Loading (50 kb)...'
(continued)
(b) Safety relief devices shall be arranged 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 structures or personnel. This requirement does not apply to DOT Specification containers having an internal volume of 2.0 cubic feet or less.
(c) 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.
s 5468. Piping, Tubing and Fittings.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 5469. Equipment Assembly.
(a) Valves, gauges, regulators and other accessories shall be suitable for hydrogen service.
(b) Installation of hydrogen systems shall be supervised by personnel familiar with proper practices with reference to their construction and use.
(c) Storage containers, piping, valves, regulating equipment and other accessories shall be readily accessible, and shall be protected against physical damage and against tampering.
(d) Cabinets or housings containing hydrogen control or operating equipment shall be adequately ventilated.
(e) Each mobile hydrogen supply unit used as part of a hydrogen system shall be adequately secured to prevent movement.
(f) Mobile hydrogen supply units shall be electrically bonded to the system before discharging hydrogen.
s 5470. Marking.
The hydrogen storage location shall be permanently placarded as follows: "HYDROGEN FLAMMABLE GAS NO SMOKING NO OPEN FLAMES," or equivalent.
s 5471. Testing.
After installation, all piping, tubing and fittings shall be tested and proved hydrogen gas tight at maximum operating pressure.
s 5472. Location of Gaseous Hydrogen Systems.
(a) The system shall be located so that it is readily accessible to delivery equipment and to authorized personnel.
(b) Systems shall be located above ground.
(c) Systems shall not be located beneath electric power lines.
(d) Systems shall not be located close to flammable liquid piping or piping of other flammable gases.
(e) Systems near above ground flammable liquid storage shall be located 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.
s 5473. Specific Requirements.
(a) The location of a system, as determined by the maximum total contained volume of hydrogen, shall be in the order of preference as indicated by Roman numerals in Table H-1.
Table H-1
_________________________________________________________
Size of Hydrogen System
Less 3,000 CF In Excess
Nature of Location than to of
3,000 CF 15,000 CF 15,000 CF
_________________________________________________________
Outdoors I I I
_________________________________________________________
In a separate building II II II
_________________________________________________________
In a special room III III Not
Permitted
_________________________________________________________
Inside buildings not in a Not Not
special room and exposed IV Permitted Permitted
to other occupancies
_________________________________________________________
(b) 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 shall be in accordance with Table H-2.
(c) The distance 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.
(d) Hydrogen systems of less than 3,000 CF when located inside buildings and exposed to other occupancies shall be situated in the building so that the system will be as follows:
(1) In an adequately ventilated area as in Section 5475(b).
(2) 20 feet from stored flammable materials or oxidizing gases.
(3) 25 feet from open flames, ordinary electrical equipment or other sources of ignition.
(4) 25 feet from concentrations of people.
(5) 50 feet from intakes of ventilation or air conditioning equipment and air compressors.
(6) 50 feet from other flammable gas storage.
(7) Protected against damage or injury due to falling objects or working activity in the area.
(8) 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.
