The installation, storage, use, and handling of compressed gases and cryogenic fluids in portable and stationary containers, cylinders, equipment, and tanks in all occupancies shall comply with the requirements of Chapter 63; NFPA 55, and Sections 60.1 through 60.4 of this Code.
Where the provisions of Chapter 63 or NFPA 55
conflict with the provisions of Chapter 60, the provisions of
Chapter 63 and NFPA 55 shall apply.
The requirements in this chapter shall apply to users,
producers, distributors, and others who are involved with the
storage, use, or handling of compressed gases or cryogenic
fluids. [55:1.3]
Chapter 63 shall not apply to the following:
- * Off-site transportation of materials covered by Chapter 63
- Storage, use, and handling of radioactive gases in accordance with NFPA 801
- * Use and handling of medical compressed gases at health care facilities in accordance with NFPA 99, except as specified in Chapter 17 of NFPA 55
- Systems consisting of cylinders of oxygen and cylinders of fuel gas used for welding and cutting in accordance with NFPA 51
- * Flammable gases used as a vehicle fuel when stored on a vehicle
- * Storage, use, and handling of liquefied and nonliquefied compressed gases in laboratory work areas in accordance with NFPA 45
- Storage, use, and handling of liquefied petroleum gases in accordance with NFPA 58
- Storage, use, and handling of compressed gases within closed-cycle refrigeration systems complying with the mechanical code
- Liquefied natural gas (LNG) storage at utility plants under NFPA 59A
- Compressed natural gas (CNG) and liquefied natural gas (LNG), utilized as a vehicle fuel in accordance with NFPA 52
- * Compressed hydrogen gas (GH2), or liquefied hydrogen gas (LH2) generated, installed, stored, piped, used, or handled in accordance with NFPA 2 when there are no specific or applicable requirements in NFPA 55
- Nonflammable mixtures of ethylene oxide with other chemicals
- Ethylene oxide in chambers 10 scf (0.283 Nm3) or less in volume or for containers holding 7.05 oz (200 g) of ethylene oxide or less
Permits, where required, shall comply with
Section 1.12.
Such application shall include any change or alteration of the facility closure plan filed pursuant to 60.1.4.7.
This 30-day period shall be permitted to be waived by
the AHJ if special circumstances require such waiver.
Permits shall not be required for routine maintenance.
See 3.3.17.
See 3.3.44.
See 3.3.146.
See 3.3.174.
A container
used for liquid oxygen not exceeding 0.396 gal (1.5 L) specifically designed for use as a medical device as defined by 21 USC
Chapter 9, the United States Food, Drug and Cosmetic Act that is intended for portable therapeutic use and to be filled from
its companion base unit which is liquid oxygen home care
container.
See
3.3.197.
See 3.3.206.
See 3.3.280,
Hazardous materials shall be classified according to hazard categories as follows:
- Physical hazards, which shall include the following:
- Flammable gas
- Flammable cryogenic fluid
- Oxidizing gas
- Oxidizing cryogenic fluid
- Pyrophoric gas
- Unstable reactive (detonable) gas, Class 3 or Class 4
- Unstable reactive (nondetonable) gas, Class 3
- Unstable reactive gas, Class 1 or Class 2
- Health hazards, which shall include the following:
Although it is possible that there are
other known hazards, the classification of such gases is not
within the scope of Chapter 63 and they shall be handled,
stored, or used as an other gas. [55:5.1.2]
Mixtures shall be classified in accordance
with the hazards of the mixture as a whole. [55:5.1.3]
Classification shall
be performed by an approved organization, individual, or testing laboratory. [55:5.1.4]
For gas mixtures other than those containing ammonia and nonflammable gases, flammability of gas mixtures shall be classified in accordance with CGA P-23, Standard for Categorizing Gas Mixtures Containing Flammable and Nonflammable Components, or by physical testing in accordance with the requirements of ASTM E681, Standard Test Method for Concentration Limits of Flammability of Chemicals (Vapors and Gases), or ISO 10156, Gases and gas mixtures — Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets. [55:5.1.4.2]
Occupancies that contain compressed gases or cryogenic fluids shall comply with Section 63.2 in addition to other applicable requirements of NFPA 55. [55:6.1.1.1]
The occupancy of a
building or structure, or portion of a building or structure,
shall be classified in accordance with the building code.
[55:6.1.1.2]
Control areas shall be
separated from each other by fire barriers in accordance with
Table 60.4.2.2.1. [55:6.2.1]
The maximum number of
control areas within a building shall be in accordance with
Table 60.4.2.2.1. [400:5.2.2.1]
Where only one control area is present in a building,
no special construction provisions shall be required.
[400:5.2.2.2]
Indoor
control areas with compressed gases or cryogenic fluids stored
or used in quantities less than or equal to those shown in Table
63.2.3.1.1 shall be in accordance with 63.2.1, 63.2.3.1.6,
63.2.3.1.7, 63.2.7, 63.2.8, 63.2.12, 63.2.16, 63.2.17, and the
applicable provisions of Chapters 1 through 5 and Chapters 7
through 16 of NFPA 55. [55:6.2.4]
Where the quantities of compressed gases or cryogenic fluids stored or used within an indoor control area exceed those shown in Table 63.2.3.1.1, the area shall meet the requirements for Protection Levels 1 through 5 in accordance with the building code, based on the requirements of 63.2.3.2. [55:6.3.1.1]
|
Class
|
Use — Closed Systems
|
Use — Open Systems
|
||||||||||
|
High Hazard Protection Level
|
Solid Pounds
|
Liquid Gallons
|
Gasa scf (lb)
|
Solid Pounds
|
Liquid Gallons
|
Gasa scf (lb)
|
Solid Pounds
|
Liquid
Gallons |
||||
| Cryogenic fluid |
Flammable
|
2
|
NA
|
45b,c
|
NA
|
NA
|
45b,c
|
NA
|
NA
|
45b,c
|
||
|
Oxidizing
|
3
|
NA
|
45d,e
|
NA
|
NA
|
45d,e
|
NA
|
NA
|
45d,e
|
|||
|
Inert
|
NA
|
NA
|
NL
|
NA
|
NA
|
NL
|
NA
|
NA
|
NL
|
|||
| Flammable, gasf |
Gaseous
|
2
|
NA
|
NA
|
1000d,e
|
NA
|
NA
|
1000d,e
|
NA
|
NA
|
||
|
Liquefied
|
2
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
|||
|
LP
|
2
|
NA
|
NA
|
(300)g,h,i
|
NA
|
NA
|
(300)g
|
NA
|
NA
|
|||
| Inert gas |
Gaseous
|
NA
|
NA
|
NA
|
NL
|
NA
|
NA
|
NL
|
NA
|
NA
|
||
|
Liquefied
|
NA
|
NA
|
NA
|
NL
|
NA
|
NA
|
NL
|
NA
|
NA
|
|||
| Oxidizing gas |
Gaseous
|
3
|
NA
|
NA
|
1500d,e
|
NA
|
NA
|
1500d,e
|
NA
|
NA
|
||
|
Liquefied
|
3
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
|||
| Pyrophoric gas |
Gaseous
|
2
|
NA
|
NA
|
50d,j
|
NA
|
NA
|
50d,j
|
NA
|
NA
|
||
|
Liquefied
|
2
|
NA
|
NA
|
(4)d,j
|
NA
|
NA
|
(4)d,j
|
NA
|
NA
|
|||
|
Unstable (reactive) gas
|
Gaseous
|
|||||||||||
|
4 or 3 detonable
|
1
|
NA
|
NA
|
10d,j
|
NA
|
NA
|
10d,j
|
NA
|
NA
|
|||
|
3 nondetonable
|
2
|
NA
|
NA
|
50d,e
|
NA
|
NA
|
50d,e
|
NA
|
NA
|
|||
|
2
|
3
|
NA
|
NA
|
750d,e
|
NA
|
NA
|
750d,e
|
NA
|
NA
|
|||
|
1
|
NA
|
NA
|
NA
|
NL
|
NA
|
NA
|
NL
|
NA
|
NA
|
|||
|
Unstable (reactive) gas
|
Liquefied
|
|||||||||||
|
4 or 3 detonable
|
1
|
NA
|
NA
|
(1)d,j
|
NA
|
NA
|
(1)d,j
|
NA
|
NA
|
|||
|
3 nondetonable
|
2
|
NA
|
NA
|
(2)d,e
|
NA
|
NA
|
(2)d,e
|
NA
|
NA
|
|||
|
2
|
3
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
|||
|
1
|
NA
|
NA
|
NA
|
NL
|
NA
|
NA
|
NL
|
NA
|
NA
|
|||
| Corrosive gas |
Gaseous
|
4
|
NA
|
NA
|
810d,e
|
NA
|
NA
|
810d,e |
NA
|
NA
|
||
|
Liquefied
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
(150)d,e |
NA
|
NA
|
||||
| Highly Toxic gas |
Gaseous
|
4
|
NA
|
NA
|
20e,k
|
NA
|
NA
|
20e,k
|
NA
|
NA
|
||
|
Liquefied
|
NA
|
NA
|
(4)e,k
|
NA
|
NA
|
(4)e,k
|
NA
|
NA
|
||||
| Toxic gas |
Gaseous
|
4
|
NA
|
NA
|
810d,e
|
NA
|
NA
|
810d,e
|
NA
|
NA
|
||
|
Liquefied
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
(150)d,e
|
NA
|
NA
|
||||
NA: Not applicable within the context of NFPA 55 (refer to the applicable building or fire code for additional information on these materials).
NL: Not limited in quantity.
Notes:
bNone allowed in unsprinklered buildings unless stored or used in gas rooms or in approved gas cabinets or exhausted enclosures, as specified in this code. cWith pressure-relief devices for stationary or portable containers vented directly outdoors or to an exhaust hood.
dQuantities are permitted to be increased 100 percent where stored or used in approved cabinets, gas cabinets, exhausted enclosures, gas rooms, as appropriate for the material stored. Where Footnote e also applies, the increase for the quantities in both footnotes is permitted to be applied accumulatively.
eMaximum quantities are permitted to be increased 100 percent in buildings equipped throughout with an automatic sprinkler system in accordance with NFPA 13. Where Footnote d also applies, the increase for the quantities in both footnotes is permitted to be applied accumulatively.
fFlammable gases in the fuel tanks of mobile equipment or vehicles are permitted to exceed the MAQ where the equipment is stored and operated in accordance with the applicable fire code.
gSee NFPA 58 and Chapter 69 for requirements for liquefied petroleum gas (LP-Gas). LP-Gas is not within the scope of NFPA 55 or Chapter 63.
hAdditional storage locations are required to be separated by a minimum of 300 ft (92 m).
iIn mercantile occupancies, storage of LP-Gas is limited to a maximum of 200 lb (91 kg) in nominal 1 lb (0.45 kg) LP-Gas containers.
jPermitted only in buildings equipped throughout with an automatic sprinkler system in accordance with NFPA 13.
kAllowed only where stored or used in gas rooms or in approved gas cabinets or exhausted enclosures, as specified in this code.
