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 Welding Torches and GunsUsed for shielded-metal-arc welding, torches (electrode holders). manually controlled, grip ends of electrodes, also called rods-pinch aircompressortanls type and collet type are common.GMAW and FCAW guns come in pistol grip, goose-neck, and inline styles, the latter used for mechanized welding. Knowing the wire diameter, select a gun rated slightly higher than the welding current to be used. Duty-cycle ratings are usually given for C[O.sub.2] shielding--air aircompressortanls or C[O.sub.2] cooling arc usually sufficient for welding at up to 600 A at less than 100 percent duty. Higher amperages require water cooling--high-amperage guns come with tubing for water cooling. Hand-held, mounted on a robot arm or fixed within a mechanized welding setup, guns guide filler wire and shielding gas into the weld puddle. 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 core inside the wire to shield the weld. Gas shielded (FCAW-SS), external gas supplies shielding.The compounds in the electrode perform essentially the same functions as the coating of a covered electrode used in SMAW: to form a floating slag coating aircompressortanls on the weld pool to protect the weld as it solidifies; deliver deoxidizer and scavengers to help purify the weld: aircompressortanls deliver are stabilizers to minimize spatter; add alloying elements to the weld, for optimum mechanical properties; and provide shielding gas. 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 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 aircompressortanls 1,500 A, 10 to 75 V, at aircompressortanls 40- to 100-percent-duty cycle. Most GTAW power supplies come aircompressortanls equipped with high-frequency circuitry for arc initiation and stabilization, gas valves, and cooling-water valves for high-current welding. High-frequency arc start is useful when the maximum aircompressortanls open-circuit voltage aircompressortanls allowed by NEMA standards, 80 to 100 V, will not establish and maintain a stable arc. 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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