API 653 Questions

Today we posted here second question bank for API 653 Tank Inspector Exam. You shall follow the same method to save this question bank, which is said in earlier posts. Please post your valuable comments for each and every post. It will boost up our interest and helpful to provide more & more question banks. The second question bank starts below: 1. A hydrostatic test for a relocated tank: a. May be waived by the Owner/Operator b. Is required c. May be waived by the Inspector d. Is not necessary 2. Minimum thickness of tank bottom in critical zone shall be at least 0.1 inch but also it shall be: a. Greater of: ½ tmin for lowest shell course and half of original thickness in critical zone b. Smaller of: ½ tmin for lowest shell course and half of original thickness in critical zone c. 0.1” only d. 0.05” as from Table 6-1, if leak detection system is provided 3. During the hydrostatic test, no less than _______ settlement measurement points shall be surveyed. a. 8 b. 10 c. 15 d. 5 4. For vacuum box test, a partial vacuum of at least _______ shall be used using _________ to check the cracks. a. 3 psi, penetrating oil b. 5 psi, water immersion c. 3 psi, film solution d. 5 psi, liquid penetrant 5. Which tests are usually conducted to verify acceptability of shell to bottom plate welds? a. Penetrating oil b. RT c. Vacuum box test d. “a” and “c” 6. Except for cast iron parts, internal coils and supports may be: a Dye penetrant tested b. Leak tested c. Hammer tested d. Magnetic particle tested 7. At the next out-of-service inspection on a tank that has had a hot tap performed, the visual inspection should include: a. Size of the hot tap nozzle holes b. Thickness of the plate at the hot tap c. Height of the hot tap from the tank bottom d. Trimming of the hot tap nozzle holes

8. The term “roof drain” is applicable for which type of tanks? a. Tanks with a breather device installed on the roof b. High octane fuel tanks (Dome roof tanks) c. Tanks with floating roofs (open top-tanks) d. Tanks with internal floating roof 9. Industry experience and laboratory test have shown that a membrane stress in tank shell plates of at least _______ is required to cause failure due to brittle fracture? a. 500 psi b. 100 Mpa c. 7 ksi d. 18 kg/mm2 10. Which of the following is an advantage of magnetic particle testing over penetrant testing? a. it can detect surface discontinuities with foreign material imbedded in them b. It is faster on individual parts c. It can detect near-surface discontinuities d. All of the above

API 653 Sample Question 1. AST fabricated to API 650 (Basic Standard) is normally designed not to exceed an operating temperature of: a. b. c. d.

260 deg C 100 deg C 90 deg C 21 deg C

2.

Minimum size of fillet welds in the construction or repairs of an AST built to API Standard 650 is:

a. b. c. d.

Higher of 6 mm (0.25”) or half of the thickness of thinner plate joined. Higher of 9 mm (0.25”) or one third of the thickness of thicker plate joined. Higher of 5 mm (0.1875”) or one third of the thickness of thinner plate joined. Lower of 6 mm (0.25”) or half of the thickness of thinner plate joined.

3. As per API Standard 650, the overlap at lap-welded joints shall be at least five times the nominal thickness of the thinner plate, but need not exceed, a. b. c. d.

2” for single-welded lap joints and 4” for double welded lap joints 1” for single-welded lap joints and 2” for double welded lap joints 1.5” for single-welded lap joints and 2” for double welded lap joints 1.5” for single-welded lap joints and 1” for double welded lap joints

4. Calculate by the 1-Foot method the design shell thickness Td in inches, of the following description of tank built to API Standard 650: H = Design liquid level = 50 feet D = Nominal Tank Diameter = 180 feet

G = Design Specific Gravity = 0.86 CA = Corrosion Allowance = 0. 0625” Sd= Allowable stress in design condition, in psi

Shell Material = ASTM A36M Td = design shell thickness, inch(es) St= Allowable stress for hydrostatic test condition, in psi Tt = hydrostatic test shell thickness, inch(es).

a. b. c. d.

Where, Td = 2.6 D (H –1) G + CA Sd 0.912” 0.850” 1” 0.922”

5. Calculate by the 1-Foot method the hydrostatic test shell thickness Tt in inches, of the above referred tank, when water is used for the test : Where, Tt = 2.6 D (H –1) St a. b. c. d.

0.935” 0.985” 1” 0.922”

6. Maximum Reinforcement thickness of vertical butt joints of a tank shell plate of 28mm, of an AST built to API Standard 650 shall be: a. b. c. d.

5mm 2.4mm 1.6mm 3mm

7. Vertical joints of a 28 mm thick shell of an AST built to API Std. 650 shall be radiographed to the extent as given below : a. b. c. d.

Full Partial Spot Nil

8. In an AST built to API Standard 650, the bottom annular plates have radial weld joints, and are single butt welded with permanent back-up bar, in which case, the extent of radiographing radial joints shall be, a. b. c. d.

One spot on 50% of radial joint One spot on 10% of radial joints Full radiography of all radial joints RT – Nil; only MT of 100% joints is adequate.

9. As per API Std. 650, personnel who perform and evaluate radiographic examinations (RT) shall have a minimum qualification as follows : a. b. c. d.

Shall have a vision of Jaeger No.2 Shall be qualified as Level II of ASNT SNT-TC-1A Shall not be color blind Shall have an experience of at least ten years in RT.