Table H-2
_______________________________________________________________________________
Size of Hydrogen System
___________________________
Less 3,000 CF In
Excess
Type of Outdoor Exposure than to of
3,000 15,000 15,000
CF CF CF
_______________________________________________________________________________
1. Building or Wood Frame Construction 10 25 50
[FNa1]
Structure Heavy Timber, Noncom-
bustible or Ordinary
Con-
struction [FNa1] 0 10 25
[FNa1]
Fire Resistive
Construction [FNa1] 0 0 0
_______________________________________________________________________________
2. Wall Openings Not above any part of a 10 10 10
system
Above any part of a 25 25 25
system
_______________________________________________________________________________
3. Flammable
liquids 0-1,000 gallons 10 25 25
above ground In excess of 1,000 25 50 50
gallons
_______________________________________________________________________________
4. Flammable
liquids Tank 10 10 10
below ground-
0-1,000
gallons Vent or fill opening of 25 25 25
tank
_______________________________________________________________________________
5. Flammable
liquids Tank 20 20 20
below ground-
in excess of
1,000
gallons Vent or fill opening of 25 25 25
tank
_______________________________________________________________________________
6. Flammable gas
storage 0-15,000 CF capacity 10 25 25
age, either high
pressure or
low in excess of 15,000 CF
pressure capacity 25 50 50
_______________________________________________________________________________
7. Oxygen
Storage 12,000 CF or less Refer to NFPA No. 51, Gas
Systems
for Welding and Cutting
More than 12,000 CF Refer to NFPA No. 50, Bulk
Oxygen
Systems at Consumer Sites
_______________________________________________________________________________
8. Fast burning solids such as ordinary lumber, 50 50 50
excelsior or paper
_______________________________________________________________________________
9. Slow burning solids such as heavy timber or 25 25 25
coal
_______________________________________________________________________________
10. Open flames and other sources of ignition 25 25 25
_______________________________________________________________________________
11. Air compressor intakes or inlets to 50 50 50
ventilating
or air-conditioning
equipment
_______________________________________________________________________________
12. Concentration of people [FNaaa1] 25 50 50
_______________________________________________________________________________
13. Public Sidewalks 15 15 15
_______________________________________________________________________________
14. Line of adjoining property which may be built 5 5 5
upon
[FNa1] Refer to NFPA No. 220, Standard Types of Building Construction for
definitions of various types of construction.
[FNa]a1 But not less than one-half the height of adjacent side wall of the
structure.
[FNa]aa1 In congested areas such as offices, lunchrooms, locker rooms,
time-clock areas and places of public assembly.
s 5474. Design Considerations at Specific Locations.
(a) Where protective walls or roofs are provided, they shall be constructed of noncombustible materials.
(b) Where the enclosing sides adjoin each other, the enclosed area shall be properly ventilated.
(c) Electrical equipment within 15 feet shall be in accordance with the California Electrical Safety Orders for Class I, Division 2 locations. (Title 24, T8-5474)
s 5475. Separate Buildings.
(a) Separate buildings shall be built of at least noncombustible construction. Windows and doors shall be located so as to be readily accessible in case of emergency. Windows shall be of glass or plastic in metal frames.
(b) Adequate ventilation to the outdoors shall be provided. Inlet openings shall be located near the floor in exterior walls only. Outlet openings shall be located at the high point of the room in exterior walls or roof. Inlet and outlet openings shall each have a minimum total area of one (1) square foot per 1,000 cubic feet of room volume. Discharge from outlet openings shall be directed or conducted to a safe location.
(c) Explosion venting shall be provided in exterior walls or roof only. The venting area shall be equal to not less than one 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 lb. per sq. ft.
(d) There shall be no sources of ignition from open flames, electrical equipment, or heating equipment.
(e) Electrical equipment shall be in accordance with the California Electrical Safety Orders for Class I, Division 2 locations.
(f) Heating, if provided, shall be by steam, hot water, or other indirect means. (Title 24, T8-5475)
s 5476. Special Rooms.
(a) Floor, walls, and ceiling shall have a fire-resistance rating of at least two 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 shall be located so as to be readily accessible in case of emergency. Windows shall be of glass or plastic in metal frames.
(b) Ventilation shall be as provided in 5475(b).
(c) Explosion venting shall be as provided in 5475(c).
(d) There shall be no sources of ignition from open flames, electrical equipment, or heating equipment.
(e) Electrical equipment shall be in accordance with the California Electrical Safety Orders for Class I, Division 2 locations.
(f) Heating, if provided, shall be by steam, hot water, or indirect means. (Title 24, T8-5476)
s 5477. Operating Instructions.
For installations which require any operation of equipment by the user, legible instructions shall be maintained at operating locations.
s 5478. Maintenance.
(a) Each hydrogen system installed on consumer premises shall be inspected annually and maintained by a qualified representative of the equipment owner.
(b) The area within 15 feet of any hydrogen container shall be kept free of dry vegetation and combustible material.
s 5480. Liquefied Hydrogen Systems at Consumer Sites.
(a) Purpose. This section covers the general principles recommended for the installation of liquefied hydrogen systems on consumer premises where the liquid hydrogen supply to the consumer premises originates outside the consumer premises and is delivered by mobile equipment.
Exceptions:
(1) Portable containers having a total liquefied hydrogen content of less than 150 liters (39.63 gallons).
