49 C.F.R. §§ 179.220-6

Current through October 31, 2024

Section 179.220-6 - Thickness of plates

(a) The wall thickness, after forming of the inner container shell and 2:1 ellipsoidal heads must be not less than specified in § 179.221-1 , or not less than that calculated by the following formula:

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Where:

d = Inside diameter in inches;

E = 0.9 welded joint efficiency; except E = 1.0 for seamless heads;

P = Minimum required bursting pressure in psig;

S = Minimum tensile strength of plate material in p.s.i. as prescribed in AAR Specifications for Tank Cars, appendix M, Table M1;

t = Minimum thickness of plate in inches after forming.

(b) The wall thickness after forming of the inner container heads, if flanged and dished, must be not less than specified in § 179.221-1 , or not less than that calculated by the following formula:

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Where:

E = 0.9 welded joint efficiency; except E = 1.0 for seamless heads;

L = Main inside radius to which head is dished, measured on concave side in inches;

P = Minimum required bursting pressure in psig;

S = Minimum tensile strength of plate material in psi as prescribed in AAR Specifications for Tank Cars, appendix M, Table M1 (IBR, see § 171.7 of this subchapter);

t = Minimum thickness of plate in inches after forming.

(c) The wall thickness after forming of the cylindrical section and heads of the outer shell must be not less than seven-sixteenths of an inch.

(d) See § 179.220-9 for plate thickness requirements for inner container when divided into compartments.

49 C.F.R. §§179.220-6

Amdt. 179-9, 36 FR 21340, Nov. 6, 1971, as amended at 66 FR 45390 , Aug. 28, 2001; 68 FR 75762 , Dec. 31, 2003