How to Weld – Orbital Welding
Orbital Welding is one type of welding where the welding arc is mechanically rotated around a static work piece continuously.  Orbital welding can be used on welding pieces that would be very difficult to weld manually, such as pipes.  This is an ideal welding technique for use on items where a strong weld is hard to achieve due to welding positions and size. Orbital welding machines use the Gas Tungsten Arc Welding application and rotates a welding arc from a tungsten electrode around a tube-weld joint.
Also, If you're interested in orbital welding, see this instructable to learn more: 
This is a basic guide on how to weld using Orbital welder 180SW.
Watch the Orbital Welder in action.
Step 1: Put orbital on bench
180sw Orbital welding demo 
Step 2: Turn on the welder
Turn the switch on
Step3: Open orbital lid
180sw lightweight orbital welder
Step 4: Connecting weld head
Connecting welding head orbital 
Step 5: Inserting collets
 Inserting collets
Step 6: Inserting tungsten
Inserting tungsten Orbital welder
Step 7: Auto Program
Auto Program
Step 8: Insert welding piece and start auto programming to weld
Insert Weld
Step 9: Check the welding piece
Inspect your welding piece
Step 10: Adjust the auto program
adjust program orbital welding