WAC 296-24-31505   Liquefied hydrogen systems.  (1) Design.

     (a) Containers.

     (i) Hydrogen containers shall comply with the following: Storage containers shall be designed, constructed, and tested in accordance with appropriate requirements of the ASME Boiler and Pressure Vessel Code, Section VIII -- Unfired Pressure Vessels (1968) or applicable provisions of API Standard 620, Recommended Rules for Design and Construction of Large, Welded, Low-Pressure Storage Tanks, Second Edition (June 1963) and Appendix R (April 1965).

     (ii) Portable containers shall be designed, constructed and tested in accordance with DOT specifications and regulations.

     (b) Supports. Permanently installed containers shall be provided with substantial noncombustible supports securely anchored on firm noncombustible foundations. Steel supports in excess of 18 inches in height shall be protected with a protective coating having a 2-hour fire-resistance rating.

     (c) Marking. Each container shall be legibly marked to indicate "LIQUEFIED HYDROGEN -- FLAMMABLE GAS."

     (d) Safety relief devices.

     (i) Stationary liquefied hydrogen containers shall be equipped with safety relief devices sized in accordance with CGA Pamphlet S-1-1966, Part 3, Safety Relief Device Standards for Compressed Gas Storage Containers.

     (A) Portable liquefied hydrogen containers complying with the U.S. Department of Transportation regulations shall be equipped with safety relief devices as required in the U.S. Department of Transportation specifications and regulations. Safety relief devices shall be sized in accordance with the requirements of CGA Pamphlet S-1-1966, Safety Relief Device Standards, Part 1, Compressed Gas Cylinders and Part 2, Cargo and Portable Tank Containers.

     (ii) Safety relief devices shall be arranged to discharge unobstructed to the outdoors and in such a manner as to prevent impingement of escaping liquid or gas upon the container, adjacent structures or personnel. See (2)(a)(vi) of this section for venting of safety relief devices in special locations.

     (iii) Safety relief devices or vent piping shall be designed or located so that moisture cannot collect and freeze in a manner which would interfere with proper operation of the device.

     (iv) Safety relief devices shall be provided in piping wherever liquefied hydrogen could be trapped between closures

     (e) Piping, tubing, and fittings.

     (i) Piping, tubing, and fittings and gasket and thread sealants shall be suitable for hydrogen service at the pressures and temperatures involved. Consideration shall be given to the thermal expansion and contraction of piping systems when exposed to temperature fluctuations of ambient to liquefied hydrogen temperatures.

     (ii) Gaseous hydrogen piping and tubing (above -- 20°F) shall conform to the applicable sections of Pressure Piping Section 2 -- Industrial Gas and Air Piping, ANSI B31.1-1967 with addenda B31.1-1969. Design of liquefied hydrogen or cold (-20°F or below) gas piping shall use Petroleum Refinery Piping ANSI B31.3-1966 or Refrigeration Piping ANSI B31.5-1966 with addenda B31.5a-1968 as a guide.

     (iii) Joints in piping and tubing shall preferably be made by welding or brazing; flanged, threaded, socket, or suitable compression fittings may be used.

     (iv) Means shall be provided to minimize exposure of personnel to piping operating at low temperatures and to prevent air condensate from contacting piping, structural members, and surfaces not suitable for cryogenic temperatures. Only those insulating materials which are rated nonburning in accordance with ASTM Procedures D1692-68 may be used. Other protective means may be used to protect personnel. The insulation shall be designed to have a vapor-tight seal in the outer covering to prevent the condensation of air and subsequent oxygen enrichment within the insulation. The insulation material and outside shield shall also be of adequate design to prevent attrition of the insulation due to normal operating conditions.

     (v) Uninsulated piping and equipment which operate at liquefied-hydrogen temperature shall not be installed above asphalt surfaces or other combustible materials in order to prevent contact of liquid air with such materials. Drip pans may be installed under uninsulated piping and equipment to retain and vaporize condensed liquid air.

