In a pressure vessel containing multiple openings of various dimensions at different parts, stress concentration at the edges of the opening is maximum which becomes negligibly small beyond the area covered by ______________ times the hole diameter?

Related Mcqs:

1. In sieve plate column, holes are drilled or punched in sizes ranging from 2.5 to 12 mm (5 mm being widely used). The hole pitch is normally ______________ times the hole diameter to give the required hole area?

   A. 0.5 to 1.5
   B. 2.5 to 4.0
   C. 5 to 10
   D. 10 to 15

2. The design stress, which is more than the damaging stress, is the least unit stress that will render a member unfit for service before the end of its normal life. The design stress factor or factor of safety indicates the margin between design stress and the _______________ stress?

   A. Working
   B. Damaging
   C. Allowable
   D. None of these

3. A certain pressure vessel manufacturer avoids doing reinforcements calculations for openings by always providing a reinforcing pad extending upto double the diameter of the opening and of the same material and thickness as that of the shell wall. If area compensation is accepted as a code guideline, his approach leads to safe design____________________?

   A. Only if the opening is on spherical vessel
   B. Only if the opening is on a vertical cylindrical vessel
   C. Only if the opening is on a horizontal cylindrical vessel
   D. Irrespective of the shape of the vessel

4. A cylindrical pressure vessel of volume 6 πm3 has to be designed to withstand a maximum internal pressure of 10 atm. The allowable design stress of the material is 125N/mm2 and corrosion allowance is 2 mm. The thickness of the vessel for a length/diameter ratio of 3 will be close to________________?

   A. 5 mm
   B. 6 mm
   C. 8 mm
   D. 10 mm

5. Circumferential (hoop) stress in a thin cylindrical vessel under internal pressure is _____________ the longitudinal stress?

   A. Half
   B. Equal to
   C. Twice
   D. Eight times

6. In a cylindrical vessel subjected to internal pressure, the longitudinal stress ζL and the circumferential stress, ζn are related by___________________?

   A. ζh = 2 ζL
   B. ζh = ζL
   C. ζh = ζL/2
   D. No relation exists

7. Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of ______________ times the paddle diameter?

   A. 0.1 to 0.25
   B. 0.3 to 0.5
   C. 0.5 to 0.6
   D. 0.65 to 0.80

8. The testing pressure of storage tanks and pressure vessels designed as per Indian standard codes should be about ______________ times the design pressure?

   A. 1.5 to 2
   B. 3 to 4
   C. 4 to 5
   D. > 5

9. The longitudinal stress induced in a thin walled cylindrical vessel under internal pressure is_________________?

   A. pd/2t
   B. pd/4t
   C. pd/t
   D. pd/8t

10. The circumferential (hoop) stress in a thin walled cylindrical vessel under internal pressure is______________________?

    A. pd/2t
    B. pd/4t
    C. pd/t
    D. pd/3t