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Work Area

Work Area. Area Should be Clear and Free of Combustibles Area Should Be Well Ventilated Fire Extinguishers Should Be Available Area Should Be Free of Open Arcs or Flames Fireproof Blankets and/or Screens Are Suggested. Personnel Protection. Wear Approved Eye Protection

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Work Area

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  1. Work Area • Area Should be Clear and Free of Combustibles • Area Should Be Well Ventilated • Fire Extinguishers Should Be Available • Area Should Be Free of Open Arcs or Flames • Fireproof Blankets and/or Screens Are Suggested

  2. Personnel Protection • Wear Approved Eye Protection • Wear Flame Resistant Clothing • Wear Long Sleeves, Pocket Flaps and No Cuffs • Wear Approved Foot Gear • Wear Approved Hand Protection 2

  3. Proper Eye Protection 2A

  4. Proper Attire Industrial Quality Face Shield Hard Hat with Visor Turned to the Back Long Sleeve Shirt Gauntlet Leather Welding Gloves Pants without Cuffs Hightop Leather Boots (Steel Toes Recommended) 2B

  5. Oxygen Gas • Considered by Many as The Most Dangerous Gas • Know the Difference Between Oxygen and “Air” • Does Not Burn Itself, But Causes Other Materials To Burn More Vigorously • Heat of Recompression – Open Valve Slowly • Keep Away From Combustibles – Especially Oil • Do Not Saturate Clothing, etc. 3

  6. Combustion Theory EQUILIBRIUM EQUILIBRIUM 3A

  7. 9A Courtesy of CGA

  8. Oxygen Cylinder Valve Cap • High Pressure Cylinder – 2200 PSIG or Higher • Hollow, Seamless Steel Construction • Do Not Abuse Cylinder • Never Use For Other Than Intended Use • Report Any Damage to Supplier Contents Vigorously Supports Combustion High Pressure Hazard Oxygen Cylinder 4

  9. Oxygen Cylinder Valve CGA 540 Upper Valve Seat Lower Valve Seat • Compressed Gas Association (CGA) 540 • Stuck Valve – Valve Wrench Only/Call Supplier • High Pressure Safety - Do Not Hang Objects On Cylinder - Never Tamper With Valve Construction • Heat Source Can “Blow” Safety • Only Fully Open or Fully Closed • Report Any Leaking or Damaged Valve to Supplier To Oxygen Regulator Burst Disc Safety From Oxygen Cylinder 5

  10. Moving Oxygen or Other High Pressure Cylinders • Moving Cylinders Not In use: • Must Have Caps On • Do Not Lift – Roll on Bottom Edge • Use An Approved Carrier • Moving Cylinders That Are In Use (Regulators Attached) • Must Be In An Approved Carrier! 6

  11. Using Oxygen And Other High Pressure Cylinder Gases • Secure Cylinder In A Cart Or to Strong Permanent Structure • Do Not Use Near Flame, Flammables, Open Arc, Etc. • Use Only In An Upright Position • Use Only In A Well Ventilated Area • Always Inspect Cylinders For Damage • Valve Fully Opened or Closed 7

  12. Acetylene Gas • Calcium Carbide and Water • Unstable and Highly Flammable • Shock Sensitive • Lighter Than Air • Not to be used above 15 PSIG 8

  13. Acetylene Cylinder Is Unique • Not Hollow –Acetone in Porous Monolithic Filler Material • Should Only Be Used And Stored Upright • Has Fast Acting ValveOpen ½ - 1 Full Turn • Has “Fusible Plugs” (212o F) 9

  14. Acetylene Cylinder • Low Pressure – 250 PSIG @ 70o F • Thin Walls, Welded And Easily Damaged • Do Not Abuse – Can Explode If Abused • Do Not Use For Other Than The Intended Use • Never Use A Damaged Cylinder • Report Damages To Supplier • Do Not Attempt To Repair Leaks • Move Leaking cylinders Outside If Permitted 10

  15. Using Acetylene • Flammable – Keep Cylinders Away From Sources of Ignition or Heat • Shock Sensitive – May Decompose Violently • Limited Withdrawal Rate – “1/7th Rule” • Asphyxiation • 15 PSIG Maximum Use Pressure • Do Not Use Copper Piping 11

  16. Acetylene Fires • Most Fires Start In Valve Area – Check for Leaks • Fusible Metal Plugs Melt At 212o F • Flames – 5’ x 3’ • Very Difficult To Extinguish • Evacuate Area • Call Fire Department 12

  17. Alternate Fuels • Propane, Propylene, Etc. • Liquid Under Pressure • Heavier Than Air • Not Shock Sensitive • Can Be Used Up To Full Cylinder Pressure • Limited Withdrawal Rate – Dependent Upon Cylinder Size, % Full and Ambient Temperature 8A

  18. Liquid Petroleum Gas (LPG)Cylinder CGA 510 Valve • Hollow, Welded, Thin Wall Cylinder • Vapor Space Above Liquid • Use Only While Standing Up • Low Pressure Less Than 500 PSIG • Has Fast Acting Valve • Open ½ to 1 Full Turn • Valve Safety Relieves and Resets • Never Use A Damaged Cylinder Handwheel Handwheel Packing Nut PackingNut To LPG Regulator To LPG Regulator Valve Seat Valve Seat Valve Safety From LPG Cylinder From LPG Cylinder Valve Safety 9A

