Mich. Admin. Code R. 29.7084
Rule 84. Sections 2-6.1 to 2-6.4 are reproduced from NFPA 50B, and sections 2-6.5 to 2-6.13 of the storage and handling of gaseous and Liquefied H2 code are added as follows:
2-6 Liquefied H2 vaporizers.
2-6.1 The vaporizer shall be anchored and its connecting piping shall be sufficiently flexible to provide for the effect of expansion and contraction due to temperature changes.
2-6.2 The vaporizer and its piping shall be protected on the hydrogen and heating media sections with pressure relief devices.
2-6.3 Heat used in a liquefied hydrogen vaporizer shall be indirectly supplied utilizing media such as air, steam, water, or water solutions.
2-6.4 A low-temperature shutoff switch or valve shall be provided in the vaporizer discharge piping to prevent flow of liquefied hydrogen in the event of the loss of the heat source.
2-6.5 Vaporizers shall be designed for a working pressure at least equal to the maximum discharge pressure of the pump or the pressurized system that supplies them, whichever is greater.
2-6.6 The discharge valve of each vaporizer, if provided, its piping components, the relief valves installed upstream of the discharge valve, the vaporizer piping, and related components shall be suitable for operation at a liquefied H2 temperature of -423 degrees Fahrenheit (217.2 degrees Celsius).
2-6.7 Multiple vaporizers shall be manifolded such that both inlet and discharge block valves are installed on each vaporizer.
2-6.8 A low temperature switch or other accepted means shall be installed on the vaporizer discharge to eliminate the possibility of cryogenic H2 entering gaseous H2 containers and other equipment not designed for cryogenic H2 temperatures.
2-6.9 Relief valves on heated vaporizers shall be located so that they are not subjected to temperatures exceeding 140 degrees Fahrenheit (60 degrees Celsius) during normal operation unless they are designed to withstand higher temperatures.
2-6.10 The combustion air required for the operation of integral heated vaporizers or the primary heat source for remote heated vaporizers shall be taken from outside an enclosed structure or building.
2-6.11 Installation of internal combustion engines or gas turbines shall conform to R 29.5101 et seq.
2-6.12 Securing of vaporizers. Vaporizers, heat exchangers, and similar equipment shall be secured to foundations, and their connecting piping shall be flexible to provide for the effects of expansion and contraction due to temperature changes.
2-6.13 Vaporizers and heaters shall be provided with instrumentation to monitor outlet temperatures.
Exception: Ambient pressure-building coil vaporizers that are fed with liquid from, and return vapor to, a container.
Mich. Admin. Code R. 29.7084