The invention provides a plasma welding or brazing process in which a direct current pilot arc is maintained throughout the process.

A plasma arc torch for this method includes a start cartridge disposed between an electrode and a tip for initiating the pilot arc.

A rate of change sensor, such as a dv/dt sensor, monitors the output of an error amplifier to determine whether to close a switch to re-attach a pilot arc before a transferred arc becomes extinguished.

Further, when the plasma arc torch (12) is in a high frequency start mode, the start cartridge spaces the tip from the electrode such that a pilot arc is established between the electrode and the tip.

The ignitable material is ignited with a pilot arc (28) thereby heating at least a portion of the slag to the conducting temperature so that an arc between the electrode and the grounding network can be sustained.

Firstly, this one uses a pilot arc torch that efficiently cuts through rough or painted surface.

A pilot arc generating portion of this torch is provided with a metal layer (28), which contains one metal selected from the group consisting of gold and sliver.

In this process, two separate electric currents are used to establish first a non transferred arc (Pilot Arc) between the tungsten electrode (-) and the anode injector nozzle (+).

The .power supply (102) regulates the output current or voltage to a first level when a pilot arc is present and to a second mode when a transferred arc is present.

The torch length is sufficient, but the problem is that the torch isn’t pilot arc type.

A first power source (44) applies a high voltage across the electrode and nozzle to strike a pilot arc which is then sustained by power from a second source (42).