[55:Table 6.3.1.1]
NL: Not limited in quantity.
Notes:
- For use of control areas, see Section 6.2 of NFPA 55.
- Table values in parentheses or brackets correspond to the unit name in parentheses or brackets at the top of the column.
- The aggregate quantity in use and storage is not permitted to exceed the quantity listed for storage. In addition, quantities in specific occupancies are not permitted to exceed the limits in the building code.
bNone allowed in unsprinklered buildings unless stored or used in gas rooms or in approved gas cabinets or exhausted enclosures, as specified in this code. cWith pressure-relief devices for stationary or portable containers vented directly outdoors or to an exhaust hood.
dQuantities are permitted to be increased 100 percent where stored or used in approved cabinets, gas cabinets, exhausted enclosures, gas rooms, as appropriate for the material stored. Where Footnote e also applies, the increase for the quantities in both footnotes is permitted to be applied accumulatively.
eMaximum quantities are permitted to be increased 100 percent in buildings equipped throughout with an automatic sprinkler system in accordance with NFPA 13. Where Footnote d also applies, the increase for the quantities in both footnotes is permitted to be applied accumulatively.
fFlammable gases in the fuel tanks of mobile equipment or vehicles are permitted to exceed the MAQ where the equipment is stored and operated in accordance with the applicable fire code.
gSee NFPA 58 and Chapter 69 for requirements for liquefied petroleum gas (LP-Gas). LP-Gas is not within the scope of NFPA 55 or Chapter 63.
hAdditional storage locations are required to be separated by a minimum of 300 ft (92 m).
iIn mercantile occupancies, storage of LP-Gas is limited to a maximum of 200 lb (91 kg) in nominal 1 lb (0.45 kg) LP-Gas containers.
jPermitted only in buildings equipped throughout with an automatic sprinkler system in accordance with NFPA 13.
kAllowed only where stored or used in gas rooms or in approved gas cabinets or exhausted enclosures, as specified in this code.
[55:Table 6.3.1.1]
Building-related controls in areas with compressed gases or cryogenic
fluids stored or used within an indoor area in quantities greater
than those shown in Table 63.2.3.1.1 shall be in accordance
with the requirements of Section 63.2. [55:6.3.1.2]
When the classification of
materials in individual containers requires the area to be
placed in more than one protection level, the separation of
protection levels shall not be required, provided the area is
constructed to meet the requirements of the most restrictive
protection level and that the incompatible materials are separated as required by 63.3.1.11.2. [55:6.3.1.4]
Where a compressed gas or cryogenic fluid has multiple hazards, all hazards shall be addressed and controlled in accordance with the provisions for the protection level for which the threshold quantity is exceeded. [55:6.3.1.5]
Flammable and oxidizing gases shall not be stored
or used in other than industrial or storage occupancies.
[55:6.3.1.6.1]
Cylinders, containers, or tanks not exceeding 250 scf (7.1 Nm3) content at normal temperature and pressure (NTP) and used for maintenance purposes, patient care, or operation of equipment shall be permitted. [55:6.3.1.6.2]
Hydrogen gas systems located in a hydrogen gas room that meet the requirements of Section 6.5 of NFPA 55 shall be permissible in quantities up to those allowed by Table 63.2.3.1.1 in assembly, educational, institutional, residential, or business occupancies. [55:6.3.1.6.3]
Except for containers or cylinders not exceeding 20 scf (0.6 Nm3) content at NTP stored or used within gas cabinets or exhausted enclosures of educational occupancies, toxic or highly toxic compressed gases shall not be stored or used in other than industrial and storage occupancies. [55:6.3.1.7]
The protection
level required shall be based on the hazard class of the material
involved as indicated in 63.2.3.2.1 through 63.2.3.2.5.
[55:6.3.2]
Occupancies used for the storage or use of unstable reactive Class 4 and unstable reactive
Class 3 detonable compressed gases in quantities that exceed
the quantity thresholds for gases requiring special provisions
shall be classified Protection Level 1. [55:6.3.2.1]
Occupancies used for the storage or use of flammable, pyrophoric, and nondetonable, unstable reactive Class 3 compressed gases or cryogenic fluids in
quantities that exceed the quantity thresholds for gases requiring special provisions shall be classified as Protection Level 2.
[55:6.3.2.2]
Occupancies used for the storage or use of oxidizing and unstable reactive Class 2
compressed gases or cryogenic fluids in quantities that exceed
the quantity thresholds for gases requiring special provisions
shall be classified as Protection Level 3. [55:6.3.2.3]
Occupancies used for the storage or use of toxic, highly toxic, and corrosive compressed
gases in quantities that exceed the quantity thresholds for gases
requiring special provisions shall be classified as Protection
Level 4. [55:6.3.2.4]
Buildings and portions thereof
used for fabrication of semiconductors or semiconductor
research and development and containing quantities of hazardous materials exceeding the maximum allowable quantities of
high hazard level 5 contents permitted in control areas shall be
classified as Protection Level 5. [55:6.3.2.5]
Gas rooms shall operate at a negative pressure in relationship to the surrounding area. [55:6.4.1]
Gas rooms shall be constructed in
accordance with the building code. [55:6.4.3]
Gas rooms shall be separated from other
occupancies by a minimum of 1-hour fire resistance. [55:6.4.4]
Occupancies used for the storage or use of compressed gases, including individual bulk hydrogen compressed gas systems in quantities exceeding those specified in Table 63.2.5, shall be in detached buildings constructed in accordance with the provisions of the building code. [55:6.6]
NA: Not applicable.
|
Quantity of Material
|
|||
|
Gas Hazard
|
Class
|
Nm3
|
|
|
Individual bulk hydrogen compressed gas systems
|
NA
|
15,000
|
425
|
|
Unstable reactive (detonable)
|
4 or 3
|
Quantity thresholds for gases requiring special provisions*
|
|
|
Unstable reactive (nondetonable)
|
3
|
2000
|
57
|
|
Unstable reactive (nondetonable)
|
2
|
10,000
|
283
|
| Pyrophoric gas† |
NA
|
2,000
|
57
|
*See Table 63.2.3.1.1.
†Detached buildings are not required for gases in high-hazard gas rooms that support Protection Level 5 fabrication facilities separated from other areas by a fire barrier with a fire resistance rating of not less than 2 hours, where the gas is located in internally sprinklered gas cabinets equipped with continuous leak detection and automatic shutdown, where the supply is from cylinders that do not exceed 125 lb (57 kg) water capacity per 49 CFR 173.192 for Hazard Zone A toxic gases, and where the gas cabinets are not manifolded upstream of pressure control devices.
[55:Table 6.6]
†Detached buildings are not required for gases in high-hazard gas rooms that support Protection Level 5 fabrication facilities separated from other areas by a fire barrier with a fire resistance rating of not less than 2 hours, where the gas is located in internally sprinklered gas cabinets equipped with continuous leak detection and automatic shutdown, where the supply is from cylinders that do not exceed 125 lb (57 kg) water capacity per 49 CFR 173.192 for Hazard Zone A toxic gases, and where the gas cabinets are not manifolded upstream of pressure control devices.
[55:Table 6.6]
For other than explosive materials and hazardous
materials presenting a detonation hazard, a weather protection
structure shall be permitted to be used for sheltering outdoor
storage or use areas, without requiring such areas to be classified as indoor storage or use. [55:6.7.1]
Buildings or structures used for weather protection shall be in accordance with the following:
- The building or structure shall be constructed of noncombustible materials.
- Walls shall not obstruct more than one side of the structure.
- Walls shall be permitted to obstruct portions of multiple sides of the structure, provided that the obstructed area does not exceed 25 percent of the structure's perimeter area.
- The building or structure shall be limited to a maximum area of 1500 ft2 (140 m2), with increases in area allowed by the building code based on occupancy and type of construction.
- The distance from the structure constructed as weather protection to buildings, lot lines, public ways, or means of egress to a public way shall not be less than the distance required for an outside hazardous material storage or use area without weather protection based on the hazard classification of the materials contained.
- Reductions in separation distance shall be permitted based on the use of fire barrier walls where permitted for specific materials in accordance with the requirements of Chapters 7 through 11 of NFPA 55.
Electrical wiring and equipment shall be in accordance with this subsection and NFPA 70.
[55:6.8]
Where the following systems are required by NFPA 55 for the storage or use of compressed gases or cryogenic fluids that exceed the quantity thresholds for gases requiring special provisions, such systems shall be connected to a standby power system in accordance with NFPA 70:
- Mechanical ventilation
- Treatment systems
- Temperature controls
- Alarms
- Detection systems
- Other electrically operated systems
The requirements of 63.2.7.1.1 shall not apply
where emergency power is provided in accordance with
63.2.7.2 and NFPA 70. [55:6.8.1.2]
Where required by government regulations, an employee alarm system shall be provided
to allow warning for necessary emergency action as called for in
the emergency action plan required by 4.2.1.1 of NFPA 55, or
for reaction time for safe egress of employees from the workplace or the immediate work area, or both. [55:6.9]
Explosion control shall be provided as required by Table 63.2.9 in accordance with NFPA 68 or NFPA 69 where amounts of compressed gases in storage or use exceed the quantity thresholds requiring special provisions. [55:6.10]
|
Class
|
Explosion Control Methods
|
||
|
Barricade Construction
|
|||
| — |
Not required
|
Required
|
|
| Flammable gas |
Nonliquefied
|
Not required
|
Required
|
|
Liquefied
|
Not required
|
Required
|
|
| Pyrophoric gas | — | Not required | Required |
|
4
|
Required | Not required | |
|
3 (detonable)
|
Required | Not required | |
|
3 (nondetonable)
|
Not required
|
Required | |
[55:Table 6.10]
Except as provided in
63.2.10.1, buildings or portions thereof required to comply
with Protection Levels 1 through 5 shall be protected by an
approved automatic fire sprinkler system complying with
Section 13.3 and NFPA 13. [55:6.11]
Rooms or areas that are of noncombustible
construction with wholly noncombustible contents shall not be
required to be protected by an automatic fire sprinkler system.