     (f) Equipment assembly.

     (i) Valves, gauges, regulators, and other accessories shall be suitable for liquefied hydrogen service and for the pressures and temperatures involved.

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

     (iii) Storage containers, piping, valves, regulating equipment, and other accessories shall be readily accessible and shall be protected against physical damage and against tampering. A shutoff valve shall be located in liquid product withdrawal lines as close to the container as practical. On containers of over 2,000 gallons capacity, this shutoff valve shall be of the remote control type with no connections, flanges, or other appurtenances (other than a welded manual shutoff valve) allowed in the piping between the shutoff valve and its connection to the inner container.

     (iv) Cabinets or housings containing hydrogen control equipment shall be ventilated to prevent any accumulation of hydrogen gas.

     (g) Testing.

     (i) After installation, all field-erected piping shall be tested and proved hydrogen gas-tight at operating pressure and temperature.

     (ii) Containers if out of service in excess of 1 year shall be inspected and tested as outlined in (1) of this section. The safety relief devices shall be checked to determine if they are operable and properly set.

     (h) Liquefied hydrogen vaporizers.

     (i) 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.

     (ii) The vaporizer and its piping shall be adequately protected on the hydrogen and heating media sections with safety relief devices.

     (iii) Heat used in a liquefied hydrogen vaporizer shall be indirectly supplied utilizing media such as air, steam, water, or water solutions.

     (iv) A low temperature shutoff switch shall be provided in the vaporizer discharge piping to prevent flow of liquefied hydrogen in the event of the loss of the heat source.

     (i) Electrical systems.

     (i) Electrical wiring and equipment located within 3 feet of a point where connections are regularly made and disconnected, shall meet the requirements of chapter 296-24 WAC Part L for Class I, Division 1 locations.

     (ii) Except as provided in (l) of this section, electrical wiring, and equipment located within 25 feet of a point where connections are regularly made and disconnected or within 25 feet of a liquid hydrogen storage container, shall meet the requirements of chapter 296-24 WAC Part L for Class I, Division 2 locations. When equipment approved for Class I, environments is not commercially available, the equipment may be:

     (A) Purged or ventilated in accordance with NFPA No. 496-1967, Standard for Purged Enclosures for Electrical Equipment in Hazardous Locations,

     (B) Intrinsically safe, or

     (C) Approved for Class I, Group C atmospheres. This requirement does not apply to electrical equipment which is installed on mobile supply trucks or tank cars from which the storage container is filled.

     (j) Bonding and grounding. The liquefied hydrogen container and associated piping shall be electrically bonded and grounded.

     (2) Location of liquefied hydrogen storage.

     (a) General requirements.

     (i) The storage containers shall be located so that they are readily accessible to mobile supply equipment at ground level and to authorized personnel.

     (ii) The containers shall not be exposed by electric power lines, flammable liquid lines, flammable gas lines, or lines carrying oxidizing materials.

     (iii) When locating liquefied hydrogen storage containers near above-ground flammable liquid storage or liquid oxygen storage, locate the liquefied hydrogen container on ground higher than flammable liquid storage or liquid oxygen storage.

     (iv) Where it is necessary to locate the liquefied hydrogen container on ground that is level with or lower than adjacent flammable liquid storage or liquid oxygen storage, suitable protective means shall be taken (such as by diking, diversion, curbs, grading), with respect to the adjacent flammable liquid storage or liquid oxygen storage, to prevent accumulation of liquids within 50 feet of the liquefied hydrogen container.

     (v) Storage sites shall be fenced and posted to prevent entrance by unauthorized personnel. Sites shall also be placarded as follows: "Liquefied hydrogen -- Flammable gas -- No smoking -- No open flames."

