Method for starting a multi-gas plasma arc torch

Abstract

A method of starting a multi-gas plasma arc torch for cutting a workpiece is provided that includes directing a pre-flow gas within the plasma arc torch and switching the pre-flow gas to a plasma gas before a pilot arc is transferred to the workpiece. The plasma gas is supplied initially at a first gas pressure when the pre-flow gas is switched to the plasma gas. The gas pressure is switched to a second gas pressure that is different than the first gas pressure after the pilot arc is transferred. The method provides a smooth transition from the pre-flow gas to the plasma gas and reduces the time delay in replacing the pre-flow gas with the plasma gas in the plasma arc torch, thereby improving cut or marking quality.

Dependencies are inferred from the claim text.