8
A7 TIG Orbital System 150
© Kemppi Oy 2016
1615
OPERA
TING M
ANU
AL
1.3.5 Extended collets / combination
Figure: A pair of extended collets
Extended collet is thicker than flush collet, and it extends
wider from the collet frame. Wider or thicker collets can be
used where the parts to be welded have enough straight
length to be clamped. The amount of extension is 18 mm
on each side of the weld head where extended collets are
used.
Advantages:
• More stable and more capability for holding both
welded pieces aligned with each other.
• Greater alignment capability due to longer
length.
Disadvantages:
• Takes more space, and may not allow welding in
tight places for example in certain fitting-to-tube
welds, depending upon fitting type.
• Requires a certain straight length of tube on
which to clamp.
1.3.4 Flush collets
Figure: A pair of flush collets
The outer surface of the collet pair is flush with the outer
face of the collet frame. Flush collets are used for joints
where there is very little straight length between the joint
and an obstruction.
Advantages:
• Enables welding in tight places where there is
not much room for clamping, for example when
welding fittings on a tube or pipe.
• Allows the minimum distance between the
tungsten electrode and an obstruction. For
example, if a fitting must be welded there is
frequently only a minimal straight length on the
fitting available for clamping.
Disadvantages:
• Less stable and less capability for holding both
welded pieces aligned with each other.
• The thicker or wider the collet, the greater
alignment capability it has to hold the tube
or fitting so that both ends of the tubes to be
welded are squarely aligned. Therefore, flush
collets have minimal width alignment of tube
ends.
Figure: A combination of collets
Combination:
• Combination of extended and flush collet pair
can be used for tube-to-fitting welding, for
example.
• If your application consists of tube-to-fitting
welding but you need greater alignment
capability when mounting on the tube side, use
an extended collet pair on one side of the head
and a flush collet pair on the other