(2) Liquefied hydrogen manufacturing plants or other establishments operated by the hydrogen supplier or his agent for the sole purpose of storing liquefied hydrogen and refilling portable containers, trailers, mobile supply trucks or tank cars.
(Title 24, T8-5480)
s 5481. Design of Liquefied Hydrogen Systems.
(a) Hydrogen containers shall comply with the following:
(1) 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 (1974) or applicable provisions of API Standard 620, Recommended Rules for Design & Construction of Large, Welded, Low-Pressure Storage Tanks, Second Edition (June 1963) and Appendix R (April 1965).
(2) Portable containers shall be designed, constructed and tested in accordance with U. S. Department of Transportation Specifications and Regulations.
s 5482. 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 protective coating having a 2-hour fire-resistance rating. (Title 24, T8-5482)
s 5483. Marking.
Each container shall be legibly marked to indicate "LIQUEFIED HYDROGEN - FLAMMABLE GAS."
(See Section 5466(c).)
s 5484. Safety Relief Devices.
(a) Stationary liquefied hydrogen containers shall be equipped with safety relief devices sized in accordance with CGA Pamphlet S-1, Part 3, Safety Relief Device Standards for Compressed Gas Storage Containers.
(b) 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, Safety Relief Device Standards, Part 1, Compressed Gas Cylinders and Part 2, Cargo and Portable Tank Containers.
(c) 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 Section 5491(f) for venting of safety relief devices in special locations.
(d) 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.
(e) Safety relief devices shall be provided in piping wherever liquefied hydrogen could be trapped between closures.
s 5485. Piping, Tubing and Fittings.
(a) Piping, tubing and fittings and gasket and thread sealants shall be suitable for hydrogen service at the pressures and temperatures involved. Cast iron pipe and fittings shall not be used.
NOTES: 1. Consideration shall be given to the thermal expansion and contraction of piping systems when exposed to temperature fluctuations of ambient to liquefied hydrogen temperatures. 2. Some materials suitable for liquefied hydrogen temperature are austenitic chromium-nickel alloys, certain copper alloys, and aluminum which retain ductility and do not become brittle at the temperature of liquefied hydrogen.
(b) Hydrogen piping and tubing.
(1) Hydrogen piping and tubing installed after May 30, 1999, shall conform to ASME B31.3-1996, Process Piping, which is hereby incorporated by reference.
(2) Hydrogen piping and tubing installed on or before May 30, 1999, shall conform to either the American National Standard Code for Pressure Piping, Petroleum Refinery Piping, ANSI B31.3-1973, or the updated version of the ANSI/ASME B31.3 standard in effect at the time of installation.
(3) For temperatures of -20 <> F to -320 <> F, hydrogen piping shall be approved as defined Section 3206 of the General Industry Safety Orders.
(c) Joints in piping and tubing shall preferably be made by welding or brazing; flanged, threaded, socket or suitable compression fittings may be used.
(d) 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 Procedure D-1692-68 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.
(e) 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.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 5486. Equipment Assembly.
(a) Valves, gages, regulators and other accessories shall be suitable for liquefied hydrogen service and for the pressures and temperatures involved.
(b) Installation of liquefied hydrogen systems shall be supervised by personnel familiar with proper practices and with reference to their construction and use.
(c) 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.
(d) Cabinets or housings containing hydrogen control equipment shall be ventilated to prevent any accumulation of hydrogen gas.
s 5487. Testing.
(a) After installation, all field erected piping shall be tested and proved hydrogen gastight at operating pressure and temperature.
(b) Containers if out of service in excess of one year shall be inspected and tested as outlined in (a). The safety relief devices shall be checked to determine if they are operable and properly set.
s 5488. Liquefied Hydrogen Vaporizers.
(a) 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.
(b) The vaporizer and its piping shall be adequately protected on the hydrogen and heating media sections with safety relief devices.
(c) Heat used in a liquefied hydrogen vaporizer shall be indirectly supplied utilizing media such as air, steam, water, or water solutions.
(d) 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.
s 5489. Electrical Systems.