[55:6.11.1]
Where sprinkler protection is required, the area in
which compressed gases or cryogenic fluids are stored or used
shall be protected with a sprinkler system designed to be not
less than that required by 11.2.3.1.1 of NFPA 13 for the Ordinary Hazard Group 2 density/area curve. [55:6.11.2.1]
When sprinkler protection is required, the area in
which the flammable or pyrophoric compressed gases or cryogenic fluids are stored or used shall be protected with a sprinkler system designed to be not less than that required by
11.2.3.1.1 of NFPA 13 for the Extra Hazard Group 1 density/
area curve. [55:6.11.2.2]
Hazard identification signs shall be
placed at all entrances to locations where compressed gases are
produced, stored, used, or handled in accordance with
NFPA 704. [55:6.13.1]
Ratings shall be assigned in accordance with
NFPA 704. [55:6.13.1.1]
Signage shall be provided as specified in 63.2.12.2.1 and 63.2.12.2.2. [55:6.13.2]
Signs shall not be obscured or removed.
[55:6.13.2.1]
Signs prohibiting smoking or open flames within 25 ft (7.6 m) of area perimeters shall be provided in areas where toxic, highly toxic, corrosive, unstable reactive, flammable, oxidizing, or pyrophoric gases are produced, stored, or used. [55:6.13.2.2]
Spill control, drainage, and secondary containment shall not
be required for compressed gases. [55:6.14]
Shelves used for the storage of cylinders, containers,
and tanks shall be of noncombustible construction and
designed to support the weight of the materials stored.
[55:6.15.1]
Shelves and containers shall be secured from overturning. [55:6.15.2]
The termination point for
piped vent systems serving cylinders, containers, tanks, and gas
systems used for the purpose of operational or emergency venting shall be located to prevent impingement exposure on the
system served and to minimize the effects of high temperature
thermal radiation or the effects of contact with the gas from
the escaping plume to the supply system, personnel, adjacent
structures, and ignition sources. [55:6.16]
Indoor storage and use areas and storage
buildings for compressed gases and cryogenic fluids shall be
provided with mechanical exhaust ventilation or fixed natural
ventilation, where natural ventilation is shown to be acceptable
for the material as stored. [55:6.17]
The requirements of 63.2.16 shall
not apply to cylinders, containers, and tanks containing
compressed air. [55:6.17.1]
In addition to the requirements of 63.2.16, ventilation systems shall be designed and
installed in accordance with the requirements of the mechanical code. [55:6.17.2]
Where mechanical
exhaust ventilation is provided, the system shall be operational
during the time the building or space is occupied. [55:6.17.3]
Mechanical exhaust or fixed natural ventilation shall be provided at a rate of not less than 1 scf/min/ft2 (0.0051 m3/sec/m2) of floor area over the area of storage or use. [55:6.17.3.2]
Where powered ventilation is
provided, a manual shutoff switch shall be provided outside the
room in a position adjacent to the principal access door to the
room or in an approved location. [55:6.17.3.3]
The exhaust ventilation system design shall take
into account the density of the potential gases released.
[55:6.17.4.1]
For gases that are heavier than air, exhaust shall be taken from a point within 12 in. (305 mm) of the floor. The use of supplemental inlets shall be allowed to be installed at points above the 12 in. (305 mm) threshold level. [55:6.17.4.2]
For gases that are lighter than air, exhaust shall
be taken from a point within 12 in. (305 mm) of the ceiling.
The use of supplemental inlets shall be allowed to be installed
at points below the 12 in. (305 mm) threshold level.
[55:6.17.4.3]
The location of both the exhaust and inlet air
openings shall be designed to provide air movement across all
portions of the floor or ceiling of the room to prevent the accumulation of vapors within the ventilated space. [55:6.17.4.4]
Exhaust ventilation shall
not be recirculated. [55:6.17.5]
Where a gas cabinet is required, is used
to provide separation of gas hazards, or is used to increase the
threshold quantity for a gas requiring special provisions, the
gas cabinet shall be in accordance with the requirements of
63.2.17.1 through 63.2.17.5. [55:6.18]
The gas cabinet shall
be constructed of not less than 0.097 in. (2.46 mm) (12 gauge)
steel. [55:6.18.1.1]
The gas cabinet shall be provided with self-closing limited access ports or noncombustible windows to give access to equipment controls. [55:6.18.1.2]
The gas cabinet shall be provided with self-closing doors. [55:6.18.1.3]
The gas cabinet shall be provided with an exhaust
ventilation system designed to operate at a negative pressure
relative to the surrounding area. [55:6.18.2.1]
Where toxic, highly toxic, pyrophoric, unstable reactive Class 3 or Class 4, or corrosive gases are contained, the velocity at the face of access ports or windows, with the access port or window open, shall not be less than 200 ft/min (61 m/min) average, with not less than 150 ft/min (46 m/min) at any single point. [55:6.18.2.2]
Gas cabinets used to contain toxic,
highly toxic, or pyrophoric gases shall be internally sprinklered. [55:6.18.3]
Incompatible gases, as defined by Table 63.3.1.11.2, shall be stored or used within separate gas cabinets. [55:6.18.5]
Where an exhausted
enclosure is required or used to increase the threshold quantity
for a gas requiring special provisions, the exhausted enclosure
shall be provided with an exhaust ventilation system designed
to operate at a negative pressure in relationship to the
surrounding area. [55:6.19.1]
Where toxic,
highly toxic, pyrophoric, unstable reactive Class 3 or Class 4, or
corrosive gases are contained, the velocity at the face openings
providing access shall be not less than 200 ft/min (61 m/min)
average, with not less than 150 ft/min (46 m/min) at any
single point. [55:6.19.1.1]
Cylinders, containers, and tanks within enclosures shall
be separated in accordance with Table 63.3.1.11.2.
[55:6.19.1.2]
Exhausted enclosures shall be
internally sprinklered. [55:6.19.1.3]
Incompatible gases, as defined by Table
63.3.1.11.2, shall be stored or used within separate exhausted
enclosures. [55:6.19.2]
Compressed gas systems shall be designed
for the intended use and shall be designed by persons competent in such design. [55:7.1.2.1]
Installation of bulk compressed gas
systems shall be supervised by personnel knowledgeable in the
application of the standards for their construction and use.
[55:7.1.2.2]
Insulated liquid carbon dioxide systems shall be in accordance with Chapter 13 of NFPA 55. [55:7.1.3]
Insulated
liquid nitrous oxide systems shall be in accordance with Chapter 16 of NFPA 55. [55:7.1.4]
Listed or approved hydrogen-generating and
hydrogen-consuming equipment shall be in accordance with
the listing requirements and manufacturers' instructions.
[55:10.2.8.1]
Such equipment shall not be required to meet the requirements of Chapter 7 of NFPA 55. [55:10.2.8.2]
Those portions of the system that are used as a means to store or supply hydrogen shall also comply with Chapter 7 and Chapter 10 of NFPA 55 as applicable. [55:10.2.9.1.2]
Compressed gas cylinders, containers, and tanks used for metal
hydride storage systems shall be designed and constructed in
accordance with 63.3.1.6.1. [55:10.2.9.1.5]
Metal
hydride storage system cylinders, containers, or tanks shall be
inspected at intervals not to exceed 5 years. [55:10.2.9.1.6]
Marking and labeling of
cylinders, containers, tanks, and systems shall be in accordance
with 63.3.1.6 and the requirements in 63.3.1.5.1.7.1 through
63.3.1.5.1.7.4. [55:10.2.9.1.7]
Metal hydride storage systems shall be marked with the following:
- Manufacturer's name
- Service life indicating the last date the system can be used
- A unique code or serial number specific to the unit
- System name or product code that identifies the system by the type of chemistry used in the system
- Emergency contact name, telephone number, or other contact information
- Limitations on refilling of containers to include rated charging pressure and capacity
Metal hydride storage system pressure relief devices shall be marked with the following:
- Manufacturer's name
- Metal hydride service in which the device can be used or a product code that is traceable to this information
- Activation parameters to include temperature, pressure, or both
The
required markings for pressure relief devices that are integral
components of valves used on cylinders, containers, and tanks
shall be allowed to be placed on the valve. [55:10.2.9.1.7.3(A)]
Cylinders, containers, and tanks used in metal hydride storage systems shall be marked with the following:
- Manufacturer's name
- Design specification to which the vessel was manufactured
- Authorized body approving the design and initial inspection and test of the vessel
- Manufacturer's original test date
- Unique serial number for the vessel
- Service life identifying the last date the vessel can be used
- System name or product code that identifies the system by the type of chemistry used in the system
Leaking systems shall be
removed from service. [55:10.2.9.1.10.1]
The purity of hydrogen used
for the purpose of refilling containers shall be in accordance
with the listing and the manufacturers' instructions.
[55:10.2.9.1.11.2]
Where a metal
hydride storage system is used on mobile equipment, the
equipment shall be designed to restrain cylinders, containers,
or tanks from dislodgement, slipping, or rotating when the
equipment is in motion. [55:10.2.9.2.1.1]
Metal hydride storage systems,
including cylinders, containers, tanks, and fittings, shall not
extend beyond the platform of the mobile equipment.
[55:10.2.9.2.1.2(A)]
Valves on cylinders, containers, and tanks
shall remain closed except when containers are connected to
closed systems and ready for use. [55:10.2.9.2.2]
Cylinders, containers, and tanks shall be designed, fabricated, tested, and marked (stamped) in accordance with Department of Transportation (DOT) regulations, Transport Canada's (TC) Transportation of Dangerous Goods Regulations, or the ASME Boiler and Pressure Vessel Code. [55:7.1.5.1]
Suppliers shall repair the cylinders, containers,
and tanks, remove them from service, or dispose of them in an
approved manner. [55:7.1.5.2.2]
Suppliers shall ensure that defective cylinders,
containers, and tanks that have been repaired are evaluated by
qualified individuals to verify that the needed repairs and any
required testing has been performed and that those repaired
or tested are in a serviceable condition before returning them
to service. [55:7.1.5.2.3]
Stationary cylinders, containers, and
tanks shall be provided with engineered supports of noncombustible material on noncombustible foundations. [55:7.1.5.3]
Compressed gas cylinders, containers, and tanks
containing residual product shall be treated as full except when
being examined, serviced, or refilled by a gas manufacturer,
authorized cylinder requalifier, or distributor. [55:7.1.5.4]
When required by 63.3.1.6.5.2, pressure relief
devices shall be provided to protect containers and systems
containing compressed gases from rupture in the event of overpressure from thermal exposure. [55:7.1.5.5.1]
Pressure relief devices to protect containers shall be designed and provided in accordance with CGA S-1.1, Pressure Relief Device Standards — Part 1 — Cylinders for Compressed Gases, for cylinders; CGA S-1.2, Pressure Relief Device Standards — Part 2 — Cargo and Portable Tanks for Compressed Gases, for portable tanks; and CGA S-1.3, Pressure Relief Device Standards — Part 3 — Stationary Storage Containers for Compressed Gases, for stationary tanks or in accordance with applicable equivalent requirements in the country of use. [55:7.1.5.5.2]
Pressure relief devices shall be sized in accordance with the specifications to which the container was fabricated. [55:7.1.5.5.3]
Pressure relief devices shall be arranged to discharge 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 shall not apply to DOT specification containers having an internal volume of 2.0 scf (0.057 Nm3) or less. [55:7.1.5.5.5]
Pressure relief devices or vent piping shall be
designed or located so that moisture cannot collect and freeze
in a manner that would interfere with operation of the device.
