63.3.6 Flammable Gases
Table 184.108.40.206 Distance to Exposures for Non—Bulk Flammable Gases
|Maximum Amount per Storage Area (scf)||Minimum Distance Between Storage Areas (ft)||Minimum Distance to Lot Lines of Property That Can Be Built Upon (ft)||Minimum Distance to Public Streets, Public Alleys or Public Ways (ft)||Minimum Distance to Buildings on the Same Property|
|Less Than 2-Hour Construction||2-Hour Construction||4-Hour Construction|
For SI units, 1 ft = 304.8 mm;; 1 scf = 0.02832 Nm3.
Note: The minimum required distances does not apply where fire barriers without openings or penetrations having a minimum fire-resistive rating of 2 hours interrupt the line of sight between the storage and the exposure. The configuration of the fire barriers shall be designed to allow natural ventilation to prevent the accumulation of hazardous gas concentrations. [55: Table 7.6.2]
- In a ventilated area in accordance with the provisions of 63.2.16
- Separated from incompatible materials in accordance with the provisions of 220.127.116.11.2
- A distance of 25 ft (7.6 m) from open flames and other sources of ignition
- A distance of 50 ft (15 m) from intakes of ventilation, air-conditioning equipment, and air compressors located in the same room or area as the hydrogen system
- The distance shall be permitted to be reduced to 10 ft (3.1 m) where the room or area in which the hydrogen system is installed is protected by a listed detection system per Article 500.7(K) of NFPA 70 and the detection system shuts down the fuel supply in the event of a leak that results in a concentration that exceeds 25 percent of the LFL.
- Emergency shutoff valves shall be provided in accordance with 18.104.22.168.11.
- A distance of 50 ft (15 m) from other flammable gas storage
- Protected against damage in accordance with the provisions of 22.214.171.124.4.