EQUIPMENT.
Describe how you fusion weld with oxy-acetylene welding equipment. - answerWith
oxy-acetylene fusion welding a high temperature flame is used to melt the metal
surfaces. The high temperature flame is achieved by combining two gases, oxygen
and acetylene. Any additional weld metal needed is added with hand held filler rod.
This process can be used for a wide range of materials, such as the welding of low
carbon steel sheet, small diameter pipes and cast iron. Oxy-acetylene can also be
used for the braze welding of steel and cast iron components which is extensively
used for maintenance applications.
Why is acetylene used with oxygen for fusion welding, instead of other fuel gases? -
answerAcetylene produces a flame temperature of ~3100 degree Celsius along with
oxygen. This high flame temperature makes acetylene a suitable choice for gas
welding steel. Welding: When burned in oxygen, acetylene produces a reducing
zone, which easily cleans the metal surface
Describe how acetylene is stored under pressure in cylinders. - answerThere is no
free gas present in acetylene cylinders. The gas is dissolved under pressure in
acetone. The effective cylinder pressure is 1600 kPa. The cylinders are painted
crimson (maroon) and have more square shoulders than oxygen cylinders. They
have left-hand threads at the regulator outlet and fusible plugs which will release
the gas and stop the cylinder exploding if the temperature reaches 100 C.
How are welders protected from harmful fumes from fluxes or metal coatings? -
answerAlways work in a well ventilated area. Extractors or respirators must be used
when there are dangerous fumes from welding.
For normal welding, the correct flame setting for fusion welding low carbon steel is -
answerNatural Flame - Equal amounts of oxygen and acetylene are supplied to the
welding tip.
Acetylene is stored under pressure in cylinders by dissolving it in - answerAcetone
The flame temperature of the oxy-acetylene flame is - answer3100°C
The welding defect caused by an incorrect torch angle is: - answerUndercut
Cracking of a weld is usually caused by - answerUsing unsuitable filler rods
What does the notch on the threaded connections of acetylene equipment mean? -
answerNotches indicates left hand thread.
List the three different sizes of oxygen and acetylene cylinders: - answerOxygen
cylinders - G 7.5kg
E 3.8kg
D 1.5kg