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Max. M

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SECOND SEMESTER M.TECH DEGREE EXAMINATION APRIL-MAY 2017
MECHANICAL ENGINEERING (MACHINE DESIGN)
OIME 6104 DESIGN OF PRESSURE VESSELS AND PIP'NG

arks : 60 Time : 3 Hours
Answer any two full questions from part A, 8 &6

PARTA

|) (a) Derive the relation for dilation in thin cylindrical and spherical pressure vessels (3 marks)

2)

3)

(b) Discuss the modes of failure in an ellipsoidal head to a cylindrical pressure vessel and
suggest suitable remedial steps (2 marks)

(c) Sketch and explain the stresses near the shell and end closure junction (4 marks)

Derive the expression for hoop stress and radial stress for thick walled cylinders subjected to
internal and external pressure and also obtain expression for radial displacement (9 marks)

(a) A thick cylinder of internal and external radii 300 mm and 500 mm respectively is
subjected to a gradually increasing internal pressure. Determine the value of pressure when
Material of the cylinder first commences to yield ii. Material yielded up to

middle of cylinder iii. | Cylinder material suffers complete collapse. Yield strength.
600 MN/m 2(6 marks)

(b) Sketch the hoop stress and radiat stress variation across the thickness of a built up cylinders

(i)a

4)

5)

6)

t the end of shrink fit (b) after applying internal pressure (3 marks)
PART B

A horizontal vessel 6 m long with hemispherical heads and 2 m diameter is subjected to 2.5
MPa pressure. It is supported on two saddles of 120° separated by 4 m. The vessel carries an
operating weight of 60 tonnes. Allowable stress (shell and support) 110 MPa. Design the
vessel and supports. Provide sketches (9 marks)

Design a tall vertical pressure vessel with skirt support for the following data:

Shell inside diameter: 1.8 m, shell overall height: 45m, skirt height: 3 m. Wind load: top
section- 4000 N/m(32-48m), middle section: 3000 N/m(16-32m), bottom section: 2000 N/m
(0-16m). Approximate Dead weight: section 2: 40 Tonnes, section 3: 70 Tonnes, bottom of
vessel: 115 Tonnes, base: 125 Tonnes, Design pressure: 2 MPa, Design temperature: 50°C,
Allowable stress (Shell, Skirt): 100 MPa (9 marks)

(a) Design reinforcement for the nozzle opening in a cylindrical shell for the following data:
Outside diameter of shell: 2.2 m, Max. Working pressure: 30 kgf/cm 2, shell wall thickness:

45 mm, Corrosion allowance 3 mm, Allowable stress (shell and nozzle) 1080 kgf/cm 2, outside
diameter of nozzle: 220 mm, nozzle wall thickness: 20 mm, length of nozzle above surface:
100 mm, No protrusion of nozzle inside the shell, allowable stress: 960 kgf/cm 2 (pad), Mili
tolerance is 12.5% (7 marks)

(b) 3riefly Explain the seismic loading distribution adopted for design of pressure vessels (2
marks)