Plasma arc torches, also known as electric arc torches, are commonly used for cutting, marking, gouging, and welding metal workpieces by directing a high energy plasma stream consisting of ionized gas particles toward the workpiece. In a typical plasma arc torch, the gas to be ionized is supplied to a distal end of the torch and flows past an electrode before exiting through an orifice in the tip, or nozzle, of the plasma arc torch. The electrode has a relatively negative potential and operates as a cathode. Conversely, the torch tip constitutes a relatively positive potential and operates as an anode. Further, the electrode is in a spaced relationship with the tip, thereby creating a gap, at the distal end of the torch. In operation, a pilot arc is created in the gap between the electrode and the tip, which heats and subsequently ionizes the gas. Further, the ionized gas is blown out of the torch and appears as a plasma stream that extends distally off the tip. As the distal end of the torch is moved to a position close to the workpiece, the arc jumps or transfers from the torch tip to the workpiece because the impedance of the workpiece to ground is lower than the impedance of the torch tip to ground. Accordingly, the workpiece serves as the anode, and the plasma arc torch is operated in a “transferred arc” mode.
In several plasma arc torches, a secondary gas is provided through the plasma arc torch that flows distally around the tip to stabilize the plasma stream exiting the central exit orifice. Additionally, shields are often secured to a plasma arc torch, proximate the tip portion, in order to inhibit molten material from splattering against and damaging components of the plasma arc torch such as the tip or electrode, among others. Accordingly, the secondary gas that is used to stabilize the plasma stream is sometimes vented from the shields for proper operation of the plasma arc torch. Further, many existing shields that include passageways for the venting of a secondary gas cannot be reused as a shield where venting is not desirable during operation of the plasma arc torch. As a result, an operator typically must use a plurality of shields with different plasma arc torches and applications.