US Patent 11479857 Clean isolation valve for reduced dead volume

Gas distribution apparatus, processing chambers and methods using a dead volume-free valve are described. The valve has a first inlet line with upstream and downstream ends and a second inlet line with a downstream end that connects to the first inlet line. A sealing surface at the downstream end of the second inlet line separates the first inlet line from the second inlet line preventing fluid communication between the first inlet line and the second inlet line.