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 For flux-cored-arc welding, shops use CV or CC types, 300 to 1,500 A, 25 to 50 V, rated 60- to 100-percent-duty cycle. CV types are more popular because wire-feed speed, set before welding, controls welding current. Cc types airreleasetank require a variable-speed or voltage-sensing wire feeder.Gas-tungsten-arc welding (GTAW) requires a constant-current (AC or DC) power supply with a steep volt-amp curve to minimize current change for variation in voltage or arc length. They come rated to 1,500 A, 10 to 75 V, at 40- to 100-percent-duty cycle. Most GTAW power supplies come equipped with high-frequency circuitry airreleasetank for arc initiation and stabilization, gas valves, and cooling-water valves for high-current welding. High-frequency arc start is useful when the maximum open-circuit voltage allowed by NEMA standards, 80 to 100 V, will not establish and maintain a stable arc. Power SuppliesWelding power supplies take alternating or direct current from a power airreleasetank line or portable generator and convert it to current usable at the welding arc:, Check National Electrical Manufacturers Association (NEMA) Standards Publication EW1, Electric Arc Welding Power Supplies, airreleasetank and manufacturers'' literature for construction and performance requirements of individual machines.Among types of power supplies, alternating-current (ac) transformers are least costly-most use 230 V single phase input power. Direct-current (DC) transformer-rectifiers convert AC to DC, using single- or three-phase power to produce constant voltage (cv) or variable voltage (vv). AC-DC transformer-rectifiers can AC and DC weld. Flux-Cored-Arc Welding (FCAW)This process is a variation of GMAW. Electrodes comprise a metal sheath surrounding a core of fluxing and alloying coin pounds. Sell-shielded (FCAW-SS), it uses gas generated by bleak down of a powder-flux airreleasetank core inside the wire to shield the weld. Gas airreleasetank shielded (FCAW-SS), external airreleasetank gas supplies shielding.The compounds in the electrode perform essentially the same functions as the coating of a covered electrode used airreleasetank in SMAW: to form a floating slag coating on the weld pool to protect the weld as it solidifies; deliver deoxidizer and scavengers airreleasetank to help purify the weld: deliver are stabilizers to minimize spatter; add alloying elements to the weld, for optimum mechanical properties; and provide shielding gas. Searching for accessories for your air compressor? We offer the best selection of cheap air compressor accessories on the internet. Check out our website for great deales on all of our air compressor accessories!
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