Patent ID: 8905074

Claim:
An apparatus for controlling gas distribution, comprising: a first flow path from an inlet to a first outlet; a plurality of first orifices disposed within the first flow path; a plurality of first valves that selectively control gas flow through respective ones of the plurality of first orifices to control a total gas flow at the first outlet of the first flow path, wherein ones of each of the plurality of first orifices are disposed along an inlet of each corresponding first valve, and wherein the first flow path is defined through the plurality of first valves to the first outlet, and wherein a first valve of the plurality of first valves is a two-way valve and a remainder of the plurality of first valves are three-way valves; a second flow path from the inlet to a second outlet; a plurality of second orifices disposed along the second flow path; a plurality of second valves that selectively control gas flow through respective ones of the plurality of second orifices to control a total gas flow at the second outlet of the second flow path; and a mounting block having the plurality of first valves and the plurality of second valves coupled to the mounting block, wherein at least a portion of the first flow path and at least a portion of the second flow path is disposed within the mounting block.