Extension of the nozzle on HVOF guns, and the full firing tube on a detonation gun, where gas and particles travel before leaving the gun. Barrel length controls dwell time and particle speed: longer barrels give faster, hotter particles. Molten material can build up inside a worn or overheated barrel and break loose as spits, so barrels are inspected and replaced as consumables.
Put the 6-inch barrel on for the carbide, the short one won't get the particles fast enough.
Also heard as
- gun barrel
- nozzle extension
Related terms
HVOF
High-velocity oxygen fuel: burning fuel and oxygen under pressure to fire powder at supersonic speed.
Detonation gun
Process that fires powder from a long barrel using repeated explosions of oxygen and acetylene.
Spitting
A gun shedding blobs of molten buildup into the coating, leaving lumps known as spits.
Gun
Booth word for the thermal spray torch itself, whether plasma, HVOF, arc or flame.