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The purpose of the Welding Handbook for maritime welders is to provide guidance in modern welding and related processes and to provide the welder with a source of practical information on the right solution to specific onboard welding problems. Experience gained from user contact and welding training of crewmembers showed that.
Oxy-Acetylene Welding (OAW) 1. Welding Terms
a. Fusing; Heating two or more metals or nonmetals until they become ______, then allowing them to ____ and solidify. b. Fusion Welding; Welding that uses fusion or _______________ metals to make a weld. c. Oxy-acetylene Welding; A welding process that burns _______ and ___________________in a flame to create a heat source for fusion. d. Weld pool or puddle; Molten area during a ___________process. e. Backfire; Popping noise when the flame suddenly burns back into the tip but ______ ______. (explosion at the tip) d. Flashback; When the flame burns back _________ the tip, torch, hose, or regulators. (pop - followed by a shrill squealing or hissing sound)
2. Oxy-Acetylene Welding Process
a. Flame creates heat source to __________base metals. b. Creates _____ gas which shields liquefied metal from atmospheric contaminates. (_________, __________) c. Filler rod can be added to help join base metals and __________ weld joint strength. d. Manual welding process. Requires skill to form, maintain, and move a uniform _________ ___________ of molten metal along the weld. e. Used primarily for welding _______ gage steel. _________ work.
3. Oxy-Acetylene Welding Equipment •
Oxygen Cylinder
•
Acetylene Cylinder
•
Oxygen Regulator& Gages
•
Acetylene Regulator& Gages
•
Oxygen Hose
•
Acetylene Hose
•
Flash Back Arresters
•
Torch Handle (body)
•
Torch Tip
1
4. Personal Protection
a. Safety glasses; ANSI Z87.1 b. Clothing; Fire resistant materials, Leather, ______ – no synthetics like polyester. No turned up or frayed cuffs. Long sleeves and collars buttoned. c. Boots; Leather, steel toes, slip on best, no exposed __________. d. Gloves; Gauntlet, flexible but _______ enough for heat protection. e. Goggles, Shield; #3 – 5 shaded lens. (ultraviolet/ infrared light) f. Ear protection; muffs, plugs, (out of position welding/ cutting) g. Never have a pressurized butane___________ on your person while in the shop.
5. Oxygen Gas
a. (O2); colorless, odorless, tasteless, ________, non-flammable, gas. b. Welding grade about ________ pure. c. Most common method- obtained from _______________. (21% O2) d. Purified & cooled under high pressure until ______________. e. Separated from Nitrogen (-320º F), O2 (-296º F) by ____________. f. Supports combustion when mixed with other _____________. g. Never use to blow off _________ or mix ________ with oxygen.
6. Acetylene Gas
a. (C2H2); Equal parts______________ & Hydrogen. b. Colorless gas, pungent odor due to _____________. c. Made by mixing Calcium Carbide &_____________. d. Dissociates (separates) under ______________& releases heat. e. Highly unstable over 15 psi. – can cause __________________. f. Highly explosive when mixed w/ ______________. g. Forms explosive compounds when mixed with ____________ or _____________.
7. Oxygen Cylinders
a. Seamless drawn steel tube, minimum ___” thick, tested to 3360 psi. b. Cylinder sized by _______ capacity. c. __________cu.ft. large size, 122cu.ft. medium, 80cu.ft. small. d. Filled to 2200 psi @ ______º F. (pressure changes w/ temperature) e. Fitted w/ high pressure, ___________ seat valve – open completely. f. Right-hand male outlet fitting, w/ __________ _______ __________. g. Protective cap screws to ____________ _______. (ring is pressed fit - not welded) h. Bottles can _________ if dropped, struck, punctured, arced across.
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8. Acetylene Cylinders a. Welded cylinders w/safety fuse plugs - release contents at _____ ºF. b. Filled w/ porous ____________ material. (Calcium Silicate 8-10%). c. Calcium Silicate saturated w/ _________. (42% of internal volume) d. Acetylene dissolves in Acetone and is safely held above _____ psi. (36% of internal volume) e. Acetone is __________, never lay Acetylene cylinders down or draw off more than _____ the volume of the cylinder. Keep cylinder upright for_____ hrs. before use. f. Possible to draw acetylene __________ than acetone can release it. Cylinder gage may read zero. Pressure will return if left alone. g. Cylinder sized by cu.ft. capacity. ____cu.ft. common size @____ psi. h. Fitted with valve (some have ________ wrench) and safety cap. i. No relief valve; __________% reserve in tank. j. Open valve ______ to ______ turn or until _____ ______ ________. k. Left-hand_________ outlet fitting.
9. Cylinder Handling
a. Handle, store, transport in ________________ position. b. Use cylinder hand-truck w/ ____________ to transport. c. Replace cylinder caps, don’t lift bottles by________. d. Open & close valves by hand – no__________. e. Never roll cylinders ______________. f. Store Oxygen & Acetylene cylinders separately, ______ft. minimum or 5’ wall w/__________ burn. g. Secure cylinders with ________ or ________ at all times.
10. Regulator Function
a. Control the amount of gas flow from the ________________. b. Maintain the required _______________ pressure. c. Produce _________ flow of gas under _____________ cylinder pressures.
11. Single- Stage Regulators
a. Cheapest; gas flows directly to ______ _____________ chamber and is controlled by diaphragm and adjusting screw. (right-hand threads) b. Must be continuously adjusted as cylinder pressure ___________. c. Adjusting screw must be ____________ before opening cylinder extreme pressure can blow out screw or damage regulator. d. Unscrewing pressure adjustment screw _____________gas flow. e. Use w/ ____________ ___________.
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12. Two - Stage Regulators
a. Gas flows from cylinder into high pressure ________________. b. High pressure controlled by __________ & ________________. c. Gas flows into __________ chamber, controlled by adjusting screw which pushes on larger stainless steel diaphragm. d. Unscrewing pressure adjustment screw ___________ gas flow. e. Use w/ ____________system.
(Picture of Oxygen Regulator)
13. Oxygen Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to _____________ psi. b. Working pressure gage; graduated from _____________ psi. c. Female inlet fitting to cylinder is ___________________ thread. d. Never use________ on fittings.
14. Acetylene Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to __________ psi. b. Working pressure gage; graduated from ___________psi. w/ red warning color above _________ psi. c. Male inlet fitting to cylinder is ___________with a left-hand thread. d. Never use _______ on fittings.
15. Flashback Arrestors & Check Valves
a. Installed between hoses and torch (_______ mounted) or hoses and regulators (regulator mounted). Install in proper _______________. b. Flash Arrester - Has built in _________ __________ that prevents reverse gas flow and a _________ barrier that prevents a flame from moving from the torch back through the hose and regulators. c. Check valves - prevents reverse gas flow _________. May not stop Flashback d. Check valves close when the pressure on the torch side _______ the pressure from the regulator. (Flashback) e. Check valves may need to be________ if a flashback has occurred. f. Never use ______ on connections.
Flashback Arrester
16. Oxygen & Acetylene Hoses
a. Oxygen hose is commonly green in the United States. b. Acetylene hose is commonly red. c. Rubber / Nylon. Different types for the type of fuel gas. d. Oxygen fittings are right-hand thread, Acetylene fittings are lefthand thread with a notch in the middle of the fitting. e. New hose is dusted w/ talcum powder and should be blown out w/ dry, clean, compressed air. Never use oil on connections. f. Use proper care for hoses. Flame resistant, can be burned through and cut. 4
17. Torch Function
a. Control and mix the oxygen and fuel gas within the ________ _______________ of the torch. b. Direct the_____________ to the work area.
18. Torch Parts
•
Welding Tip
•
Mixing Chamber
•
Torch Body (Barrel)
•
Valves
•
Oxygen & Fuel gas Connections
19. Torch Types
a. Positive Pressure; (also called an _________ ________________ or medium pressure torch) b. Injector; (also called a ______ _______________torch)
20. Positive Pressure Torches
a. Most common type. b. Feeds oxygen and fuel into mixing chamber at relatively _________ pressures. c. Mixing chambers may be in _________ _____________ or tip. d. Fuel gas pressures must be above __________psi. to function.
21. Injector Torches
a. Forces high pressure Oxygen through ____________, which draws low pressure fuel gas into the mixing chamber. b. Fuel gas pressure can be as low as _______psi. (Acetylene Generator) c. Draws more ________________out of cylinders. 5
22. Torch Valves & Connectors
a. Valves may be located on either____________ of the torch body. b. ________valves; use finger force only – never a wrench. c. Over-tightening valves will damage _______ ________ and cause it to leak. d. Oxygen connector is ________-hand thread. e. Acetylene connector is __________-hand thread. f. Oxy or Fuel - usually marked on _________________at torch body. g. Never use ________on valves or connections.
