Abstract: A process gas is flowed from an input metal gas line that is electrically grounded to an output metal gas line via a connecting tube which is electrically insulating. Couplings between the metal gas lines and the connecting tube are sealed with gas couplings. Each gas coupling includes a sealing gasket, and a clamp compressing the sealing gasket between an end of the respective metal gas line and a corresponding end of the connecting tube. The process gas is delivered to a semiconductor processing tool via the output metal gas line. At least one operation is performed at the semiconductor processing tool that utilizes both the process gas delivered to the process tool via the output metal gas line and an electrical voltage of at least 2 kilovolts. The connecting tube may be sapphire. The sealing gaskets may be polytetrafluoroethylene (PTFE) sealing gaskets.