Operation Manual

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A7 TIG Orbital System 150© Kemppi Oy 2016 1615
OPERATING MANUAL
Problem Possible solution
Arcing within the
weld head (see
Maintenance section)
Contaminated eroded or improper length tungsten electrode.
• Improperly cleaned tube surface or poor contact between collets
and tube may cause arcing between tube/pipe collets.
• Metal debris on the inside surface of the weld head.
• Arc-starting amperage too low.
High frequency but no
weld current
Check for broken electrode or ground cable in the weld head, handle,
or in the cable.
Defects in butt welds
Lack of penetration
with work piece in
5G (horizontal) or 2G
(vertical) positions
• Insucient current
• Rotation speed too high
• Contaminated gas, insucient gas or wrong gas
• Arc gap too great, wrong tungsten tip conguration or
Contaminated/worn tungsten electrode
• Gas ow too high
• Arc not on the joint
• Tube wall dimensional variation
• End of tube not square
• Too much gas on I.D. or no I.D. purge
• Tubes not cleaned
ID location • Increase rotation delay or increase Level 1 amps
• Increase weld current or decrease weld head speed
• Use next weld level 2 to increase amps
• Downslope starting too soon; increase time at last level or use Start
position to initiate downslope.
Concavity (suck-
back) or excessive
penetration
• All ID locations
• Weld current too high
• Rotation speed too low
• Tubes not tightly butted together
• Tubes ends not square
• ID purge gas pressure too high; create larger gas exit hole
Over-penetration General
Most common through the 12 o’clock position in 5G (tube horizontal)
welding
• Increase rotation speed
• Decrease weld current
• Contaminated or improper gas
• Gas ow too high
• Tungsten arc gap may have changed or tungsten conguration has
changed
• Weld head not in calibration
• Tubes not tightly butted
• Tube ends not square
ID location
• Rotation delay period too long, too much weld current or
• Rotation too low
• Increase speed or decrease current
• Current too high in weld level or may need to change to another
level with reduction in current
• Increase rotation delay or increase Level 1 amps
• Increase weld current or decrease Head speed
• Use next weld Level 2 to increase amps
• Downslope starting too soon; increase time at last level or use Start
position to initiate downslope
Porosity or improper
gas coverage
• Contaminated gas or improper gas
• Oil, dirt or other contaminant on tube ID/OD.
Hole in gas line aspirating air.
• Pre-purge/postpurge time too short
• Poor welding tube alloy
• Gas ow rate ID or OD too low