DAILY EXAM 2 (OPEN) Note: Encircle the letter of only one answer which you think is most appropriate.
1.
A standard standard seamless, ASME F & D head (Torispherical) is is used for the following conditions: Material of Construction Design Pressure Design temp Inside Crown Radius Minimum available thk.
= = =
SA 515 gr 60 = 250 psig 580ºF 72 inches = 1.14 inches
Category B welds are spot radiographed. Corrosion allowance = 0.125 inches Allowable stress at design temp. = 16400 psig Your assessment is: a. b. c. d. 2.
A pressure vessel is to be constructed with MDMT = +20°F, M.O.C = SA 515 gr 60 . Impact testing not performed. Required shell thickness thickness = ¾ , dished head thk. = 1-⅛ " ( torisph. head). Determine if this material is suitable for: a. b. c. d.
3.
The head does not meet code requirements. The head meets the code requirements. Suitability would depend on decision of Pressure Vessel inspector. Data are not adequate.
Both shell as well as dished head Suitable for head but not for shell Suitable for shell only but not for head Not suitable for either
For a certain pressure vessel with sp spot ot radiography, and all Welds type 1, Vessel diameter = 72 inch I.D. M.O. C = SA 515 gr 70 Design temp. = 600°F Allowable stress at design temp. = 20,000 psi If shell thk. = 5/8" and C. A = 1/8", the MAWP for the shell will be: a. b. c. d.
234 psi 168 psi 256 psi None of the above
DAILY EXAM 2 (OPEN) 4.
A pressure vessel (M.O.C. 516 gr. 70) has external jacket spread over 72 inches length of the shell. (Jacket pressure = 180 psi, Jacket temperature = 350°F) the vessel OD = 36 inches. Shell thickness= 0.5 inch, C.A. = Nil. Decide which of the following are applicable in the present case. a. b. c. d.
5.
Shell thickness is OK. Shell thickness is NOT OK. Data are not adequate. Acceptance of shell thickness depends on opinion o f vessel engineer.
Choose correct hydrostatic test pressure from given options for a vessel the following data: Design Pr Design temp = M.O.C = Allow stress (Ambient) Allow stress (675°F) = a. b. c. d.
6.
= 360 psi 675ºF SA 537 Cl. 1 = 18600 psi 16900 psi
540 psig 515 psig 450 psig None of above
Impact test requirement for the two plates is to be assessed for MDMT = 0ºF, to be used for Vessel which will be hydrotested and used for steady operation. Plate A. Plate B.
Plates 537 class 1, Plates 515 gr 60,
2.0 inch thick 0.75 inch thick
Your assessment is: a. b. c. d. 7.
Plate (A) and plate (B) both require impact test. Only (A) requires, (B) is exempt. Only (B) requires, (A) is exempt. Both do not require impact testing.
For vessel shell, thk= 4.0 inch, max. weld mismatch shall be as follows: a. b. c. d.
8.
with
Long Long Long Long
seam seam seam seam
= = = =
¼”, circ seam = ½” ¼”, circ seam = 7/32” 7/32”, circ seam = ¼” 5/8”, circ seam = ½”
Toughness (opposite of brittleness) will be best for which materials: a. b. c. d.
Materials Materials Materials Materials
represented represented represented represented
by by by by
curve curve curve curve
A B C D
DAILY EXAM 2 (OPEN) 9.
In a pressure vessel one of the 2:1 ellipsoidal dished head is removed and a new seamless dished head of same type is installed with a single ‘V’ joint with backing strip and full radiography. What is the joint category, type and efficiency of the joint now? a. b. c. d.
10.
Category-B, Category-B, Category-A, Category-B,
Type-1 Type-2 Type-2 Type-2
& & & &
E-0.9 E-0.9 E-1.0 E-1.0
A pressure vessel of overall height 80’ has its part MAWP at various parts as detailed in the sketch. What is the vessel MAWP (hydrostatic head 1’ = 0.433 psi)? a. b. c. d.
419 420 430 426
psi psi psi psi
4'
426 psi 32'
54'
80'
440 psi
442.5 psi
454.64 psi
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