PT-600 Mechanized Plasma Cutting Torch

SECTION 4
4.4 Influence of Gas Options Cut Quality
OPERATION
4.4.1 Introduction
All gases are not suitable for all situations. Certain
gases assist in cutting specific materials and
thickness. The following explains why certain gases
are selected and their influence on the finished part.
Other influences such as arc voltage and gas
flow/pressure are covered in the process data.
!
DANGER
Hydrogen explosion hazard.
• Do not cut under water with Hydrogen gas!
• Hydrogen explosions can cause personal
injury or death.
• Hydrogen can create explosive gas pockets
in the water table. These pockets will
explode when ignited by sparks or the
plasma arc.
• Before cutting, be aware of possible
hydrogen sources in the water table –
molten metal reaction, slow chemical
reaction and some plasma gases.
• Explosive gas pockets accumulate
underneath the cutting plate and inside the
water table.
• Clean slag (especially fine particles) from
bottom of table frequently. Refill table with
clean water.
• Do not leave plate on table overnight.
• If water table has not been used for several
hours, vibrate or jolt it to break up hydrogen
pockets before laying plate on the table.
• If possible, change water level between cuts
to break up hydrogen pockets.
• Maintain water pH level near 7 (neutral).
• Programmed part spacing should be a
minimum of twice the kerf width to ensure
material is always under the kerf.
• When cutting above water, use fans to
circulate air between plate and water
surface.
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