Materials.

(a) Steel plate: Steel plate materials used to fabricate tank shell and manway nozzle must comply with one of the following specifications with the indicated minimum tensile strength and elongation in the welded condition. The maximum allowable carbon content must be 0.31 percent when the individual specification allows carbon greater than this amount. The plates may be clad with other approved materials.

Specifications Minimum tensile strength (p.s.i.) welded condition1 Minimum elongation in 2 inches (percent) welded condition (longitudinal) AAR TC 128, Gr. B 81,000 19 ASTM A 302 2, Gr. B 80,000 20 ASTM A 516 2 70,000 20 ASTM A 537 2, Class 1 70,000 23 1 Maximum stresses to be used in calculations. 2 These specifications are incorporated by reference (IBR, see § 171.7 of this subchapter).

(b) Aluminum alloy plate: Aluminum alloy plate material used to fabricate tank shell and manway nozzle must be suitable for fusion welding and must comply with one of the following specifications (IBR, see § 171.7 of this subchapter) with its indicated minimum tensile strength and elongation in the welded condition. * * *

Specifications Minimum tensile strength (p.s.i.) 0 temper, welded condition 3 4 Minimum elongation in 2 inches (percent) 0 temper, welded condition (longitudinal) ASTM B 209, Alloy 5052 1 25,000 18 ASTM B 209, Alloy 5083 2 38,000 16 ASTM B 209, Alloy 5086 1 35,000 14 ASTM B 209, Alloy 5154 1 30,000 18 ASTM B 209, Alloy 5254 1 30,000 18 ASTM B 209, Alloy 5454 1 31,000 18 ASTM B 209, Alloy 5652 1 25,000 18 1 For fabrication, the parent plate material may be 0, H112, or H32 temper, but design calculations must be based on minimum tensile strength shown. 2 0 temper only. 3 Weld filler metal 5556 must not be used. 4 Maximum stress to be used in calculations.

(c) High alloy steel plate. (1) High alloy steel plate must conform to the following specifications:

Specifications Minimum tensile strength (p.s.i.) welded condition1 Minimum elongation in 2 inches (percent) weld metal (longitudinal) ASTM A 240/A 240M (incorporated by reference; see § 171.7 of this subchapter), Type 304L 70,000 30 ASTM A 240/A 240M (incorporated by reference; see § 171.7 of this subchapter), Type 316L 70,000 30 1 Maximum stresses to be used in calculations.

(2)(i) High alloy steels used to fabricate tank must be tested in accordance with the following procedures in ASTM A 262, “Standard Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steel” (IBR, see § 171.7 of this subchapter), and must exhibit corrosion rates not exceeding the following: * * *

Test procedures Material Corrosion rate i.p.m. Practice B Types 304L and 316L 0.0040 Practice C Type 304L 0.0020

(ii) Type 304L and 316L test specimens must be given a sensitizing treatment prior to testing.

(d) All attachments welded to tank shell must be of approved material which is suitable for welding to the tank.

[Amdt. 179-10, 36 FR 21344, Nov. 6, 1971, as amended by Amdt. 179-32, 48 FR 27707, June 16, 1983; Amdt. 179-47, 58 FR 50237, Sept. 24, 1993; Amdt. 179-52, 61 FR 28679, June 5, 1996; Amdt. 179-52, 61 FR 50255, Sept. 25, 1996; 66 FR 45186, Aug. 28, 2001; 67 FR 51660, Aug. 8, 2002; 68 FR 75759, Dec. 31, 2003]