Page 171 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

Remove one end of the plug.

Ensure that the pipe is cooled before removing the plug.
Remove the sand by tapping the pipe gently with a hammer.
Calculate the length of material for bending

Objectives : At the end of this exercise you shall be able to
• calculate the required length of pipe for bending.

While bending a rod, sheet or pipe, due to the tensile force in the outer part of the material at the bending point,
the material is stretched. (Fig 1 and 2) Due to the force of pressure in the inner part of the material at the bending
point, the material is compressed.

The layer in the middle of the material is not subjected to either tension or compression.

This is called the neutral axis. (Fig 2)

For calculating the length of material for bending, the material length at the neutral axis is taken into account.
The length of the blank/ rod/pipe is the stretched length before bending. The stretched length is determined along
the neutral axis. For calculating the stretched/ elongated length of a rod/sheet/pipe while bending (Fig 3),
first add all straight portions together.

156

CITS : C G & M - Fitter - Exercise 86 - 88