(a) Electrical wiring and equipment located within 3 feet of a point where connections are regularly made and disconnected, shall be in accordance with the California Electrical Safety Orders for Class I, Group B, Division 1 locations.
(b) Except as provided in (a), 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 be in accordance with the California Electrical Safety Orders for Class I, Group B, Division 2 locations. When equipment approved for Class I, Group B atmospheres is not commercially available, the equipment may be purged or ventilated in accordance with NFPA No. 496, Standard for Purged Enclosures for Electrical Equipment in Hazardous Locations, or intrinsically safe, or 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. (Title 24, T8-5489)
s 5490. Bonding and Grounding.
The liquefied hydrogen container and associated piping shall be electrically bonded and grounded.
s 5491. Location of Liquefied Hydrogen Storage.
(a) The storage containers shall be located so that they are readily accessible to non-sparking mobile supply equipment at ground level and to authorized personnel.
(b) The containers shall not be exposed by electric power lines, flammable liquid lines, flammable gas lines, or lines carrying oxidizing materials.
(c) When locating liquefied hydrogen storage containers near aboveground flammable liquid storage or liquid oxygen storage, it is advisable to locate the liquefied hydrogen container on ground higher than flammable liquid storage or liquid oxygen storage.
(d) 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, or 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.
(e) 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."
(f) If liquefied hydrogen is located (as specified in Table H-3) in 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 5484(b).
s 5492. Specific Requirements.
(a) 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)
39.63 In excess
Nature of Location (150 liters) 51 to 300 301 to 600 of 600
to 50
Outdoors I I I I
In a separate building II II II Not permitted
In a special room III III Not permitted Not permitted
Inside buildings not in
a special room and
exposed to other
occupancies IV Not Not Not
permitted permitted permitted
Note: This table does not apply to the storage in dewars of the type generally used in laboratories for experimental purposes.
(b) 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 Exposures
Liquefied Hydrogen Storage
39.63 3,501 15,001
Type of Exposure (150 liters) to to
3,500 15,000 30,000
1. Fire-resistive Building and 5 5 5
Fire Walls [FNa1]
2. Noncombustible Building [FNa1] 25 50 75
3. Other Buildings [FNa1] 50 75 100
4. Wall Openings, Air Compressor 75 75 75
Intakes, Inlets for Air-
Conditioning or Ventilating Equipment
5. Flammable Liquids (Above- 50 75 100
ground and Vent or Fill
Openings if Below Ground)
(See 5491(c) and (d))
6. Between Stationary Liquefied 5 5 5
Hydrogen Containers
7. Flammable Gas Storage 50 75 100
8. Liquid Oxygen Storage and 100 100 100
other Oxidizers (See 5491(c) and (d))
9. Combustible Solids 50 75 100
10. Open Flames, Smoking and 50 50 50
Welding
11. Concentrations of People [FNaa1] 75 75 75
12. Public Ways, Railroads, and 25 50 75
Property Lines
[FNa1] Refer to NFPA No. 220, "Standard Types of Building Construction," for
definitions of construction types.
[FNa]a1 In congested areas such as offices, lunchrooms, locker rooms, time
clock areas, and places of public assembly.
Note: 1: The distances in Nos. 2, 3, 5, 7, 8, 9 and 12, in Table 2, may be reduced where protective structures, such as fire walls 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. (See definition of Outdoor Location, Section 5415.)
Note: 2: Where protective structures are provided, ventilation and confinement of product shall be considered. The 5-foot distance in Nos. 1 and 6 facilitates maintenance and enhances ventilation.
s 5493. Handling of Liquefied Hydrogen Inside Buildings Other Than Separate Buildings and Special Rooms.
(a) Portable liquefied hydrogen containers of 50 gallons or less capacity as permitted in Table H-3 and in compliance with Section 5491(f) when housed inside buildings not located in a special room and exposed to other occupancies shall comply with the following minimum requirements:
(1) Be located 20 feet from flammable liquids and readily combustible materials such as excelsior or paper.
(2) Be located 25 feet from ordinary electrical equipment, and other sources of ignition including process or analytical equipment. (See Section 5489.)
(3) Be located 25 feet from concentrations of people.