23. Types of Tips
a. Welding. b. Cutting. c. Heating (_______ ______).
24. Welding Tip Styles
a. One-piece tube-and-tip ________________. b. Two-piece tip; small torch tip threaded into _______________tube. c. Both are attached to the torch body and mixing chamber. d. In-tip mixers; torch tips with their own _______________ chamber.
25. Tip Sizes
a. Measured by the diameter of the ___________ at the end of the tip. b. Tip size affects the amount of _____ – not temperature of the flame. c. Must select correct _________size for the job. (thickness of metal) d. No standard tip size measurement____________________. e. Use_______________ system; 000 (smallest) to 15 (largest). f. Use ______ _______ number; 1 - 80, larger # = smaller orifice size.
26. Tip Selection
a. ________________ of metal. b. Working pressures must match ________ __________. Follow manufactures recommendation.
27. Tip Care
a. Keep tip __________. (slag, carbon, molten metal distorts flame and can cause backfire or flashback) b. Use correct size tip ___________. (don’t enlarge or elongate orifice) c. Do not remove ________ tips from tip tube or install _________ tip on hot tip tube. d. Do not___________ the torch or the tip. e. _________ ________ torch when not in use. 6
28. Equipment Set-up Procedure
a. Securely _____________or fasten cylinders in vertical position. b. Remove safety caps. c. Quickly crack open cylinder ________ to clear dirt. (stand to side) d. Connect _____________ by hand and tighten with a proper fitting wrench. (Attach Flashback arrester to regulator) e. Attach ________ to respective regulators. (purge regulator & hose) f. Attach check valve or ________________arrester to torch. g. Attach torch body & check valve/arrester to hoses by hand and _____________ with proper fitting wrench. h. Select and install correct ________ _________. Align w/ valves. i. _________-tighten only; tightening with a wrench will damage seal and allow connection to leak. j. Pressurize system following proper procedures and check all connections and fittings for leaks using ____________ water or commercial leak test solution. (check valve stem at the cylinder) k. Never test for leaks with___________ or heat source.
29. Pressurizing System & Lighting Torch
a. Check that torch valves are ____________ and pressure adjustment screws on the regulators are backed ________. b. ___________ crack open cylinder valves. Open Oxygen ______________ - Acetylene ____________ turn. Always stand to the side of the gages – never in front of them. c. Set working pressures separately. Open torch valve. Adjust pressure adjustment screw at regulator to desired pressure. ______ torch valve. Always purge gas lines – 3 to 4 seconds per 25’ of hose before lighting torch. d. To light torch, open acetylene valve first, ________ turn. Light torch facing ______________with sparklighter held approximately 1” from torch tip. e. Adjust acetylene flame until ________________almost disappears. f. Open torch _________ _________ and adjust to desired flame type.
30. Welding Flame
a. Reducing or Carburizing; ___________ acetylene. b. Neutral; ___________ amounts of gases. c. Oxidizing; excess _____________. d. Flame affected by too little or too much ___________ __________. e. Inner cone releases over ____ of heat. f. Too small or large flame; can cause tip to ________ ____________, backfire, poor weld quality. 7
31. Reducing or Carburizing Flame
a. Excess acetylene, cooler, soft flame ºF b. Three flames; inner cone, intermediate or secondary cone, (____________ ____________) outer flame. c. Used for soldering & ___________ applications. d. Introduces excess _____________into weld puddle – causes hard, brittle weld. Not used for fusion welding on mild steel.
32. Neutral Flame
a. _________________ parts of oxygen & acetylene. b. Two flames; well defined _________ __________ & near colorless outer flame. c. Soft sound, burns @ approximately ____________º F. d. Chemically neutral. Protects puddle w/ ____________ by product. e. Used for________________ welding operations.
33. Oxidizing Flame
a. ______________oxygen. b. Two flames; smaller, sharp - pointed inner cone & bright ________, smaller, flared - outer flame. c. Harsh, hissing sound; burns @ approximately ___________º F. d. Used for some _____________ operations. e. Excess oxygen forms oxides in weld puddle causing brittleness, weakness. f. Tendency to leave _________________ in weld pool (harsh flame) and burn steel.
34. Holding the Torch
a. Over-Hand or________ grip; balance the torch in hand w/ light grip. b. Place hoses over shoulder to reduce weight. Do not wrap around ___________. c. Support ______________; get comfortable.
35. Torch Manipulation
a. Forehand; welding flame pointed in ________of travel in downward angle. Filler metal dipped in front edge of puddle ahead of the flame. Flame pushes puddle. Used on thinner metals.
b. Backhand; welding flame pointed _______________the direction of travel in a downward angle. Filler material dipped between flame and puddle. Flame pulls puddle. Used on thicker material and cover pass. 8
36. Torch Movement Patterns
a. Circular; approx. 1/4” dia. w/ _________” advance per circle. b. Semicircular; approx. 1/4” wide w/ ___” advance per semicircle. c. Weave; approx. 1/4” wide w/ ____” advance per side movement.
37. Work Angle
a. Angle of torch tip; measured ________________ to travel direction. b. Changes w/ type and______________ of joint. (90 to surface for flat position bead) c. Use to control puddle &___________ distribution.
38. Travel Angle
a. Angle of torch tip, measured ______________ to direction of travel. b. Changes w/_________ and position of joint. (0-45 to surface for flat position bead) c. Use to control _____________ & heat distribution.
39. Travel Speed
a. Speed at which torch moves in_____________ direction. b. Constant speed produces even width, __________________ bead w/ consistent penetration. c. Give heat and puddle time to stay _____________ of flame.
40. Torch Height
a. Distance from the tip of the neutral flame _________ to the puddle surface. b. Keep approximately _____” from molten pool. (changes w/ tip size) c. Do not allow cone to________ into puddle. (Backfire, dirty tip, weld impurities, depressions in weld bead.
41. Filler Metal
a. Match filler metal properties to__________ metal properties. b. Cut length rods, ___” standard length, 5-10 lb. tubes/ 50 lb. cartons. c. Diameters; 1/16” – 3/16” in ______” graduations, 1/4”, 5/16”, 3/8”. d. Classified by American Welding Society (__________). e. RG 45, RG60, RG65. R =__________. G = __________Welding. 45 = Minimum _______________Strength (lbs.) X 10,000. (ex. RG45 = 45,000 lbs.) f. Use manufactures recommendations for tip size, _______ diameter, working pressures, per metal thickness. 9
42. Manipulating Filler Metal
a. Use correct _________________; too large cools puddle – too small will not fill puddle. b. Slant filler metal away from tip but at approximately the__________ angle as the tip. c. Create and maintain full size puddle in base metal______________ dipping filler rod. (Stay off edges of material – they will over-heat) d. Keep filler ________ to puddle when not dipping, keep it ______ but not molten. Use straight up and down dipping motion. e. Forehand technique – Flat, Vertical, Over-head positions; dip slightly towards the____________ edge of the puddle. Forehand technique – Horizontal position; dip towards _____ _____ edge of puddle f. Allow puddle to melt __________ – not flame. h. Melt rod away from base metal if rod becomes stuck – don’t _____. i. Obtain smooth and _________________ rhythm. j. Bend over__________ end of rod for safety. k. Weld small lengths of ___________ _________ together. l. Use to set _________ opening.
43. Backfire
a. Popping noise when the flame suddenly burns back into the tip but _______ _____. (explosion at the tip) b. Can be caused by operating torch at too________ pressure for tip. c. Touching the welding _________ to the work or puddle. d. _______________ the tip. e. __________________ in the tip. f. After Backfire: Shut off________ valves – GAS IS STILL FLOWING, remedy the cause, relight torch
43. Flashback
a. When the flame burns back inside the tip, torch, hose, or regulators and ________ ______ go out. (pop - followed by a shrill squealing or hissing sound) b. Generally indicates something is wrong with equipment or _______. c. Touching tip to the work or puddle - __________________ in the tip. d. ___________________the tip. e. Wrong gas_______________ pressure. f. After Flashback: Shut off valves ____________– GAS IS BURNING INSIDE THE TORCH AND WILL DAMAGE THE TORCH. Remedy the cause, inspect system, relight torch. g. Flash Arresters will ________ flame at the torch if installed between the torch and the hoses.
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44. Shutting Off Torch
a. Turn off torch _____________ valve first – Acetylene second. b. Close tank or manifold ____________. c. Open torch _______________ valve, bleed all gas from hose and regulator. d. Back out Acetylene pressure ______________ ____________at regulator. Close torch Acetylene valve. e. Open torch _____________ valve, bleed all gas from hose and regulator. f. Back out Oxygen pressure _________________ ___________ at regulator. Close torch Oxygen valve. g. Place torch on ____________. Clean up work area. Cool metal _______________ placing it in scrap bin.