  19. Oxy/Fuel EquipmentEquipment Set Up • Secure Cylinders Before Removing Caps • “Crack” Oxygen Valve and Wipe Fuel Gas Valve With a Clean Cloth • Attach Regulators With Smooth Jawed Wrench • Back Out Adjusting Screws • Torch Valves Must Be Closed • Tighten Wrench Connections According To Manufacturers Instructions • Inspect and Test Equipment 13

  20. NEVER REMOVE THE VALVE PROTECTION CAP UNTIL CYLINDER IS SECURED PROPERLY 6A

  21. Secured Cylinders 13A

  22. Tighten all connections with smooth jaw wrench 13B

  23. Equipment Inspection • Look For Any Physical Damage • Look For Other Signs of Abuse or Improper Use • Look For Contamination – Oil, Dirt, etc. • Clean, Replace Or Repair Before Use 14

  24. Equipment Testing • Properly Tighten All Connections and Check To See If All Valves Are Closed • Stand To The side And Open Valves Slowly • Check For Leaks • Use Approved Bubble Solution or Pressure Test • Fix Any And All Leaks Before Proceeding 15

  25. Before Lighting Oxy/Fuel Gas Torches • Make Sure All Valves Are Closed And Regulator • Adjusting Screws Are Backed Out • Set Gas Pressures According to the Manufacturers Tip Charts • Open Then Close Each Gas Valve Independently To “Bleed” The System • Set Pressures “At Flow” 16

  26. Lighting An Oxy/Acetylene Torch • Slightly Open Acetylene Valve And Light With An Approved Device • Root Flame and Clear Smoke • Open Oxygen Valve And Set Flame To “Neutral” • Sharp, Defined Inner Cone • Never Light Torch With Both Oxygen And Acetylene Flowing 17

  27. Welding Flame Types Carburizing Flame Neutral Flame Oxidizing Flame 17A

  28. Lighting Equal Pressure Torches Using Alternate Fuel Gases • Open Torch Valves 1/8 to ¼ Turn • Ignite Fuel Gas With Approved Igniter and Adjust Flame • Introduce Oxygen And Adjust To The Desired Flame • “Star Pattern” or Sound • Tip Edge Touching Plate • It is Permissible To Light The Flame With Both Gases Flowing • Sometimes it is Necessary • Adjusting For Large or Heating Tips: • Increase Fuel Then Oxygen In Successive Steps 17B

  29. Lighting Low Pressure Injector Torches • It is Permissible To Light Torch With Both Gases Flowing • Use Special Purge Sequence To Clear The System of Mixed Gases • Open Fuel Gas Valve ½ to ¾ Turn • Open Oxygen Valve Slightly 1/8 to ¼ Turn • Ignite Flame With An Approved Igniter • Adjust To Desired Flame • Tip Edge Touching Plate • “Star Pattern” or Sound • Adjusting For Large or Heating Tips: • Increase Fuel Then Oxygen In Successive Steps 17C

  30. Turning Off An Oxy/Acetylene Torch • Proper Sequence Checks Integrity of Torch Valves • Close Oxygen Valve First • Close Acetylene Valve Second • If Acetylene Valve is Leaking a Small Flame Will Continue Burning • If Oxygen Valve is Leaking, Torch Will “Pop” as Acetylene Valve Is Closed • If Either Valve Is Leaking, Repair Before Further Use 18

  31. Turning Off Alternate Fuel Torches • Close Fuel Gas Valve First • Close Oxygen Valve Second • This Sequence Can Prevent The Operator From Being Burned • If Fuel Pressure is Great Enough - Check Valves At Initial Light Up By Turning Oxygen Off First 18A

  32. Shutting Down An Oxy/Fuel Torch • Overnight Or For An Extended Period of Time • Turn Off Torch • Close Cylinder Valves • Open Then Close Each Torch Valve Independently To Bleed Pressure • Back Regulator Adjusting Screw Out Until Loose • Store Hose and Equipment In a Clean Area Away From Potential Damage 19

  33. Check Valves and Flashback Arrestors CHECK VALVES • Are a one way valve that stops the reverse flow of gases FLASHBACK ARRESTORS • Have a special element, sintered metal filter, that can quench a flame • Generally also include a check valve 20

  34. Check Valves and Flashback Arrestors CHECK VALVES • Are the basic safety device • Prevents flash back accidents caused by “reverse flow” -Flashbacks can cause the most serious injuries • Check valves can fail because of “dirt” or other contamination -Keep equipment clean -Check them periodically 21

  35. Checkvalves HOW THEY WORK… REVERSE FLOW CORRECT FLOW 21A

  36. Check Valves and Flashback Arrestors FLASHBACK ARRESTORS • Flashback arrestors are the ultimate safety device • Usually have a check valve built into it, but, can also stop a flame -The check valve can fail because of contamination • The Heat sink element will absorb heat from a fire • The element should also be kept free of contamination and checked periodically 22

  37. Torch vs Regulator Flash Back Arrestors Where should Check Valves and Flashback Arrestors be Mounted The Golden Rule: “Mount them as close to the point of mixing as possible” Torch Mount • Gives the best and most protection • May be inconvenient for the operator • Cannot be used for “high flow” applications • Are subjected to more abuse 23

  38. Mount at the Torch vs Regulator-continued Regulator Mount • Should use check valves at the torch also • High flow types are physically too large for torch • Take less abuse because they are out of the way Do Not Use Both • Too much restriction • Could cause other safety problems 24

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