(4) Be located 50 feet from intakes of ventilation and air-conditioning equipment or intakes of compressors.
(5) Be located 50 feet from storage of other flammable gases or storage of oxidizing gases.
(6) Containers shall be protected against damage or injury due to falling objects or work activity in the area.
(7) Containers shall be firmly secured and stored in an upright position.
(8) Welding or cutting operations, and smoking shall be prohibited while hydrogen is in the room.
(9) The area shall be adequately ventilated. Safety relief devices on the containers shall be vented directly outdoors or to a suitable hood. See Sections 5469(b) and 5491(f).
s 5494. Design Considerations at Specific Locations.
(a) Roadways and yard surfaces located below liquefied hydrogen piping, from which liquid air may drip, shall be constructed of noncombustible materials.
(b) If protective walls are provided, they shall be constructed of noncombustible materials and in accordance with the provisions of the definition of "Outdoor Location" (See Section 5415) as applicable.
(c) Electrical wiring and equipment shall comply with Sections 5489 (a) and (b).
(d) Adequate lighting shall be provided for nighttime transfer operation. (Title 24, T8-54954).
s 5495. Separate Buildings.
(a) 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.
(b) 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 one square foot per 1,000 cubic feet of room volume. Discharge from outlet openings shall be directed or conducted to a safe location.
(c) There shall be no sources of ignition.
(d) Electrical wiring and equipment shall comply with Section 5489 except that the provisions of Subsection (b) of Section 5489 shall apply to all electrical wiring and equipment in the separate building.
(e) Heating, if provided, shall be by steam, hot water, or other indirect means. (Title 24, T8-5495)
s 5496. Special Rooms.
(a) Floors, walls and ceilings shall have a fire resistance rating of at least two 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.
(b) Ventilation shall be as provided in Section 5495(b).
(c) Explosion venting shall be provided in exterior walls or roof only. The venting area shall be equal to not less than one 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.
(d) There shall be no sources of ignition.
(e) Electrical wiring and equipment shall comply with Section 5489 except that the provisions of Subsection (b) of Section 5489 shall apply to all electrical wiring and equipment in the special room.
(f) Heating, if provided, shall be steam, hot water, or by other indirect means. (Title 24, T8-5496)
s 5497. Operating Instructions.
(a) For installations which require any operation of equipment by the user, legible instructions shall be maintained at operating locations.
(b) A qualified person shall be in attendance at all times while the mobile hydrogen supply unit is being unloaded.
(c) Each mobile liquefied hydrogen supply unit used as part of a hydrogen system shall be adequately secured to prevent movement.
(d) The mobile hydrogen supply unit shall be grounded.
s 5498. Maintenance.
(a) Each liquefied hydrogen system installed on consumer premises shall be inspected annually and maintained by a qualified representative of the equipment owner.
(b) The area within 25 feet of any liquefied hydrogen equipment shall be kept free of dry vegetation and combustible material.
s 5500. Bulk Oxygen Systems at Consumer Sites.
(a) Purpose. This Section covers the general principles recommended for the installation of bulk oxygen systems on industrial and institutional consumer premises where the supply to the consumer premises originates outside the consumer premises and is delivered by mobile equipment.
Exceptions:
(1) Oxygen manufacturing plants or other establishments operated by the oxygen supplier or his agent for the purpose of storing oxygen and refilling portable containers, trailers, mobile supply trucks or tank cars.
(2) Bulk oxygen storage systems having capacities less than 20,000 cubic feet.
(Title 24, T8-5500)
s 5501. Location of Bulk Oxygen Systems.
(a) Bulk oxygen storage systems shall be located aboveground out of doors, or shall be installed in a building of noncombustible construction, adequately vented, and used for that purpose exclusively. The location selected shall be such that containers and associated equipment shall not be exposed by electric power lines, flammable or combustible liquid lines, or flammable gas lines.
(b) The system shall be located so that it is readily accessible to mobile supply equipment at ground level and to authorized personnel.