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a. Fusing; Heating two or more metals or nonmetals until they become ______, then allowing them to ____ and solidify. b. Fusion Welding; Welding that uses fusion or _______________ metals to make a weld. c. Oxy-acetylene Welding; A welding process that burns _______ and ___________________in a flame to create a heat source for fusion. d. Weld pool or puddle; Molten area during a ___________process. e. Backfire; Popping noise when the flame suddenly burns back into the tip but ______ ______. (explosion at the tip) d. Flashback; When the flame burns back _________ the tip, torch, hose, or regulators. (pop - followed by a shrill squealing or hissing sound)
2. Oxy-Acetylene Welding Process
a. Flame creates heat source to __________base metals. b. Creates _____ gas which shields liquefied metal from atmospheric contaminates. (_________, __________) c. Filler rod can be added to help join base metals and __________ weld joint strength. d. Manual welding process. Requires skill to form, maintain, and move a uniform _________ ___________ of molten metal along the weld. e. Used primarily for welding _______ gage steel. _________ work.
3. Oxy-Acetylene Welding Equipment •
Oxygen Cylinder
•
Acetylene Cylinder
•
Oxygen Regulator& Gages
•
Acetylene Regulator& Gages
•
Oxygen Hose
•
Acetylene Hose
•
Flash Back Arresters
•
Torch Handle (body)
•
Torch Tip
1
4. Personal Protection
a. Safety glasses; ANSI Z87.1 b. Clothing; Fire resistant materials, Leather, ______ – no synthetics like polyester. No turned up or frayed cuffs. Long sleeves and collars buttoned. c. Boots; Leather, steel toes, slip on best, no exposed __________. d. Gloves; Gauntlet, flexible but _______ enough for heat protection. e. Goggles, Shield; #3 – 5 shaded lens. (ultraviolet/ infrared light) f. Ear protection; muffs, plugs, (out of position welding/ cutting) g. Never have a pressurized butane___________ on your person while in the shop.
5. Oxygen Gas
a. (O2); colorless, odorless, tasteless, ________, non-flammable, gas. b. Welding grade about ________ pure. c. Most common method- obtained from _______________. (21% O2) d. Purified & cooled under high pressure until ______________. e. Separated from Nitrogen (-320º F), O2 (-296º F) by ____________. f. Supports combustion when mixed with other _____________. g. Never use to blow off _________ or mix ________ with oxygen.
6. Acetylene Gas
a. (C2H2); Equal parts______________ & Hydrogen. b. Colorless gas, pungent odor due to _____________. c. Made by mixing Calcium Carbide &_____________. d. Dissociates (separates) under ______________& releases heat. e. Highly unstable over 15 psi. – can cause __________________. f. Highly explosive when mixed w/ ______________. g. Forms explosive compounds when mixed with ____________ or _____________.
7. Oxygen Cylinders
a. Seamless drawn steel tube, minimum ___” thick, tested to 3360 psi. b. Cylinder sized by _______ capacity. c. __________cu.ft. large size, 122cu.ft. medium, 80cu.ft. small. d. Filled to 2200 psi @ ______º F. (pressure changes w/ temperature) e. Fitted w/ high pressure, ___________ seat valve – open completely. f. Right-hand male outlet fitting, w/ __________ _______ __________. g. Protective cap screws to ____________ _______. (ring is pressed fit - not welded) h. Bottles can _________ if dropped, struck, punctured, arced across.
2
8. Acetylene Cylinders a. Welded cylinders w/safety fuse plugs - release contents at _____ ºF. b. Filled w/ porous ____________ material. (Calcium Silicate 8-10%). c. Calcium Silicate saturated w/ _________. (42% of internal volume) d. Acetylene dissolves in Acetone and is safely held above _____ psi. (36% of internal volume) e. Acetone is __________, never lay Acetylene cylinders down or draw off more than _____ the volume of the cylinder. Keep cylinder upright for_____ hrs. before use. f. Possible to draw acetylene __________ than acetone can release it. Cylinder gage may read zero. Pressure will return if left alone. g. Cylinder sized by cu.ft. capacity. ____cu.ft. common size @____ psi. h. Fitted with valve (some have ________ wrench) and safety cap. i. No relief valve; __________% reserve in tank. j. Open valve ______ to ______ turn or until _____ ______ ________. k. Left-hand_________ outlet fitting.
9. Cylinder Handling
a. Handle, store, transport in ________________ position. b. Use cylinder hand-truck w/ ____________ to transport. c. Replace cylinder caps, don’t lift bottles by________. d. Open & close valves by hand – no__________. e. Never roll cylinders ______________. f. Store Oxygen & Acetylene cylinders separately, ______ft. minimum or 5’ wall w/__________ burn. g. Secure cylinders with ________ or ________ at all times.
10. Regulator Function
a. Control the amount of gas flow from the ________________. b. Maintain the required _______________ pressure. c. Produce _________ flow of gas under _____________ cylinder pressures.
11. Single- Stage Regulators
a. Cheapest; gas flows directly to ______ _____________ chamber and is controlled by diaphragm and adjusting screw. (right-hand threads) b. Must be continuously adjusted as cylinder pressure ___________. c. Adjusting screw must be ____________ before opening cylinder extreme pressure can blow out screw or damage regulator. d. Unscrewing pressure adjustment screw _____________gas flow. e. Use w/ ____________ ___________.
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12. Two - Stage Regulators
a. Gas flows from cylinder into high pressure ________________. b. High pressure controlled by __________ & ________________. c. Gas flows into __________ chamber, controlled by adjusting screw which pushes on larger stainless steel diaphragm. d. Unscrewing pressure adjustment screw ___________ gas flow. e. Use w/ ____________system.
(Picture of Oxygen Regulator)
13. Oxygen Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to _____________ psi. b. Working pressure gage; graduated from _____________ psi. c. Female inlet fitting to cylinder is ___________________ thread. d. Never use________ on fittings.
14. Acetylene Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to __________ psi. b. Working pressure gage; graduated from ___________psi. w/ red warning color above _________ psi. c. Male inlet fitting to cylinder is ___________with a left-hand thread. d. Never use _______ on fittings.
15. Flashback Arrestors & Check Valves
a. Installed between hoses and torch (_______ mounted) or hoses and regulators (regulator mounted). Install in proper _______________. b. Flash Arrester - Has built in _________ __________ that prevents reverse gas flow and a _________ barrier that prevents a flame from moving from the torch back through the hose and regulators. c. Check valves - prevents reverse gas flow _________. May not stop Flashback d. Check valves close when the pressure on the torch side _______ the pressure from the regulator. (Flashback) e. Check valves may need to be________ if a flashback has occurred. f. Never use ______ on connections.
Flashback Arrester
16. Oxygen & Acetylene Hoses
a. Oxygen hose is commonly green in the United States. b. Acetylene hose is commonly red. c. Rubber / Nylon. Different types for the type of fuel gas. d. Oxygen fittings are right-hand thread, Acetylene fittings are lefthand thread with a notch in the middle of the fitting. e. New hose is dusted w/ talcum powder and should be blown out w/ dry, clean, compressed air. Never use oil on connections. f. Use proper care for hoses. Flame resistant, can be burned through and cut. 4
17. Torch Function
a. Control and mix the oxygen and fuel gas within the ________ _______________ of the torch. b. Direct the_____________ to the work area.
18. Torch Parts
•
Welding Tip
•
Mixing Chamber
•
Torch Body (Barrel)
•
Valves
•
Oxygen & Fuel gas Connections
19. Torch Types
a. Positive Pressure; (also called an _________ ________________ or medium pressure torch) b. Injector; (also called a ______ _______________torch)
20. Positive Pressure Torches
a. Most common type. b. Feeds oxygen and fuel into mixing chamber at relatively _________ pressures. c. Mixing chambers may be in _________ _____________ or tip. d. Fuel gas pressures must be above __________psi. to function.
21. Injector Torches
a. Forces high pressure Oxygen through ____________, which draws low pressure fuel gas into the mixing chamber. b. Fuel gas pressure can be as low as _______psi. (Acetylene Generator) c. Draws more ________________out of cylinders. 5
22. Torch Valves & Connectors
a. Valves may be located on either____________ of the torch body. b. ________valves; use finger force only – never a wrench. c. Over-tightening valves will damage _______ ________ and cause it to leak. d. Oxygen connector is ________-hand thread. e. Acetylene connector is __________-hand thread. f. Oxy or Fuel - usually marked on _________________at torch body. g. Never use ________on valves or connections.
