Minnesota Administrative Rules

7151.5600 CORROSION PROTECTION.

Subpart 1.

Tanks.

The floor of a steel aboveground storage tank must be protected from corrosion using one of the following methods:

A.

the tank is elevated so that the underside of the tank floor is not in contact with any surface other than the tank supports;

B.

the tank rests on a continuous concrete slab that is designed to prevent water from accumulating under the tank floor;

C.

the tank is double walled;

D.

the tank is double-bottomed with:

(1)

a vacuum pulled on the interstitial space; or

(2)

a cathodic protection system installed in the interstitial space;

E.

the tank floor is:

(1)

cathodically protected; and

(2)

internally lined in accordance with American Petroleum Institute Standard 652;

F.

the tank floor is:

(1)

cathodically protected; and

(2)

internally inspected in accordance with American Petroleum Institute Standard 653; or

G.

the tank floor is:

(1)

internally lined in accordance with American Petroleum Institute Standard 652; and

(2)

internally inspected in accordance with American Petroleum Institute Standard 653.

Subp. 2.

Lines.

A steel line must be protected from external corrosion using one of the following methods:

A.

the line is not in contact with soil;

B.

the line is cathodically protected; or

C.

the line is double walled.

Subp. 3.

Design criteria.

Cathodic protection of new steel tanks and lines must meet the following design criteria:

A.

the cathodic protection system must be designed by a corrosion expert in accordance with American Petroleum Institute Standards 651 and 1632, as applicable; and

B.

underground lines and the underside of the floor of a shop-fabricated steel tank must be coated with dielectric material in accordance with Steel Tank Institute Recommended Practice R893-89.

Statutory Authority:

MS s 115.03

History:

23 SR 883; 25 SR 556

Published Electronically:

October 2, 2007