Oxyfuel Gas Welding Cutting Welding n process in
- Slides: 47
Oxyfuel Gas Welding & Cutting
Welding n process in which metals are joined by heating them to the melting point and allowg the molten portions to flow together to form one
Processes confused with oxyfuel gas welding are: soldering - two metals not melted are joined by a third metal with a melting point below 840 deg F. n brazing - temps above 840 deg F. n
Torch n allows for controlling and mixing gases
Torch tip cleaner
Fuel Gasses used with O 2 acetylene n hydrogen n natural gas - (high hydrogen concentration – brittle welds) n propane n mapp – (methylacetylenepropadiene) (no special containers) n
Acetylene (most common) most unstable n 1/7 rule of contents - 1/7 on contents per hour n asbestus and porous concrete or balsa core filled with acetone liquid n
Acetylene (Cont. ) unstable acetylene is suspended in core n keep upright or acetone leaks out of core into cylinder n • open valve - get acetone n takes 7 hours for acetone to migrate back into core
Oxyfuel Flames n Carburizing - too much fuel gas adds carbon to the metal being welded
n Oxidizing - too much oxygen - burns the metal
n Neutral - the oxygen and fuel gases combine • oxygen burns up the carbon and the hydrogen in the fuel gas then releases only heat and harmless gases • flame temp is 5589 deg F.
Temps required to melt various metals
Quantity of heat determined by: type of gas n number of cubit feet per hour of gas burned n for more heat - larger orifice in torch tip along with more pressure to feed gas through n
Safety
Clothing and Eye protection
Acetylene more dangerous than oxygen? Makes things burn faster n oxygen must be consumed even under water n no O 2 in air tools n no blowing off clothes n 20 lb propane grill tanks in car trunks n
Oxygen cylinders
Cylinder safety read label - different colors for same gas n orange - O 2 or helium n red - O 2 or hydrogen n blue - O 2 or nitrous oxide n green n
Handling cylinders caps on when moving n secure to truck or wall n keep upright n
Preparing cylinders and hoses cylinder valve should be opened slightly to blow out dirt n high pressure valves - open all the way n gas valves - open 1/4 to 1/2 turn n
Preparing (Cont. ) n hose and cylinder valve threads • fuel gas - left hand • oxygen - right hand after assembly - test for leaks with soap suds n flash arrestor - stops reverse flow of gases and fire n • put at tank for torch?
Torch position, angle, motion
Joints
Plug Weld
Use additional filler rod where joint design and strength require
Positioning Tacking n Shrinkage n Wedge n
Turning on and shutting down the oxy acetylene welding outfit
Cutting
oxyfuel gas flame is used to heat the metal and an oxygen jet is used to perform the cutting
steel is combustible if sufficiently heated
burning metal helps to maintain the high temp
Process same flame as for welding n preheat flame about 1/16 to 1/8” from surface n heat a spot on steel to cherry red (1300 to 1400 deg F) n oxygen jet is turned on n torch moved n preheat flame kept operating during cutting action n
Cutting torch outfit differs from welding only in torch - separate passage for oxygen jet - center orifice n possibly a higher pressure O 2 regulator n oxygen cutting lever to control cutting operation n
indicator of a good cut no slag at bottom of cut n no bell-mouthed kurf n
Alignment of torch tip orifices with the kerf • one orifice should proceed and one should follow the cut
Usually no torch motion used - sometimes oscillating
torch movement should be away from operator so kerf can be seen
Speed
safety leggings n safety boots with high tops n no cuffs n
Cutting thin steel under 1/2” n smallest cutting tip available n point tip in direction the torch is traveling (15 -20 deg) from metal n
Metal over 1/2” thick n Tip perpendicular
Starting a cut - thicker material n cuts normally started at the edge of the work
Pipe small diameter - hold tip almost tangent to pipe n large diameter (over 4”) tip perpendicular n
Beveled edge on plate
Beveled end on pipe
Turning on and shutting down the oxy acetylene welding outfit
- Mig weld technique
- Sewing tools measuring tools
- Enamel hatchet instrument formula
- Cutting instruments in operative dentistry
- Chapter 18 basic chairside instruments and tray systems
- Flank wear
- Welding and cutting safety toolbox talk
- Bharat metal cutting gas properties
- Gas cutting set
- Lip angle of drill
- The process of chamfering the entrance of a drilled hole
- Five basic welding joints
- Tungsten inert gas welding
- Gas welding conclusion
- Gas welding conclusion
- Gas welding conclusion
- Tungsten inert gas welding
- Oxyacetylene torch
- Rosette weld vs plug weld
- Las busur adalah
- Welding disadvantages
- Gas welding safety tips
- Introduction of gas welding
- Types of welding
- Oxy acetylene gas flame
- Ideal gas vs perfect gas
- Imaginary gas
- Gas law
- Computational fluid dynamics
- Reason of bhopal gas tragedy
- Gas leaked in bhopal gas tragedy
- Gas reale e gas ideale
- Flue gas desulfurisation gas filter
- Poisonous gas leaked in bhopal gas tragedy
- Difference between ideal gas and real gas
- Kinetika kimia
- Gas exchange key events in gas exchange
- Selection of welding process
- Seam weld
- Double u
- Oaw welding process
- Miab welding process
- Fcaw-ss welding
- Flux definition in welding
- Rutile based flux definition
- Percussion welding process
- Fast fill electrode
- Resistance seam welding process