23. Types of Tips
a. Welding. b. Cutting. c. Heating (_______ ______).
24. Welding Tip Styles
a. One-piece tube-and-tip ________________. b. Two-piece tip; small torch tip threaded into _______________tube. c. Both are attached to the torch body and mixing chamber. d. In-tip mixers; torch tips with their own _______________ chamber.
25. Tip Sizes
a. Measured by the diameter of the ___________ at the end of the tip. b. Tip size affects the amount of _____ – not temperature of the flame. c. Must select correct _________size for the job. (thickness of metal) d. No standard tip size measurement____________________. e. Use_______________ system; 000 (smallest) to 15 (largest). f. Use ______ _______ number; 1 - 80, larger # = smaller orifice size.
26. Tip Selection
a. ________________ of metal. b. Working pressures must match ________ __________. Follow manufactures recommendation.
27. Tip Care
a. Keep tip __________. (slag, carbon, molten metal distorts flame and can cause backfire or flashback) b. Use correct size tip ___________. (don’t enlarge or elongate orifice) c. Do not remove ________ tips from tip tube or install _________ tip on hot tip tube. d. Do not___________ the torch or the tip. e. _________ ________ torch when not in use. 6
28. Equipment Set-up Procedure
a. Securely _____________or fasten cylinders in vertical position. b. Remove safety caps. c. Quickly crack open cylinder ________ to clear dirt. (stand to side) d. Connect _____________ by hand and tighten with a proper fitting wrench. (Attach Flashback arrester to regulator) e. Attach ________ to respective regulators. (purge regulator & hose) f. Attach check valve or ________________arrester to torch. g. Attach torch body & check valve/arrester to hoses by hand and _____________ with proper fitting wrench. h. Select and install correct ________ _________. Align w/ valves. i. _________-tighten only; tightening with a wrench will damage seal and allow connection to leak. j. Pressurize system following proper procedures and check all connections and fittings for leaks using ____________ water or commercial leak test solution. (check valve stem at the cylinder) k. Never test for leaks with___________ or heat source.
29. Pressurizing System & Lighting Torch
a. Check that torch valves are ____________ and pressure adjustment screws on the regulators are backed ________. b. ___________ crack open cylinder valves. Open Oxygen ______________ - Acetylene ____________ turn. Always stand to the side of the gages – never in front of them. c. Set working pressures separately. Open torch valve. Adjust pressure adjustment screw at regulator to desired pressure. ______ torch valve. Always purge gas lines – 3 to 4 seconds per 25’ of hose before lighting torch. d. To light torch, open acetylene valve first, ________ turn. Light torch facing ______________with sparklighter held approximately 1” from torch tip. e. Adjust acetylene flame until ________________almost disappears. f. Open torch _________ _________ and adjust to desired flame type.
30. Welding Flame
a. Reducing or Carburizing; ___________ acetylene. b. Neutral; ___________ amounts of gases. c. Oxidizing; excess _____________. d. Flame affected by too little or too much ___________ __________. e. Inner cone releases over ____ of heat. f. Too small or large flame; can cause tip to ________ ____________, backfire, poor weld quality. 7
31. Reducing or Carburizing Flame
a. Excess acetylene, cooler, soft flame ºF b. Three flames; inner cone, intermediate or secondary cone, (____________ ____________) outer flame. c. Used for soldering & ___________ applications. d. Introduces excess _____________into weld puddle – causes hard, brittle weld. Not used for fusion welding on mild steel.
32. Neutral Flame
a. _________________ parts of oxygen & acetylene. b. Two flames; well defined _________ __________ & near colorless outer flame. c. Soft sound, burns @ approximately ____________º F. d. Chemically neutral. Protects puddle w/ ____________ by product. e. Used for________________ welding operations.
33. Oxidizing Flame
a. ______________oxygen. b. Two flames; smaller, sharp - pointed inner cone & bright ________, smaller, flared - outer flame. c. Harsh, hissing sound; burns @ approximately ___________º F. d. Used for some _____________ operations. e. Excess oxygen forms oxides in weld puddle causing brittleness, weakness. f. Tendency to leave _________________ in weld pool (harsh flame) and burn steel.
34. Holding the Torch
a. Over-Hand or________ grip; balance the torch in hand w/ light grip. b. Place hoses over shoulder to reduce weight. Do not wrap around ___________. c. Support ______________; get comfortable.
35. Torch Manipulation
a. Forehand; welding flame pointed in ________of travel in downward angle. Filler metal dipped in front edge of puddle ahead of the flame. Flame pushes puddle. Used on thinner metals.
b. Backhand; welding flame pointed _______________the direction of travel in a downward angle. Filler material dipped between flame and puddle. Flame pulls puddle. Used on thicker material and cover pass. 8
36. Torch Movement Patterns
a. Circular; approx. 1/4” dia. w/ _________” advance per circle. b. Semicircular; approx. 1/4” wide w/ ___” advance per semicircle. c. Weave; approx. 1/4” wide w/ ____” advance per side movement.
37. Work Angle
a. Angle of torch tip; measured ________________ to travel direction. b. Changes w/ type and______________ of joint. (90 to surface for flat position bead) c. Use to control puddle &___________ distribution.
38. Travel Angle
a. Angle of torch tip, measured ______________ to direction of travel. b. Changes w/_________ and position of joint. (0-45 to surface for flat position bead) c. Use to control _____________ & heat distribution.
39. Travel Speed
a. Speed at which torch moves in_____________ direction. b. Constant speed produces even width, __________________ bead w/ consistent penetration. c. Give heat and puddle time to stay _____________ of flame.
40. Torch Height
a. Distance from the tip of the neutral flame _________ to the puddle surface. b. Keep approximately _____” from molten pool. (changes w/ tip size) c. Do not allow cone to________ into puddle. (Backfire, dirty tip, weld impurities, depressions in weld bead.
41. Filler Metal
a. Match filler metal properties to__________ metal properties. b. Cut length rods, ___” standard length, 5-10 lb. tubes/ 50 lb. cartons. c. Diameters; 1/16” – 3/16” in ______” graduations, 1/4”, 5/16”, 3/8”. d. Classified by American Welding Society (__________). e. RG 45, RG60, RG65. R =__________. G = __________Welding. 45 = Minimum _______________Strength (lbs.) X 10,000. (ex. RG45 = 45,000 lbs.) f. Use manufactures recommendations for tip size, _______ diameter, working pressures, per metal thickness. 9
42. Manipulating Filler Metal
a. Use correct _________________; too large cools puddle – too small will not fill puddle. b. Slant filler metal away from tip but at approximately the__________ angle as the tip. c. Create and maintain full size puddle in base metal______________ dipping filler rod. (Stay off edges of material – they will over-heat) d. Keep filler ________ to puddle when not dipping, keep it ______ but not molten. Use straight up and down dipping motion. e. Forehand technique – Flat, Vertical, Over-head positions; dip slightly towards the____________ edge of the puddle. Forehand technique – Horizontal position; dip towards _____ _____ edge of puddle f. Allow puddle to melt __________ – not flame. h. Melt rod away from base metal if rod becomes stuck – don’t _____. i. Obtain smooth and _________________ rhythm. j. Bend over__________ end of rod for safety. k. Weld small lengths of ___________ _________ together. l. Use to set _________ opening.
43. Backfire
a. Popping noise when the flame suddenly burns back into the tip but _______ _____. (explosion at the tip) b. Can be caused by operating torch at too________ pressure for tip. c. Touching the welding _________ to the work or puddle. d. _______________ the tip. e. __________________ in the tip. f. After Backfire: Shut off________ valves – GAS IS STILL FLOWING, remedy the cause, relight torch
43. Flashback
a. When the flame burns back inside the tip, torch, hose, or regulators and ________ ______ go out. (pop - followed by a shrill squealing or hissing sound) b. Generally indicates something is wrong with equipment or _______. c. Touching tip to the work or puddle - __________________ in the tip. d. ___________________the tip. e. Wrong gas_______________ pressure. f. After Flashback: Shut off valves ____________– GAS IS BURNING INSIDE THE TORCH AND WILL DAMAGE THE TORCH. Remedy the cause, inspect system, relight torch. g. Flash Arresters will ________ flame at the torch if installed between the torch and the hoses.
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44. Shutting Off Torch
a. Turn off torch _____________ valve first – Acetylene second. b. Close tank or manifold ____________. c. Open torch _______________ valve, bleed all gas from hose and regulator. d. Back out Acetylene pressure ______________ ____________at regulator. Close torch Acetylene valve. e. Open torch _____________ valve, bleed all gas from hose and regulator. f. Back out Oxygen pressure _________________ ___________ at regulator. Close torch Oxygen valve. g. Place torch on ____________. Clean up work area. Cool metal _______________ placing it in scrap bin.
