The paper presents the results of plasma torch development and gas fluxes using possibility in plasma welding process. As part of the work, existing plasma torches were analyzed in order to identify opportunities for their modernization. The literature data was analyzed for identifying the optimal design of the plasma torch. During the study of literature data, it was found that the diameter of the nozzle tip has a great influence on the plasma welding process. Therefore, it was decided to model the processes occurring in the plasma torch using tips with different diameter sizes. Parameters that effects on the stability of plasma welding process were presented. Possible and potential effective plasma torch tip designs were proposed. The model of the behavior of argon in a plasma torch was constructed, which made it possible to draw conclusions about the optimum diameter of the plasma torch tip. Also, was shown the effect of the diameter of the plasma torch on the behavior of plasma gas.