(Le/D) for fully open globe value may be around__________________?

Related Mcqs:

1. (Le/D) for fully open gate valves would be __________________?

   A. Much more than that for fully open globe valves
   B. Much less (say 2% than that for fully open globe valves)
   C. Around 7
   D. Both B. and C.

2. To keep the power input constant for a stirred vessel operating under fully developed turbulent flow conditions (constant power number), if the impeller diameter is increased by 20%, the impeller speed should be decreased by a factor of_________________?

   A. (1.2)3/2
   B. (1.2)3/5
   C. (1.2)2/3
   D. (1.2)5/3

3. Poisson’s ratio of a material is the ratio of unit lateral strain to the unit axial elongation within its elastic limit. The value of Poisson’s ratio for structural and pressure vessel steel may be taken as ____________________?

   A. 0.01
   B. 0.3
   C. 0.75
   D. 0.95

4. In case of a continuous distillation column, increase in reflux ratio may result in the______________?

   A. Lower fixed charges for the column
   B. Greater cost for the reboiler heat supply
   C. Greater cost for the condenser coolant
   D. All A., B. and C.

5. Excessive liquid gradient on a tray may result in the______________________?

   A. Maldistribution of gas
   B. Back trapping
   C. Gas blowing beneath cap skit
   D. All A., B. and C.

6. Baffles may be eliminated for_________________?

   A. Low viscosity liquids (< 200 poise)
   B. High viscosity liquids (> 600 poise)
   C. Large diameter tanks
   D. None of these

7. Typical static submergence for bubble cap plate column operating at atmospheric pressure may be around _________________?

   A. 2.5″
   B. 0.5″
   C. 5″
   D. 50% of the plate spacing

8. A shell may by termed as thin if its thickness to diameter ratio is less than 0.1. The factor which can be neglected in the calculation of membrane stresses is________________?

   A. Bending
   B. Deformation
   C. Shear
   D. Elongation

9. Angled baffles are preferred in the agitation tank to control the swirling action; if the viscosity of the liquid to be mixed is about 200 poise. However, the baffle may be completely eliminated for mixing liquids having viscosity above ____________________ poise?

   A. 300
   B. 600
   C. 1000
   D. 1500

10. For a cylindrical vessel of moderate height, the weld joint efficiency for joints parallel to the cylindrical axis is given as 1.0; while for joints along the girth (circumference) it is given as 0.8. In calculating the shell wall thickness using code formula for an internally pressurised cylindrical vessel, what value of weld joint efficiency should be used ?

    A. 0.8
    B. 0.9
    C. 1.0
    D. (0.8)0.5