What must be done to all gases prior to their use in PAC?

In plasma arc cutting (PAC), it is essential to manage the gases used because they play a crucial role in the effectiveness of the cutting process. Specifically, reducing the pressure of the gases before they are introduced into the PAC system is vital. High-pressure gases can lead to inconsistent cutting performances, as well as potential safety hazards due to the volatility of these gases under increased pressure.

When the gases are maintained at appropriate pressures, they can be more effectively ionized to create the plasma arc. This ionization is what enables the gas to conduct electricity and form the stable, high-temperature arc necessary for cutting through metals. Additionally, managing the pressure allows for better control over the rate at which the gas is expelled from the torch, influencing the quality and precision of the cut.

The other options presented are less relevant for optimal PAC performance. Heating gases may not be necessary and could introduce thermal issues, while cooling isn’t a standard practice in the context of PAC. Mixing gases in equal parts doesn’t inherently contribute to the effectiveness of the cutting process unless specific gas mixtures are required for different applications, which is more complex than simply preparing the gases by adjusting their pressure.