API 653 Questions and Answers


1)         __________ is a change from previous operating conditions involving different properties of the stored product such as specific gravity or corrosivity and / or different service conditions of temperature and / or pressure”

(a) Re-rating;                                                 (b) Change in service;

(c) Repair;                                                      (d) Reconstruction

REF : API-653, – 1.5.4

ANS : (b)

2)         A __________ is a device used to determine the image quality of a radiograph.

(a) A step wedge comparison film;                        (b) A densitometer;

(c) A penetramter                                         (d) All of the above.

REF : Section V, T-233

ANS : (c)

3)         A corroded roof plate is found to have an average thickness of 0.1″ measured over an area of 100 sq. inches. This area shall be :-

(a) Repaired or replaced;                            (b) Found to be acceptable;

(c) Repair is prohibited;                               (d) Replacement is mandated

REF : API-653,

ANS : (b)

4)         A double-welded butt joint is defined as :-

(a) A joint between two members that intersect at an angle between 0 degrees (a butt joint) and 90 degrees (a corner joint).

(b) A joint between two abutting parts lying in approximately the same plane that is welded from both sides.

(c) A joint whose size is equal to the thickness of the thinner jointed member.

(d) A joint  between two  overlapping members in which the overlapped edge is welded.

REF : 650

ANS : (b)

5)         An external floating roof shall be provided with atleast one manhole having a minimum inside diameter of __________ inches.

(a) 18;             (b) 15;             (c) 24;             (d) 30.

REF : 650 APP. C. 3.11

ANS : (c)

6)         A formal Visual External inspection by a qualified inspector shall be done atleast :-

(a) Every 5 years of ¼ CR life whichever is less

(b) Every 5 years of ½ CR life whichever is less

(c) Every 2 years

(d) Every 1- years or ¼ CR life whichever is greater

REF : 653

ANS : (a)

7)         A full hydrostatic test (when required) shall be held for __________ hours :-

(a) 24;             (b) 8;               (c) 18;             (d) 12

REF : 653

ANS : (a)

8)         A full-fillet weld is a weld that :-

(a) not less than 1/3 the thinner plate;

(b) the legs equal the thickness of the thinner plate;

(c) the largest isosceles triangle that can be inscribed within the cross section of the weld

(d) is atleast the thickness of the thicker plate

REF : API 650

ANS : (b)

9)         A hot tap in a 1.25″ thick tank with a minimum metal temperature of 65oF at time of hot tap, without having material toughness data is :-

(a) not permitted;                                          (b) permitted

(c) not enough information;                                   (d) not addressed by the code

REF : API 653 – 7.13.4 & Fig. 7-5

ANS : (a)

10)      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

REF : 653 (a)

ANS : (b)

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