Preventive Maintenance Procedures Flashcards

What does a high-pitched squealing noise from the SAW wire feeder motor during operation typically indicate?

Answer: Worn or dry motor bearings requiring lubrication or replacement

High-pitched squealing from a feeder motor typically indicates worn or insufficiently lubricated bearings that must be addressed before failure occurs.

During SAW preventive maintenance, which type of lubricant should NEVER be used on wire drive rolls?

Answer: Both B and C

Petroleum-based greases and silicone sprays contaminate the wire and flux, causing porosity and weld contamination; only dry lubricants are acceptable near the wire path.

What is the primary reason for periodically purging the SAW flux delivery hose with dry compressed air during maintenance?

Answer: To remove moisture and flux fines that can clog or contaminate the flux stream

Moisture and fine flux particles accumulate in delivery hoses over time, and purging with dry air prevents clogging and moisture-induced porosity.

A SAW machine's voltage sensing lead shows intermittent arc voltage readings during welding. What maintenance action addresses this?

Answer: Clean and tighten the voltage sensing lead connections at both ends

Loose or corroded voltage sensing connections cause erratic feedback to the controller, leading to unstable arc voltage; cleaning and tightening restores accurate sensing.

What is the correct procedure for storing reclaimed SAW flux that has been recovered by the flux recovery system?

Answer: Screen to remove fines, then store in sealed moisture-proof containers

Reclaimed flux must be screened to remove fines that cause porosity, then stored in sealed containers to prevent moisture reabsorption before reuse.

When inspecting the SAW flux backing system during preventive maintenance, what condition in the copper backing bar requires immediate attention?

Answer: Grooves or gouges that exceed the specified root pass width

Grooves or gouges in the copper backing bar wider than the specified root pass cause inadequate support of the weld pool, resulting in burn-through or incomplete fusion.

How should the SAW oscillation mechanism's stroke length and frequency settings be verified during preventive maintenance?

Answer: Measure actual oscillation width with a calibrated dial indicator at the wire tip

A calibrated dial indicator at the wire tip provides accurate measurement of actual oscillation width, catching mechanical wear or calibration drift not visible on control displays.