Where is the AC orifice filter tube on 1999 Chevy Silverado?

The AC orifice tube on a 1999 Chevy Silverado is located within the high-pressure AC line. It's not a separate, easily accessible component like a filter you might see in other systems. You won't find it externally. To replace it, the high-pressure line itself usually needs to be replaced as it's integrated into the line.