11
Oxy-Acetylene Welding (OAW) 1. Welding Terms
a. Fusing; Heating two or more metals or nonmetals until they become ______, then allowing them to ____ and solidify. b. Fusion Welding; Welding that uses fusion or _______________ metals to make a weld. c. Oxy-acetylene Welding; A welding process that burns _______ and ___________________in a flame to create a heat source for fusion. d. Weld pool or puddle; Molten area during a ___________process. e. Backfire; Popping noise when the flame suddenly burns back into the tip but ______ ______. (explosion at the tip) d. Flashback; When the flame burns back _________ the tip, torch, hose, or regulators. (pop - followed by a shrill squealing or hissing sound)
2. Oxy-Acetylene Welding Process
a. Flame creates heat source to __________base metals. b. Creates _____ gas which shields liquefied metal from atmospheric contaminates. (_________, __________) c. Filler rod can be added to help join base metals and __________ weld joint strength. d. Manual welding process. Requires skill to form, maintain, and move a uniform _________ ___________ of molten metal along the weld. e. Used primarily for welding _______ gage steel. _________ work.
3. Oxy-Acetylene Welding Equipment •
Oxygen Cylinder
•
Acetylene Cylinder
•
Oxygen Regulator& Gages
•
Acetylene Regulator& Gages
•
Oxygen Hose
•
Acetylene Hose
•
Flash Back Arresters
•
Torch Handle (body)
•
Torch Tip
1
4. Personal Protection
a. Safety glasses; ANSI Z87.1 b. Clothing; Fire resistant materials, Leather, ______ – no synthetics like polyester. No turned up or frayed cuffs. Long sleeves and collars buttoned. c. Boots; Leather, steel toes, slip on best, no exposed __________. d. Gloves; Gauntlet, flexible but _______ enough for heat protection. e. Goggles, Shield; #3 – 5 shaded lens. (ultraviolet/ infrared light) f. Ear protection; muffs, plugs, (out of position welding/ cutting) g. Never have a pressurized butane___________ on your person while in the shop.
5. Oxygen Gas
a. (O2); colorless, odorless, tasteless, ________, non-flammable, gas. b. Welding grade about ________ pure. c. Most common method- obtained from _______________. (21% O2) d. Purified & cooled under high pressure until ______________. e. Separated from Nitrogen (-320º F), O2 (-296º F) by ____________. f. Supports combustion when mixed with other _____________. g. Never use to blow off _________ or mix ________ with oxygen.
6. Acetylene Gas
a. (C2H2); Equal parts______________ & Hydrogen. b. Colorless gas, pungent odor due to _____________. c. Made by mixing Calcium Carbide &_____________. d. Dissociates (separates) under ______________& releases heat. e. Highly unstable over 15 psi. – can cause __________________. f. Highly explosive when mixed w/ ______________. g. Forms explosive compounds when mixed with ____________ or _____________.
7. Oxygen Cylinders
a. Seamless drawn steel tube, minimum ___” thick, tested to 3360 psi. b. Cylinder sized by _______ capacity. c. __________cu.ft. large size, 122cu.ft. medium, 80cu.ft. small. d. Filled to 2200 psi @ ______º F. (pressure changes w/ temperature) e. Fitted w/ high pressure, ___________ seat valve – open completely. f. Right-hand male outlet fitting, w/ __________ _______ __________. g. Protective cap screws to ____________ _______. (ring is pressed fit - not welded) h. Bottles can _________ if dropped, struck, punctured, arced across.
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8. Acetylene Cylinders a. Welded cylinders w/safety fuse plugs - release contents at _____ ºF. b. Filled w/ porous ____________ material. (Calcium Silicate 8-10%). c. Calcium Silicate saturated w/ _________. (42% of internal volume) d. Acetylene dissolves in Acetone and is safely held above _____ psi. (36% of internal volume) e. Acetone is __________, never lay Acetylene cylinders down or draw off more than _____ the volume of the cylinder. Keep cylinder upright for_____ hrs. before use. f. Possible to draw acetylene __________ than acetone can release it. Cylinder gage may read zero. Pressure will return if left alone. g. Cylinder sized by cu.ft. capacity. ____cu.ft. common size @____ psi. h. Fitted with valve (some have ________ wrench) and safety cap. i. No relief valve; __________% reserve in tank. j. Open valve ______ to ______ turn or until _____ ______ ________. k. Left-hand_________ outlet fitting.
9. Cylinder Handling
a. Handle, store, transport in ________________ position. b. Use cylinder hand-truck w/ ____________ to transport. c. Replace cylinder caps, don’t lift bottles by________. d. Open & close valves by hand – no__________. e. Never roll cylinders ______________. f. Store Oxygen & Acetylene cylinders separately, ______ft. minimum or 5’ wall w/__________ burn. g. Secure cylinders with ________ or ________ at all times.
10. Regulator Function
a. Control the amount of gas flow from the ________________. b. Maintain the required _______________ pressure. c. Produce _________ flow of gas under _____________ cylinder pressures.
11. Single- Stage Regulators
a. Cheapest; gas flows directly to ______ _____________ chamber and is controlled by diaphragm and adjusting screw. (right-hand threads) b. Must be continuously adjusted as cylinder pressure ___________. c. Adjusting screw must be ____________ before opening cylinder extreme pressure can blow out screw or damage regulator. d. Unscrewing pressure adjustment screw _____________gas flow. e. Use w/ ____________ ___________.
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12. Two - Stage Regulators
a. Gas flows from cylinder into high pressure ________________. b. High pressure controlled by __________ & ________________. c. Gas flows into __________ chamber, controlled by adjusting screw which pushes on larger stainless steel diaphragm. d. Unscrewing pressure adjustment screw ___________ gas flow. e. Use w/ ____________system.
(Picture of Oxygen Regulator)
13. Oxygen Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to _____________ psi. b. Working pressure gage; graduated from _____________ psi. c. Female inlet fitting to cylinder is ___________________ thread. d. Never use________ on fittings.
14. Acetylene Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to __________ psi. b. Working pressure gage; graduated from ___________psi. w/ red warning color above _________ psi. c. Male inlet fitting to cylinder is ___________with a left-hand thread. d. Never use _______ on fittings.
15. Flashback Arrestors & Check Valves
a. Installed between hoses and torch (_______ mounted) or hoses and regulators (regulator mounted). Install in proper _______________. b. Flash Arrester - Has built in _________ __________ that prevents reverse gas flow and a _________ barrier that prevents a flame from moving from the torch back through the hose and regulators. c. Check valves - prevents reverse gas flow _________. May not stop Flashback d. Check valves close when the pressure on the torch side _______ the pressure from the regulator. (Flashback) e. Check valves may need to be________ if a flashback has occurred. f. Never use ______ on connections.
Flashback Arrester
16. Oxygen & Acetylene Hoses
a. Oxygen hose is commonly green in the United States. b. Acetylene hose is commonly red. c. Rubber / Nylon. Different types for the type of fuel gas. d. Oxygen fittings are right-hand thread, Acetylene fittings are lefthand thread with a notch in the middle of the fitting. e. New hose is dusted w/ talcum powder and should be blown out w/ dry, clean, compressed air. Never use oil on connections. f. Use proper care for hoses. Flame resistant, can be burned through and cut. 4
17. Torch Function
a. Control and mix the oxygen and fuel gas within the ________ _______________ of the torch. b. Direct the_____________ to the work area.
18. Torch Parts
•
Welding Tip
•
Mixing Chamber
•
Torch Body (Barrel)
•
Valves
•
Oxygen & Fuel gas Connections
19. Torch Types
a. Positive Pressure; (also called an _________ ________________ or medium pressure torch) b. Injector; (also called a ______ _______________torch)
20. Positive Pressure Torches
a. Most common type. b. Feeds oxygen and fuel into mixing chamber at relatively _________ pressures. c. Mixing chambers may be in _________ _____________ or tip. d. Fuel gas pressures must be above __________psi. to function.
21. Injector Torches
a. Forces high pressure Oxygen through ____________, which draws low pressure fuel gas into the mixing chamber. b. Fuel gas pressure can be as low as _______psi. (Acetylene Generator) c. Draws more ________________out of cylinders. 5
22. Torch Valves & Connectors
a. Valves may be located on either____________ of the torch body. b. ________valves; use finger force only – never a wrench. c. Over-tightening valves will damage _______ ________ and cause it to leak. d. Oxygen connector is ________-hand thread. e. Acetylene connector is __________-hand thread. f. Oxy or Fuel - usually marked on _________________at torch body. g. Never use ________on valves or connections.
23. Types of Tips
a. Welding. b. Cutting. c. Heating (_______ ______).