     (vi) If liquefied hydrogen is located in (as specified in Table H-3) a separate building, in a special room, or inside buildings when not in a special room and exposed to other occupancies, containers shall have the safety relief devices vented unobstructed to the outdoors at a minimum elevation of 25 feet above grade to a safe location as required in (l)(d)(ii) of this section.

     (b) Specific requirements.

     (i) The location of liquefied hydrogen storage, as determined by the maximum total quantity of liquefied hydrogen, shall be in the order of preference as indicated by Roman numerals in the following Table H-3.


TABLE H-3


MAXIMUM TOTAL QUANTITY OF LIQUEFIED HYDROGEN STORAGE PERMITTED

Size of hydrogen storage (capacity in gallons)

Nature of location

39.63 (150 liters) to 50

51 to 300

301 to 600

In excess of 600

Outdoors

I

I

I

I

In a separate building

II

II

II

Not per- mitted.

In a special room

III

III

Not per- mitted

Not per- mitted.

Inside buildings not in a

No per- mitted

Not per- mitted

Not per- mitted.

special room and exposed to

other occupancies

IV

Note:

This table does not apply to the storage in dewars of the type generally used in laboratories for experimental purposes.

     (ii) The minimum distance in feet from liquefied hydrogen systems of indicated storage capacity located outdoors, in a separate building, or in a special room to any specified exposure shall be in accordance with Table H-4.


TABLE H-4


MINIMUM DISTANCE (FEET) FROM LIQUEFIED HYDROGEN SYSTEMS TO EXPOSURE

										Liquefied hydrogen storage (capacity in gallons)
Type of exposure					39.63 (150 liters) to 3,500					3,501 to 15,000			15,001 to 30,000
1. Fire-resistive building
	and fire walls*								5			5			5
2. Noncombustible
	building*								25			50			75
3. Other buildings*									50			75			100
4. Wall openings, air-com-
	pressor intakes, inlets
	for air-conditioning or
	ventilating equipment -								75			75			75
5. Flammable liquids (above
	ground and vent or fill
	openings if below
	ground) (see 513 and
	514)								50			75			100
6. Between stationary
	liquefied hydrogen
	containers								5			5			5
7. Flammable gas storage -									50			75			100
8. Liquid oxygen storage and
	other oxidizers (see
	513 and 514)								100			100			100
9. Combustible solids									50			75			100
10. Open flames, smoking,
	and welding								50			50			50
11. Concentrations of
	people**								75			75			75
12. Public ways, railroads,
	and property lines								25			50			75

*	Refer to standard types of building construction, NFPA No.                220-1969 for definitions of various types of construction.
**	In congested areas such as offices, lunchrooms, locker rooms,           time-clock areas, and places of public assembly.
Note 1:	The distance in Nos. 2, 3, 5, 7, 9, and 12 in Table H-4 may be           reduced where protective structures,such as firewalls equal to           height of top of the container, to safeguard the liquefied                hydrogen storage system, are located between the liquefied                hydrogen storage installation and the exposure.
Note 2:	Where protective structures are provided, ventilation and confinement of product should be considered. The 5-foot distance in Nos. 1 and 6 facilitates maintenance and enhances ventilation.

     (c) Handling of liquefied hydrogen inside buildings other than separate buildings and special rooms. Portable liquefied hydrogen containers of 50 gallons or less capacity as permitted in Table H-3 and in compliance with (2)(a)(vi) of this section when housed inside buildings not located in a special room and exposed to other occupancies shall comply with the following minimum requirements:

     (i) Be located 20 feet from flammable liquids and readily combustible materials such as excelsior or paper.

     (ii) Be located 25 feet from ordinary electrical equipment and other sources of ignition including process or analytical equipment.

     (iii) Be located 25 feet from concentrations of people.

     (iv) Be located 50 feet from intakes of ventilation and air-conditioning equipment or intakes of compressors.

     (v) Be located 50 feet from storage of other flammable-gases or storage of oxidizing gases.