[55:7.1.5.5.6]
Where required, cathodic
protection shall be in accordance with 63.3.1.7. [55:7.1.6]
Where installed, cathodic protection
systems shall be operated and maintained to continuously
provide corrosion protection. [55:7.1.6.1]
Container systems equipped with
cathodic protection shall be inspected for the intended operation by a cathodic protection tester. The frequency of inspection shall be determined by the designer of the cathodic
protection system. [55:7.1.6.2]
The cathodic protection tester shall be certified as
being qualified by the National Association of Corrosion Engineers, International (NACE). [55:7.1.6.2.1]
Systems equipped with
impressed current cathodic protection systems shall be inspected in accordance with the requirements of the design and
63.3.1.7.2. [55:7.1.6.3]
The design limits of the cathodic protection
system shall be available to the AHJ upon request.
[55:7.1.6.3.1]
The system owner shall maintain the following records to demonstrate that the cathodic protection is in conformance with the requirements of the design:
- The results of inspections of the system
- The results of testing that has been completed
Repairs, maintenance, or replacement of a cathodic
protection system shall be under the supervision of a corrosion
expert certified by NACE. [55:7.1.6.4]
The corrosion expert shall be certified by NACE
as a senior corrosion technologist, a cathodic protection
specialist, or a corrosion specialist or shall be a registered engineer with registration in a field that includes education and
experience in corrosion control. [55:7.1.6.4.1]
Individual compressed gas cylinders,
containers, and tanks shall be marked or labeled in accordance
with DOT requirements or those of the applicable regulatory
agency. [55:7.1.7.1 ]
The labels applied by the gas
manufacturer to identify the liquefied or nonliquefied
compressed gas cylinder contents shall not be altered or
removed by the user. [55:7.1.7.2]
Stationary compressed gas cylinders, containers,
and tanks shall be marked in accordance with NFPA 704.
[55:7.1.7.3.1]
Markings shall be visible from any direction of
approach. [55:7.1.7.3.2]
Except as provided in 63.3.1.8.4.2, piping systems shall be marked in accordance with ASME A13.1, Scheme for the Identification of Piping Systems, or other applicable approved standards as follows:
- Marking shall include the name of the gas and a direction-of-flow arrow.
- Piping that is used to convey more than one gas at various times shall be marked to provide clear identification and warning of the hazard.
- Markings for piping systems shall be provided at the
following locations:
- At each critical process control valve
- At wall, floor, or ceiling penetrations
- At each change of direction
- At a minimum of every 20 ft (6.1 m) or fraction thereof throughout the piping run
Piping within gas manufacturing plants, gas
processing plants, refineries, and similar occupancies shall be
marked in an approved manner. [55:7.1.7.4.2]
Compressed gas cylinders, containers,
tanks, and systems shall be secured against accidental dislodgement and against access by unauthorized personnel.
[55:7.1.8.1]
Administrative controls shall be allowed to be used
to control access to individual storage, use, and handling areas
located in secure facilities not accessible by the general public.
[55:7.1.8.2.1]
Compressed gas cylinders, containers, tanks, and
systems that could be exposed to physical damage shall be
protected. [55:7.1.8.3.1]
Guard posts or other means shall be provided to protect compressed gas cylinders, containers, tanks, and systems indoors and outdoors from vehicular damage in accordance with Section 4.11 of NFPA 55. [55:7.1.8.3.2]
Compressed gas cylinders, containers, and tanks in
use or in storage shall be secured to prevent them from falling
or being knocked over by corralling them and securing them
to a cart, framework, or fixed object by use of a restraint, unless
otherwise permitted by 63.3.1.9.5.1 and 63.3.1.9.5.2.
[55:7.1.8.4]
Compressed gas cylinders, containers and tanks in
the process of examination, servicing, and refilling shall not be
required to be secured. [55:7.1.8.4.1]
At cylinder-filling plants, authorized cylinder
requalifier's facilities, and distributors' warehouses, the nesting
of cylinders shall be permitted as a means to secure cylinders.
[55:7.1.8.4.2]
Compressed gas cylinder, container, and
tank valves shall be protected from physical damage by means
of protective caps, collars, or similar devices. [55:7.1.9.1]
Valve protection of individual valves shall not be
required to be installed on individual cylinders, containers, or
tanks installed on tube trailers or similar transportable bulk gas
systems equipped with manifolds that are provided with a
means of physical protection that will protect the valves from
physical damage when the equipment is in use. Protective
systems required by DOT for over the road transport shall
provide an acceptable means of protection. [55:7.1.9.1.1]
Valve protection of individual valves shall not
be required on cylinders, containers, or tanks that comprise
bulk or non-bulk gas systems where the containers are stationary, or portable equipped with manifolds, that are provided
with physical protection in accordance with Section 4.11 of
NFPA 55 and 63.3.1.9.4 or other approved means. Protective
systems required by DOT for over the road transport shall
provide an acceptable means of protection. [55:7.1.9.1.1.1]
Where compressed gas cylinders, containers, and tanks are designed to accept valve-protective caps, the user shall keep such caps on the compressed gas cylinders, containers, and tanks at all times, except when empty, being processed, or connected for use. [55:7.1.9.2]
Gastight valve outlet caps or plugs shall be provided and in place for all full or partially full cylinders, containers, and tanks containing toxic, highly toxic, pyrophoric, or
unstable reactive Class 3 or Class 4 gases that are in storage.
[55:7.1.9.3.1]
Compressed gas cylinders, containers, tanks, and
systems in storage or use shall be separated from materials and
conditions that present exposure hazards to or from each
other. [55:7.1.10.1]
Gas cylinders, containers, and tanks shall be separated in accordance with Table 63.3.1.11.2. [55:7.1.10.2]
|
Gas Category
|
Corrosive
|
Oxidizing
|
Flammable
|
Toxic or Highly Toxic
|
|||||||||||||||
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
||||||||
|
Toxic or highly toxic
|
NR
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
—
|
—
|
||||||
|
NR
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
—
|
—
|
20
|
6.1
|
|||||||
| Flammable |
NR
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
—
|
—
|
20
|
6.1
|
20
|
6.1
|
||||||
| Oxidizing |
NR
|
20
|
6.1
|
20
|
6.1
|
—
|
—
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
||||||
|
Corrosive
|
NR
|
20
|
6.1
|
—
|
—
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
||||||
|
NR
|
—
|
—
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
20
|
6.1
|
|||||||
| Other gas |
—
|
NR
|
NR
|
NR
|
NR
|
NR
|
NR
|
||||||||||||
NR: No separation required.
[55: Table 7.1.10.2]
[55: Table 7.1.10.2]
Subparagraph 63.3.1.11.2 shall not apply to gases
contained within closed piping systems. [55:7.1.10.2.1]
The distances shown in Table 63.3.1.11.2 shall be
permitted to be reduced without limit where compressed gas
cylinders, containers, and tanks are separated by a barrier of
noncombustible construction that has a fire resistance rating of
at least 0.5 hour and interrupts the line of sight between the
containers. [55:7.1.10.2.2]
The 20 ft (6.1 m) distance shall be permitted to
be reduced to 5 ft (1.5 m) where one of the gases is enclosed in
a gas cabinet or without limit where both gases are enclosed in
gas cabinets. [55:7.1.10.2.3]
Cylinders without pressure relief devices shall
not be stored without separation from flammable and pyrophoric gases with pressure relief devices. [55:7.1.10.2.4]
Spatial separation shall not be required
between cylinders deemed to be incompatible in gas production facilities where cylinders are connected to manifolds for
the purposes of filling, analysis of compressed gases, or manufacturing procedures, assuming the prescribed controls for the
manufacture of gas mixtures are in place. [55:7.1.10.2.5]
Combustible waste, vegetation, and similar materials shall be
kept a minimum of 10 ft (3.1 m) from compressed gas cylinders, containers, tanks, and systems. [55:7.1.10.3]
A noncombustible partition without openings or
penetrations and extending not less than 18 in. (457 mm)
above and to the sides of the storage area shall be permitted in
lieu of the minimum distance. [55:7.1.10.3.1]
The noncombustible partition shall be either an
independent structure or the exterior wall of the building adjacent to the storage area. [55:7.1.10.3.2]
Compressed
gas cylinders, containers, and tanks shall not be placed near
elevators, unprotected platform ledges, or other areas where
compressed gas cylinders, containers, or tanks could fall distances exceeding one-half the height of the container, cylinder, or
tank. [55:7.1.10.4]
Compressed gas cylinders, containers, and tanks, whether full or partially full, shall
not be exposed to temperatures exceeding 125°F (52°C) or
subambient (low) temperatures unless designed for use under
such exposure. [55:7.1.10.5]
Compressed gas cylinders, containers, and tanks
that have not been designed for use under elevated temperature conditions shall not be exposed to direct sunlight
outdoors where ambient temperatures exceed 125°F (52°C).
The use of a weather protected structure or shaded environment for storage or use shall be permitted as a means to
protect against direct exposure to sunlight. [55:7.1.10.5.1]
Compressed gas cylinders,
containers, and tanks shall not be placed in areas where they
are capable of being damaged by falling objects. [55:7.1.10.6]
Compressed gas cylinders, containers, and tanks, whether full or partially full, shall not be heated by devices that could raise the surface temperature of the container, cylinder, or tank to above 125°F (52°C). [55:7.1.10.7]
Electrical heating devices shall be in accordance with NFPA 70. [55:7.1.10.7.1]
Devices designed to maintain
individual compressed gas cylinders, containers, and tanks at constant temperature shall be designed to be fail-safe.
