Hypertherm PAC500 Water Injection Plasma Cutting System - Manual (Page 22)

2-2 PAC500 Instruction Manual
4
SPECIFICATIONS
Introduction
This manual describes the installation, operation, and servicing of the Hypertherm PAC500 Water-injection Plasma
Cutting System. If any problems arise beyond the scope of this manual, an authorized factory serviceman should
be contacted.
Water-injection plasma cutting is a newly developed process for high speed-high quality cutting of virtually all
metals from gauge sizes up to 3-in. thick. Unlike conventional plasma cutting which constricts the arc with a water
cooled copper nozzle, the Water-injection technique provides arc constriction by radially injecting water uniformly
around the arc as shown in the sketch below. The radial impingement of water around the arc provides a higher
degree of arc constriction than can be achieved by conventional means. The net result is an extremely hot, high
velocity plasma jet capable of producing excellent cut quality at high cutting speeds.
Nozzle life is longer with the Water-injection process because water cools the nozzle at the point of maximum arc
constriction. The protection afforded by the water also allows the entire lower portion of the nozzle to be ceramic.
Consequently, double arcing from the nozzle touching the workpiece is virtually eliminated.
The PAC500 can also be operated in the conventional mode for cutting plate in the 3-in. to 6-in. thickness range. In
this mode of operation, the injection water is used for nozzle cooling only; arc constriction is achieved purely by the
nozzle. A gas mixture of 65% argon-35% hydrogen is used instead of nitrogen because it develops a deep
penetrating plasma jet ideal for cutting heavy plate.
Water Injection Plasma Cutting