Free Plant Design and Economics MCQs with Answers
803 Plant Design and Economics MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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803 questions · page 26 of 41
- A. None of these
- B. Reduction of discontinuity in shape at the junction
- C. Making the joint leak proof
- D. Preventing the local overstressing of the shell around the opening
Explanation: A large opening weakens the shell and creates concentrated stresses around its edge, so reinforcement is added to prevent local…
Correct answer: Preventing the local overstressing of the shell around the opening- A. All A, B. & C.
- B. Outside diameter
- C. Height
- D. Shape
Explanation: Wind force on a tall vessel is governed by its projected area, which depends on height and outside diameter, and by the shape-dependent…
Correct answer: All A, B. & C.- A. 1
- B. 2
- C. 3
- D. 3.5
Explanation: For liquid or petroleum-fuel storage tanks above 45 kL capacity, the recommended safe proportion is a height-to-diameter ratio below 1.
Correct answer: 1- A. Conical
- B. Flat
- C. Floating
- D. Fixed
Explanation: Floating roofs are used for volatile liquids such as naphtha because they move with the liquid level and greatly reduce the vapour space…
Correct answer: Floating- A. Temperature
- B. Noise
- C. Turbulence
- D. Pressure/pressure fluctuation
Explanation: A safety valve opens automatically when equipment pressure exceeds its set limit, preventing rupture or dangerous overpressure.
Correct answer: Pressure/pressure fluctuation506. Welded joint efficiency in the design of chemical process equipment is taken as_________________?
- A. 0.55
- B. 0.75
- C. 0.85
- D. 0.95
Explanation: A joint efficiency of 0.85 is the conventional design value used when full weld quality or radiographic credit is not assumed.
Correct answer: 0.85- A. Very accurate flow control
- B. High pressure throttling service
- C. Very large diameter pipes
- D. Smaller sizes of pipe
Explanation: Needle valves provide precise throttling through a small tapered opening, but their fine construction is impractical and expensive for…
Correct answer: Very large diameter pipes- A. No relation exists
- B. ζh = ζL
- C. ζh = ζL/2
- D. ζh = 2 ζL
Explanation: For a thin-walled cylindrical vessel, force balance on a longitudinal section gives hoop stress equal to twice the longitudinal stress.
Correct answer: ζh = 2 ζL- A. Head diameter
- B. None of these
- C. Overall length
- D. Shank diameter
Explanation: Rivets are conventionally identified by the nominal diameter of their shank, along with their length and head type when full specification…
Correct answer: Shank diameter- A. 1 to 1.5
- B. 2.5 to 3.5
- C. 4 to 5
- D. 6 to 8
Explanation: Tank spacing is commonly expressed relative to tank diameter, and a minimum separation of about one to one and a half diameters is used…
Correct answer: 1 to 1.5- A. pd/4t
- B. pd/2t
- C. pd/t
- D. pd/3t
Explanation: Balancing the internal pressure force with the resisting force in the two longitudinal walls gives the hoop stress, σh = pd/2t.
Correct answer: pd/2t- A. Radial
- B. Compressive
- C. Circumferential tensile
- D. Longitudinal
Explanation: Hoop stress acts tangentially around the circumference of the shell, so it is a circumferential tensile stress.
Correct answer: Circumferential tensile- A. Screwing
- B. Welding
- C. Brazing
- D. All A., B. and C.
Explanation: Pipe flanges may be attached using threaded connections, welding, or brazing, depending on pressure, temperature, material, and flange…
Correct answer: All A., B. and C.- A. Lug
- B. Saddle
- C. Skirt
- D. Guy wire
Explanation: Horizontal cylindrical pressure vessels are commonly supported on saddles, which distribute the vessel load over broad contact areas.
Correct answer: Saddle- A. Central dished section and straight flange section
- B. Corner torus section and central dished section
- C. Central dished section and corner torus section
- D. Straight flange section and corner torus section
Explanation: The crown radius describes the central dished portion of the head, while the knuckle radius describes the corner torus that joins the dish…
Correct answer: Central dished section and corner torus section- A. None of these
- B. Dikes
- C. Surge chamber
- D. Rupture diaphragm
Explanation: A rupture diaphragm or rupture disk placed with the relief valve provides a barrier against leakage of an extremely hazardous material…
Correct answer: Rupture diaphragm- A. Nozzle or rim
- B. Flared out
- C. Fluid in
- D. Ring plate
Explanation: A nozzle or rim-type reinforcement transfers the load around an opening efficiently and restores vessel strength and rigidity with…
Correct answer: Nozzle or rim- A. Axial tensile stress in the pipe
- B. Circumferential pipe-wall tension
- C. Forces exerted by static and dynamic action at bends
- D. Temperature stresses
Explanation: Internal pressure produces hoop stress approximately twice the longitudinal stress in a thin cylindrical pipe, so circumferential wall…
Correct answer: Circumferential pipe-wall tension- A. 10
- B. 20
- C. 30
- D. 5
Explanation: For equipment walls thicker than about 30 mm, the extra thickness generally provides sufficient margin, so a separate corrosion allowance…
Correct answer: 30- A. pD/4t
- B. pD/2t
- C. pD/3t
- D. pD/6t
Explanation: For a thin cylindrical vessel, pressure produces a longitudinal stress of pD/(4t), while the circumferential stress is twice as large…
Correct answer: pD/4t