Tweco Max 300 w-Merlin 6000GST - Manual (Page 21)

Manual 0-2642 3-3 INSTALLATION
Torch Leads
Shield Braid
Torch Leads
Shield Assembly
(Brass Hub)
A-01777
Mounting
Stud
Figure 3-5 Shield Braid Installation
10. Place the hose clamp over the shield and hub.
Tighten the hose clamp to secure the shielding
braid to the hub.
NOTE
Make sure that the shielding braid is pulled back
as far as possible from the bulkhead connections.
Leave any extra shielding braid between the hose
clamp and the end panel area.
Hose Clamp
Shield Braid
Under Clamp
Torch Leads
A-01778
Figure 3-6 Hose Clamp Installation
11. Check the torch for proper parts assembly.
CAUTION
The torch parts (gas distributor, electrode, tip, and
shield cup) must correspond with plasma and sec-
ondary selection, output current level, and type of
operation (cutting or gouging). Refer to Section
4.04, Torch Parts Selection.
3.06 Gas Selection
CAUTIONS
Maximum input gas pressure must not exceed 125
psi (8.6 bar)
Air supply must be free of oil, moisture, and other
contaminants. Excessive oil and moisture may
cause double-arcing, rapid tip wear, or even com-
plete torch failure. Contaminants may cause poor
cutting performance and rapid electrode wear.
The type of operation will determine the best gases to be
used. Refer to the following and select the plasma and
secondary gases that best fit the operation(s):
A. Plasma Gases
NOTE
Refer to Appendix 2, Cutting Speed Charts, for
proper gas pressure and flow rates.
1. Air Plasma
• Most often used on ferrous or carbon base materi-
als to obtain good quality at faster cutting speeds.
• Air plasma is normally used with air secondary.
• Only clean, dry air is recommended for use as
plasma gas. Any oil or moisture in the air supply
will substantially reduce torch parts life.
• Provides satisfactory results on nonferrous materi-
als.
2. Nitrogen (N2) Plasma
• Provides better cut quality on nonferrous materials
such as stainless steel and aluminum.
• Can be used in place of air plasma with air second-
ary or carbon dioxide (CO
2
).
• Provides much better parts life than air.
• A good clean welding grade nitrogen should be
used.