5 - Design

Question 1

Restrictions on Joints:
The minimum size of fillet welds shall be,
On plates 5 mm (3/16 in.) thick, the weld shall be a,,,,,
On plates more than 5 mm (3/16 in.) thick, the weld thickness shall not be ,,,,,

Answer 1

• full fillet weld

- 1/3 of the thinner plat and atleast 5mm

Question 2

Joint: (Lap)

Single-welded lap joints are permissible only on ,,,,,,

Answer 2

bottom plates and roof plates.

Question 3

Joint: (Lap)
Single-welded joints shall be lapped at least ,,,,,,the nominal thickness of the thinner plate joined, or ,,,,, whichever is smaller

Answer 3

five times 
25 mm (1 in.),

Question 4

Joint: (Lap)
Double-welded joints shall be lapped at least ,,,,,the nominal thickness of the thinner plate joined, or
,,,,,,, whichever is smaller

Answer 4

5t 
50 mm (2 in.)

Question 5

Joint: (Bottom - Weld Passes)

For manual welding processes, fillet weld legs or groove weld depths greater than ,,, shall be multipass

Answer 5

6 mm (1/4 in.)

Question 6

Joint: (Bottom - Weld Passes)
For semi-automatic, machine, and automatic welding processes, fillet weld legs or groove weld depths greater than ,,,,,shall be multipass

Answer 6

10 mm (3/8 in.)

Question 7

Joint: (Typical)

The top surfaces of bottom welds, shall be ,,,,, where they will contact the bottoms of the

Answer 7

-Ground flush
-Shell, insert plates, thickened insert plates, or
reinforcing plates.

Question 8

Joint: (Vertical-Shell)

Joints shall be ,,,, joints with ,,,, and ,,,,

Answer 8

butt
complete penetration
complete fusion

Question 9

Joint: (Vertical-Shell)
Vertical joints in adjacent shell courses shall not be ,,,, but shall be offset from each other a minimum
distance of,,,,

Answer 9

aligned

5t

Question 10

Joint: (Horizontal-Shell)

Horizontal shell joints shall have,,,,, and ,,,

Answer 10

complete penetration

complete fusion

Question 11

Joints: (Lap-Welded Bottom)
Three-plate laps in tank bottoms shall be at least ,,,,, from each other, from the tank shell, and from joints between annular plates and the bottom

Answer 11

300 mm (12 in.)

Question 12

Joints: (Butt-Welded Bottom)

The use of a backing strip at least ,,,, thick tack welded to the underside of the plate is permitted

Answer 12

3 mm (1/8 in.)

Question 13

Joints: (Bottom Annular-Plate)

Bottom annular-plate radial joints shall be ,,,,,-and shall have

Answer 13

butt welded

complete penetration and complete fusion

Question 14

Joints: (Roof and Top-Angle Welds)

Roof plates shall, as a minimum, be welded on the ,,,, side with a ,,,,, full-fillet weld on all seams.

Answer 14

top

continuous

Question 15

Loads:

,,,,,,,The weight of the tank or tank component, including any corrosion allowance

Answer 15

Dead Load (DL)

Question 16

Loads: (Design External Pressure)

Shall not be less than ,,,,,

Answer 16

0.25 kPa (1 in. of water)

Question 17

Loads: (Design Internal Pressure)

Shall not exceed ,,,,,,

Answer 17

18 kPa (2.5 lbf/in.2)

Question 18

1-Foot Method :

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

Answer 18

0.3 m (1 ft)

Question 19

1-Foot Method :

This method shall not be used for tanks larger than ,,,, in diameter.

Answer 19

61 m (200 ft)

Question 20

Joint : (Shell Openings)
A rectangular insert plate or thickened insert plate shall have rounded corners with a radius which is greater than or equal to the larger of ,,,,,,

Answer 20

150 mm (6 in.) or 6t

Question 21

Joint : (Shell Openings)
The periphery of thickened insert plates shall have a ,,,,, tapered transition to the thickness of the adjoining shell material

Answer 21

1:4

Question 22

Joint : (Shell Openings)

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

Answer 22

NPS 2

Question 23

Joint: (Roof Openings)

Tanks designed as per API 650 and having a fixed roof shall be vented for both ,,,,, and ,,,,

Answer 23

normal conditions
emergency conditions
(Mean vents opening is required for roof)

Question 24

Joint: (Roof Openings)
All free vents shall be provided with corrosion-resistant coarse-mesh bird screens of a maximum opening
size of ,,,,,

Answer 24

(19 mm [3/4 in.]

Question 25

Roofs: (supported cone roof)

supported by ,,,, and columns or by ,,,,, with or without columns.

Answer 25

rafters on girders

rafters on trusses

Question 26

Roofs: (self-supported cone roof)

supported by only at its ,,,,,,

Answer 26

periphery.

Question 27

Roofs: (self-supported cone roof)

supported only at its ,,,,,,,

Answer 27

periphery

Question 28

Roofs: (self-supporting umbrella roof)

supported only at its ,,,,,

Answer 28

periphery

Question 29

Roof: (Plate)

Roof plates shall have a nominal thickness of not less than ,,,,,

Answer 29

5 mm (3/16 in.) or 7- gauge sheet

Question 30

Roof: (Fragile)
A roof is considered frangible if the roof to-shell joint will fail prior to the ,,,,, joint in the event of excessive internal pressure.

Answer 30

shell-to-bottom

Question 31

Roof: (Supported cone roof)

The slope of the roof shall be ,,,, or greater if specified by the Purchaser

Answer 31

1:16

Question 32

Roof: (with dia meter > 15m)
The slope of the roof at the top angle attachment does not exceed ,,,,
The roof support members shall not be attached to the ,,,,,
The roof is attached to the top angle with a single continuous fillet weld on the top side (only) that does not exceed ,,,

Answer 32

2:12
roof plate
5 mm (3/16 in.)

Question 33

Load: (Lateral Movement)

The guides shall remain effective in the event of vertical movement of columns relative to tank bottom of up to ,,,,

Answer 33

75 mm(3 in.).