Standard for Steel Underground Tanks for Flammable and Combustible Liquids

1 SCOPE

1.1 Except as described in Clause 1.7, these minimum requirements cover single and double wall

cylindrical steel, non-pressure tanks of the horizontal type that are used for the underground storage of

flammable liquids and combustible liquids, that are compatible with the material of construction.

1.2 These minimum requirements cover double wall tanks with provision for leak detection monitoring of

the interstice between the walls.

NOTE: The designs identified in this Standard are satisfactory for vacuum and/or electronic monitoring devices. (Refer

to Figure 1.)

1.3 This Standard also provides design criteria for integral connections (connection rings/collars) for spill

containment sumps or manway risers.

1.4 These minimum requirements cover tanks, which are fabricated, inspected and tested for leakage

before shipment from the factory as completely assembled vessels.

NOTE: For the requirements for tanks provided with corrosion protection systems at the factory, refer to the Standard

CAN/ULC-S603.1, Standard for External Corrosion Protection Systems for Steel Underground Tanks for Flammable

and Combustible Liquids.

1.5 These minimum requirements cover tanks up to a maximum capacity of 250 000 L.

1.6 The requirements in this Standard are for the construction of stationary tanks and do not cover their

installation, maintenance and operation. The installation, maintenance and operation of these tanks may

be covered by any of, but not limited to, the following documents:

A National Fire Code of Canada, Part 4;

B CSA B139, Installation Code for Oil Burning Equipment;

C API RP 1615, Installation of Underground Petroleum Storage Systems;

D CCME PN 1326, Environmental Code of Practice for Aboveground and Underground Storage

Tank Systems Containing Petroleum and Allied Petroleum Products;

E NFPA 30, Flammable and Combustible Liquids Code; and

F Regulations of the appropriate authority having jurisdiction.

1.7 Where described elsewhere in the Standard, an alternative means of demonstrating compliance is

provided in Subsection 8.3, Alternative Compliance Path. Tank designs subjected to the alternative

compliance path need not be cylindrical. It is intended that proponents will use one of the design-based

approaches identified in the rest of the Standard, or that described in Subsection 8.3, Alternative

Compliance Path, as an equivalent means of obtaining certifications for their products.

1.8 The requirements in this Standard cover products that are integral or built-in to the tank.

NOTE: These requirements do not cover products not integral to the tank, such as spill containment sumps.