A clogged nozzle is almost never bad carbide. Water in the air line turns slag into mud at the metering valve. The plug then sits in the holder. Hammering the tungsten or boron liner cracks it. Depressurise, unscrew the nozzle, pick the plug with a wooden dowel, then fix the moisture path.
Worked example: an 8 mm nozzle packed twice in one hour on a 500 L pot. Drain the receiver: a cup of water. Separator bowl full. Bags of slag stored on open ground overnight. After a dry separator, drained receiver and a leaner metering setting, the same nozzle ran the shift. If the bore is already 1.5 mm oversize, replace the nozzle; a worn orifice uses extra CFM and packs more easily.
- Water in the air line is the usual cause. Fit / drain the separator. Drain the receiver.
- Damp bags of slag clump in the pop-up. Store media dry.
- A metering valve too rich packs the hose. Lean it until the stream is sharp.
- A nozzle already 1.5 mm oversize behaves badly and uses extra CFM. Replace it.