Ask X3What does 49 CFR 173.302b (Additional requirements for shipment of non-liquefied (permanent) compressed gases in UN pressure receptacles) require?
Generated guidance. Confirm the source and its applicability before you act. How we check sources.
As Ask X3, your fleet-compliance assistant, here is what 49 CFR 173.302b requires for shipping non-liquefied (permanent) compressed gases in UN pressure receptacles:
* General Requirements: A cylinder filled with a non-liquefied gas must be offered for transportation in UN pressure receptacles subject to 49 CFR 173.302b, § 173.302, and the additional requirements in §§ 173.301 and 173.301b.
* Filling Limits: Except where specifically prescribed, the working pressure of a UN pressure receptacle cannot exceed 2/3 of its test pressure. Alternatively, you may use the filling limits specified in Table 1 of P200 of the UN Recommendations. In all cases, the internal pressure at 65 °C (149 °F) must not exceed the test pressure.
* Fluorine (UN 1045) & Oxygen Difluoride (UN 2190): Must be packaged in a UN pressure receptacle with a minimum test pressure of 200 bar and a maximum working pressure of no more than 30 bar. Aluminum alloy receptacles are not allowed, and the maximum quantity per receptacle is 5 kg.
* Diborane and Diborane Mixtures (UN 1911): Must use a UN pressure receptacle with a minimum test pressure of 250 bar and a maximum filling ratio (based on the test pressure) of no more than 0.07. Filling must be further limited so that if complete decomposition occurs, the pressure will not exceed the cylinder's working pressure. UN tubes and MEGCs are not authorized.
* Carbon Monoxide (UN 1016): For steel pressure receptacles, the settled pressure at 65 °C (149 °F) cannot exceed 1/3 of the test pressure, *unless* the gas is dry and sulfur-free, in which case the settled pressure may not exceed 1/2 of the marked test pressure.
* Methane or Natural Gas (UN 1971): Authorized in UN seamless steel pressure receptacles under specific conditions:
* *For methane or natural gas with $\ge$98.0% methane:* The maximum tensile strength of the steel receptacle cannot exceed 1100 MPa (159,542 psi), and the contents must be commercially free of corroding components.
* *For natural gas with $<$98.0% methane:* The maximum tensile strength cannot exceed 950 MPa (137,750 psi), each discharge end of a refillable seamless steel tube must have an internal drain tube, and moisture/corroding components must meet § 173.301b(a)(2).
* Fluorine Mixtures with Nitrogen or Inert Gases: Mixtures with a fluorine concentration below 35% by volume may be filled up to a maximum allowable working pressure where the partial pressure of fluorine does not exceed 31 bar (abs.). For mixtures with inert gases, the working pressure cannot exceed 200 bar, and the minimum test pressure must be 1.5 times the working pressure or 200 bar, whichever is greater (taking into account the coefficient of nitrogen equivalency per ISO 10156:2017).