§178.57. Specification 4L welded insulated cylinders. — Inbound Citations

(47) ASTM E 23-98 Standard Test Methods for Notched Bar Impact Testing of Metallic Materials, 1998, into § 178.57.

(e) After October 1, 1984, cylinders manufactured for use under special permit (SP) or exemption (E) 6668 or 8404 may be continued in use, and must be marked “DOT-4LXXXYY” (XXX to be replaced by the service pressure, YY to be replaced by the letters “AL”, if applicable) in compliance with Specification 4L (§ 178.57 of this subchapter) on or before January 1, 1986. The “DOT-4LXXXYY” must appear in proximity to other required special permit or exemption markings.

(c) Specification DOT-4L cylinders (§ 178.57 of this subchapter) are authorized for the transportation of cryogenic liquids when carried in the vertical position as follows:

(1) For purposes of this section, “filling density,” except for hydrogen, is defined as the percent ratio of the weight of lading in the packaging to the weight of water that the packaging will hold at 60 °F. (1 lb. of water = 27.737 cubic inches at 60 °F.).

(2) The cryogenic liquids of argon, nitrogen, oxygen, helium and neon must be loaded and shipped in accordance with the following table:

(3) Hydrogen (minimum 95 percent parahydrogen) must be loaded and shipped as follows:

(i) Each cylinder must be constructed, insulated and maintained so that during transportation the total rate of venting shall not exceed 30 SCF of hydrogen per hour.

(ii) In addition to the marking requirements in § 178.35 of this subchapter, the total rate of venting in SCF per hour (SCFH) shall be marked on the top head or valve protection band in letters at least one-half inch high as follows: “VENT RATE**SCFH” (with the asterisks replaced by the number representing the total rate of venting, in SCF per hour).

(iii) Carriage by highway is subject to the conditions specified in § 177.840(a) of this subchapter.

(b) Specification DOT-4L (§ 178.57 of this subchapter) cylinders being transported in a rail car must be loaded in an upright position and be securely braced.