THIN-WALLED PRESSURE VESSELS:
- A tank or pipe carrying a fluid or gas under a pressure
is subjected to tensile forces, which resists bursting,
develops across longitudinal and transverse directions.
SPHERICAL SHELLS:
Illustrative Problem:
A cylindrical steel pressure vessel 400 mm in diameter with
a wall thickness 0f 20 mm is subjected to an internal
pressure of 4.5 MPa. Determine;
a) the tangential stress in the steel
b) the longitudinal stress in the steel
c) to what value may the internal pressure be increased if
the stress in the steel is limited to 120 MPa
Solution:
Solution cont’d:
Solution cont’d:
Illustrative Problem:
Solution:
Solution cont’d:
Illustrative Problem:
Solution:
Problem Set No.01:
A water tank is 8 meters in diameter and 12 meters high. If
the tank is to be completely filled, determine the minimum
thickness of the tank plating if the stress is limited to
40 MPa.
Problem Set No.02:
A pipe carrying steam at 3.5 MPa has an outside diameter of
450-mm and a wall thickness of 10-mm. A gasket is inserted
between the flange at one end of the pipe and a flat plate
used to cap the end. How many 40-mm diameter bolts must be
used to hold the cap on if the allowable stress in the bolts
is 80 MPa of which 55 MPa is the initial stress. What
circumferential stress is developed in the pipe?
Problem Set No.03:
A spiral riveted pen stack 1.5-m in diameter is made of
steel plate 10-mm thick. The pitch of the spiral or helix is
3-m. The spiral seam is a single riveted lap joint
consisting of 20-mm diameter rivets. Using a shear stress of
70 MPa and bearing stress of 140 MPa, determine the spacing
of the rivets along the seam for a water pressure of
1.25 MPa. Neglecting the end thrust, what is the
circumferential stress.
Problem Set No.04:
The undersea research vehicle Alvin has a spherical pressure
hull 1 m radius and shell thickness of 30 mm. The pressure
hull is steel having a yield point of 700 MPa. Determine the
depth of submergence that would set up the yield-point
stress in the spherical shell. Consider sea water to have
specific weight of 10.27 kN per cubic meter