24. Welding Tip Styles
a. One-piece tube-and-tip ________________. b. Two-piece tip; small torch tip threaded into _______________tube. c. Both are attached to the torch body and mixing chamber. d. In-tip mixers; torch tips with their own _______________ chamber.
25. Tip Sizes
a. Measured by the diameter of the ___________ at the end of the tip. b. Tip size affects the amount of _____ – not temperature of the flame. c. Must select correct _________size for the job. (thickness of metal) d. No standard tip size measurement____________________. e. Use_______________ system; 000 (smallest) to 15 (largest). f. Use ______ _______ number; 1 - 80, larger # = smaller orifice size.
26. Tip Selection
a. ________________ of metal. b. Working pressures must match ________ __________. Follow manufactures recommendation.
27. Tip Care
a. Keep tip __________. (slag, carbon, molten metal distorts flame and can cause backfire or flashback) b. Use correct size tip ___________. (don’t enlarge or elongate orifice) c. Do not remove ________ tips from tip tube or install _________ tip on hot tip tube. d. Do not___________ the torch or the tip. e. _________ ________ torch when not in use. 6
28. Equipment Set-up Procedure
a. Securely _____________or fasten cylinders in vertical position. b. Remove safety caps. c. Quickly crack open cylinder ________ to clear dirt. (stand to side) d. Connect _____________ by hand and tighten with a proper fitting wrench. (Attach Flashback arrester to regulator) e. Attach ________ to respective regulators. (purge regulator & hose) f. Attach check valve or ________________arrester to torch. g. Attach torch body & check valve/arrester to hoses by hand and _____________ with proper fitting wrench. h. Select and install correct ________ _________. Align w/ valves. i. _________-tighten only; tightening with a wrench will damage seal and allow connection to leak. j. Pressurize system following proper procedures and check all connections and fittings for leaks using ____________ water or commercial leak test solution. (check valve stem at the cylinder) k. Never test for leaks with___________ or heat source.
29. Pressurizing System & Lighting Torch
a. Check that torch valves are ____________ and pressure adjustment screws on the regulators are backed ________. b. ___________ crack open cylinder valves. Open Oxygen ______________ - Acetylene ____________ turn. Always stand to the side of the gages – never in front of them. c. Set working pressures separately. Open torch valve. Adjust pressure adjustment screw at regulator to desired pressure. ______ torch valve. Always purge gas lines – 3 to 4 seconds per 25’ of hose before lighting torch. d. To light torch, open acetylene valve first, ________ turn. Light torch facing ______________with sparklighter held approximately 1” from torch tip. e. Adjust acetylene flame until ________________almost disappears. f. Open torch _________ _________ and adjust to desired flame type.
30. Welding Flame
a. Reducing or Carburizing; ___________ acetylene. b. Neutral; ___________ amounts of gases. c. Oxidizing; excess _____________. d. Flame affected by too little or too much ___________ __________. e. Inner cone releases over ____ of heat. f. Too small or large flame; can cause tip to ________ ____________, backfire, poor weld quality. 7
31. Reducing or Carburizing Flame
a. Excess acetylene, cooler, soft flame ºF b. Three flames; inner cone, intermediate or secondary cone, (____________ ____________) outer flame. c. Used for soldering & ___________ applications. d. Introduces excess _____________into weld puddle – causes hard, brittle weld. Not used for fusion welding on mild steel.
32. Neutral Flame
a. _________________ parts of oxygen & acetylene. b. Two flames; well defined _________ __________ & near colorless outer flame. c. Soft sound, burns @ approximately ____________º F. d. Chemically neutral. Protects puddle w/ ____________ by product. e. Used for________________ welding operations.
33. Oxidizing Flame
a. ______________oxygen. b. Two flames; smaller, sharp - pointed inner cone & bright ________, smaller, flared - outer flame. c. Harsh, hissing sound; burns @ approximately ___________º F. d. Used for some _____________ operations. e. Excess oxygen forms oxides in weld puddle causing brittleness, weakness. f. Tendency to leave _________________ in weld pool (harsh flame) and burn steel.
34. Holding the Torch
a. Over-Hand or________ grip; balance the torch in hand w/ light grip. b. Place hoses over shoulder to reduce weight. Do not wrap around ___________. c. Support ______________; get comfortable.
35. Torch Manipulation
a. Forehand; welding flame pointed in ________of travel in downward angle. Filler metal dipped in front edge of puddle ahead of the flame. Flame pushes puddle. Used on thinner metals.
b. Backhand; welding flame pointed _______________the direction of travel in a downward angle. Filler material dipped between flame and puddle. Flame pulls puddle. Used on thicker material and cover pass. 8
36. Torch Movement Patterns
a. Circular; approx. 1/4” dia. w/ _________” advance per circle. b. Semicircular; approx. 1/4” wide w/ ___” advance per semicircle. c. Weave; approx. 1/4” wide w/ ____” advance per side movement.
37. Work Angle
a. Angle of torch tip; measured ________________ to travel direction. b. Changes w/ type and______________ of joint. (90 to surface for flat position bead) c. Use to control puddle &___________ distribution.
38. Travel Angle
a. Angle of torch tip, measured ______________ to direction of travel. b. Changes w/_________ and position of joint. (0-45 to surface for flat position bead) c. Use to control _____________ & heat distribution.
39. Travel Speed
a. Speed at which torch moves in_____________ direction. b. Constant speed produces even width, __________________ bead w/ consistent penetration. c. Give heat and puddle time to stay _____________ of flame.
40. Torch Height
a. Distance from the tip of the neutral flame _________ to the puddle surface. b. Keep approximately _____” from molten pool. (changes w/ tip size) c. Do not allow cone to________ into puddle. (Backfire, dirty tip, weld impurities, depressions in weld bead.
41. Filler Metal
a. Match filler metal properties to__________ metal properties. b. Cut length rods, ___” standard length, 5-10 lb. tubes/ 50 lb. cartons. c. Diameters; 1/16” – 3/16” in ______” graduations, 1/4”, 5/16”, 3/8”. d. Classified by American Welding Society (__________). e. RG 45, RG60, RG65. R =__________. G = __________Welding. 45 = Minimum _______________Strength (lbs.) X 10,000. (ex. RG45 = 45,000 lbs.) f. Use manufactures recommendations for tip size, _______ diameter, working pressures, per metal thickness. 9
42. Manipulating Filler Metal
a. Use correct _________________; too large cools puddle – too small will not fill puddle. b. Slant filler metal away from tip but at approximately the__________ angle as the tip. c. Create and maintain full size puddle in base metal______________ dipping filler rod. (Stay off edges of material – they will over-heat) d. Keep filler ________ to puddle when not dipping, keep it ______ but not molten. Use straight up and down dipping motion. e. Forehand technique – Flat, Vertical, Over-head positions; dip slightly towards the____________ edge of the puddle. Forehand technique – Horizontal position; dip towards _____ _____ edge of puddle f. Allow puddle to melt __________ – not flame. h. Melt rod away from base metal if rod becomes stuck – don’t _____. i. Obtain smooth and _________________ rhythm. j. Bend over__________ end of rod for safety. k. Weld small lengths of ___________ _________ together. l. Use to set _________ opening.
43. Backfire
a. Popping noise when the flame suddenly burns back into the tip but _______ _____. (explosion at the tip) b. Can be caused by operating torch at too________ pressure for tip. c. Touching the welding _________ to the work or puddle. d. _______________ the tip. e. __________________ in the tip. f. After Backfire: Shut off________ valves – GAS IS STILL FLOWING, remedy the cause, relight torch
43. Flashback
a. When the flame burns back inside the tip, torch, hose, or regulators and ________ ______ go out. (pop - followed by a shrill squealing or hissing sound) b. Generally indicates something is wrong with equipment or _______. c. Touching tip to the work or puddle - __________________ in the tip. d. ___________________the tip. e. Wrong gas_______________ pressure. f. After Flashback: Shut off valves ____________– GAS IS BURNING INSIDE THE TORCH AND WILL DAMAGE THE TORCH. Remedy the cause, inspect system, relight torch. g. Flash Arresters will ________ flame at the torch if installed between the torch and the hoses.
10
44. Shutting Off Torch
a. Turn off torch _____________ valve first – Acetylene second. b. Close tank or manifold ____________. c. Open torch _______________ valve, bleed all gas from hose and regulator. d. Back out Acetylene pressure ______________ ____________at regulator. Close torch Acetylene valve. e. Open torch _____________ valve, bleed all gas from hose and regulator. f. Back out Oxygen pressure _________________ ___________ at regulator. Close torch Oxygen valve. g. Place torch on ____________. Clean up work area. Cool metal _______________ placing it in scrap bin.
