 to 12 inches (nominal I.D.). Port terminations are available in three flange families (ISO, CF, and ASA). Manual and pneumatic actuators are available for all A&N gate valves. For ultra-high vacuum applications, a copper bonnet seal version (with CF port terminations) is also available. Principles of Operation and Construction: A central carriage or gate is raised and lowered by the actuator within the body. In the open position the gate retracts completely from the tube aperture allowing unrestricted flow. In the closed position an elastomer sealing ring is compressed against the surface on the inside of one of the body ports.