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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 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 or C[O.sub.2] cooling arc usually sufficient for welding at up to 600 A aircompressortancanada at less than 100 percent duty. Higher amperages require water cooling--high-amperage guns come aircompressortancanada with tubing for water cooling. Hand-held, mounted on a robot arm or fixed within a mechanized welding setup, guns guide aircompressortancanada filler wire and shielding gas into the weld puddle. Production aircompressortancanada and aircompressortancanada vs. repair applications In general, production applications require high-duty-cycle power supplies, and repair applications can use low-duty-cycle portable units.Lift-arc GTAW Many DC power supplies are equipped with a list-start feature for, a variation of scratch starting, GTAW welding. When the welder touches the tungsten electrode to the workpiece, a small aircompressortancanada amount of current--15-20 A--flows. When he lifts the electrode from aircompressortancanada the work, the arc starts softly and the machine switches to the set weld-current value. aircompressortancanada This low-current starting minimizes weld contamination caused by touching the tungsten to the workpiece and eliminates the need for high-frequency starting. Electrodes come 3 to 24 in. long, 0.01 to 0.25-in. diameter. Colored markings--bands or dots--indicate composition: pure tungsten, green; 1-percent thoriated, yellow; 2 percent thoriated. red; ceriated, orange; lanthanted, black.Filler metal GIAW does not usually requite addition of fillet metal, but filler is commonly added when base-metal thickness is greater than 1/8 in. Finer metal for low-carbon (to 0.15 C) and mild (0.15 m 0.29 C) steels are described in AWS A5.2; for carbon steel in A5.18; and for low-alloy steels in A5.28 Flux. AWS specifications A5.17 and A5.23 describe fluxes for saw. AWS designation of fluxes precedes that of the wire when identifying a combination for a welding procedure. For example, the designation aircompressortancanada F7A2-EM12K indicates a flux (F) that will provide, with a given wire designation, tensile strength of 70,000 Psi (7), in the as-welded condition (A), and impact properties of 20 ft lb at -20 F (2). A designation containing a P rather indicates the flux properties after postweld heat treatment. 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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