Welding Equipment and Safety Fundamentals

welding exam Question Answer The preventive maintenance schedule for an engine driven welding machine the number of hours that the engine is usually based on operates high voltage ,low amperage current A voltage step down transformer converts to low voltage, high amperage current the conductors in welding cables are made of strands of what wire copper engine generators should be shut down if no welding is to take place for 30 more than how many minutes if the tip of a smaw electrode is touched and help against the workpiece pass electricity directly to the instead of allowing for a gap between the two the electrode will workpiece without creating an arc hand tools for preparing a welding surface and cleaning a completed weld files, wire brush and chipping include hammers weld slag chippers and needle scalers are what tools pneumatically powered smaw power supplies are designed to produce an output that has a what nearly constant current larger the welding cable must be to the longer the distance the welding current must travel the reduce voltage drop in a transformer rectifier type welding system AC voltage is reduced to a DC voltage lower voltage level and then converted (rectified) into when lifting heavy objects objects that tend to spin or swing always tag lines remember to use the primary current for a welding machine can be 120v or 240v single phase 480v or _________ three phase the size of an arc welding machine is determined by its rated amperage and duty cycle when stringing welding cable overhead or between floors use ____ to tie off rope the cables the standard frequency of alternating current (AC) in the US is set at 60 _________ cycles per second the flux coating of electrodes _________ the metal cleans and deoxidizes the metal non low hydrogen electrodes may be used if their coatings are not damaged water or oil and they have not come in direct contact with ______ the chemical and mechanical properties of the base metal can be obtained bt base metal mill specifications referring the the ______ All electrodes used for code work must have the AWS classification number container in which they are shipped printed on them as well as on the normally an electrode should be ______ than the metal being welded smaller in diameter The . powdered metal added to some flux coatings adds filler metal to a weld improve the appearance of and helps ________the weld if quality control representatives find that welds made on critical equipment replaced were made with high moisture electrodes the welds made will have to be wire core mixing with the melted the weld in smaw is formed by the base metal Electrodes with powdered iron in their flux belong to the ______ electrode fast fill group The most common electrodes are discussed in the American welding society A5.1 and A5.5 specifications society of Mechanical Acceptable base metal and filler metal combinations are listed in section II, American Engineers (ASME) Boiler and material specifications of the pressure vessel code Low hydrogen electrodes that exceed the maximum exposure time can be dried one time The period of time a low hydrogen electrode can be outside a heated oven is defined by exposure time To determine the minimum tensile strength per square inch of the deposited weld metal created by an electrode multiply the first 2 digits ( or 3 if 100 or 1000 over ) of the marking on the electrode by _______ After sealed container of low hydrogen electrodes is opened the electrodes must be stored in special ovens at a temperature setting of welding codes require that the crater made by a termination of the weld be filled to the full __________ of the weld Arc strikes are left on the base metal by the ________ method of striking an arc a weld bead that is made with a side to side motion of the electrode is called a __________ bead. The best method of striking an arc when using a transformer DC welding machine is the _______ method Magnetic fields created during welding tend to concentrate in the corners of the ________. When striking an arc in SMAW welding the general rule is that the arc length should be _________ concentrated magnetic fields in the base metal cause the arc to . the most common fillet welds made are in ___________ joints When practicing welding, reuse weld coupons until to control the weld puddle when depositing an E6010 electrode stringer bead use a _________ motion welding codes require that the crater made by a termination of the weld be filled to the full __________ of the weld Arc strikes are left on the base metal by the ________ method of striking an arc a weld bead that is made with a side to side motion of the electrode is called a __________ bead. The best method of striking an arc when using a transformer DC welding machine is the _______ method Magnetic fields created during welding tend to concentrate in the corners of the ________. When striking an arc in SMAW welding the general rule is that the arc length should be _________ concentrated magnetic fields in the base metal cause the arc to . the most common fillet welds made are in ___________ joints When practicing welding, reuse weld coupons until to control the weld puddle when depositing an E6010 electrode stringer bead use a _________ motion A fillet weld is acceptable even if it has _______ before welding coupons made of 1/4" to 3/4" mild steel use a wire brush or grinder to ______ the coupons the point at which the back of the weld intersects the base metal is called the weld _____ when overlapping stringer beads use a work angle of ________ degrees toward the first stringer bead to obtain proper tie - in 250 Cross Section scratching weave Tapping base metal the same as the diameter of the electrode Deflect lap andT joints all surfaces have been welded on whipping Cross Section scratching weave Tapping base metal the same as the diameter of the electrode Deflect lap andT joints all surfaces have been welded on whipping a slight non-uniform face remove heavy mill scale or corrosion root 10 to 15 arc length is measured from______ the end of the electrode core to the base metal. When using stringer beads on V groove welds in the horizontal position keep the electrode drag angle at _______ degrees the distance the joint preparation extends into the base metal is called the prior to welding any surface in a weld groove is called a the most common American welding society plate welding qualifications test requires the use of _______ electrodes when preparing weld coupons for V groove welds with backing center the beveled strips on the backing strip with a ________ gap and tack - weld them in place prior to welding any surface in a weld groove is called a cooling welds with water can cause weld cracks and affect the mechanical properties of the _______ single groove welds with metal backing are used for ______ welds. When practicing horizontal v-groove welds, pay particular attention at the termination of the weld to fill the 10 to 15 depth of bevel groove face low hydrogen 1/4" groove face base metal high- strength crater When running vertical stringer beads on a v- groove joint in the vertical position, set the welder amperage in the ____________ of the range for better puddle control When preparing weld coupons for v- groove welds with backing, cut the metal backing strips so that they are at least The most common American Welding Society plate welding qualification test requires the use of Groove welds should be made with slight reinforcement and a gradual transition to the base metal at each lower part 1" by 8" low hydrogen electrodes toe The centering head attachment of a combination square is used to measure round stock and to locate the center of shafts or other round objects Chain clamps are used to align and hold pipe for fit up and tacking A simple welding sequence with short welds ___________ of the joint is on alternating sides recommended to reduce the effects of shrinkage Internal misalignment between two sections of pipe to be welded end to end Hi-Lo gauge is checked using a When using weave beads in flat open root v groove welds use a ___________ 10-15 degree drag angle Welding codes allow the __________________ on an open -root v groove welds to root face be within the range of 0" to 1/8" When running vertical weave beads on a v groove joint in the vertical position the width of the weave beads should be no more than ________ times five the diameter of the electrode being used if 3/8" carbon steel is not available, practice welds can be made on steel ____ 1/4" to 3/4" thick cooling with water is only done on practice coupons when using weave beads on an open root v groove welds in the vertical position , keep the electrode at a work angle of ____________ degrees to the 0 degrees plate surface for the first pass for an open root v groove weld, root reinforcement should be flush to 1/8'' should pause slightly at each weld To prevent undercut in a vertical open root v groove weld , the welder toe to penetrate and fill the crater to control the weld puddle when welding horizontal open root v groove 10 degrees welds drop the angle of the electrode slightly, but no more than Horizontal welds can be made on a horizontal open root v groove or on a vertically positioned flat surface groove welds should be made with slight reinforcement and a gradual toe transition to the base metal at each when the plates are vertical and the axis of the weld is horizontal, the code 2G for this position of groove weld is