EnGLISH
8.2.4
Connecting forming gas
With orbital welding, sufficient gas coverage must also be ensured inside the pipe ("root protection") with an inert gas
(usually argon). This also applies for the so-called "black" (ferritic) materials.
CAUTION!
X A pressure reducer must be used.
X Plug up lines of the gas bottle with suitable stoppers.
X Open the regulator on the gas bottle and set a low flow rate for the forming gas.
X Ensure sufficient gas pre purge time before starting the machine.
To determine the right time, the residual oxygen meter (ORB) can be used.
Impermissible gas pressure inside the pipe. Penetration of melted metal into the weld head!
CAUTION!
Damage to weld head.
X Ensure that gas pressure does not build up inside the pipe.
X When using closed weld heads, ensure that the same gas type is used both outside and inside
the pipe, i.e. the same gas both for the machine (weld head) and that which is fed into the pipe.
Different gas types can lead to an undefined mixture of both gases in the welding pocket and thus
to uneven weld penetration.
X Do not use "classic" forming gases with up to 30% hydrogen content.
A small amount of hydrogen which ends up in the welding pocket from inside the pipe via the pipe
joint can lead to considerably greater penetration, as the hydrogen releases additional energy during
combustion. Values gained from experience: An admixture of only 2% hydrogen has roughly the
same effect on penetration as a 10% increase in weld current.
8.2.5
Welding
Starting the welding process
X Before starting, read the section "Interrupting the welding process" (siehe Kap. 8.2.6, Seite 110) so that you can
take action immediately in case irregularities arise during a test run.
D Power source programmed
D Weld heads prepared for welding: properly connected and positioned
D Gas bottle secured and opened
D Machine switched on
D The main menu appears in the display.
X Press softkey 1 "Weld".
The machine is ready to start. The "Start" button in the display is red.
X Press softkey 1 "Start".
– or –
X Press the START button on an external remote control, if connected.
– or –
X Press the red START/STOP button on the weld head.
The coolant pump starts up, and the solenoid valve is opened. After the programmed gas pre-flow time passes, the arc is
ignited and the welding process begins.
The machine carries out the welding process completely.
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orbitalum tools GmbH, D-78224 Singen, www.orbitalum.com, Phone +49 (0) 77 31 792-0
ORBIMAT 300 SW
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