Teknologi Dan Rekayasa SHIELDED METAL ARC WELDING (SMAW)

SHIELDED METAL ARC WELDING EQUIPMENT OBJECTIVE : After studying this lesson, the students can be to : identify of welding equipments explain the name of welding equipments select for welding equipments explain welding equipments setting Teknologi dan Rekayasa

SHIELDED METAL ARC WELDING EQUIPMENT UNDERSTANDING : Shield metal arc welding is a process where coalescence is achieved by generating an electric arc between a coated metallic electrode and the work piece. Teknologi dan Rekayasa

SHIELDED METAL ARC WELDING EQUIPMENT Fig. 1. Shield metal arc welding process Teknologi dan Rekayasa

SHIELDED METAL ARC WELDING EQUIPMENT Application : The Shielded Metal Arc Welding process is used extensively in welding both ferrous and non ferrous metals. Shielded Metal Arc Welding is universal in repairing and servicing equipment. Teknologi dan Rekayasa

SHIELDED METAL ARC WELDING EQUIPMENT The general of welding equipment are three kinds : Main equipment Assist equipment Health and safety equipment Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT The basic units of any shielded metal arc welding system consist of : Power Supply Electrode holder Ground clamp Power cable Protective shield Teknologi dan Rekayasa 7

THE MAIN WELDING EQUIPMENT Power Supply The three basic welding machines are referred to as generators, transformers and rectifier a. DC generator : The direct current power supply consist of a generator driven by an electric motor or a gasoline engine. One of the characteristics of a direct current welding generator is that the welding can be done with straight or reverse polarity Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT To identify this DC machine Fig. 2. DC-welding machine Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT In straight polarity the electrode is negative and the work piece positive and electrons flow from the electrode to the work piece. STRAIGHT POLARITY (DCSP) GENERATOR + - WORK Fig. 3. DCSP-welding machine connections Teknologi dan Rekayasa

REVERSED POLARITY (DCRP) THE MAIN WELDING EQUIPMENT In reverse polarity the electrode is positive and the work piece negative and the electrons flow from the work piece to the electrode. GENERATOR + - WORK REVERSED POLARITY (DCRP) Fig. 4. DCRP-welding machine connections Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT b. Transformer : The transformer type of welding machine produces alternating current where power is taken directly from a power supply line and transformed into a voltage required for welding. In its simplest form an AC transformer consists of a primary and secondary coil with an adjustment to regulate the current out put. Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT To identify this AC machine Fig. 5. AC-welding machine Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT c. Rectifier : Rectifier is essentially transformers containing an electrical device which changes alternating current into direct current. Rectifier are made to provide DC current only or both DC and AC welding current. Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT To identify this AC/DC machine Fig. 5. AC/DC welding machine. Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT 2. Electrode Holder The electrode holder is used to hold the electrode and guide it over the seam to be welded. Fig. 6. Electrode Holder Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT 3. Ground Clamp A very important unit of any electrical welding equipment is the ground clamp. Without proper grounding the full potential of the circuit will fail to provide the required heat for welding Fig.7. Ground Clamp Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT 4. Power cable Power cable selection that will be used should appropriate with the burden, it is ampere and input tension voltage regulator includes : wire size, long wire and type wire (fiber or not) Fig. 8. Power cable

THE MAIN WELDING EQUIPMENT 5. Protective shield A suitable helmet or handshield is required for all arc welding. An electric arc produces a brilliant light and also gives invisible ultraviolet and infrared rays which are extremely dangerous to the eyes and skin. Both the helmet and hand shield are equipped with special colored lenses that reduce the brilliancy of the light and screen out the infrared and ultraviolet rays. Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT Lenses come in different shades and the types used depends on the kind of welding done. In general, the recommended practice is: Shade 5 : for light spot welding Shade 6 and 7: for welding up to 30 amperes Shade 8 : for welding 30 to 75 amperes Shade 10 : for welding 75 to 200 amperes Shade 12 : for welding 200 to 400 amperes Shade 14 : for over 400 amperes Teknologi dan Rekayasa

THE MAIN WELDING EQUIPMENT Lens Clear lens Filter lens Fig. 9. Protective Shielded Teknologi dan Rekayasa

ASSIST WELDING EQUIPMENT 1 WELDING TABLE 2 CHINDER HAMMER 3 CURVE HAMMER 4 HAND GRINDSTONE

ASSIST WELDING EQUIPMENT 1. Welding table Welding table is place to put work think in position

ASSIST WELDING EQUIPMENT 2. Chinder hammer Chinder hammer is a tool for cleaning chinder from welding product

ASSIST WELDING EQUIPMENT 3. Curve hammer Curve hammer is used to straighten, levelling the surface of curve or bend work think.

ASSIST WELDING EQUIPMENT 4. Hand Grindstone Its function is to prepare materials that will be welding, it is preparing welding shawl, it is also used to support in welding process specially in cleaning welding product

HEALTH AND SAFETY EQUIPMENT 1. WELD CLOTHES 2. APPRON (CHEST PROTECTOR) 3. GLOVES 4. LEATHER SHOES

HEALTH AND SAFETY EQUIPMENT 1. Weld Clothes By wearing this clothes, welder will fill comfort and free in movement

HEALTH AND SAFETY EQUIPMENT 2. Apron (Chest protector) Appron is used to protect welder chest from UV ray, infra red, weld fire work sprinkling and the hot of welding.

HEALTH AND SAFETY EQUIPMENT 3. Gloves Gloves it used to protect welder hand from electricity, the of welding and sharp material.

HEALTH AND SAFETY EQUIPMENT 4. Leather Shoes This shoes made of leather that there is metal in top of it, this shoes will protect welder from electricity, downfall material, hot material and sharp material.

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