[55:7.1.10.7.2]
Open flames and high-temperature devices shall not be used in a manner that creates a hazardous condition. [55:7.1.10.8]
Compressed gas cylinders, containers, and tanks shall not be exposed to corrosive
chemicals or fumes that could damage cylinders, containers,
tanks, or valve-protective caps. [55:7.1.10.9]
Compressed gas
cylinders, containers, and tanks shall not be placed where they
could become a part of an electrical circuit. [55:7.1.10.10]
Electrical devices mounted on compressed gas
piping, cylinders, containers, or tanks shall be installed, grounded, and bonded in accordance with the methods specified in
NFPA 70(NEC). [55:7.1.10.10.1]
Compressed gas cylinders,
containers, and tanks shall not be used for any purpose other
than to serve as a vessel for containing the product for which it
was designed. [55:7.1.12]
Compressed gas cylinders, containers, and tanks exposed to
fire shall not be used or shipped while full or partially full until
they are requalified in accordance with the pressure vessel code
under which they were manufactured. [55:7.1.13]
Leaking, damaged, or
corroded compressed gas cylinders, containers, and tanks shall
be removed from service. [55:7.1.14.1]
Leaking, damaged, or
corroded compressed gas systems shall be replaced or repaired.
[55:7.1.14.2]
Compressed gas cylinders, containers,
and tanks that have been removed from service shall be
handled in an approved manner. [55:7.1.14.3]
Compressed gas systems that are determined to be leaking, damaged, or corroded shall be repaired to a serviceable condition or shall be removed from service. [55:7.1.14.4]
To prevent bottom corrosion, cylinders, containers, and tanks shall be protected from direct contact with soil
or surfaces where water might accumulate. [55:7.1.15.1]
Surfaces shall be graded to prevent accumulation
of water. [55:7.1.15.2]
Storage area
temperatures shall not exceed 125°F (52°C). [55:7.1.16.1]
Underground piping shall be of welded construction without valves, unwelded mechanical joints, or connections installed underground. [55:7.1.17.1]
Piping installed in trench systems located below
grade where the trench is open to above shall not be considered to be underground. [55:7.1.17.1.2]
When cathodic protection is provided, it shall be
in accordance with 63.3.1.7. [55:7.1.17.2.1]
Underground piping shall be installed on at least
6 in. (150 mm) of well-compacted bedding material.
[30:27.6.5.1]
In paved areas where a minimum 2 in. (50 mm) of
asphalt is used, backfill between the pipe and the asphalt shall
be permitted to be reduced to 8 in. (200 mm) minimum.
[30:27.6.5.3]
In paved areas where a minimum 4 in. (100 mm)
of reinforced concrete is used, backfill between the pipe and
the asphalt shall be permitted to be reduced to 4 in. (100 mm)
minimum. [30:27.6.5.4]
A greater burial depth shall be provided when
required by the manufacturer's instructions or where frost
conditions are present. [30:27.6.5.6]
Piping within the same trench shall be separated
horizontally by at least two pipe diameters. Separation shall
need not exceed 9 in. (230 mm). [30:27.6.5.7]
Two or more levels of piping within the same
trench shall be separated vertically by a minimum 6 in.
(150 mm) of well-compacted bedding material. [30:27.6.5.8]
Piping systems shall be cleaned and purged in accordance with the requirements of 63.3.1.19 when one or more of the following conditions exist:
- The system is installed and prior to being placed into service
- There is a change in service
- * There are alterations or repair of the system involving the replacement of parts or addition to the piping system and prior to returning the system to service
- * The design standards or written procedures specify cleaning and purging
Cleaning and purging of the internal surfaces of
piping systems shall be conducted by qualified individuals
trained in cleaning and purging operations and procedures,
including the recognition of potential hazards associated with
cleaning and purging. [55:7.1.18.1.2]
A written cleaning or purging procedure shall
be provided to establish the requirements for the cleaning and
purging operations to be conducted. [55:7.1.18.1.3]
An independent or third-party review of the written procedure shall be conducted after the procedure has been written and shall accomplish the following:
- Evaluate hazards, errors, and malfunctions related to each step in the procedure
- Review the measures prescribed in the procedure for applicability
- Make recommendations for additional hazard mitigation measures if deemed necessary
The completed written procedure shall be:
- Maintained on site by the facility owner/operator
- Provided to operating personnel engaged in cleaning or purging operations
- Made available to the AHJ upon request
Where generic cleaning or purging procedures
have been established, a job-specific operating procedure shall
not be required. [55:7.1.18.1.3.3]
Generic procedures shall be reviewed when
originally published or when the procedure or operation is
changed. [55:7.1.18.1.3.4]
Written procedures to manage a change in process materials, technology, equipment, procedures, and facilities
shall be established by the facility owner/operator.
[55:7.1.18.1.4]
The management-of-change procedures shall ensure that the following topics are addressed prior to any change in the configuration or design of the piping system:
- The technical basis for the proposed change
- The safety and health implications
- Whether the change is permanent or temporary
- Whether modifications to the cleaning and purging procedures are required as a result of the identified changes
When modifications to the cleaning and purging procedures are required, the written procedure shall be
updated to incorporate any elements identified by the
management-of-change procedures. [55:7.1.18.1.4.2]
Prior to cleaning or purging, piping systems
shall be inspected and tested to determine that the installation,
including the materials of construction, and method of fabrication, comply with the requirements of the design standard used
and the intended application for which the system was
designed. [55:7.1.18.1.5]
Purging of piping systems shall not be required
for systems that are utilized for operations designated by written operating procedures in accordance with the requirements
of the cleaning or purging procedure specified in 63.3.1.19.1.1.
[55:7.1.18.1.5.2]
Personnel in the affected area(s), as determined by the cleaning or purging procedure, shall be
informed of the hazards associated with the operational activity
and notified prior to the initiation of any such activity.
[55:7.1.18.1.5.3]
When piping systems are cleaned in stages
during installation or assembly, the interior of the cleaned
piping shall be protected against the infiltration of unwanted
contaminants. [55:7.1.18.2.2]
Piping systems shall be purged to remove the internal contents preceding the following activities or operations:
- Activating or placing a piping system into service
- Deactivating or removing a piping system from service
- Changing the service of a piping system from one gas to another, except when such gas is supplied to a manifold or piping system designed for the purpose of filling or otherwise processing cylinders, containers, or tanks in a process with established procedures
- Performing service, maintenance, or modifications on a system where personnel or designated areas will potentially be exposed to the internal contents of the piping system
- Performing hot work, including but not limited to welding, cutting or brazing on the piping system
The termination point for the release of purged
gases shall be in accordance with 63.2.15. [55:7.1.18.3.2]
The release of purged gases or mixtures
containing any quantity of corrosive, toxic, or highly toxic gases
shall be through a treatment system in accordance with the
applicable requirements of 63.3.5.3.4 or 63.3.9.3.
[55:7.1.18.3.2.1]
The termination point for the release of purged gases resultant from the purging of piping systems out of service, other than those in accordance with 63.3.1.19.3.2.1, shall not be required to be in accordance with 63.2.15 where the contained volume of the piping system (when released to indoor areas) does not result in a concentration in the room or area that will reduce the oxygen concentration in the room or area below a level of 19.5 percent or that exceeds any of the following limits:
- Ceiling limit
- Permissible exposure limit
- Short-term exposure limit
- Twenty-five percent of the lower flammable limit
The storage of compressed gas cylinders, containers, and tanks shall be in accordance with 63.3.2.
[55:7.2.1.1]
Cylinders, containers, and tanks
containing liquefied flammable gases and flammable gases in
solution shall be positioned in the upright position.
[55:7.2.1.2]
Containers with a capacity of 1.3 gal (5 L) or less shall be permitted to be stored in a horizontal position. [55:7.2.1.2.1]
Cylinders, containers, and tanks designed for
use in a horizontal position shall be permitted to be stored in a
horizontal position. [55:7.2.1.2.2]
Cylinders, containers, and tanks, with the exception of those
containing flammable liquefied compressed gases, that are
palletized for transportation purposes shall be permitted to be
stored in a horizontal position. [55:7.2.1.2.3]
For other than explosive materials and hazardous materials presenting a detonation hazard, a
weather protection structure shall be permitted to be used for
sheltering outdoor storage or use areas without requiring such
areas to be classified as indoor storage. [55:7.2.1.3]
Compressed gas system controls shall be designed
to prevent materials from entering or leaving the process at an
unintended time, rate, or path. [55:7.3.1.2.1]
Automatic controls shall be designed to be failsafe. [55:7.3.1.2.2]
Piping, tubing, fittings, and related
components shall be designed, fabricated, and tested in accordance with the requirements of the applicable parts in ASME
B31.3, Process Piping. [55:7.3.1.3]
Piping, tubing, pressure regulators,
valves, and other apparatus shall be kept gastight to prevent
leakage. [55:7.3.1.3.1]
Backflow prevention or
check valves shall be provided where the backflow of hazardous
materials could create a hazardous condition or cause the
unauthorized discharge of hazardous materials. [55:7.3.1.3.2]
Valves utilized on compressed gas systems shall be
designed for the gas or gases and pressure intended and shall
be accessible. [55:7.3.1.4.1]
Venting of gases shall be directed to an approved
location. [55:7.3.1.5.1]
Compressed gas cylinders, containers, and tanks
containing flammable liquefied gas, except those designed for
use in a horizontal position and those compressed gas cylinders, containers, and tanks containing nonliquefied gases, shall
be used in a "valve end up" upright position. [55:7.3.1.6.1]
Cylinders, containers, and tanks
containing nonflammable liquefied gases shall be permitted to
be used in the inverted position when the liquid phase is used.
[55:7.3.1.7]
Flammable liquefied gases at processing plants
shall be permitted to use this inverted position method while
transfilling. [55:7.3.1.7.1]
The cylinder, container, or tank shall be secured, and the dispensing apparatus shall be designed for use with liquefied gas. [55:7.3.1.7.2]
Cylinders or containers with a water volume of 1.3 gal (5 L) or less shall be permitted to be used in a horizontal position. [55:7.3.1.8]
Transfer of gases between cylinders,
containers, and tanks shall be performed by qualified personnel using equipment and operating procedures in accordance
with CGA P-1, Safe Handling of Compressed Gases in Containers.