(c) Where oxygen is stored as a liquid, noncombustible surfacing shall be provided in an area extending at least 3 feet from points at ground level upon which any leakage of liquid oxygen might fall during operation of the system and filling of a storage container. Such an area under liquid delivery connections of mobile supply equipment shall be at least the full width of the vehicle and at least 8 feet in the transverse direction. For purposes of this Article, asphaltic or bitumastic paving is considered to be combustible. The slope, if any, of such areas shall consider possible flow of spilled liquid oxygen to adjacent combustible material.
Note: When locating bulk oxygen systems near aboveground flammable or combustible liquid storage which may be either indoors or outdoors, it is advisable to locate the system on ground higher than the flammable or combustible liquid storage.
(d) Where it is necessary to locate a bulk oxygen system on ground lower than adjacent flammable or combustible liquid storage, suitable means shall be taken (such as by diking, diversion curbs, or grading) with respect to the adjacent flammable or combustible liquid storage to prevent accumulation of liquids under the bulk oxygen system. (Title 24, T8-5501(a), (b))
s 5502. Distance Between Bulk Oxygen Systems and Exposures.
(a) Except as provided in (15), the minimum distance from any bulk oxygen storage container to exposures, measured in the most direct line (except as indicated in (5), shall be as indicated in (1) to (15) inclusive.
(1) 50 feet from buildings of wood frame construction.
(2) Not less than one foot (or other distance to permit system maintenance) from buildings of other than wood frame construction, including fire resistive, heavy timber, noncombustible, and ordinary construction.
(3) At least 10 feet from any opening in walls of adjacent structures. This provision shall apply to all elements of a bulk oxygen system where the oxygen storage is high pressure gas. Where the storage is as liquid, this provision shall apply to only pressure regulators, safety devices, vaporizers, manifolds, and interconnecting piping.
(4) Flammable and Combustible Liquid Storage Aboveground:
Distance (feet) Capacity (gallons)
25 1000 or less
50 1001 or more
(5) Flammable and Combustible Liquid Storage Belowground:
Distance Measured Horizontally Distance from Oxygen Storage
from Oxygen Storage Container Container to Filling and Vent
to Tank (feet) Connections or Openings to Tank (feet)
15 25
(6) 25 feet from quantities of flammable gases not exceeding 1,000 gallons of liquefied gases, or 25,000 cubic feet NTP for nonliquefied or dissolved gases. For quantities in excess of these, the distance shall be 50 feet.
(7) 50 feet from solid materials which burn rapidly, such as excelsior or paper.
(8) 25 feet from solid materials which burn slowly, such as coal and heavy timber.
(9) 75 feet in one direction and 35 feet in approximately 90 direction from confining walls (not including fire walls less than 20 feet high) to provide adequate ventilation in courtyards and similar confining areas.
(10) 25 feet from congested areas such as offices, lunchrooms, locker rooms, time clock areas, and similar locations where employees may congregate.
(11) 50 feet from places of public assembly.
(12) 50 feet from areas occupied by nonambulatory patients.
(13) 10 feet from any public sidewalk or parked vehicles.
(14) 5 feet from any line of adjoining property which may be built upon.
(15) The distances in (1), (4) to (8) inclusive, (13), and (14) do not apply where protective structures, such as fire walls or insulated liquid oxygen storage containers, interrupt the line-of-sight between uninsulated portions of the bulk oxygen storage installation and the exposure. In such cases, the uninsulated bulk oxygen installation shall be a minimum distance of 1 foot (or greater distance if required for system maintenance) from the protective structure. (Title 24, Part 6, Section T8-5502)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 5503. Bulk Oxygen Storage Containers.
(a) Foundation and Supports. Permanently installed containers shall be provided with substantial noncombustible supports on firm noncombustible foundations.
(b) Liquid oxygen containers shall comply with (b)(1) or (b)(2).
(1) Be fabricated from materials meeting the impact test requirements of Paragraph UG-84 of the ASME Boiler and Pressure Vessel Code, Section VIII - Unfired Pressure Vessels (1974). Containers operating at pressures above 15 psig shall be designed, constructed and tested in accordance with appropriate requirements of the ASME Boiler and Pressure Vessel Code, Section VIII -Unfired Pressure Vessels (1974). Insulation surrounding the liquid oxygen container shall be noncombustible.
