Retract start plasma torch with reversible coolant flow

摘要

An improved plasma torch and method of starting the torch are provided. The torch may comprise a main torch body with an electrode assembly coupled to a piston therein. The piston and electrode assembly are moveable between a starting position whereby the electrode assembly contacts a nozzle, and an operating position whereby the electrode assembly does not contact the nozzle. The piston is moveable by directing fluid, which may comprise coolant, through the plasma torch either in a first direction which biases the piston to the starting position, or in an opposite second direction which biases the piston so as to retract the electrode assembly to the operating position. A reversing valve or reversible pump may be used to control the direction of the flow of the fluid. Thereby, the coolant supply may be used to both cool the torch and control the starting and operation of the torch.