Question

1. a technique in welding used normally for vertical joints in which the electrode sweeps back and forth in a semi - circular motion? a. layering c. back step welding b. wash welding d. both a & b 24. when a welder passes on 5g pipe qualification, which of the following is cover in his/her qualification? a. 6f plate and 4g pipe position c. 2g pipe and 5g pipe position b. 1f plate up to 6g pipe position d. all welding position. 25. using electrode with moisture may result to? a. spatter d. porosity b. good fusion d. undercut 26. what is the recommended shade for dark glass is advisable to use in 3mm diameter electrode? a. #10 b. #12 c. #6 d. #8 27. weld defects like undercut may be prevented by which of the following? a. increasing current and voltage b. maintaining correct arc length c. decreasing stop time on weave bead d. grinding the sharp edges of the weld toes 28. a safety device to stop the flame or reverse flow of gas back to the equipment hence, it protects the user and equipment from damage and explosion during oxy - fuel welding and cutting. a. non return valve b. relief valve c. backflow arrestor d. check valve. 29. edge preparation for welding in which plate thickness? a. ≤6mm b. >6mm c. ≥10mm d. ±10mm 30. which electrode coating is best used to weld low alloy steel? a. cellulose c. rutile b. low hydrogen d. acid direction: enumerate the 5 essentials of welding. correct amperage setting correct tip and size of electrode correct arc gap/length correct angle of electrode correct travel speed

Explanation:

1. Washing welding involves the electrode moving back - and - forth in a semi - circular motion for vertical joints.
2. Passing 5G pipe qualification usually implies all welding positions.
3. Moisture in electrodes can cause porosity in welds.
4. For 3mm diameter electrodes, #10 shade is recommended for dark glass.
5. Maintaining correct arc length helps prevent undercut.
6. A backflow arrestor stops gas backflow in oxy - fuel welding and cutting.
7. Edge preparation is typically for plate thickness ≤6mm.
8. Low hydrogen electrode coating is best for low alloy steel.

Answer:

1. b. Wash welding
2. d. All welding position
3. d. Porosity
4. a. #10
5. b. Maintaining correct arc length
6. c. Backflow Arrestor
7. a. ≤6mm
8. b. Low hydrogen