(2) Be designed, constructed, tested and maintained in accordance with U. S. Department of Transportation (DOT) Specifications and Regulations for 4L containers.
(c) High pressure gaseous oxygen containers shall comply with (c)(1) or (c)(2).
(1) Be designed, constructed and tested in accordance with appropriate requirements of the ASME Boiler and Pressure Vessel Code, Section VIII -Unfired Pressure Vessels (1974).
(2) Be designed, constructed, tested and maintained in accordance with U. S. Department of Transportation (DOT) Specifications and Regulations.
s 5504. Piping, Tubing and Fittings.
(a) Piping, tubing and fittings shall be suitable for oxygen service and for the pressures and temperatures involved.
(b) Piping and tubing installed after May 30, 1999, shall conform to ASME B31.3-1996, Process Piping, which is hereby incorporated by reference. Piping and tubing installed on or before May 30, 1999, shall conform to either the American National Standard Code for Pressure Piping, Petroleum Refinery Piping, ANSI B31.3-1973, or the updated version of the ANSI/ASME B31.3 standard in effect at the time of installation.
(c) Piping or tubing for operating temperatures below -20 <> F. shall be fabricated from materials meeting the impact test requirements of Paragraph UG-84 of ASME Boiler and Pressure Vessel Code, Section VIII Unfired Pressure Vessels (1974), when tested at the minimum operating temperature to which the piping may be subjected in service.
Note: Some materials suitable for low temperature piping are austenitic chromium-nickel alloy steels, copper, copper-silicon alloys, aluminum, and some brasses and bronzes.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 5505. Safety Relief Devices.
(a) Bulk oxygen storage containers, regardless of design pressure, shall be equipped with safety relief devices as required by the ASME Code or the DOT Specifications and Regulations. (See Section 5503.)
(b) Bulk oxygen storage containers designed and constructed in accordance with a DOT Specification shall be equipped with safety relief devices as required by the DOT. See Subsection 5503(c)(2).
(c) Bulk oxygen storage containers designed and constructed in accordance with the ASME Boiler and Pressure Vessel Code, Section VIII -Unfired Pressure Vessels (1974), shall be equipped with safety relief devices meeting the provisions of Compressed Gas Association Pamphlet "Safety Relief Device Standards for Compressed Gas Storage Containers," S-1, Part 3.
(d) Insulation casings on liquid oxygen containers shall be equipped with suitable safety relief devices.
(e) All safety relief devices shall be so designed or located that moisture cannot collect and freeze in a manner which could interfere with proper operation of the device.
s 5506. Liquid Oxygen Vaporizers.
(a) The vaporizer shall be anchored and its connecting piping be sufficiently flexible to provide for the effect of expansion and contraction due to temperature changes.
(b) The vaporizer and its piping shall be adequately protected on the oxygen and heating medium sections with safety relief devices.
(c) Heat used in an oxygen vaporizer shall be indirectly supplied only through mediums such as steam, air, water, or water solutions which do not react with oxygen.
(d) If electric heaters are used to provide the heat, the vaporizing system shall be electrically grounded.
s 5507. Equipment Assembly and Installation.
(a) Equipment making up a bulk oxygen system shall be cleaned in order to remove oil, grease or other readily oxidizable materials before placing the system in service.
(b) Joints in piping and tubing may be made by welding or by use of flanged, threaded, slip or compression fittings. Gaskets or thread sealants shall be suitable for oxygen service.
(c) Valves, gages, regulators and other accessories shall be suitable for oxygen service.
(d) Installation of bulk oxygen systems shall be supervised by personnel familiar with proper practices with reference to their construction and use.
(e) After installation all field erected piping shall be tested and proved gas tight at maximum operating pressure. Any medium used for testing shall be inert and oil free.
(f) Storage containers, piping, valves, regulating equipment, and other accessories shall be protected against physical damage and against tampering.
(g) Any enclosure containing oxygen control or operating equipment shall be adequately vented.
(h) The bulk oxygen storage location shall be permanently placarded to indicate: "OXYGEN -NO SMOKING -NO OPEN FLAMES," or an equivalent warning.
Note: Bulk oxygen installations are not hazardous locations as defined and covered in the California Electrical Safety Orders.
s 5508. Operating Instructions.
