Michigan Administrative Code
Department - Licensing and Regulatory Affairs
Bureau of Fire Services
Storage and Handling of Gaseous and Liquefied Hydrogen Systems
Part 2 - STORAGE AND HANDLING OF GASEOUS HYDROGEN NFPA 50A
Chapter 4 - Design considerations at specific locations
Section R. 29.7041 - Indoor H2 storage system location
Current through Vol. 24-16, September 15, 2024
Rule 41. Sections 4-4 to 4-4.6, and table 4-4.1of the storage and handling of gaseous and Liquefied H2 code are added as follows:
4-4 Indoor H2 storage system location.
4-4.1 H2 systems of less than 3,500 scf (99 cubic meters) and greater than the maximum allowable quantity found in table 4.4.1, where located inside buildings outside of special rooms, shall be located in the building so that the system will be as follows:
(a) In a ventilated area in accordance with the provisions of section 4-3.7.
(b) Separated from incompatible materials.
(c) 15 feet (4.6 meters) from ordinary electrical equipment, and 25 feet (7.6 meters) from open flames or welding or other sources of ignition.
(d) 50 feet (15.2 meters) from other low-pressure flammable gas storage (less than 500 psig).
(e) Protected against damage in accordance with the provisions of section 2.1.5.
Table 4-4.1 Quantity Thresholds for Gases Requiring Special Provisions
| Unsprinklered areas | Sprinklered areas | |||
| Material | No gas cabinet, gas room, or exhausted enclosure | Gas cabinet, gas room, or exhausted enclosure | No gas cabinet, gas room, or exhausted enclosure | Gas cabinet, gas room, or exhausted enclosure |
| Cryogenic liquid (flammable or oxidizing) | 45 gal | 90 gal | 90 gal | 180 gal |
| Flammable gas liquefied nonliquefied | 14 kg3 (30 lb) | 27 kg3 (60 lb) | 27 kg3 (60 lb) | 55 kg3 (120 lb) |
| 28 m3 (1,000 ft3) | 28 m3 (2,000 ft3) | 28 m3 (2,000 ft3) | 56 m3 (4,000 ft3) | |
4-4.2 More than 1 system of 3,500 scf (99 cubic meters) or less shall be permitted to be installed in the same room or area outside of special rooms, provided the systems are separated by at least 50 feet (15.2 meters), or by a full height fire-resistive partition having a minimum fire resistance rating of 2 hours is located between the systems.
4-4.3 Each system described in section 4-4.2 shall meet all of the requirements of section 4-4.1.
4-4.4 The separation distance between multiple systems of 3,500 scf (99 cubic meters) or less shall be permitted to be reduced to 25 feet (7.6 meters) in buildings where the space between storage areas is free of combustible materials and protected with a sprinkler system.
4-4.5 When sprinkler protection is provided, the area in which H2 is stored or used shall be protected with a sprinkler system designed to be not less than that required by NFPA 13, "Standard for the Installation of Sprinkler Systems," adopted by reference in section 8-1, for ordinary hazard group 2 with a minimum design area of 3,000 square feet (914.4 square meters).
4-4.6 When sprinkler protection is provided, the area in which the H2 is stored or used shall be protected with a sprinkler system designed to be not less than that required by NFPA 13, "Standard for the Installation of Sprinkler Systems," adopted by reference in section 8-1, for extra hazard group 1 with a minimum design area of 2,500 square feet (762 square meters).
