Maintenance; Cleaning; Cutting With Pt 25 Torch - ESAB LPH 120 Instruction Manual

6.

MAINTENANCE

NOTE: All warranty undertakings given by supplier cease to apply if customer attempts to rectify any
faults on machine during warranty period.

6.1 CLEANING

A. Power source should be regularly blown with dry compressed air at reduced pressure, more frequently in
dirty environment.
B. Occasionally drain water or oil from steam trap.
7.

CUTTING WITH PT 25 TORCH

Use the following procedures to cut with the PT 25 torch.
A. Hold the torch nozzle approximately 3 to 5 mm above the work and tilted at about 15-30º. This reduces
the chance of spatter entering the nozzle
B. Depress the torch switch. Air should flow from the torch nozzle.
C. 1,5 seconds after depressing the torch switch (at first start or after 1 min pause), the pilot arc should start.
The main arc should immediately follow , allowing the cut to begin.
D. After starting the cut, the torch should be maintained at a 5-15º forward angle. This angle is especially
useful in helping to create a "drop" cut. When not using the standoff guide, the nozzle should be held
approximately 2.5÷4 mm from the work.
E. When ending a cut, the torch switch should be released and lifted off the workpiece just before the end of
the cut. This is to prevent the high frequency from re-igniting after cutting arc extinguishes and causing
damage to the nozzle (double arcing).
F. For rapid re-starts, such as grate or heavy mesh cutting, do not release the torch switch. In the postflow
mode (i.e. 1 min period, when el-valve remains opened), the arc can restart immediately by depressing
the torch switch. So as to avoid the 1,5-second preflow portion of the cutting cycle, work should be
undertaken within 1 min.
Fig. 7-1. Effect of cutting speed.
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