11
a. Fusing; Heating two or more metals or nonmetals until they become ______, then allowing them to ____ and solidify. b. Fusion Welding; Welding that uses fusion or _______________ metals to make a weld. c. Oxy-acetylene Welding; A welding process that burns _______ and ___________________in a flame to create a heat source for fusion. d. Weld pool or puddle; Molten area during a ___________process. e. Backfire; Popping noise when the flame suddenly burns back into the tip but ______ ______. (explosion at the tip) d. Flashback; When the flame burns back _________ the tip, torch, hose, or regulators. (pop - followed by a shrill squealing or hissing sound)
2. Oxy-Acetylene Welding Process
a. Flame creates heat source to __________base metals. b. Creates _____ gas which shields liquefied metal from atmospheric contaminates. (_________, __________) c. Filler rod can be added to help join base metals and __________ weld joint strength. d. Manual welding process. Requires skill to form, maintain, and move a uniform _________ ___________ of molten metal along the weld. e. Used primarily for welding _______ gage steel. _________ work.
3. Oxy-Acetylene Welding Equipment •
Oxygen Cylinder
•
Acetylene Cylinder
•
Oxygen Regulator& Gages
•
Acetylene Regulator& Gages
•
Oxygen Hose
•
Acetylene Hose
•
Flash Back Arresters
•
Torch Handle (body)
•
Torch Tip
1
4. Personal Protection
a. Safety glasses; ANSI Z87.1 b. Clothing; Fire resistant materials, Leather, ______ – no synthetics like polyester. No turned up or frayed cuffs. Long sleeves and collars buttoned. c. Boots; Leather, steel toes, slip on best, no exposed __________. d. Gloves; Gauntlet, flexible but _______ enough for heat protection. e. Goggles, Shield; #3 – 5 shaded lens. (ultraviolet/ infrared light) f. Ear protection; muffs, plugs, (out of position welding/ cutting) g. Never have a pressurized butane___________ on your person while in the shop.
5. Oxygen Gas
a. (O2); colorless, odorless, tasteless, ________, non-flammable, gas. b. Welding grade about ________ pure. c. Most common method- obtained from _______________. (21% O2) d. Purified & cooled under high pressure until ______________. e. Separated from Nitrogen (-320º F), O2 (-296º F) by ____________. f. Supports combustion when mixed with other _____________. g. Never use to blow off _________ or mix ________ with oxygen.
6. Acetylene Gas
a. (C2H2); Equal parts______________ & Hydrogen. b. Colorless gas, pungent odor due to _____________. c. Made by mixing Calcium Carbide &_____________. d. Dissociates (separates) under ______________& releases heat. e. Highly unstable over 15 psi. – can cause __________________. f. Highly explosive when mixed w/ ______________. g. Forms explosive compounds when mixed with ____________ or _____________.
7. Oxygen Cylinders
a. Seamless drawn steel tube, minimum ___” thick, tested to 3360 psi. b. Cylinder sized by _______ capacity. c. __________cu.ft. large size, 122cu.ft. medium, 80cu.ft. small. d. Filled to 2200 psi @ ______º F. (pressure changes w/ temperature) e. Fitted w/ high pressure, ___________ seat valve – open completely. f. Right-hand male outlet fitting, w/ __________ _______ __________. g. Protective cap screws to ____________ _______. (ring is pressed fit - not welded) h. Bottles can _________ if dropped, struck, punctured, arced across.
2
8. Acetylene Cylinders a. Welded cylinders w/safety fuse plugs - release contents at _____ ºF. b. Filled w/ porous ____________ material. (Calcium Silicate 8-10%). c. Calcium Silicate saturated w/ _________. (42% of internal volume) d. Acetylene dissolves in Acetone and is safely held above _____ psi. (36% of internal volume) e. Acetone is __________, never lay Acetylene cylinders down or draw off more than _____ the volume of the cylinder. Keep cylinder upright for_____ hrs. before use. f. Possible to draw acetylene __________ than acetone can release it. Cylinder gage may read zero. Pressure will return if left alone. g. Cylinder sized by cu.ft. capacity. ____cu.ft. common size @____ psi. h. Fitted with valve (some have ________ wrench) and safety cap. i. No relief valve; __________% reserve in tank. j. Open valve ______ to ______ turn or until _____ ______ ________. k. Left-hand_________ outlet fitting.
9. Cylinder Handling
a. Handle, store, transport in ________________ position. b. Use cylinder hand-truck w/ ____________ to transport. c. Replace cylinder caps, don’t lift bottles by________. d. Open & close valves by hand – no__________. e. Never roll cylinders ______________. f. Store Oxygen & Acetylene cylinders separately, ______ft. minimum or 5’ wall w/__________ burn. g. Secure cylinders with ________ or ________ at all times.
10. Regulator Function
a. Control the amount of gas flow from the ________________. b. Maintain the required _______________ pressure. c. Produce _________ flow of gas under _____________ cylinder pressures.
11. Single- Stage Regulators
a. Cheapest; gas flows directly to ______ _____________ chamber and is controlled by diaphragm and adjusting screw. (right-hand threads) b. Must be continuously adjusted as cylinder pressure ___________. c. Adjusting screw must be ____________ before opening cylinder extreme pressure can blow out screw or damage regulator. d. Unscrewing pressure adjustment screw _____________gas flow. e. Use w/ ____________ ___________.
3
12. Two - Stage Regulators
a. Gas flows from cylinder into high pressure ________________. b. High pressure controlled by __________ & ________________. c. Gas flows into __________ chamber, controlled by adjusting screw which pushes on larger stainless steel diaphragm. d. Unscrewing pressure adjustment screw ___________ gas flow. e. Use w/ ____________system.
(Picture of Oxygen Regulator)
13. Oxygen Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to _____________ psi. b. Working pressure gage; graduated from _____________ psi. c. Female inlet fitting to cylinder is ___________________ thread. d. Never use________ on fittings.
14. Acetylene Regulator Gages & Fittings
a. Cylinder pressure gage; graduated up to __________ psi. b. Working pressure gage; graduated from ___________psi. w/ red warning color above _________ psi. c. Male inlet fitting to cylinder is ___________with a left-hand thread. d. Never use _______ on fittings.
15. Flashback Arrestors & Check Valves
a. Installed between hoses and torch (_______ mounted) or hoses and regulators (regulator mounted). Install in proper _______________. b. Flash Arrester - Has built in _________ __________ that prevents reverse gas flow and a _________ barrier that prevents a flame from moving from the torch back through the hose and regulators. c. Check valves - prevents reverse gas flow _________. May not stop Flashback d. Check valves close when the pressure on the torch side _______ the pressure from the regulator. (Flashback) e. Check valves may need to be________ if a flashback has occurred. f. Never use ______ on connections.
Flashback Arrester
16. Oxygen & Acetylene Hoses
a. Oxygen hose is commonly green in the United States. b. Acetylene hose is commonly red. c. Rubber / Nylon. Different types for the type of fuel gas. d. Oxygen fittings are right-hand thread, Acetylene fittings are lefthand thread with a notch in the middle of the fitting. e. New hose is dusted w/ talcum powder and should be blown out w/ dry, clean, compressed air. Never use oil on connections. f. Use proper care for hoses. Flame resistant, can be burned through and cut. 4
17. Torch Function
a. Control and mix the oxygen and fuel gas within the ________ _______________ of the torch. b. Direct the_____________ to the work area.
18. Torch Parts
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Welding Tip
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Mixing Chamber
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Torch Body (Barrel)
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Valves
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Oxygen & Fuel gas Connections
19. Torch Types
a. Positive Pressure; (also called an _________ ________________ or medium pressure torch) b. Injector; (also called a ______ _______________torch)
20. Positive Pressure Torches
a. Most common type. b. Feeds oxygen and fuel into mixing chamber at relatively _________ pressures. c. Mixing chambers may be in _________ _____________ or tip. d. Fuel gas pressures must be above __________psi. to function.
21. Injector Torches
a. Forces high pressure Oxygen through ____________, which draws low pressure fuel gas into the mixing chamber. b. Fuel gas pressure can be as low as _______psi. (Acetylene Generator) c. Draws more ________________out of cylinders. 5
22. Torch Valves & Connectors
a. Valves may be located on either____________ of the torch body. b. ________valves; use finger force only – never a wrench. c. Over-tightening valves will damage _______ ________ and cause it to leak. d. Oxygen connector is ________-hand thread. e. Acetylene connector is __________-hand thread. f. Oxy or Fuel - usually marked on _________________at torch body. g. Never use ________on valves or connections.
23. Types of Tips
a. Welding. b. Cutting. c. Heating (_______ ______).
