DOMRAC 2

• Discipline

  Good Taste<|>Excellence
• This module was designed and written with you in mind. It is here to help you master Dom RAC.
• Lessons in the module

  • Lesson 1: Copper tube and tube cutter
  • Lesson 2: How to use flaring tools?
  • Lesson 3: How to swage and flare
  • Lesson 4: Soldering and bracing
  • Lesson 5: Operation of blow torch and oxyacetylene
• Tube cutter

  1. Cutting wheel<|>2. Groove<|>3. Roller<|>4. Tightening knob<|>5. Body<|>6. Blade reamer
• How to use the tube cutter

  1. Mark the desired length the tube

  2. Turn the tightening knob clockwise to move the cutting wheel forward to the marked tube, until a moderate pressure is applied to the tubing

  3. Insert the tube and align the marked tube to the groove, roller, and the cutting wheel

  4. Turn the tightening knob clockwise to move the cutting wheel forward to the marked tube, until a moderate pressure is applied to the tubing

  5. Revolve the tube cutter around the tubing, keep moderate pressure applied to the tubing by gradually turning the tightening knob

  6. Continue the process until the tubing is cut. Do not apply excessive pressure because it may break the cutter wheel and constrict the opening of the tubing
• Copper tube


  Soft copper<|>Hard drawn copper
• Swaging


  Joining of two pieces of copper tubing of the same diameter by expanding or stretching the end of the piece to fit over the other so the joint maybe soldered or brazed
• How to swage a tubing

  1. Cut the tube to right length

  2. File square end the tube and ream to remove all buffs, clean all residues and metal chips around the tube

  3. Place the tubing in a flare block to the corresponding diameter hole. The tube should extend above the block by amount equal to the outside diameter to the tube plus approximately 1/8 inch

  4. Place the correct size swaging punch in the tube and strike it with a hammer until the proper shape and length of the joint has been obtained

  5. Inspect the tubing after swaging to see if there are cracks or other defects. If any are seen or suspected, cut off the swage and start all over again
• Flaring


  When connecting tubing to fitting, it is common practice to flare the end of copper tube and used fittings design to grip the flare for vapor tight seal
• How to flare tubes

  1. Cut the tube into the right length

  2. File square end the tube and ream to remove all burrs, clean all residues and metal chips around the tube

  3. Slip the flare nut or wing off the flaring block and insert the tube in its corresponding diameter hole; tighten the wing nut to hold the tube

  4. Place the yoke on the block with the spinner over the end of the tube

  5. Turn the screw down firmly, continue to turn the screw until the flare is complete

  6. Remove the tubing from the block and inspect for defects. If there is one, cut off the flare and start all over again

  7. Assemble the joint
• Flaring


  1. File square end the tube and ream to remove all burrs, clean all residues and metal chips around the tube

  2. Cut the tube into the right length

  3. Slip the flare nut or wing off the flaring block and insert the tube in its corresponding diameter hole; tighten the wing nut to hold the tube

  4. Place the yoke on the block with the spinner over the end of the tube

  5. Turn the screw down firmly, continue to turn the screw until the flare is complete

  6. Remove the tubing from the block and inspect for defects. If there is one, cut off the flare and start all over again

  7. Assemble the joint
• Swaging


  The process of jointing two copper tubes into one piece by using nuts and coupling
• Flaring block is used to make a swage
• Flaring yoke is the partner of flaring block in making a perfect flare
• Purpose of swage and flare

  To join piping and tubing to fittings
• Flaring


  The process of expanding the end of a tube to form a flared end
• Swaging


  The process of joining two copper tubes into one piece using nuts and coupling
• Tool used for swaging

  • Swaging punch
• Tool used for flaring

  • Flaring block
• Heat sources for soldering and brazing

  • Gasoline blow torch
  • Butane torch
  • Oxy acetylene
• How to operate gasoline blow torch

  1. Invert the torch up-side down, remove the wing nut and fill the tank with gasoline 3/4 full

  2. Screw-in the wing nut tight enough to avoid leak, wipe any gasoline on torch

  3. Invert back to its original position; pump 15 strokes to pressurize the tank. Make sure the adjusting knob valve is closed. Observe any leak

  4. Open valve and let gasoline out of the burner, hold the burner by your palm to flow down the gasoline in the priming cap 3/4 full

  5. Place the torch on level surface work on cemented floor. Not wood Enflame the priming cap, to heat the burner

  6. When gasoline on the priming cap is nearly burned-out, open the valve slightly and the burner will produce flame

  7. To increase pressure pump 15 times more and regulate the control valve to increase flame volume. Observe the bluish flame

  8. To stop torch, turn the knob clockwise gently, and remove the air pressure by loosening the wing nut
• How to operate oxy acetylene apparatus

  1. Open the oxygen valve on the welding torch, open the oxygen valve regulator and adjust to the desired range (usually 40 psig)

  2. Close the oxygen valve on the welding torch

  3. Open the acetylene valve on the welding torch, open the acetylene valve regulator and adjust to the desired range (usually 6 psig)

  4. Close the acetylene valve on the welding torch

  5. Wear protective goggles to shield eyes from bright light

  6. Hold the torch in one hand. Slightly upon the fuel or acetylene valve on the torch welding spark light on the welding tip

  7. As the acetylene is burning keep opening the valve on the welding torch until the flame stops the smoke on the welding tip

  8. As the smoke stops slightly reduce the fuel supply to bring back the flame to the tip

  9. Open the oxygen valve on the welding torch until a bright neutral flame is reached flammable materials
• How to solder or braze tubing

  1. Clean the tubing; it must be free from burrs and metal chips

  2. Apply flux on the tube to be soldered; join the tubing

  3. Open the torch and apply heat on the joint; "reddish" in color means that you can apply your silver rod
• Silver rod is used to fill the 2 ends of tube to be brazed
• Lead is used in soldering
• Blow torch is used for brazing
• You can use sandpaper in cleaning the copper tubes
• If the copper tube is reddish in color, you can now start brazing
• Apply flux during brazing
• 6 psig is the desired range for acetylene
• 40 Psig is the desired range for oxygen
• Low Welding torch is not a part of blow torch
• Combustion Chamber is a part of oxy acetylene apparatus
• How to make a charging line (example project)

  1. Cut 3" x 1/4" diameter copper tube

  2. Clean the end tube free from burrs and metal chips

  3. Place a flare nut 1/4" diameter to copper tube; flare the tube

  4. Insert capillary tube 12 inches length, pinch the tube side

  5. Make hole on the tubing insert the other end of capillary tube

  6. Solder the joint
• The purpose of soldering and silver brazing is to join piping and tubing to fittings