API 653 PRACTICE QUESTION Sec. 2 Flashcards
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
12 inches
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.
1:4
The joint between the new material of the insert plate and the old material of the existing shell plate shall be:
butt-welded
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?
Reinforcement plate replacement is not permitted on existing stress relieved assemblies.
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.
3/8”
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.
one foot
When a welded-on patch plate, smaller than 12” diameter, on a tank bottom is considered, which of the following statements is true
Welded-on patch plates must be extended at least 2” beyond the corroded are.
What is the maximum thickness of a welded-on patch plate that is used to make a bottom repair within the critical zone?
1/4 inch
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?
0.1 inch
Welded-on patch plates are not permitted in the critical zone on a stainless steel tank bottom if:
The operating operating temperature exceeds 100 degrees F
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?
4.5 ft.
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?
The corroded are is greater than the area allowed for a bottom lap patch.
What are some examples of a suitable non-corrosive material cushion that shall be used between an ld and new tank bottom
concrete or sand
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?
4 inches
The minimum thickness of new roof plates for a supported cone roof shall be ________ plus any corrosion allowance
3/16
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?
A corrosion resistant coarse mesh screen with 1/2” nominal openings
What method of repair is acceptable for external floating roofs?
Any method of repair is acceptable that will restore the roof to a condition enabling it to perform as required
If the original construction drawings are not available, What is used as a guide for marking the repairs to an internal floating roof?
API 650, Appendix H
Floating roof perimeter seals deteriorate from:
wear and corrosion on metallic elements, chemical and weather deterioration of seal fabric
If the roof rim thickness is _____ inch thick it shall be replaced
.10
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?
3/16 inch
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?
12 inches
The minimum height of a tank liquid above the hot tap location shall be at least _____ during the hot tapping operation
3 feet
