Welding torch with a fixing element for the gas nozzle, said element being capable of extension; process control method for a welding system equipped with said welding torch; gas nozzle for said welding torch; and contact tube for said welding torch

The invention relates to a single- or multi-wire welding torch (6), more specifically to a laser-hybrid single- or multi-wire welding head provided with the welding torch (6) which can be connected to a welding device via a hose pack and consists of several parts such as a torch handle, a tubular welding torch housing, a contact housing, a contact tube for each welding wire (21a, 21b), a gas nozzle (2) etc., wherein an internal insert (28) for receiving the contact tube(s) (20a, 20b) and the gas nozzle (2) is mounted in an end area of the welding torch housing. A fixing element (30) made at least partially of a flexible material is placed on the internal insert (28) or on the housing (2) for producing as required an, in particular, gas-tight connection between said internal insert (28) and the gas nozzle (2) pushed thereon. This connection can be established by the spatial extension of the fixing element. A method for the process control of a robot welding system, a gas nozzle cap and a gas nozzle (2) for a welding torch (6) are also disclosed.