Types of Welding and Components of Gas Welding

1. Prepared By:
MayurSinh Rathod

2. • It is the process of joining two pieces of metal by the
application of heat or pressure or both and with or
without the use of filler metal.

4. • Welding process use a flame produced by burning a
mixture of oxygen and other fuel gas.
• Generally mixer of Oxygen and Hydrogen is used
for gas welding.
• Its called Oxy-Hydrogen Welding (OHW).

5. • Separate cylinders and a hose pipe from each
cylinder transports the gases to a torch as shown in
figure.

6.  Gas Pressure Regulators :
• One gauge indicates the pressure of the cylinder
and the other indicates the pressure in the supply
pipe to the torch.

7.  Welding Torch :
• Oxygen and acetylene are delivered to the torch
by separate hoses. Each gas is controlled by a
valve on the torch. The two gases mix in the torch
and after they are ignited burn at the nozzle.
Mixer Needle valves

8.  Filler Rods :
• Filler rods are used when additional filler metal is
required in the weld area they come in different
diameters.

9. • During the welding, heat from the flame is
concentrated on the joint edges until the metal melts.
• When the molten metal from both sides melts it
starts to fuse, when the metal cools down the two
parts become Permanently joined.

10.  Welding Flame :
Oxidizing
Excess oxygen (1.5:1)
(Brasses, Bronzes, copper)
Neutral
Equal Hydrogen acetylene &
oxygen (low carbon steel,
mild steels).
Reducing or Carburizing
Excess Hydrogen (0.9:1)
(Alloy steels and
aluminium alloys)
Inner Cone
Max. Temp.
Zone