API 650 PRACTICE QUESTIONS

Question 1

API 650 covers material, design, fabrication, erection, and testing requirements for aboveground welded steel storage tanks. Internal pressure allowed for these tanks approximates atmospheric pressure. However, the internal pressures must not:

Answer 1

exceed the weight of the roof plates

1.1.1

Question 2

Tanks that have bottoms that are not uniformly supported are:

Answer 2

not covered by API 650

1.1.1

Question 3

Tanks covered by API 650 are restricted to a maximum operating temperature of ___degrees F, unless additional requirements of Appendix M of API 650 are followed.

Answer 3

200

1.1.1

Question 4

who decides whether tanks constructed to API 650 will have SI dimensions and comply with applicable SI unit standards or have US Customary dimensions and comply with applicable US customary unit standards?

Answer 4

It shall be decided by a mutual agreement between the manufacturer and the purchaser.
1.1.3

Question 5

Appendix A provides alternative simplified design requirements for tanks where the stressed components, such as shell plates and reinforcing plates, are limited to a maximum nominal thickness of_____, including corrosion allowance.

Answer 5

13mm (1/2in)

A1.1

Question 6

Who is responsible for complying with all of the provisions of API 650 when a new tank is built?

Answer 6

The manufacturer

1.3

Question 7

The term used to define the condition where-as the mid-thickness centerlines of shell plates in all shell courses coincide is____________.

Answer 7

Centerline-stacked

3.1

Question 8

Required sections of this Standard become _______ if the Standard has been adopted by a legs jurisdiction.

Answer 8

Mandatory

3.1.5

Question 9

The lowest temperature considered in the design shall be assumed to be _______ above the lowest one-day mean ambient temperature of the locality where the tank is to be installed.

Answer 9

15 degrees F

3.6

Question 10

Material used to construct a tank shall conform to the specifications of API 650; however, other material may be used:

Answer 10

provided that the material is certified to meet all requirements of a material listed in API 650 and the purchaser approves.

Question 11

When any new or unused plate and pipe material cannot be completely identified by records that are satisfactory, the material may be used in the construction of tanks covered by API 650 only if the:

Answer 11

material passes tests prescribed in Appendix N of API 650

4.1.3

Question 12

Whether an edge-thickness or weight basis is used in the ordering of plate for construction of tanks, an under run not more than _____ inch from the computed design thickness or the minimum permitted thickness is acceptable

Answer 12

0. 01

4. 2.1.2.3

Question 13

Shell plates for API 650 tanks are limited tow hat maximum thickness?

Answer 13

1. 75 inches

4. 2.1.4

Question 14

Plates thicker than_____ inches shall be normalized or quench tempered, killed, made to fine-grain practice, and impact tested.

Answer 14

1. 50

4. 2.1.4

Question 15

A purchaser requires a tank to be built from ASTM A-283 Grade C plate. What maximum thickness limitation is placed on this plate?

Answer 15

1. 00 inch

4. 2.2c

Question 16

Define a full-fillet weld

Answer 16

A full-fillet weld is a fillet weld whose sizes is equal to the thickness of the thinner joined member.
5.1.1.7

Question 17

An AST’s bottom plates are 1/4 inch thick. They are single-welded lap-jointed. The lap need not exceed how much?

Answer 17

1. 00”

5. 1.3.5

Question 18

In a lap-welded bottom, three plate lap joints shall be at least ____ inches from each other, from the tank shell, from butt-welded annular-plate joints, and from joints between annular plates and the bottom.

Answer 18

12

5.1.5.4

Question 19

Unless otherwise specified by the purchaser, lap welded plates on sloped bottoms shall be______ in a manner to reduce the tendency for liquid to________ during draw-down

Answer 19

overlapped, puddle

5.1.5.4

Question 20

In a butt-welded bottom, three plate joints shall be at least _____ inches from each other and from the tank shell.

Answer 20

12

5.1.5.5

Question 21

An AST has an annular plate that is .25 inch thick. The bottom shell course of the tank is .50 inch thick. What is the minimum size fillet weld that must be laid on each side of the shell plate to attach it to the annular bottom plate?

Answer 21

0. 2500” (1/4”)

5. 1.5.7

Question 22

An AST has an annular plate that is .625” thick. The bottom shell course of the tank is 1.125 inches thick. The bottom shell plate is beveled on both sides 5/16 inch for welding. What size filled weld is required on each side of the shell to bottom attachment?

Answer 22

12. 5 mm

5. 1.5.7

Question 23

Who specifies the design metal temperature, the design specific gravity, the corrosion allowance (if andy), and the design wind velocity for a new AST?

Answer 23

The purchaser

5.2.2

Question 24

API 650, Appendix V provides requirements that may be specified by the purchaser for tanks that are intended to operate under external pressure (vacuum). However, what amount of vacuum CAN a tank that has been designed to the minimum requirements of API 650 take?

Answer 24

1 inch of water pressure.

5.2.1b

Question 25

Unless otherwise agreed to by the purchaser, all rectangular and sketch plates (bottom plates on which the shell rests that have one end rectangular) shall have a minimum nominal width of:

Answer 25

72 inches | 5.4.1

Question 26

What is the weight per square foot of the minimum thickness plate used for tank bottoms?

Answer 26

9. 6 lbs/square foot | 5. 4.1

Question 27

A new AST is built. How far should the bottom sketch plates project beyond the outside of the shell weld attaching the bottom to the shell plate? (These are not annular plates)

Answer 27

2 inches | 5.4.2

Question 28

Annular bottom plates shall have a radial width that provides at least 24 inches:

Answer 28

between the inside of the shell and any lap-welded joint in the remainder of the bottom. 5.5.2

Question 29

Annula bottom plates shall project at least ____ outside the tank shell.

Answer 29

2 inches | 5.4.2

Question 30

Unless otherwise specified on the Tank Data Sheet, tank bottoms requiring sloping shall have a minimum slope of _____ upwards towards the center of the tank.

Answer 30

1: 120 | 5. 4.4

Question 31

If specified in the Tank Data Sheet, a foundation __________ shall be provided to prevent ingress of water between the tank bottom & foundation and shall be carbon steel with a minimum of______.

Answer 31

drip ring, 1/8" | 5.4.5

Question 32

The entire bottom of an AST is butt welded and all other provisions of API 650 are met. This may be done in lieu of installing:

Answer 32

annular plates | 5.5.5

Question 33

An AST that is 100 feet in diameter is required by API 650 to have a minimum nominal shell thickness of _______, even if the calculated thickness is less.

Answer 33

.2500 inch | 5.6.1.1

Question 34

What is the minimum nominal width of shell plates (unless specified otherwise by the purchaser)?

Answer 34

72 inches | 5.6.1.2

Question 35

The 1-foot method for calculation of AST shell thickness shall not be used for tanks larger than ___ feet in diameter

Answer 35

200 | 5.6.3.1

Question 36

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

Answer 36

NPS 2 | 5.7.2.1

Question 37

Reinforcing plates for shell openings, or each segment of the plates if they are not made in one piece, shall be provided with a ____ diameter tell-tale hole. Such holes shall be located ________ & shall be open to the atmosphere.

Answer 37

1/4", on horizontal centerline

Question 38

A minimum distance of _____ shall be maintained between the toe of a weld around a non-reinforced penetration and the toe of the shell-to-bottom weld.

Answer 38

3" | 5.7.3.3

Question 39

All flush-type clean out fittings and flush-type shell connections shall be thermally stress relieved after assembly prior to installation in the tank shell or after installation into the tank shell if the entire tank is stress relieved. The stress relief shall be carried out within a temperature range of _______ for 1 hour per inch of shell thickness

Answer 39

1100-1200 degrees F | 5.7.4.1

Question 40

A new AST is built. The tank is to be used to store a product that causes stress corrosion cracking (such as amine). The thickness of the bottom shell plate is one inch (first shell course). The heat is applied to the welds, but only 1025 degrees F temperature can be obtained. How long must this temperature be held on the bottom plate welds to obtain the desired results?

Answer 40

3 hours | 5.4.7.5