Oxyacetylene Welding (OAW). The oxyacetylene welding process uses a combination of oxygen and acetylene gas to provide a high temperature flame. Oxyacetylene Welding (OAW). OAW is a manual process in which the welder must personally control the the torch movement and filler rod application
Oxyacetylene Welding (OAW)
The oxyacetylene welding process uses a combination of oxygen and acetylene gas to provide a high temperature flame.
Cylinders are regularly re-tested using hydrostatic (NDE) while in service
Cylinders are regularly chemically cleaned and annealed to relieve “jobsite” stresses created by handling .
Oxygen cylinders incorporate a thin metal “pressure safety disk” made from stainless steel and are designed to rupture prior to the cylinder becoming damaged by pressure.
The cylinder valve should always be handled carefully
Reduce high storage cylinder pressure to lower working pressure.
Most regulators have a gauge for cylinder pressure and working pressure.
Regulators are shut off when the adjusting screw is turn out completely.
Regulators maintain a constant torch pressure although cylinder pressure may vary
Regulator diaphragms are made of stainless steel
Gas entering the gauge fills a Bourdon tube
As pressure in the semicircular end increases it causes the free end of the tube to move outward.
This movement is transmitted through to a curved rack which engages a pinion gear on the pointer shaft ultimately showing pressure.
Hoses are are fabricated from rubber
Oxygen hoses are green in color and have right hand thread.
Acetylene hoses are red in color with left hand thread.
Left hand threads can be identified by a grove in the body of the nut and it may have “ACET” stamped on it
Check valves allow gas flow in one direction only
Flashback arrestors are designed to eliminate the possibility of an explosion at the cylinder.
Combination Check/ Flashback Valves can be placed at the torch or regulator.
Cylinders are filled with a very porous substance “monolithic filler” to help prevent large pockets of pure acetylene form forming
Cylinders have safety (Fuse) plugs in the top and bottom designed to melt at 212° F (100 °C)
Acetylene cylinder shut off valves should only be opened 1/4 to 1/2 turn
This will allow the cylinder to be closed quickly in case of fire.
Cylinder valve wrenches should be left in place on cylinders that do not have a hand wheel.
A small welding torch, with throttle valves located at the front end of the handle. Ideally suited to sheet metal welding. Can be fitted with cutting
attachment in place of the welding head shown. Welding torches of this general design are by far the most widely used. They will handle any oxyacetylene welding job, can be fitted with multiflame (Rosebud) heads for heating applications, and accommodate cutting attachments that will cut steel 6 in. thick.
A full-size oxygen cutting torch which has all valves located in its rear body. Another style of cutting torch, with oxygen valves located at the front end of its handle.
A: reinforced rubber
B: malleable iron
C: tempered aluminum
D: stainless steel
A: a left hand thread.
B: has a grove cut around it. C: may have ACET stamped on it.
D: All of the above.
A: 8 psig (55 kPa)
B: 15 psig (103 kPa)
C: 22 psig (152 kPa)
D: 30 psig (207 kPa)
A: A fusible plug
B: A check valve
C: A pressure safety disk
D: A spring loaded plug
A: 1/4”in (6.4 mm)
B: 3/8”in (9.5 mm)
C: 3/16”in (4.8 mm)
D: 7/32”in (5.6 mm)
A: a two way check valve.
B: flame screen.
C: flashback arrestor.
D: three way check valve.
A: A spring loaded plug
B: A pressure safety disk
C: A fusible plug
D: A check valve
A: calcium carbide
B: potassium carbonate
C: carbon dioxide
D: acetylene carbide