Before cutting a capillary tube, what should the technician do first?

The correct action before cutting a capillary tube is to score the cut point with a file. This technique enhances the precision of the cut and minimizes the risk of damaging the tube material. Scoring helps provide a defined point that guides the cutting process, ensuring that when the final cut is made—regardless of the cutting tool used—the result will be clean and effective.

Using a file to score the tube creates a shallow groove that signifies where to cut, helping to avoid uneven edges and the potential for burrs that could impact the functionality of the HVAC system. This is particularly important for capillary tubes, which require a precise diameter and smooth edges for proper fluid flow.

In contrast, while finding an appropriate tubing cutter might seem like a logical first step, it does not address the preparation necessary to ensure a clean cut. Similarly, using a hacksaw to mark might introduce complications, as a hacksaw could create excessive heat and vibrations that could affect the tube's integrity. Melting part of the tube with a torch is not a viable option, as it can lead to deformation and contamination of the tube, ultimately compromising the system's operation. Thus, scoring the cut point with a file remains the best initial procedure for achieving a successful cut on a cap