(1) Design.

(a) Containers.

(i) You must ensure that hydrogen containers comply with one of the following:

(A) Designed, constructed, and tested in accordance with appropriate requirements of ASME Boiler and Pressure Vessel Code, Section VIII—Unfired Pressure Vessels—1968.

(B) Designed, constructed, tested and maintained in accordance with U.S. Department of Transportation specifications and regulations.

(ii) You must provide permanently installed containers with substantial noncombustible supports on firm noncombustible foundations.

(iii) You must legibly mark each portable container with the name "hydrogen" in accordance with "marking compressed gas containers to identify the material contained" ANSI Z48.1-1954. You must legibly mark each manifolded hydrogen supply unit with the name hydrogen or a legend such as "this unit contains hydrogen."

(b) Safety relief devices.

(i) You must ensure that hydrogen containers are equipped with safety relief devices as required by the ASME Boiler and Pressure Vessel Code, Section VIII Unfired Pressure Vessels, 1968 or the DOT specifications and regulations under which the container is fabricated.

(ii) You must arrange safety relief devices to discharge upward and unobstructed to the open air in such a manner as to prevent any impingement of escaping gas upon the container, adjacent structure of personnel. This requirement does not apply to DOT specification containers having an internal volume of 2 cubic feet or less.

(iii) You must design or locate safety relief devices or vent piping so that moisture cannot collect and freeze in a manner which would interfere with proper operation of the device.

(c) Piping, tubing, and fittings.

(i) You must ensure that piping, tubing, and fittings are suitable for hydrogen service and for the pressures and temperatures involved. You must not use case iron pipe and fittings.

(ii) You must ensure that piping and tubing conforms to Section 2—"Industrial Gas and Air Piping"—Code for Pressure Piping, ANSI B31.1-1967 with addenda B31.1-1969.

(iii) Joints in piping and tubing may be made by welding or brazing or by use of flanged, threaded, socket, or compression fittings. You must ensure that gaskets and thread sealants are suitable for hydrogen service.

(d) Equipment assembly.

(i) You must ensure that valves, gauges, regulators, and other accessories are suitable for hydrogen service.

(ii) Installation of hydrogen systems must be supervised by personnel familiar with proper practices with reference to their construction and use.

(iii) You must make storage containers, piping, valves, regulating equipment, and other accessories readily accessible, and ensure they are protected against physical damage and against tampering.

(iv) You must adequately ventilate cabinets or housings containing hydrogen control or operating equipment.

(v) You must adequately secure each mobile hydrogen supply unit used as part of a hydrogen system to prevent movement.

(vi) You must electrically bond mobile hydrogen supply units to the system before discharging hydrogen.

(e) Marking. You must permanently placard hydrogen storage location as follows: "hydrogen—flammable gas—no smoking—no open flames," or equivalent.

(f) Testing. After installations, you must test all piping, tubing, and fittings and prove it to be hydrogen gas tight at maximum operating pressure.

(2) Location.

(a) General.

(i) You must locate the system so that it is readily accessible to delivery equipment and to authorized personnel.

(ii) You must locate the systems above ground.

(iii) You must not locate the systems beneath electric power lines.

(iv) You must not locate the systems close to flammable liquid piping or piping of other flammable gases.

(v) You must locate the systems near aboveground flammable liquid storage on ground higher than the flammable liquid storage except when dikes, diversion curbs, grading, or separating solid walls are used to prevent accumulation of flammable liquids under the system.

(b) Specific requirements.

(i) You must ensure that the location of a system, as determined by the maximum total contained volume of hydrogen, is in the order of preference as indicated by Roman numerals in Table H-1.

(ii) The minimum distance in feet from a hydrogen system of indicated capacity located outdoors, in separate buildings or in special rooms to any specified outdoor exposure must be in accordance with Table H-2.

(iii) The distances in Table H-2 Items 1, 14, and 3 to 10 inclusive do not apply where protective structures such as adequate fire walls are located between the system and the exposure.

(iv) Hydrogen systems of less than 3,000 CF when located inside buildings and exposed to other occupancies must be situated in the building so that the system will be as follows:

(A) In an adequately ventilated area as in (3)(b)(ii) of this section.

(B) Twenty feet from stored flammable materials or oxidizing gases.

(C) Twenty-five feet from open flames, ordinary electrical equipment or other sources of ignition.

(D) Twenty-five feet from concentrations of people.

(E) Fifty feet from intakes of ventilation or air-conditioning equipment and air compressors.

(F) Fifty feet from other flammable gas storage.

(G) Protected against damage or injury due to falling objects or working activity in the area.

(H) More than one system of 3,000 CF or less may be installed in the same room, provided the systems are separated by at least 50 feet. Each such system shall meet all of the requirements of this section.

(3) Design consideration at specific locations.

(a) Outdoor locations.

(i) Where protective walls or roofs are provided, you must ensure that they are constructed of noncombustible materials.

(ii) Where the enclosing sides adjoin each other, you must ensure that the area is properly ventilated.

(iii) You must ensure that electrical equipment meets the requirements for Class I, Division 2 hazardous locations of WAC 296-24-95613.

(b) Separate buildings.

(i) Separate buildings must be built of at least noncombustible construction. Windows and doors must be located so as to be readily accessible in case of emergency. Windows must be of glass or plastic in metal frames.

(ii) Adequate ventilation to the outdoors must be provided. Inlet openings must be located near the floor in exterior walls only. Outlet openings must be located at the high point of the room in exterior walls or roof. Inlet and outlet openings must each have minimum total area of one square foot per 1,000 cubic feet of room volume. Discharge from outlet openings must be directed or conducted to a safe location.

(iii) Explosion venting must be provided in exterior walls or roof only. The venting area must be equal to not less than 1 square foot per 30 cubic feet of room volume and may consist of any one or any combination of the following: Walls of light noncombustible material, preferably single thickness, single strength glass; lightly fastened hatch covers; lightly fastened swinging doors in exterior walls opening outward; lightly fastened walls or roof designed to relieve at a maximum pressure of 25 pounds per square foot.

(iv) There must be no sources of ignition from open flames, electrical equipment, or heating equipment.

(v) Electrical equipment must meet the requirements of chapter 296-24 WAC Part L.

(vi) Heating, if provided, must be by steam, hot water, or other indirect means.

(c) Special rooms.

(i) Floor, walls, and ceiling must have a fire-resistance rating of at least 2 hours. Walls or partitions must be continuous from floor to ceiling and must be securely anchored. At least one wall must be an exterior wall. Openings to other parts of the building must not be permitted. Windows and doors must be in exterior walls and must be located so as to be readily accessible in case of emergency. Windows must be of glass or plastic in metal frames.

(ii) Ventilation must be as provided in (3)(b)(ii) of this section.

(iii) Explosion venting must be as provided in (3)(b)(iii) of this section.

(iv) There must be no sources of ignition from open flames, electrical equipment or heating equipment.

(v) Electrical equipment must meet the requirements of chapter 296-24 WAC Part L.

(vi) Heating, if provided, must be by steam, hot water, or indirect means.

(4) Operating instructions. For installations which require any operation of equipment by the user, you must maintain legible instructions at operating locations.

(5) Maintenance. The equipment and functioning of each charged gaseous hydrogen system must be maintained in a safe operating condition in accordance with the requirements of this section. You must keep the area within 15 feet of any hydrogen container free of dry vegetation and combustible material.