7)

8)

9)

PART C
(a) What is meant by pressure temperature rating? What are its classification under ASME
codes {2 marks)
(b) Sketch and explain classification of flanges based on facings (4 marks)
(c) Check whether schedule 40 pipe thickness is sufficient for 6" NB pipe subjected to an
external pressure of 30 bars at 400 '0. Mill tolerance is 12.5% and corrosion allowance is
1.6 mm, Factor of safety is 4. Spacing to diameter ratio is 30. If not, find minimum thickness
required (6 marks)
(a) Derive the minimum buckling pressure relation for a iong thin cylindrical shell under
external pressure (10 marks)
(b) Discuss effect of plastic yielding and initial non circularity on the buckling pressure (2
marks)
(a) Find the allowable displacement stress range fora pipe line operated ina 6 hour cycle every
24 hours. The life span of the plant is 20 years. The operating temp is 300'C and pipe material
is ASTM A 106 Gr. B. Allowable stress at room temperature is 138 MPa and at operating
temperature is 120 MPa. The stress range reduction factor is 0.7. (3 marks) (b) Explain quick
method of flexibility analysis of piping systems in case of atwo anchor point uniform size piping
system with no intermediate restraints (6 marks)
(c) Explain guided cantilever method in expansion loops to increase flexibility of piping systems
(3 marks)