28) Why the acetylene gas is avoided with copper pipe lines or fittings in oxy-acetylene welding set?

Copper is expensive

Copper is not flexible hose

Copper and acetylene form explosive

Copper pipe consumes more acetylene

Answer is:

Copper and acetylene form explosive

Excess use of flux

Due to excess of polished surface

Surface coated with oxides or oily material

Excessive heating of metal s surface

Answer is:

Shut off both valve quickly and dip in water

Shut off oxygen first and acetylene next

Shut off acetylene first, oxygen next and dip in water

Shut off both valve, oxygen first and dip in water

Answer is:

Explanation:

In oxy acetylene welding Acetylene gas is closed first to avoid back fire.

Destructive test

Non destructive test

Radio graphic test

Magnetic test

Answer is: