API 653 PRACTICE QUESTION Sec. 2

Question 1

When a reinforcement plate is used with a penetration, the minimum diameter of the insert plate shall be equal to the diameter of the reinforcing plate plus ____ inches

Answer 1

12 inches

Question 2

If an integral reinforcement is used for a penetration, the thickness of the insert plate – at its periphery — shall be the same thickness as the shell, or the insert plate shall have a ___________ taper to match the shell plate thickness.

Answer 2

1:4

Question 3

The joint between the new material of the insert plate and the old material of the existing shell plate shall be:

Answer 3

butt-welded

Question 4

When an existing shell penetration has a reinforcing pad and it becomes necessary to remove the existing pad and alter it, under what condition is this not allowed?

Answer 4

Reinforcement plate replacement is not permitted on existing stress relieved assemblies.

Question 5

Installing a new bottom through an existing tombstone repad from the inside shall only be used on tanks where the annular plate or bottom sketch plate thickness is equal to or greater than.

Answer 5

3/8”

Question 6

What is the minimum dimension of a welded-on patch plate, smaller than 12” diameter, on a tank bottom is considered, which of the following statements is true.

Answer 6

one foot

Question 7

When a welded-on patch plate, smaller than 12” diameter, on a tank bottom is considered, which of the following statements is true

Answer 7

Welded-on patch plates must be extended at least 2” beyond the corroded are.

Question 8

What is the maximum thickness of a welded-on patch plate that is used to make a bottom repair within the critical zone?

Answer 8

1/4 inch

Question 9

An AST has no means for detection and containment of a bottom leak. What is the minimum acceptable thickness of the bottom if a welded-on patch plate that is used to make a bottom repair within the critical zone?

Answer 9

0.1 inch

Question 10

Welded-on patch plates are not permitted in the critical zone on a stainless steel tank bottom if:

Answer 10

The operating operating temperature exceeds 100 degrees F

Question 11

A corroded area in the critical zone of an AST bottom extends 30” around the periphery of the tank. The inspector notes that this area is too large for a bottom lap patch. The shell to bottom weld is removed in preparation for installing a new bottom to replace the corroded area. How much of the shell to bottom weld should be removed?

Answer 11

4.5 ft.

Question 12

A corroded area in the critical zone of an AST bottom bottom extends 40 “ around the periphery of the tank. The inspector notes that a bottom lap patch in this area is not the correct repair. Why does he make this decision?

Answer 12

The corroded are is greater than the area allowed for a bottom lap patch.

Question 13

What are some examples of a suitable non-corrosive material cushion that shall be used between an ld and new tank bottom

Answer 13

concrete or sand

Question 14

An existing AST that has shell plates of unknown toughness (0.80 inch thick and operates at 40 degrees F) has a bottom sketch plate weld joint located near a vertical shell weld. How close to the vertical weld can you locate the bottom weld joint when replacing floor plates?

Answer 14

4 inches

Question 15

The minimum thickness of new roof plates for a supported cone roof shall be ________ plus any corrosion allowance

Answer 15

3/16

Question 16

during the inspection of an AST an inspector finds that the mesh is missing from a bird screen of a free vent on the roof of an AST. What type mesh should be used to replace the missing bird screen?

Answer 16

A corrosion resistant coarse mesh screen with 1/2” nominal openings

Question 17

What method of repair is acceptable for external floating roofs?

Answer 17

Any method of repair is acceptable that will restore the roof to a condition enabling it to perform as required

Question 18

If the original construction drawings are not available, What is used as a guide for marking the repairs to an internal floating roof?

Answer 18

API 650, Appendix H

Question 19

Floating roof perimeter seals deteriorate from:

Answer 19

wear and corrosion on metallic elements, chemical and weather deterioration of seal fabric

Question 20

If the roof rim thickness is _____ inch thick it shall be replaced

Answer 20

.10

Question 21

An owner/user of an existing AST that has constructed with material of known toughness requests that a hot tapped NPS 3 nozzle be installed in the third course of his tank. What minimum thickness must the shell plate be in order to install the nozzle?

Answer 21

3/16 inch

Question 22

A NPS 4 schedule X-strong nozzle is installed in a tank shell5/8” thick. The hot tap drill is 4 inches in diameter. The shell plates are of known touchiness. What is the reinforcing plate outside diameter?

Answer 22

12 inches

Question 23

The minimum height of a tank liquid above the hot tap location shall be at least _____ during the hot tapping operation

Answer 23

3 feet