14. Flexibility Analysis
1. Introduction
This write-up gives particulars of the flexibility analysis of piping.
2. Strength
The piping is subjected to internal pressure. Required thickness is provided to resist the internal pressure.
3.Stiffness
Suitable supports are provided to withstand the self weight and imposed loads.
4. Flexibility
The piping is subjected to thermal and occasional loads. Required flexible loops are provided to take care of the thermal loads.
5. Restraints
The piping is provided with required restraints to take care of the occasional loads, such as wing load and seismic load (earth-quake load).
6. Flexibility Check as per The Indian Boiler Regulations, 1950
The following equation shall be satisfied for a two anchor problem:
DY                                                                    <208
(L – U)2
Where,
D = nominal diameter of pipe, mm
Y = total thermal movement to be absorbed, mm
L = developed length of piping, m
U = shortest distance between the two anchors, m
7. Exercise
a) D = 100 mm
b) Y = 24 mm
c) L = 6.8 mm
d) U = 3.3 m
100x24                                                                 196<208
(6.8 – 3.3)2