[55:7.3.1.9]
Inflatable
equipment, devices, or balloons shall only be pressurized or
filled with compressed air or inert gases. [55:7.3.1.10]
Accessible manual or automatic emergency shutoff valves shall be provided to shut off the flow of gas in case of
emergency. [55:7.3.1.11.1]
Manual emergency shutoff valves or the
device that activates an automatic emergency shutoff valve on a
bulk source or piping system serving the bulk supply shall be
identified by means of a sign. [55:7.3.1.11.1.1]
Where compressed gases from sources in excess of the quantity thresholds in Table 63.2.3.1.1 having a hazard ranking in one or more of the following hazard classes in accordance with NFPA 704 are carried in pressurized piping above a gauge pressure of 15 psi (103 kPa), an approved method of emergency isolation shall be provided:
[55:7.3.1.12.1]
Approved means of meeting the requirements for emergency isolation shall include any of the following:
- Automatic shutoff valves, located as close to the bulk source as practical, tied to leak detection systems
- Attended control stations where trained personnel can monitor alarms or supervisory signals and can trigger emergency responses
- A constantly monitored control station with an alarm and remote shutoff of the gas supply system
- Excess flow valves at the bulk source
The requirements of 63.3.3.1.12 shall not be required for the following:
- Piping for inlet connections designed to prevent backflow at the source
- Piping for pressure relief devices
The requirements of 63.3.3.1.12 shall not apply to the following:
- Piping for inlet connections designed to prevent backflow
- Piping for pressure relief devices
- Systems containing 430 scf (12.7 Nm3) or less of flammable gas
The handling of compressed gas
cylinders, containers, and tanks shall be in accordance with
63.3.3.3. [55:7.3.3.1]
Where cylinders, containers, and tanks are moved
by hand cart, hand truck, or other mobile device, such carts,
trucks, or devices shall be designed for the secure movement of
cylinders, containers, and tanks. [55:7.3.3.2.2]
Ropes, chains, or slings shall not
be used to suspend compressed gas cylinders, containers, and
tanks unless provisions at time of manufacture have been made
on the cylinder, container, or tank for appropriate lifting
attachments, such as lugs. [55:7.3.3.3]
Medical gas systems for health care shall be in accordance with NFPA 99. [55:7.4]
The outdoor storage or use
of corrosive compressed gas shall not be within 20 ft (6.1 m) of
buildings not associated with the manufacture or distribution
of corrosive gases, lot lines, streets, alleys, public ways, or means
of egress. [55:7.5.2]
A 2-hour fire barrier wall without openings or penetrations and that extends not less than 30 in. (762 mm) above
and to the sides of the storage or use area shall be permitted in
lieu of the 20 ft (6.1 m) distance. [55:7.5.2.1]
Where a fire barrier is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.5.2.1.1]
The fire barrier wall shall be either an independent structure or the exterior wall of the building adjacent to
the storage or use area. [55:7.5.2.1.2]
The 2-hour fire barrier shall be located at least
5 ft (1.5 m) from any exposure. [55:7.5.2.1.3]
The 2-hour fire barrier wall shall not have more
than two sides at approximately 90 degree (1.57 rad) directions
or not more than three sides with connecting angles of approximately 135 degrees (2.36 rad). [55:7.5.2.1.4]
The indoor use of corrosive gases shall
be provided with a gas cabinet, exhausted enclosure, or gas
room. [55:7.5.3]
Gas cabinets shall be in accordance
with 63.2.17. [55:7.5.3.1]
Exhausted enclosures shall
be in accordance with 63.2.18. [55:7.5.3.2]
Treatment systems, except as
provided for in 63.3.5.3.4.1, gas cabinets, exhausted enclosures,
and gas rooms containing corrosive gases in use shall be provided with exhaust ventilation, with all exhaust directed to a
treatment system designed to process the accidental release of
gas. [55:7.5.3.4]
Treatment systems shall not be required for corrosive gases in use where provided with the following:
- Gas detection in accordance with 63.3.9.3.2.1.1
- Fail-safe automatic closing valves in accordance with 63.3.9.3.2.2
Treatment systems shall be capable of diluting,
adsorbing, absorbing, containing, neutralizing, burning, or
otherwise processing the release of corrosive gas in accordance
with 63.3.9.3.4.1. [55:7.5.3.4.2]
Treatment system sizing shall be in accordance
with 63.3.9.3.4. [55:7.5.3.4.3]
Storage, use, and handling of gaseous hydrogen shall be in accordance with 63.3.6.1 and Chapter 10 of NFPA 55. [55:7.6.1.2]
The outdoor storage or use of non-bulk flammable compressed gas shall be located from lot lines, public streets, public alleys, public ways, or buildings not associated with the manufacture or distribution of such gases in accordance with Table 63.3.6.2. [55:7.6.2]
|
|
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
|
||||
|
0-4225
|
5
|
5
|
5
|
5
|
0
|
0
|
|
4226-21,125
|
10
|
10
|
10
|
10
|
5
|
0
|
|
21,126-50,700
|
10
|
15
|
15
|
20
|
5
|
0
|
|
50,701-84,500
|
10
|
20
|
20
|
20
|
5
|
0
|
|
84,501-200,000
|
20
|
25
|
25
|
20
|
5
|
0
|
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 fine 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]
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 fine 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]
Bulk hydrogen gas installations shall be in accordance with Chapter 10 of NFPA 55. [55:7.6.2.1]
Where a protective structure is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.6.2.1.1]
The fire barrier wall shall be either an independent structure or the exterior wall of the building adjacent to
the storage or use area. [55:7.6.2.1.2]
Bulk gas systems for flammable gases other than hydrogen shall be in accordance with Table 10.4.2.2.1(a), Table 10.4.2.2.1(b), or Table 10.4.2.2.1(c) of NFPA 55 where the quantity of flammable compressed gas exceeds 5000 scf (141.6 Nm3). [55:7.6.2.2]
Where fire barriers are used as a means of
distance reduction, fire barriers shall be in accordance with
10.4.2.2.4 of NFPA 55. [55:7.6.2.2.1]
Mobile acetylene trailer systems (MATS) shall be
located in accordance with 15.2.3 of NFPA 55. [55:7.6.2.2.2]
The configuration of the protective structure shall
be designed to allow natural ventilation to prevent the accumulation of hazardous gas concentrations. [55:7.6.2.3]
Storage and use of flammable compressed gases
shall not be located within 50 ft (15.2 m) of air intakes.
[55:7.6.2.4]
Storage and use of flammable gases outside of
buildings shall also be separated from building openings by
25 ft (7.6 m). Fire barriers shall be permitted to be used as a
means to separate storage areas from openings or a means of
egress used to access the public way. [55:7.6.2.5]
Hydrogen systems of less than 5000 scf (141.6 Nm3) and greater than the MAQ, where located inside buildings, shall be in accordance with the following:
- In a ventilated area in accordance with the provisions of 63.2.16
- Separated from incompatible materials in accordance with the provisions of 63.3.1.11.2
- 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 63.3.3.1.11.
- A distance of 50 ft (15 m) from other flammable gas storage
- Protected against damage in accordance with the provisions of 63.3.1.9.4.
More than one system of 5000 scf (141.6 Nm3) or less shall be permitted to be installed in the same room or area, provided the systems are separated by at least 50 ft (15 m) or a full-height fire-resistive partition having a minimum fire resistance rating of 2 hours is located between the systems. [55:10.3.5.2.1]
The separation distance between multiple systems of 5000 scf (141.6 Nm3) or less shall be permitted to be reduced to 25 ft (7.6 m) in buildings where the space between storage areas is free of combustible materials and protected with a sprinkler system designed for Extra Hazard, Group 1 occupancies in accordance with the requirements of 63.2.10. [55:10.3.5.2.2]
The required separation distance between individual portable systems in the process of being filled or serviced
in facilities associated with the manufacture or distribution of
hydrogen and its mixtures shall not be limited by 63.3.6.3.2.1
or 63.3.6.3.2.2 when such facilities are provided with Protection
Level 2 controls and the applicable requirements of Chapters 1
through 7 of NFPA 55. [55:10.3.5.2.3]
[55:10.3.7]
Maintenance shall be performed annually by a
qualified representative of the equipment owner. [55:10.3.7.1]
The maintenance shall include inspection for physical damage, leak tightness, ground system integrity, vent system operation, equipment identification, warning signs, operator information and training records, scheduled maintenance and retest records, alarm operation, and other safety-related features. [55:10.3.7.2]
Scheduled maintenance and retest activities shall be
formally documented, and records shall be maintained a minimum of 3 years. [55:10.3.7.3]
Ignition sources in areas
containing flammable gases shall be in accordance with
63.3.6.5. [55:7.6.3]
Static producing
equipment located in flammable gas areas shall be grounded.
[55:7.6.3.1]
Heating, where provided, shall be by indirect means. Equipment used for heating applications in rooms or areas where flammable gases are stored or used shall be listed and labeled for use in hazardous environments established by the gases present and shall be installed in accordance with the conditions of the listing and the manufacturer's installation instructions. [55:7.6.3.3]
Maintenance of flammable gas system piping and
components shall be performed annually by a qualified representative of the equipment owner. [55:7.6.5.1]
This maintenance shall include inspection for physical damage, leak tightness, ground system integrity, vent system operation, equipment identification, warning signs, operator information and training records, scheduled maintenance and retest records, alarm operation, and other safety-related features. [55:7.6.5.2]
Scheduled maintenance and retest activities shall be
formally documented, and records shall be maintained a minimum of 3 years. [55:7.6.5.3]
The outdoor storage or use of oxidizing compressed gas shall be in accordance with Table 63.3.7.2. [55:7.7.2]
|
Quantity of Gas Stored (at NTP)
|
Distance to a Building Not Associated with the Manufacture or Distribution of Oxidizing Gases or to a Public Way or Property Line
|
Minimum Distance Between Storage Areas
|
|||||
|
Nm3
|
ft
|
m
|
ft
|
m
|
|||
|
0—50,000
|
0—1416
|
5
|
1.5
|
5
|
1.5
|
||
|
50,001—100,000
|
1417—2832
|
10
|
3.0
|
10
|
3.0
|
||
|
≤100,001
|
≤2833
|
15
|
4.6
|
15
|
4.6
|
||
[55: Table 7.7.2]
The distances shall not apply where fire barriers
having a minimum fire resistance of 2 hours interrupt the line
of sight between the container and the exposure. [55:7.7.2.1]
Where a fire barrier is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.7.2.1.1]
The fire barrier wall shall be either an independent structure or the exterior wall of the building adjacent to
the storage or use area. [55:7.7.2.1.2]
The fire barrier shall be at least 5 ft (1.5 m) from
the storage or use area perimeter. [55:7.7.2.2]
The configuration of the fire barrier shall allow
natural ventilation to prevent the accumulation of hazardous
gas concentrations. [55:7.7.2.3]
The outdoor storage or use of pyrophoric compressed gas shall be in accordance with Table 63.3.8.3. [55:7.8.3]
|
Minimum Distance to Buildings on the Same Property
|
|||||||||||||||||||
|
Maximum Amount per Storage Area
|
Minimum Distance Between Storage Areas
|
Minimum Distance to Property Lines
|
Minimum Distance to Public Ways
|
Less Than 2-Hour Construction
|
2-Hour Construction
|
4-Hour Construction
|
|||||||||||||
|
Nm3
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
ft
|
m
|
|||||||
|
250
|
7.1
|
5
|
1.5
|
25
|
7.6
|
5
|
1.5
|
5
|
1.5
|
0
|
0
|
0
|
0
|
||||||
|
>250 to 2500
|
>7.1 to 71.0
|
10
|
3.0
|
50
|
15.2
|
10
|
3.0
|
10
|
3.0
|
5
|
1.5
|
0
|
0
|
||||||
|
>2500 to 7500
|
>71.0 to 212.4
|
20
|
6.0
|
100
|
30.5
|
20
|
6.0
|
20
|
6.0
|
10
|
3.0
|
0
|
0
|
||||||
[55: Table 7.8.3]
The distances shall be allowed to be reduced to 5 ft
(1.5 m) where fire barriers having a minimum fire resistance of
2 hours interrupt the line of sight between the container and
the exposure. [55:7.8.3.1]
Where a fire barrier is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.8.3.1.1]
The fire barrier shall be either an independent
structure or the exterior wall of the building adjacent to the
storage or use area. [55:7.8.3.1.2]
The fire barrier shall be at least 5 ft (1.5 m) from
the storage or use area perimeter. [55:7.8.3.1.3]
The configuration of the fire barrier shall allow
natural ventilation to prevent the accumulation of hazardous
gas concentrations. [55:7.8.3.1.4]
Storage and use of pyrophoric gases outside buildings shall be separated from building openings by 25 ft (7.6 m).