     (vi) Containers shall be protected against damage or injury due to falling objects or work activity in the area.

     (vii) Containers shall be firmly secured and stored in an upright position.

     (viii) Welding or cutting operations, and smoking shall be prohibited while hydrogen is in the room.

     (ix) The area shall be adequately ventilated. Safety relief devices on the containers shall be vented directly outdoors or to a suitable hood. See (1)(d)(ii) of this section and (2)(a)(vi) of this section.

     (3) Design considerations at specific locations.

     (a) Outdoor locations.

     (i) Outdoor location shall mean outside of any building or structure, and includes locations under a weather shelter or canopy provided such locations are not enclosed by more than two walls set at right angles and are provided with vent-space between the walls and vented roof or canopy.

     (ii) Roadways and yard surfaces located below liquefied hydrogen piping, from which liquid air may drop, shall be constructed of noncombustible materials.

     (iii) If protective walls are provided, they shall be constructed of noncombustible materials and in accordance with the provisions of (3)(a)(i) of this section as applicable.

     (iv) Electrical wiring and equipment shall comply with chapter 296-24 WAC Part L.

     (v) Adequate lighting shall be provided for nighttime transfer operation.

     (b) Separate buildings.

     (i) Separate buildings shall be of light noncombustible construction on a substantial frame. Walls and roofs shall be lightly fastened and designed to relieve at a maximum internal pressure of 25 pounds per square foot. Windows shall be of shatterproof glass or plastic in metal frames. Doors shall be located in such a manner that they will be readily accessible to personnel in an emergency.

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

     (iii) There shall be no sources of ignition.

     (iv) Electrical wiring and equipment shall comply with chapter 296-24 WAC Part L.

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

     (c) Special rooms.

     (i) Floors, walls, and ceilings shall have a fire resistance rating of at least 2 hours. Walls or partitions shall be continuous from floor to ceiling and shall be securely anchored. At least one wall shall be an exterior wall. Openings to other parts of the building shall not be permitted. Windows and doors shall be in exterior walls and doors shall be located in such a manner that they will be accessible in an emergency. Windows shall be of shatterproof glass or plastic in metal frames.

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

     (iii) Explosion venting shall be provided in exterior walls or roof only. The venting area shall 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; lightly fastened hatch covers; lightly fastened swinging doors opening outward in exterior walls; lightly fastened walls or roofs designed to relieve at a maximum pressure of 25 pounds per square foot.

     (iv) There shall be no sources of ignition.

     (v) Electrical wiring and equipment shall comply with chapter 296-24 WAC Part L.

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

     (4) Operating instructions.

     (a) Written instructions. For installation which require any operation of equipment by the user, legible instructions shall be maintained at operating locations.

     (b) Attendant. A qualified person shall be in attendance at all times while the mobile hydrogen supply unit is being unloaded.

     (c) Security. Each mobile liquefied hydrogen supply unit used as part of a hydrogen system shall be adequately secured to prevent movement.

     (d) Grounding. The mobile liquefied hydrogen supply unit shall be grounded for static electricity.

     (5) Maintenance.

     (a) The equipment and functioning of each charged liquefied hydrogen system shall be maintained in a safe operating condition in accordance with the requirements of this section. Weeds or similar combustibles shall not be permitted within 25 feet of any liquified hydrogen equipment.



[Statutory Authority: Chapter 49.17 RCW. 91-24-017 (Order 91-07), § 296-24-31505, filed 11/22/91, effective 12/24/91; 88-23-054 (Order 88-25), § 296-24-31505, filed 11/14/88. Statutory Authority: RCW 49.17.040 and 49.17.050. 85-10-004 (Order 85-09), § 296-24-31505, filed 4/19/85; Order 76-6, § 296-24-31505, filed 3/1/76; Order 73-5, § 296-24-31505, filed 5/9/73 and Order 73-4, § 296-24-31505, filed 5/7/73.]