For installations which require any operation of equipment by the user, legible instructions shall be maintained at operating locations.
s 5509. Maintenance.
(a) Each bulk oxygen system installed on consumer premises shall be periodically inspected and maintained by a qualified representative of the equipment owner.
(b) The area within 15 feet of any bulk oxygen storage container shall be kept free of dry vegetation and combustible material.
s 5530. Scope.
This article shall apply to areas where Class I liquids are stored or handled or where Class II or Class III liquids are stored or handled at a temperature above their flash points.
For areas where Class II or Class III liquids only are stored or handled at a temperature below their flash points, the electrical equipment may be installed in accordance with the provisions of the California Electrical Safety Orders for ordinary locations; however, care shall be used in locating electrical apparatus to prevent hot metal from falling into open equipment.
(a) All electrical equipment and wiring shall be of a type specified by and shall be installed in accordance with the California Electrical Safety Orders.
(b) In the application of classified areas, a classified area shall not extend beyond an unpierced floor, wall, roof or other solid partition.
(c) Where the provisions of this article require the installation of electrical equipment suitable for Class I, Division 1 or Division 2 locations, ordinary electrical equipment including switchgear may be used if installed in a room or enclosure which is maintained under positive pressure with respect to the classified area. Ventilation make-up air shall be uncontaminated by flammable vapors.
(1) Pressurizing or purging of classified areas shall be in compliance with NFPA 496-1974.
(d) The area classifications listed in Table FL-1 are based on the premise that the installation meets the applicable requirements of this section in all respects.
(e) Extent of classified areas shall be as contained in Table FL-1. (Title 24, T8-5530)
Table FL-1
Class I Extent of
Location Divisi- Classified Area
on
Indoors equipment in- 1 Area within 5 feet of any edge of such equip-
stalled in accordance ment, extending in all directions.
with
5546(d) where
flammable
vapor-air mixtures
may ex-
ist under normal 2 Area between 5 feet and 8 feet of any edge of
operations.
such equipment, extending in all directions.
Also, area up to 3 feet above floor or grade
level within 5 feet to 25 feet horizontally
from any edge of such equipment. [FNa1]
Outdoor equipment of 1 Area within 3 feet of any edge of such equip-
the
type covered in ment, extending in all directions.
5546(d)
where flammable
vapor-
air mixtures may
exist un-
der normal 2 Area between 3 feet and 8 feet of any edge of
operations.
such equipment extending in all directions.
Also, area up to 3 feet above floor or grade
level within 3 feet to 10 feet horizontally
from any edge of such equipment.
Tank -Aboveground
(Un-
derground, see 5574)
Shell, Ends, or Roof 2 Within 10 feet from shell, ends or roof of
and
tank
Dike Area Area inside dikes to level of top of dike.
Vent 1 Within 5 feet of open end of vent, extending
in all directions.
Floating Roof 1 Area above the roof and within the shell.
Drum and Container 1 Within 3 feet of vent and fill opening, ex
Filling
Outdoors, or Indoors tending in all directions
with Adequate 2 Area between 3 feet and 5 feet from vent or
Ventilation
fill opening, extending in all directions. Also
up to 18 inches above floor or grade level
within a horizontal radius of 10 feet from
vent or fill opening.
Pumps, Bleeders,
With-
drawal, Fittings,
Meters
and Similar Devices
Indoors 2 Within 5 feet of any edge of such devices ex-
tending in all directions. Also up to 3 feet
above floor or grade level within 25 feet hor-
izontally from any edge of such devices.
Outdoors 2 Within 3 feet of any edge of such devices,
extending in all directions. Also up to 18
inches above grade level within 10 feet ho-
rizontally from any edge of such devices.
Pits
Without Mechanical 1 Entire area within pit if any part is within a
Ventilation within a Division 1 or 2 classified area.
With Mechanical 2 Entire area within pit if any part is within a
Vent-
lation Division 1 or 2 classified area.
Containing Valves, 2 Entire pit.
Fit-
tings or Piping, and
Not
Within a Division 1
or 2
Classified Area
Drainage Ditches, 2 Area upto 18 inches above ditch, separ- (continued)