Ask X3What does 49 CFR 173.316 (Cryogenic liquids in cylinders) require?
Generated guidance. Confirm the source and its applicability before you act. How we check sources.
According to 49 CFR 173.316, motor carriers transporting cryogenic liquids in cylinders must comply with the following general and operational requirements:
* Loading limits: Do not load a cylinder with a cryogenic liquid colder than its design service temperature, or with any material that can chemically combine with packaging residues to create an unsafe condition. For cylinders with a design service temperature colder than −320 °F, the maximum weight of the contents must not exceed the design weight marked on the cylinder.
* Jacket material: The jacket covering the insulation on cylinders used for flammable cryogenic liquids must be made of steel.
* Valves and fittings:
* Aluminum valves or fittings with internal rubbing or abrading parts that may contact liquid oxygen must not be installed unless the parts are anodized according to ASTM Standard B 580.
* Aluminum valves, pipes, or fittings are prohibited on cylinders used to transport flammable cryogenic liquids.
* Pressure relief devices: Each cylinder must have one or more pressure relief devices installed, located, and maintained so that the cooling effect of venting contents does not hinder their operation. Relief device inlets must be in the vapor space under maximum filling conditions, and the devices must allow unobstructed vapor escape.
* Pressure control systems: Cylinders must feature a pressure control system conforming to § 173.301(f) designed and installed to prevent the cylinder from becoming liquid full.
* Specification cylinders and filling limits: DOT-4L specification cylinders are authorized if carried in the vertical position and loaded according to specific filling densities and pressure control valve settings outlined in the regulation for specific gases (such as air, argon, nitrogen, oxygen, helium, neon, and hydrogen).
* Hydrogen-specific rules: Hydrogen shipments must meet specific parahydrogen purity, filling density, venting rate limits (not to exceed 30 SCF of hydrogen per hour), marking requirements on the top head or valve protection band, and highway carriage conditions specified in § 177.840(a).
* Mixtures: Cryogenic liquid mixtures without specifically prescribed charging requirements must be shipped in packagings and under conditions approved by the Associate Administrator.