API 650 - Section -5 (Design)

Question 1

Joint Design of plate thickness more than 5 mm (3/16), the weld thickness shall not less than ,,,,,,

Answer 1

one-third the thickness of thinner plate ans shall be atleast 5mm

Question 2

The required shell thickness shall be the greater of the ,,,,,,,,,,,,,,, including any corrosion
allowance

Answer 2

design shell thickness

Question 3

When specified by the Purchaser, plate with a nominal thickness of 6 mm may be substituted for ,,,,,,,,,,,, plate

Answer 3

1/4-in.

Question 4

For diameters less than 15 m (50 ft) but greater than 3.2 m (10.5 ft), the nominal thickness of the lowest shell course shall not be less than ,,,,,,,,,,

Answer 4

,6 mm (1/4 in.).

Question 5

The design stress basis, Sd, shall be either ,,,,,,,,,,,the yield strength or ,,,,,,,,,,,the tensile strength, whichever is less

Answer 5

two-thirds

two-fifths

Question 6

The hydrostatic test basis shall be either ,,,,,,,,, the yield strength or ,,,,,,, the tensile strength, whichever is less

Answer 6

three-fourths (3/4)

three-sevenths (3/7)

Question 7

Annex A permits an alternative shell design with a fixed allowable stress of ,,,,,,,,,,,,, and a
joint efficiency factor of,,,,. This design may only be used for tanks with shell thicknesses less than or equal to
,,,,,,,,,

Answer 7

145 MPa (21,000 lbf/in.2)
 0.85 or 0.70
13 mm (1/2 in.)

Question 8

The 1-foot method calculates the thicknesses required at design points ,,,,,,,,,,, above the bottom of each
shell course.

Answer 8

0.3 m (1 ft)

Question 9

Annex A permits, The 1-foot method only for design

that shall not be used for tanks larger than ……..

Answer 9

61 m

(200 ft) in diameter.

Question 10

A rectangular insert plate or thickened insert plate shall have rounded corners (except for edges terminating at the tank bottom or at joints between shell courses) with a radius which is ,,,,,,,,,,,,

Answer 10

greater than or equal to the larger of 150 mm (6 in.) or 6t where t

Question 11

The periphery of thickened insert plates shall have a ,,,,,,,,,,,tapered transition to the thickness of the adjoining shell material when the insert plate thickness exceeds the adjacent shell thickness by ,

Answer 11

1:4

more than 3 mm (1/8 in.).

Question 12

Openings in tank shells larger than required to accommodate a ,,,,,,,,,,, flanged or threaded nozzle shall be reinforced.

Answer 12

NPS 2

Question 13

The cross-sectional area of the reinforcement shall be measured ,,,,,,,, coincident with the diameter of the opening

Answer 13

vertically

Question 14

All bottom plates shall have a corroded thickness of not less than ,,,,,,,,,

Answer 14

6 mm (0.236 in.) [49.8 kg/m2 (9.6 lbf/ft2

Question 15

all rectangular and sketch plates (bottom plates on which the shell rests that have one end rectangular) shall have a nominal width of not less than ,,,,,,,,,

Answer 15

,,1800 mm (72 in.).

Question 16

Bottom plates of sufficient size shall be ordered so that, when trimmed, at least a ,,,,,,,,,,,width will project outside the shell or

Answer 16

50 mm (2 in.)

Question 17

Line 12, tank bottoms requiring sloping shall have a minimum slope of ,,,,,,,, upwards toward center of the tank.

Answer 17

1:120

Question 18

The drip ring shall extend at least ,,,, beyond the outer periphery of the foundation ring wall and then
turn down ,,,,,,,,at its outer diameter.

Answer 18

75 mm (3 in.)
(up to 90°)

Question 19

lap-welded bottom plates may be used in lieu of butt-welded annular bottom plates. if product stress for the first shell course is ….. or the maximum hydro static test stress is

Answer 19

≤ 160 MPa (23,200 lbf/in.2)

≤ 171 MPa (24,900 lbf/in.2)

Question 20

Annular bottom plates shall have a radial width that provides at least ,,,,,,,,,between the inside of the shell and any lap-welded joint in the remainder of the bottom

Answer 20

600 mm (24 in.)

Question 21

Permanent attachments may be welded directly to the shell with fillet welds having a maximum leg dimension of ,,,,,,,

Answer 21

13 mm (1/2 in.)

Question 22

The edge of any permanent attachment welds shall be at least ,,,,,,from the horizontal joints of the shell and at least ,,,, from the vertical joints, insert-plate joints, thickened insert plate joints, or reinforcing-plate fillet welds.

Answer 22

75 mm (3 in.) 
150 mm (6 in.)

Question 23

Permanent attachment welds may cross shell horizontal or vertical butt welds providing the welds are continuous within these limits and the angle of incidence between the two welds is greater than or equal to ,,,,,

Answer 23

45 degrees.

Question 24

Temporary attachments to shell courses shall preferably be made prior to welding of the ,,,,,,,,,,,,

Answer 24

shell joints

Question 25

Design External Pressure (Pe): Shall not be less than ,,,,,,

Answer 25

0.25 kPa (1 in. of water)

Question 26

Design Internal Pressure (Pi): Shall not exceed ,,,,,,

Answer 26

18 kPa (2.5 lbf/in.2)

Question 27

A tank roof formed to approximately the surface of a right cone that is supported principally either by rafters on girders and columns or by rafters on trusses with or without columns

Answer 27

supported cone roof

Question 28

A tank roof formed to approximately the surface of a right cone that is supported only at its periphery

Answer 28

self-supporting cone roof

Question 29

A tank roof formed to approximately a spherical surface that is supported only at its periphery.

Answer 29

self-supporting dome roof