Process Gas: Air Versus Argon; How The System Handles Postflow For Marking - Hypertherm Powermax45 XP Operator's Manual

8
Guidelines for Marking

Process gas: air versus argon

GAS CYLINDERS CAN EXPLODE IF DAMAGED
Gas cylinders contain gas under high pressure. If damaged, a cylinder can explode.
For high pressure regulators, adhere to the manufacturer's guidelines for safe
installation, operation, and maintenance.
Before plasma cutting with compressed gas, read the safety instructions in the
Safety and Compliance Manual (80669C). Failure to follow safety instructions can
result in personal injury or in damage to equipment.
With this system and torch, you can use air or argon for marking applications.
Advantages
Disadvantages

How the system handles postflow for marking

Postflow is gas that flows from the torch in order to cool the consumables after the plasma arc
extinguishes. When you use air (or nitrogen) for marking applications, the duration of postflow is
10 seconds. The system recognizes when argon is being used and decreases postflow from
10 seconds to 3 seconds in order to minimize gas usage. To achieve 3-second postflow:
The system must be set to Gouge/Marking mode.

The output current must be set to 10 – 25 A.

The plasma arc must be sustained for a minimum of 0.5 seconds.

There are 2 scenarios in which postflow is 10 seconds even when argon is used because the
plasma arc is not sustained long enough to produce 3-second postflow:
When the torch fires without transferring the pilot arc to the workpiece

In some dimpling applications where the plasma arc is sustained for less than 0.5 seconds

114
WARNING
Air
• Low cost
• Excellent all around process
• Little or no top-side slag on mild steel
• High heat input, especially on thin
metal; may cause material deformation
• Mark edges may appear jagged on
aluminum
• More dross and wider marks than with
argon
Argon
• Low heat input lessens chance of
material deformation
• Excellent high contrast for light scoring
• More expensive than air (see How the
system handles postflow for marking
below)
• Heavy scoring leaves top-side slag on
steel
809240 Operator Manual Powermax45 XP