MEFB 121
MANUFACTURING LAB
SEMESTER 2 (2013/2014)
GAS WELDING
LABARATORY REPORT
NAME : MOHD SHAFIZAN BIN MOHAMAD
STUDENT ID : ME092677
SECTION : GROUP B
SUBMISSON DATE : 31TH DISEMBER 2013
LECTURER NAME :EN ADZLY ANUAR
Introduction
Gas welding, also called oxy-fuel welding, is a system of welding
that uses one of various gases and oxygen to ignite a torch. Welding is
defined as the process of combining two materials, usually metal, by
heating them until both ends become molten. Filler materials are generally
added into this molten material, and the two ends are joined together and
allowed to cool, forming one solid piece.
Common gases used in gas welding include natural gas, propane, hydrogen,
MAPP gas, liquefied petroleum, propylene, and acetylene, with acetylene
being the most common. In many cases, one gas is not beneficial over
another, although in some situations a specific gas may be preferable. For
example, one gas may heat higher or lower than another, making it more
convenient to use with certain metals.
A variety of metals can be joined using gas welding techniques, although a
skilled torch operator is necessary in order to ensure a smooth weld. Not
all metals melt at the same temperature, so the welder must know how long
to heat varying types of material. There is also a certain level of skill
required for gas welding, to ensure that the weld is flawlessly done. Less
experienced welders may end up with a joint that is lumpy or uneven.
Type of flames:
The reaction of the oxyacetylene flame can be corrected by changing the
ratio of the volume of oxygen to acetylene.
Objective:
1. To know the types of welding joints.
2. To practicing the gas welding process.
3. To learn how to welding in a proper way
List of equipment/tools:
1 Gas cylinder(oxygen,acetylene)
2 Metal plate
3 Goggle,apron and safety shoe
4 Lighters
5 Tong pliers
6 Regulators
7 Cylinder valve
8 Cylinder cap
9 Flashback Arrester
10 Tip cleaner
11 Check valve
12 Torch
13 Torch tip
GAS CYLINDER COMPONENT
Safety precautions:
1. Only operate welding equipment you have been trained to use
2. Weld only in designated area
3. Avoid cylinders away from fire or expose heat
4. Always wear approved goggles and apron while doing the welding
process.
5. Never use acetylene working pressures in excess.
6. Remove all the flammable material
Procedure:
1. The pressure was checked and both gas valves were switched on. The
pressure reading was kept in the correct reading.
2. Acetylene gas was released in a small amount through the nozzle.
3. The flame was ignited using the friction on the torch. The flame was
then set as neutral flame. The process of gas welding was then
started.
4. With the inner cone of the flame, small circle was made at the
beginning point of the weld until a pool of molten metal formed.
5. By maintaining the molten pool with a series of circular movements,
the molten was then moved slowly to the other end.
6. If you move too fast across the work piece, you will lose the molten
pool. If you move too slowly across the work piece, you will burn
through the metal.
7. After the welding process was finished, the flame was then
distinguished by turning off the oxygen valve and acetylene valve..
8. The work piece was then picked up using tong pliers.
9. The workplace was then cleaned up.
Result:
Metal plate before process
Expected result after the process
Discussion:
1) The alignment errors occurs because of the technique to hold the
torch when welding flame is not proper
2) The ratio of oxygen and acetylene must be right
3) Staying too long at one spot will cause a hole .
4) The speed while move the tip is too fast that will effect the
penetration of the plate
Conclusion:
As conclusion that can be obtained from gas welding process is the
problem that occurs on the metal in neutral weld process. Students also
learned the correct way how to handle the equipment of gas welding and weld
with correct position. Other than that, from the activity students knows
type of different flame and type of gas welding.
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Figure 1: Gas Cylinders
