API 12R1: Recommended Practice for Setting, Maintenance, Inspection, Operation and Repair of Tanks in Production Service Flashcards
What is the minimum shell-to-shell spacing for personnel access between tanks? (API 12R1-97, Section 4.1.3)
3 ft (91 cm), with spacing adjusted so that pipe headers can be prefabricated to standard patterns.
What should the foundation sub-base for a tank consist of? (API 12R1-97, Section 4.1.5)
Well-graded, compacted soil
What should be done if the sub-base is not sufficiently impermeable to prevent the migration of fluids into soils below the tank? (API 12R1-97, Section 4.1.5)
A plastic sheet or other barrier to liquid should be placed over the sub-base to provide an impermeable barrier.
How should the sub-base be graded? Why should it be graded this way? (API 12R1-97, Section 4.1.5)
a) Raised at the center of the tank to facilitate drainage toward the perimeter.
b) Drainage should be provided away from the tank.
What should the foundation base for a tank consist of? (API 12R1-97, Section 4.1.6)
Gravel, shell, sand, concrete, or other material that facilitates drainage and provides structural support. A retainer ring may be used to confine loose material and to facilitate detection of liquid drainage from below the tank.
What is the purpose of “seep holes?” (API 12R1-97, Section 4.1.8)
As a means for visible leak detection and drainage.
Under what conditions should seep holes be provided? (API 12R1-97, Section 4.1.8)
If a retainer ring is used and it does not extend beyond the diameter of the tank.
How large a volume should dikes or firewalls be constructed to contain? (API 12R1-97, Section 3.2)
The volume of the largest tank enclosed plus an allowance for rainwater (normally, 10 % additional tank volume).
If a pipe drain is used, it should be provided at what point in the dike? (API 12R1-97, Section 5.2.2)
The lowest point to permit draining accumulations of storm water.
