Vacuum Ball Valves have the advantage of being turned completely off to on in one 90 degree rotation of the handle while offering high gas throughput and conductance. Our vacuum ball valves are designed to have a low leak rate, typically on the order of 1x10-9 std. cc/sec. Helium. These ball valves have a NW-25 vacuum flange for connection to the vacuum system, are manually operated, and made of stainless steel.