API 653 - Appendex - B

Question 1

As per API 653 - Appe- B,
For existing tanks that do not have initial
settlement data, a program of settlement monitoring should be based on ,,,,,,

Answer 1

prior service history

Question 2

As per API 653 - Appe- B,

If at any time settlement is deemed excessive, the tank should be ,,,,,,

Answer 2

emptied and re-leveled

Question 3

As per API 653 - Appe- B,

Approaches used to correct tank shell and bottom settlement include techniques such as…….

Answer 3

• localized repairsof the bottom plates,
• partial re-leveling of the tank periphery,
• major re-leveling of the entire tank bottom

Question 4

Major re-leveling of the tank, involving ,,,,,, of the tank shell and bottom at one time, can introduce highly ,,,,,, in the structure and impair its integrity

Answer 4

total lifting

localized stresses

Question 5

As per API 653 - Appe- B,,

Tank settlements can be recorded by taking elevation measurements around the ,,,,,,,,,, and across the ,,,,,

Answer 5

tank circumference

tank diameter

Question 6

In cases of distortion or corrosion of the tank bottom extending beyond the shell, shell settlement measurements taken near lap welds in the tank bottom can result in ,,,,,,,,,, in measured elevation

Answer 6

significant errors

Question 7

As per API 653 - Appe- B,,

There must be at least ,,,,,points. The maximum spacing of the settlement points is ,,,,,around the circumference.

Answer 7

eight settlement

32 ft

Question 8

As per API 653 - Appe- B,
Maximum spacing for settlement of ,,,,,,,,, across tank
diameter

Answer 8

10 ft

Question 9

Settlement of a tank is the result of either one, or a combination of the following three settlement components.

Answer 9

Uniform settlement
Rigid body tilting of a tank (planar tilt)
Edge Settlement

Question 10

Edge settlement occurs when the tank shell settles sharply around the periphery, resulting in deformation of
the ,,,,,,, near the shell-to-bottom corner junction

Answer 10

bottom plate

Question 11

Localized bottom settlement remote from tank shell are ,,,,,, that occur in a random manner, remote from the shell

Answer 11

depressions (or bulges)

Question 12

Measure the bulge or depression. The permissible bulge or depression is given by the following equation,,,,,

Answer 12

Bb = 0.37R
where;
Bb = Measure the bulge or depression.in Inches
R= radius of in bulged or depression, in feet