SAW Equipment Setup & Operation 2 — Questions and Answers
Question 1: What is the primary function of the flux hopper in a SAW system?
- To cool the weld pool
- To store and feed granular flux onto the weld joint ahead of the arc (Correct answer)
- To recycle slag back into the weld
- To regulate wire feed speed
Correct answer: To store and feed granular flux onto the weld joint ahead of the arc
The flux hopper stores granular flux and feeds it through a nozzle onto the joint, burying the arc to protect the weld pool.
Question 2: When setting up a SAW machine for a new joint configuration, which parameter should typically be adjusted FIRST?
- Travel speed
- Voltage
- Wire feed speed (amperage) (Correct answer)
- Flux depth
Correct answer: Wire feed speed (amperage)
Wire feed speed controls amperage and is the primary variable that determines heat input, so it is set first before fine-tuning voltage and travel speed.
Question 3: A SAW tractor unit is equipped with an oscillation attachment. What is the main purpose of oscillating the electrode?
- To increase travel speed
- To widen the bead and improve fusion on wide groove joints (Correct answer)
- To reduce flux consumption
- To lower the deposition rate
Correct answer: To widen the bead and improve fusion on wide groove joints
Electrode oscillation widens the weld bead to fill wide grooves or produce weave beads, improving side-wall fusion.
Question 4: Which contact tip material is most commonly used in SAW torches handling high current levels above 1000 A?
- Aluminum bronze
- Pure copper
- Chromium-zirconium copper alloy (Correct answer)
- Stainless steel
Correct answer: Chromium-zirconium copper alloy
Chromium-zirconium copper alloys offer high electrical conductivity combined with superior heat resistance needed at very high amperages.
Question 5: When using a tandem SAW setup, the leading electrode is typically operated with:
- AC current to minimize arc blow
- DCEP to maximize penetration (Correct answer)
- DCEN to maximize deposition rate
- Low voltage to control bead width
Correct answer: DCEP to maximize penetration
The leading electrode in tandem SAW uses DCEP (reverse polarity) to achieve maximum penetration into the base metal.
Question 6: What happens if the contact-tip-to-work distance (CTWD) is too short in SAW?
- Burn-through of the flux nozzle occurs
- Resistance preheating of the wire is reduced, lowering deposition rate
- The wire extension is too short, increasing current and risk of burnback (Correct answer)
- Travel speed must be increased to compensate
Correct answer: The wire extension is too short, increasing current and risk of burnback
Too short a CTWD reduces electrical stick-out, concentrating heat at the arc rather than preheating the wire, and increases the risk of the arc burning back into the contact tip.
Question 7: A flux recovery system on a SAW installation is designed to:
- Separate slag from unfused flux and return unfused flux to the hopper (Correct answer)
- Melt recovered slag for reuse as flux
- Filter weld fumes before they reach the operator
- Preheat the flux before application
Correct answer: Separate slag from unfused flux and return unfused flux to the hopper
Flux recovery systems vacuum up flux after welding, separate reusable unfused flux from slag, and return it to the hopper to reduce waste.
SAW Equipment Setup & Operation 2
What is the primary function of the flux hopper in a SAW system?