API 575

Question 1

What is the maximum internal pressure for tanks per API 650 & API 653?

Answer 1

2.5 psig

API 575 par 3.3

Question 2

What is the exterior surface of the tank bottom called?

Answer 2

Bottom slide

API 575 par 3.6

Question 3

What is a device that protects atmospheric storage tanks by maintaining the pressure difference between the tank vapor space and the out atmosphere to just a few ounces per in²?

Answer 3

Pressure-Vacuum Vent

API 575 par 4.2.2

Question 4

What is the most common type of AST?

Answer 4

Fixed Cone Tank

API 575 par 4.2.3

Question 5

What is the purpose of a geodesic dome on a tank?

Answer 5

Prevent vapor loss and to eliminate the need for water draw off

API 575 4.2.3

Question 6

What is the maximum internal pressure for tank per API 620?

Answer 6

15 psig

API 4.3.2

Question 7

What are atmospheric storage tanks generally inspected?

Answer 7

To determind the physical condition of the tank and to determine the type, rate, and causes of damage mechanisms and associated deterioration

API 575 5.1

Question 8

What is the primary cause of deterioration of steel storage tanks?

Answer 8

Corrosion

API 575 5.2

Question 10

During the inspection of a tank, a section of the bottom is removed. Several globs of clay are found in the pad. What would you suspect?

Answer 10

Pitting corrosion on bottom side of tank bottom

API 575 5.2.1 Note: API 652 5.4 indicates ‘severe’ corrosion can be caused

Question 11

What usually causes internal corrosion of an atmospheric storage tank in vapor zone?

Answer 11

H2S vapors, H2O, O2 or combination

API 575 5.2.2

Question 12

Where is the most likely point and one of the potentially most critical points for a crack to occur in a large storage tank?

Answer 12

Shell-to-bottom weld

API 575 5.4

Question 13

How should AST foundations be checked for settlement?

Answer 13

Surveyor’s level

API 575 8.2.3

Question 14

Coatings (paint, etc) may affect UT readings. What should be done?

Answer 14

Compensate for the coating

API 575 8.2.8.2

Question 15

A riveted of bolted tank should have a number of random selected rivets or bolts checked for tightness. How is this done?

Answer 15

Tapping rivet or bolt head laterally with hammer while holding the other side

API 575 8.2.8.7

Question 16

What is the maximum electrical resistance permitted from tank to earth?

Answer 16

25 ohms

API 575 8.2.5

Question 17

Why do dry pyrophoric materials present a problem?

Answer 17

Can self ignite

API 575 8.4.2

Question 18

When statistical methods are ued for assessing the probable condition of a tank bottom, what controls the number of UT measurements taken?

Answer 18

Tank diameter and degress of soil side corrosion found

API 575 8.4.4

Question 19

What size coupon is recommended for removal from a tank bottom to check for underside corrosion?

Answer 19

12” minimum

API 575 8.4.4

Question 21

What is the minimum angle that your eye must be to the part for visual inspection?

Answer 21

30 degrees

API 575 9.2.1

Question 22

When penetrating oil is sprayed on the outside shell to bottom weld for a test, what is the test called?

Answer 22

Wicking

API 575 9.2.2

Question 23

What is a method for checking for weld leaks in the bottom and in the shell

Answer 23

Bubble test or vacuum box

API 575 9.2.4

Question 24

Why is two pass welding recommended for seal welding leaking rivets?

Answer 24

To allow for a poor first pass due to hydrocarbon contamination

API 575 10.2.2

Question 25

How long should the AST records be maintained?

Answer 25

Throughout the srvice life of the tank

API 575 11.2