[55:7.8.3.2]
Fire barriers shall be permitted to be used as a
means to separate storage areas from building openings that
are used to access the public way. [55:7.8.3.2.1]
The indoor storage or use of highly toxic
gases or toxic gases shall be provided with a gas cabinet,
exhausted enclosure, or gas room. [55:7.9.2.1]
Gas cabinets shall be in accordance with 63.2.17.
[55:7.9.2.1.1]
Exhausted enclosures shall be in accordance with
63.2.18. [55:7.9.2.1.2]
The outdoor storage or use
of toxic or highly toxic compressed gases shall not be within
75 ft (23 m) of lot lines, streets, alleys, public ways or means of
egress, or buildings not associated with such storage or use.
[55:7.9.2.2]
A 2-hour fire barrier wall without openings or
penetrations that extends not less than 30 in. (762 mm) above
and to the sides of the storage or use area and that interrupts
the line of sight between the storage or use area and the exposure shall be permitted in lieu of the 75 ft (23 m) distance.
[55:7.9.2.2.1]
Where a fire barrier is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.9.2.2.1.1]
The fire barrier wall shall be either an independent structure or the exterior wall of the building adjacent to the storage or use area. [55:7.9.2.2.1.2]
The 2-hour fire barrier wall shall be located at
least 5 ft (1.5 m) from any exposure. [55:7.9.2.2.1.3]
The 2-hour fire barrier wall shall not have more
than two sides at approximately 90 degree (1.5 rad) directions
or more than three sides with connecting angles of approximately 135 degrees (2.36 rad). [55:7.9.2.2.1.4]
Where the storage or use area is located closer
than 75 ft (23 m) to a building not associated with the manufacture or distribution of toxic or highly toxic compressed
gases, openings in the building other than for piping shall not
be permitted above the height of the top of the 2-hour fire
barrier wall or within 50 ft (15 m) horizontally from the storage
area, regardless of whether the openings are shielded by a fire
barrier. [55:7.9.2.2.2]
Storage and use of toxic and highly
toxic compressed gases shall not be located within 75 ft (23 m)
of air intakes. [55:7.9.2.3]
Except as provided in 63.3.9.3.1
and 63.3.9.3.2, gas cabinets, exhausted enclosures, and gas
rooms containing toxic or highly toxic gases shall be provided
with exhaust ventilation, with all exhaust directed to a treatment system designed to process accidental release of gas.
[55:7.9.3]
Treatment
systems shall not be required for toxic or highly toxic gases in
storage where cylinders, containers, and tanks are provided
with the controls specified in 63.3.9.3.1.1 through 63.3.9.3.1.3.
[55:7.9.3.1]
Where provided,
handwheel-operated valves shall be secured to prevent movement. [55:7.9.3.1.2]
Approved cylinder containment vessels or cylinder containment systems shall
be provided at an approved location. [55:7.9.3.1.3]
Treatment systems shall not be
required for toxic gases in use where cylinders, containers, and
tanks are provided with the controls specified in 63.3.9.3.2.1
and 63.3.9.3.2.2. [55:7.9.3.2]
A gas detection system with a sensing interval
not exceeding 5 minutes shall be provided. [55:7.9.3.2.1.1]
The gas detection system shall monitor the
exhaust system at the point of discharge from the gas cabinet,
exhausted enclosure, or gas room. [55:7.9.3.2.1.2]
The fail-safe valve shall close when gas is detected at the permissible exposure limit, short-term exposure limit
(STEL), or ceiling limit by the gas detection system.
[55:7.9.3.2.2.1]
For attended operations, a manual closing valve
shall be permitted when in accordance with 63.3.9.3.4.3.
[55:7.9.3.2.2.2]
For gases used at unattended operations for the
protection of public health, such as chlorine at water or wastewater treatment sites, the automatic valve shall close if the
concentration of gas detected by a gas detection system reaches
one-half of the IDLH. [55:7.9.3.2.2.3]
Treatment systems shall be capable of diluting, adsorbing, absorbing, containing, neutralizing, burning, or otherwise processing
stored or used toxic or highly toxic gas, or both. [55:7.9.3.3]
Treatment systems shall be capable of reducing
the allowable discharge concentrations to one-half the IDLH
threshold at the point of discharge. [55:7.9.3.3.2]
Treatment systems
shall be sized to process the maximum worst-case release of gas
based on the maximum flow rate of release from the largest
vessel utilized in accordance with 63.3.9.3.4.2. [55:7.9.3.4.1]
The entire
contents of the single largest compressed gas vessel shall be
considered. [55:7.9.3.4.2]
Where source cylinders, containers, and tanks
are used in attended process operations, with an operator
present at the enclosure where the activity occurs, the volume
of the release shall be limited to the estimated amount released
from the process piping system within a period not to exceed
5 minutes. [55:7.9.3.4.3.1]
Such process piping systems shall comply with
the requirements of 63.3.9.3.4.3.2(A) through
63.3.9.3.4.3.2(E). [55:7.9.3.4.3.2]
All gas transfer operations shall be conducted within a zone of local exhaust that is connected to a treatment system. [55:7.9.3.4.3.2(A)]
Gas detection shall be used to provide a warning to alert the operators to emission of gas into the zone of local exhaust, and the following requirements also shall apply:
- The system shall be capable of detecting gas at the permissible exposure limit (PEL) or the ceiling limit for the gas being processed.
- Activation of the gas detection system shall provide a local alarm.
Operations involving the gas detected
shall be shut down and leaks repaired. [55:7.9.3.4.3.2(C)]
Piping systems used to
convey gases shall be of all-welded construction throughout,
with the exception of fittings used to connect cylinders,
containers, or tanks, or any combination thereof, to the process
system. [55:7.9.3.4.3.2(D)]
Piping systems shall be designed to provide for readily accessible manual shutdown controls. [55:7.9.3.4.3.2(E)]
The time release shall be in accordance with Table 63.3.9.3.5 for the type of container indicated. [55:7.9.3.5]
[55: Table 7.9.3.5]
|
Container Type
|
Time Release
|
|
|
Nonliquefied Gases
|
Liquefied Gases
|
|
|
Cylinders without restrictive flow orifices
|
5 minutes | 30 minutes |
|
Portable tanks without restrictive flow orifices
|
40 minutes | 240 minutes |
| All others |
Based on peak flow from maximum valve orifice
|
Based on peak flow from maximum valve orifice
|
For portable cylinders, containers, and tanks, the
maximum flow rate of release shall be calculated based on
assuming the total release from the cylinder or tank within the
time specified. [55:7.9.3.6.1]
When portable cylinders, containers, or tanks are equipped with reduced flow orifices, the worst-case rate of release shall be determined by the maximum achievable flow from the valve based on the following formula:
[63.3.9.3.6.2]
where:
[63.3.9.3.6.2]|
CFM
|
= | standard cubic feet per minute of gas of concern under flow conditions |
|
A
|
= | area of orifice in square inches (See Table A.63.3.9.3.6 for areas of typical restricted flow orifices.) |
|
P
|
= | supply pressure of gas at NTP in pounds per square inch absolute |
|
MW
|
= | molecular weight [55:7.9.3.6.2] |
For mixtures, the average of the molecular
weights shall be used. [55:7.9.3.6.3]
When
cylinders, containers, or tanks are used outdoors in excess of
the quantities specified in Table 63.2.3.1.1 in the column for
unsprinklered areas (unprotected by gas cabinets or exhausted
enclosures), a gas cabinet, exhausted enclosure, or containment vessel or system shall be provided to control leaks from
leaking cylinders, containers, and tanks in accordance with
63.3.9.4.1 through 63.3.9.4.2.3. [55:7.9.4]
Where gas
cabinets or exhausted enclosures are provided to handle leaks
from cylinders, containers, or tanks, exhaust ventilation shall
be provided that is directed to a treatment system in accordance with the provisions of 63.3.9.3. [55:7.9.4.1]
Where containment vessels or containment systems are provided, they shall
comply with the requirements of 63.3.9.4.2.1 through
63.3.9.4.2.3. [55:7.9.4.2]
Containment vessels or containment systems shall be capable of fully containing or terminating a release. [55:7.9.4.2.1]
Emergency power
shall not be required where fail-safe engineering is provided
for mechanical exhaust ventilation, treatment systems, and
temperature control, and standby power is provided to alternative systems that utilize electrical energy. [55:7.9.5.2]
Except as provided in 63.3.9.6.1, a
continuous gas detection system in accordance with the
requirements of 63.3.9.6.2 through 63.3.9.6.6 shall be provided
for the indoor storage or use of toxic or highly toxic
compressed gases. [55:7.9.6]
A gas detection system shall not be required for toxic gases where the
physiological warning properties for the gas are at a level below
the accepted PEL or the ceiling limit for the gas. [55:7.9.6.1]
The gas detection system shall
transmit a signal to a constantly attended control station for
quantities exceeding one toxic or highly toxic compressed gas
cylinder. [55:7.9.6.3]
An automatic shutdown shall not be required for
reactors utilized for the production of toxic or highly toxic
gases when such reactors are operated at gauge pressures less
than 15 psi (103.4 kPa), constantly attended, and provided with
readily accessible emergency shutoff valves. [55:7.9.6.4.2]
Detection shall be provided at
the locations specified in 63.3.9.6.5.1 through 63.3.9.6.5.4.
