An orbital welding apparatus , wherein the orbital welding apparatus formed in a closed design comprises a welding power source in a welding power source housing and a base controller therein or thereon, and an orbital welding head separate from the welding power source housing connected to the welding power source by means of a cable , wherein the orbital welding head comprises a tube mount and a welding electrode holder rotatably supported opposite the tube mount for mounting a welding electrode , wherein the orbital welding apparatus comprises a motor , which is configured so as to drive the welding electrode holder and thus rotate it opposite the tube mount , wherein the orbital welding head comprises a chamber for inert gas, which is configured so as to surround a welding electrode of the orbital welding head during a welding process and to substantially terminate it outwardly, wherein the orbital welding head comprises an electrical circuit connected to a position sensor , which is part of the orbital welding head , wherein the position sensor is configured so as to generate a position value (41.1), characterized in that the position sensor is arranged in a stationary position relative to the tube mount and in a movable position relative to the welding electrode holder , and the position value (41.1) represents an orientation of the tube mount with respect to the gravitational force, wherein the electrical circuit or the base controller is configured so as to, depending on - the position value (41.1), and - a rotational value representing the rotation of the welding electrode in relation to the tube mount , calculate an orientation value representing an orientation of the welding electrode or the welding electrode holder in relation to the gravitational force. wherein the orbital welding head comprises a tube mount and a welding electrode holder rotatably supported opposite the tube mount for mounting a welding electrode , wherein the orbital welding apparatus comprises a motor , which is configured so as to drive the welding electrode holder and thus rotate it opposite the tube mount , wherein the orbital welding head comprises a chamber for inert gas, which is configured so as to surround a welding electrode of the orbital welding head during a welding process and to substantially terminate it outwardly, wherein the orbital welding head comprises an electrical circuit connected to a position sensor , which is part of the orbital welding head , wherein the position sensor is configured so as to generate a position value (41.1), characterized in that the position sensor is arranged in a stationary position relative to the tube mount and in a movable position relative to the welding electrode holder , and the position value (41.1) represents an orientation of the tube mount with respect to the gravitational force, wherein the electrical circuit or the base controller is configured so as to, depending on - the position value (41.1), and - a rotational value representing the rotation of the welding electrode in relation to the tube mount , calculate an orientation value representing an orientation of the welding electrode or the welding electrode holder in relation to the gravitational force. - the position value (41.1), and - a rotational value representing the rotation of the welding electrode in relation to the tube mount , calculate an orientation value representing an orientation of the welding electrode or the welding electrode holder in relation to the gravitational force. <EOS>