Helium shipment

NECK PLUG HAZARDS IN LIQUID-HELIUM SHIPMENT... 

Neck Plug Hazards in Liquid-Helium Shipment... 

To verify the membrane integrity prior to attempting separations, pure gas permeation rates for nitrogen and helium were determined and compared to the vendor s data supplied with the membrane. Figure 4 and Table V verify the vendor s data reasonably well for the only membrane which survived shipment and startup. The agreement of the nitrogen values is particularly indicative of the membrane s integrity. 

During 1961 and 1962, several malfunctions of liquid-helium containers caused certain airlines to place a temporary embargo on the air shipment of this cargo. No real practical data were available to substantiate burst pressures, hold times, and the effect of loss of vacuum. Tests were conducted by Air Reduction in conjunction with Superior Air Products to determine the required data. 

Under the appropriate DOT and TC regulations, helium is authorized for shipment as follows [5, 6] ... 

Helium gas is authorized for shipment in cylinders, tank cars, and tube trailers in accordance with DOT and TC regulations [5, 6]. Liquid helium is shipped as a cryogenic fluid in insulated cylinders, insulated portable and cargo tanks, and insulated intermodal containers. 

Cylinders that comply with TC/DOT specifications 3A and 3AA are the types usually used to ship gaseous helium, but it is authorized for shipment in any cylinders approved for nonliq-uefied compressed gas. (These include cylinders meeting TC/DOT specifications 3A, 3AA, 3AX, and 3AAX 3B, 3E, 3T, 3AL, 39, 4B, 4BA, and 4BW. In addition, continued use of cylinders complying with TC/DOT specifications 3C, 3D, 4, 4A, 4C, 3, 25, 26, 33, and 38 is authorized, but new construction is not authorized.)... 

Liquid helium is authorized for shipment in cylinders that meet TC/DOT specification 4L. At operating pressures under 25.3 psig (174 kPa), the container specification is not regulated by DOT. 

Gaseous helium is authorized for rail shipment in tank cars that comply with TC/DOT specification 107A. DOT regulations require that the pressure to which the containers are charged must not exceed 10 percent in excess of the marked maximum gas pressure at 130°F (54.4°C). 

By Air In cylinders aboard passenger aircraft up to 150 lb (68 kg) and aboard cargo aircraft up to 300 lb (136 kg) maximum net weight per cylinder. Liquid helium aboard passenger aircraft up to 100 lb (45 kg) maximum net contents per container, aboard cargo aircraft up to 1100 lb (499 kg) maximum net weight per container. Shipment of nonpressurized (open dewars) is prohibited aboard aircraft. 

Liquid hydrogen is rapidly assuming its position as a major commercial chemical. Bulk transcontinental shipments of liquid helium are also planned for the near future. These activities have been implemented by the development of efficient and practical storage equipment. 

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