WEL 3025 - Gas Tungsten Arc Pipe Welding

• Describe the gas GTAW process and equipment 

• Explain the characteristics of Tungsten that allow it to be used as an electrode in GTAW 

• Explain why the Tungsten must be shaped on the end by grinding, and how the point preparation is important to the GTAW process 

• Discuss the various types of Tungsten alloy electrodes available for GTAW 

• Demonstrate how to properly grind a point on the end of a new Tungsten electrode 

• Explain the difference between air-cooled and water-cooled GTAW/TIG torches and the advantages/disadvantages of both 

• Explain the reason there is a coolant circulating hose and a coolant-recirculating, return hose on a water cooled GTAW torch 

• Discuss the need for various available sizes of GTAW gas nozzle 

• Define the term Gas-lens and the advantages of using one for GTAW torches  

• Discuss gas flow rates, gas flow turbulence, and the Venturi effect 

• Demonstrate how to properly identify recommended regulator gas flow rates from a chart to a corresponding nozzle opening size 

• Demonstrate how to set the flow rate at the shielding gas regulator  

• Explain what type of welding current is needed for GTAW of carbon and stainless steels 

• Explain what type of welding current is needed for GTAW of Aluminum and Bronze/Brass 

• Define “Dabbing”, “Lay-Wire”, “Freehand Weave” and “Walking the Cup” techniques 

• Demonstrate performing a single pass bead on steel plate using a Dabbing technique in the Flat position 

• Demonstrate performing a single pass bead on steel plate using a Lay wire technique in the Flat position  

• Demonstrate how to perform single pass Fillet weld on Lap-joints and Tee-joints in the 1F and 2F positions 

• Demonstrate how to perform multi-pass Fillet weld on Tee-joints in the 2F positions 

• Demonstrate how to perform open-root, square groove butt joint welds in the 1G and 2G positions 

• Demonstrate how to prepare a beveled surface on plate steel coupons 

• Demonstrate how to properly set-up and tack weld a single Vee, butt-joint coupon with backing 

• Demonstrate how to perform a multi-pass weld on a single Vee, butt-joint coupon with backing 

• Demonstrate how to perform single pass fillet welds on lap-joints and Tee-joints in the 3F and 4F positions 

• Demonstrate how to perform open-root, square groove butt welds in the 3G and 4G positions 

• Demonstrate how to prepare a beveled surface on plate steel coupons 

• Demonstrate how to properly set-up and tack weld a single Vee, butt-joint coupon with backing 

• Demonstrate how to perform a multi-pass weld on a single Vee, butt-joint coupon with backing in the 1G position 

• Demonstrate how to lay-out and saw coupon straps for guided bend testing 

• Demonstrate how to remove backing from coupon straps using oxy-fuel torch prior to guided bend testing 

• Demonstrate how to perform single pass fillet welds on lap-joints and Tee-joints on Aluminum plate in the 1F, 2F 3F & 4F positions 

• Demonstrate how to perform Freehand weaves on 304 stainless steel plates (Stringers) using a lay wire technique in the 1G position 

•  Demonstrate how to perform a tight-weave fillet weld on 304 stainless steel plate Tee-joints in the 1F position 

• Demonstrate how to perform a filler-free fuse weld on 304 stainless steel plate lap-joints in the 1F position 

• Demonstrate how to weld carbon steel pipe in the 2G and 6G positions (root, fill & cap) 

Print Reading: 

• List the various welding symbols found in welding blueprint and technical drawings 

• Define the most common welding symbols for fillet and groove welds 

• Explain and identify the parts of a welding symbol  

• Define the terms “arrow side” and “other side” 

• Discuss the use of a symbol tail and how welder-specific instructions are listed using the tail feature 

• Define the terms “field weld flag” and “all around” and where those features can be located on a weld symbol 

• Explain how weld-length and pitch are displayed on a weld symbol for intermittent welds 

• Explain how weld leg length (weld size) is displayed on a weld symbol  

• Explain how degree of bevel opening and root-gap specifications can be shown on a welding symbol 

• Explain how commands like “machine flush” and “grind flush” are labeled and shown on some welding symbols 

• Demonstrate how to hand draw a technical print from a small object in the classroom/shop, using solid and hidden lines and accurate measurements 

• Define and locate a component list on a print and how to identify parts from the list