24. Welding Tip Styles
a. One-piece tube-and-tip ________________. b. Two-piece tip; small torch tip threaded into _______________tube. c. Both are attached to the torch body and mixing chamber. d. In-tip mixers; torch tips with their own _______________ chamber.
25. Tip Sizes
a. Measured by the diameter of the ___________ at the end of the tip. b. Tip size affects the amount of _____ – not temperature of the flame. c. Must select correct _________size for the job. (thickness of metal) d. No standard tip size measurement____________________. e. Use_______________ system; 000 (smallest) to 15 (largest). f. Use ______ _______ number; 1 - 80, larger # = smaller orifice size.
26. Tip Selection
a. ________________ of metal. b. Working pressures must match ________ __________. Follow manufactures recommendation.
27. Tip Care
a. Keep tip __________. (slag, carbon, molten metal distorts flame and can cause backfire or flashback) b. Use correct size tip ___________. (don’t enlarge or elongate orifice) c. Do not remove ________ tips from tip tube or install _________ tip on hot tip tube. d. Do not___________ the torch or the tip. e. _________ ________ torch when not in use. 6
28. Equipment Set-up Procedure
a. Securely _____________or fasten cylinders in vertical position. b. Remove safety caps. c. Quickly crack open cylinder ________ to clear dirt. (stand to side) d. Connect _____________ by hand and tighten with a proper fitting wrench. (Attach Flashback arrester to regulator) e. Attach ________ to respective regulators. (purge regulator & hose) f. Attach check valve or ________________arrester to torch. g. Attach torch body & check valve/arrester to hoses by hand and _____________ with proper fitting wrench. h. Select and install correct ________ _________. Align w/ valves. i. _________-tighten only; tightening with a wrench will damage seal and allow connection to leak. j. Pressurize system following proper procedures and check all connections and fittings for leaks using ____________ water or commercial leak test solution. (check valve stem at the cylinder) k. Never test for leaks with___________ or heat source.
29. Pressurizing System & Lighting Torch
a. Check that torch valves are ____________ and pressure adjustment screws on the regulators are backed ________. b. ___________ crack open cylinder valves. Open Oxygen ______________ - Acetylene ____________ turn. Always stand to the side of the gages – never in front of them. c. Set working pressures separately. Open torch valve. Adjust pressure adjustment screw at regulator to desired pressure. ______ torch valve. Always purge gas lines – 3 to 4 seconds per 25’ of hose before lighting torch. d. To light torch, open acetylene valve first, ________ turn. Light torch facing ______________with sparklighter held approximately 1” from torch tip. e. Adjust acetylene flame until ________________almost disappears. f. Open torch _________ _________ and adjust to desired flame type.
30. Welding Flame
a. Reducing or Carburizing; ___________ acetylene. b. Neutral; ___________ amounts of gases. c. Oxidizing; excess _____________. d. Flame affected by too little or too much ___________ __________. e. Inner cone releases over ____ of heat. f. Too small or large flame; can cause tip to ________ ____________, backfire, poor weld quality. 7
31. Reducing or Carburizing Flame
a. Excess acetylene, cooler, soft flame ºF b. Three flames; inner cone, intermediate or secondary cone, (____________ ____________) outer flame. c. Used for soldering & ___________ applications. d. Introduces excess _____________into weld puddle – causes hard, brittle weld. Not used for fusion welding on mild steel.
32. Neutral Flame
a. _________________ parts of oxygen & acetylene. b. Two flames; well defined _________ __________ & near colorless outer flame. c. Soft sound, burns @ approximately ____________º F. d. Chemically neutral. Protects puddle w/ ____________ by product. e. Used for________________ welding operations.
33. Oxidizing Flame
a. ______________oxygen. b. Two flames; smaller, sharp - pointed inner cone & bright ________, smaller, flared - outer flame. c. Harsh, hissing sound; burns @ approximately ___________º F. d. Used for some _____________ operations. e. Excess oxygen forms oxides in weld puddle causing brittleness, weakness. f. Tendency to leave _________________ in weld pool (harsh flame) and burn steel.
34. Holding the Torch
a. Over-Hand or________ grip; balance the torch in hand w/ light grip. b. Place hoses over shoulder to reduce weight. Do not wrap around ___________. c. Support ______________; get comfortable.
35. Torch Manipulation
a. Forehand; welding flame pointed in ________of travel in downward angle. Filler metal dipped in front edge of puddle ahead of the flame. Flame pushes puddle. Used on thinner metals.
b. Backhand; welding flame pointed _______________the direction of travel in a downward angle. Filler material dipped between flame and puddle. Flame pulls puddle. Used on thicker material and cover pass. 8
36. Torch Movement Patterns
a. Circular; approx. 1/4” dia. w/ _________” advance per circle. b. Semicircular; approx. 1/4” wide w/ ___” advance per semicircle. c. Weave; approx. 1/4” wide w/ ____” advance per side movement.
37. Work Angle
a. Angle of torch tip; measured ________________ to travel direction. b. Changes w/ type and______________ of joint. (90 to surface for flat position bead) c. Use to control puddle &___________ distribution.
38. Travel Angle
a. Angle of torch tip, measured ______________ to direction of travel. b. Changes w/_________ and position of joint. (0-45 to surface for flat position bead) c. Use to control _____________ & heat distribution.
39. Travel Speed
a. Speed at which torch moves in_____________ direction. b. Constant speed produces even width, __________________ bead w/ consistent penetration. c. Give heat and puddle time to stay _____________ of flame.
40. Torch Height
a. Distance from the tip of the neutral flame _________ to the puddle surface. b. Keep approximately _____” from molten pool. (changes w/ tip size) c. Do not allow cone to________ into puddle. (Backfire, dirty tip, weld impurities, depressions in weld bead.
41. Filler Metal
a. Match filler metal properties to__________ metal properties. b. Cut length rods, ___” standard length, 5-10 lb. tubes/ 50 lb. cartons. c. Diameters; 1/16” – 3/16” in ______” graduations, 1/4”, 5/16”, 3/8”. d. Classified by American Welding Society (__________). e. RG 45, RG60, RG65. R =__________. G = __________Welding. 45 = Minimum _______________Strength (lbs.) X 10,000. (ex. RG45 = 45,000 lbs.) f. Use manufactures recommendations for tip size, _______ diameter, working pressures, per metal thickness. 9
42. Manipulating Filler Metal
a. Use correct _________________; too large cools puddle – too small will not fill puddle. b. Slant filler metal away from tip but at approximately the__________ angle as the tip. c. Create and maintain full size puddle in base metal______________ dipping filler rod. (Stay off edges of material – they will over-heat) d. Keep filler ________ to puddle when not dipping, keep it ______ but not molten. Use straight up and down dipping motion. e. Forehand technique – Flat, Vertical, Over-head positions; dip slightly towards the____________ edge of the puddle. Forehand technique – Horizontal position; dip towards _____ _____ edge of puddle f. Allow puddle to melt __________ – not flame. h. Melt rod away from base metal if rod becomes stuck – don’t _____. i. Obtain smooth and _________________ rhythm. j. Bend over__________ end of rod for safety. k. Weld small lengths of ___________ _________ together. l. Use to set _________ opening.
43. Backfire
a. Popping noise when the flame suddenly burns back into the tip but _______ _____. (explosion at the tip) b. Can be caused by operating torch at too________ pressure for tip. c. Touching the welding _________ to the work or puddle. d. _______________ the tip. e. __________________ in the tip. f. After Backfire: Shut off________ valves – GAS IS STILL FLOWING, remedy the cause, relight torch
43. Flashback
a. When the flame burns back inside the tip, torch, hose, or regulators and ________ ______ go out. (pop - followed by a shrill squealing or hissing sound) b. Generally indicates something is wrong with equipment or _______. c. Touching tip to the work or puddle - __________________ in the tip. d. ___________________the tip. e. Wrong gas_______________ pressure. f. After Flashback: Shut off valves ____________– GAS IS BURNING INSIDE THE TORCH AND WILL DAMAGE THE TORCH. Remedy the cause, inspect system, relight torch. g. Flash Arresters will ________ flame at the torch if installed between the torch and the hoses.
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44. Shutting Off Torch
a. Turn off torch _____________ valve first – Acetylene second. b. Close tank or manifold ____________. c. Open torch _______________ valve, bleed all gas from hose and regulator. d. Back out Acetylene pressure ______________ ____________at regulator. Close torch Acetylene valve. e. Open torch _____________ valve, bleed all gas from hose and regulator. f. Back out Oxygen pressure _________________ ___________ at regulator. Close torch Oxygen valve. g. Place torch on ____________. Clean up work area. Cool metal _______________ placing it in scrap bin.
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