[55:7.9.6.5]
Detection shall be
provided at the discharge from the treatment system.
[55:7.9.6.5.1]
Detection shall be provided in the
room or area in which the gas is used. [55:7.9.6.5.2]
Detection shall be provided in the room
or area in which the gas is stored. [55:7.9.6.5.4]
The gas detection system shall
detect the presence of gas at or below the PEL or the ceiling
limit of the gas for those points identified in 63.3.9.6.5.2 and
63.3.9.6.5.3 and at not less than one-half the IDLH level for
points identified in 63.3.9.6.5.1. [55:7.9.6.6]
The outdoor storage or use of unstable reactive
Class 2 compressed gas shall not be within 20 ft (6 m) of buildings, lot lines, streets, alleys, or public ways or means of egress.
[55:7.10.1.1]
A 2-hour fire barrier wall without openings or
penetrations shall be permitted in lieu of the 20 ft (6 m)
distance required by 63.3.10.1.1. [55:7.10.1.2]
Where a fire barrier wall is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.10.1.2.1]
The fire barrier wall shall be either an independent structure or the exterior wall of the building.
[55:7.10.1.2.2]
The 2-hour fire barrier wall shall be located at
least 5 ft (1.5 m) from any exposure. [55:7.10.1.2.3]
The 2-hour fire barrier wall shall not have more
than two sides at approximately 90 degree (1.57 rad) directions
or not more than three sides with connecting angles of approximately 135 degrees (2.36 rad). [55:7.10.1.2.4]
The outdoor storage or use of unstable reactive
Class 3 (nondetonable) compressed gas shall not be within
75 ft (23 m) of buildings, lot lines, streets, alleys, or public ways
or means of egress. [55:7.10.2.1]
A 2-hour fire barrier wall without openings or
penetrations, extending not less than 30 in. (762 mm) above
and to the sides of the storage or use area, that interrupts the
line of sight between the storage or use and the exposure shall
be permitted in lieu of the 75 ft (23 m) distance specified in
63.3.10.2.1. [55:7.10.2.2]
Where a fire barrier wall is used to protect
compressed gas systems, the system shall terminate downstream
of the source valve. [55:7.10.2.2.1]
The fire barrier wall shall be either an independent structure or the exterior wall of the building adjacent to
the storage or use area. [55:7.10.2.2.2]
The 2-hour fire barrier wall shall be located at
least 5 ft (1.5 m) from any exposure. [55:7.10.2.2.3]
The 2-hour fire barrier wall shall not have more
than two sides at approximately 90 degree (1.57 rad) directions
or more than three sides with connecting angles of approximately 135 degrees (2.36 rad). [55:7.10.2.2.4]
Unstable reactive Class 3 compressed gases stored in cylinders, containers, or tanks shall be arranged to limit individual groups of cylinders, containers, or tanks to areas not exceeding 100 ft2 (9.3 m2). [55:7.10.3.1]
Multiple areas shall be separated by aisles.
[55:7.10.3.2]
Aisle widths shall not be less than the height of the
cylinders, containers, or tanks or 4 ft (1.2 m), whichever is
greater. [55:7.10.3.3]
Unstable reactive compressed gases
shall not be stored in basements. [55:7.10.4]
The location of storage areas shall be
determined based on the requirements of the building code
for explosive materials. [55:7.10.5.2]
This section shall apply to all cryogenic fluids,
including those fluids regulated elsewhere in this Code, except
that where specific requirements are provided in Sections 63.5,
63.7, or 63.12, those specific requirements shall apply in
accordance with the applicable chapter. [55:8.1]
Storage, use, and handling of cryogenic fluids shall
be in accordance with Chapters 1 through 6 of NFPA 55 and
Section 63.4 as applicable. [55:8.1.1]
Containers employed for the storage or use of cryogenic fluids shall be designed, fabricated, tested, marked (i.e., stamped), and maintained in accordance with Department of Transportation (DOT) regulations, Transport Canada's (TC) Transportation of Dangerous Goods Regulations, the ASME Boiler and Pressure Vessel Code, "Rules for the Construction of Unfired Pressure Vessels", or regulations of other administering agencies.
[55:8.2]
Aboveground tanks for the storage of cryogenic fluids shall be in accordance with 63.4.2.1.
[55:8.2.1]
The inner vessel
of storage tanks in cryogenic fluid service shall be designed and
constructed in accordance with the ASME Boiler and Pressure
Vessel Code and shall be vacuum jacketed in accordance with
63.4.2.1.2. [55:8.2.1.1]
The vacuum jacket used as an outer vessel for
storage tanks in cryogenic fluid service shall be designed to
withstand the maximum internal and external pressure to
which it will be subjected under operating conditions, including conditions of emergency pressure relief of the annular
space between the inner vessel and the outer vessel.
[55:8.2.1.2.1]
The jacket shall be designed to withstand a minimum collapsing pressure differential of 30 psi (207 kPa).
[55:8.2.1.2.2]
A connection shall be provided on the exterior
of the vacuum jacket to allow measurement of the pressure
within the annular space between the inner vessel and the
outer vessel. [55:8.2.1.2.3.1]
The connection shall be fitted with a bellows-sealed or diaphragm-type valve equipped with a vacuum gauge tube that is shielded to protect against damage from impact. [55:8.2.1.2.3.2]
Containers, equipment, and devices that are not in
compliance with recognized standards for design and construction shall be permitted if approved by the AHJ upon presentation of evidence that they are designed and constructed for
safe operation. [55:8.2.2.1]
The following data shall be submitted to the AHJ with reference to the deviation from the standard with the application for approval:
- Type and use of container, equipment, or device
- Material to be stored, used, or transported
- Description showing dimensions and materials used in construction
- Design pressure, maximum operating pressure, and test pressure
- Type, size, and setting of pressure relief devices
Stationary tanks shall be
provided with concrete or masonry foundations or structural
steel supports on firm concrete or masonry foundations, and
the requirements of 63.4.2.3.1 through 63.4.2.3.5 also shall
apply. [55:8.2.3]
Stationary tanks shall be supported to prevent the concentration of excessive loads on the
supporting portion of the shell. [55:8.2.3.1]
Foundations for horizontal containers shall be constructed to accommodate expansion and contraction of the container. [55:8.2.3.2]
Foundations shall be provided to support the
weight of vaporizers or heat exchangers. [55:8.2.3.3.1]
Foundations shall be designed to withstand soil
and frost conditions as well as the anticipated seismic, snow,
wind, and hydrostatic loading under operating conditions.
[55:8.2.3.3.2]
Where drainage systems,
terrain, or surfaces beneath stationary tanks are arranged in a
manner that can subject stationary tank foundations or
supports to temperatures below -130°F (-90°C), the foundations or supports shall be constructed of materials that are
capable of withstanding the low-temperature effects of cryogenic fluid spillage. [55:8.2.3.4]
Portions of stationary tanks
in contact with foundations or saddles shall be painted to
protect against corrosion. [55:8.2.3.5]
Where a bulk gas source system is connected to
an indoor cryogenic fluid piping system protected by a pressure relief device that is designed to protect against exceeding
the maximum allowable working pressure or maximum process
operating pressure, releases shall be directed to a safe location
outdoors to the open air. [55:8.2.4.1.1]
Pressure relief devices shall be provided to protect
containers and piping systems containing cryogenic fluids from
damage due to overpressure. [55:8.2.4.1.2]
Pressure relief devices shall be designed in accordance with CGA S-1.1, Pressure Relief Device Standards — Part 1 — Cylinders for Compressed Gases, and CGA S-1.2, Pressure Relief Device Standards — Part 2 — Cargo and Portable Tanks for Compressed Gases, for portable tanks; and CGA S-1.3, Pressure Relief Device Standards — Part 3 — Stationary Storage Containers for Compressed Gases, for stationary tanks. [55:8.2.4.1.3]
Portable
containers that are open to the atmosphere and are designed
to contain cryogenic fluids at atmospheric pressure shall not be
required to be equipped with pressure relief devices.
[55:8.2.4.2]
Heat exchangers, vaporizers, insulation casings surrounding containers,
vessels, and coaxial piping systems in which liquefied cryogenic
fluids could be trapped due to leakage from the primary
container shall be provided with a pressure relief device.
[55:8.2.4.3]
Pressure relief devices shall be sized in accordance with the specifications to which the container was fabricated. [55:8.2.4.4.1]
Pressure relief devices shall be located
such that they are accessible for inspection and repair.
[55:8.2.4.5]
Pressure relief devices
shall be arranged to discharge unobstructed to the open air in
such a manner as to prevent impingement of escaping gas on
personnel, containers, equipment, and adjacent structures or
its entrance into enclosed spaces. [55:8.2.4.6.1]
The arrangement of the discharge from pressure relief devices from DOT-specified containers with an internal water volume of 2.0 scf (0.057 Nm3) or less shall be incorporated in the design of the container. [55:8.2.4.6.2.1]
Additional safeguards regarding placement or arrangement shall not be required. [55:8.2.4.6.2.2]
Shutoff valves installed between pressure relief devices and containers shall be in accordance with
63.4.2.4.7. [55:8.2.4.7.1]
Shutoff valves shall not be installed
between pressure relief devices and containers unless the valves
or their use meet the requirements of 63.4.2.4.7.2.1 or
63.4.2.4.7.2.2. [55:8.2.4.7.2]
Shutoff valves shall be locked in the
open position, and their use shall be limited to service-related
work performed by the supplier under the requirements of the
ASME Boiler and Pressure Vessel Code. [55:8.2.4.7.2.1]
Pressure relief devices shall
not be subjected to cryogenic fluid temperatures except when
operating. [55:8.2.4.8]
Pressure relief device vent piping shall have a
cross-sectional area not less than that of the pressure relief
device vent opening and shall be arranged so as not to restrict
the flow of escaping gas. [55:8.3.2]
Pressure relief device vent piping and
drains in vent lines shall be arranged so that escaping gas
discharges unobstructed to the open air and does not impinge on personnel, containers, equipment, and adjacent structures
or enter enclosed spaces. [55:8.3.3]
Pressure relief device vent lines shall be
installed in a manner that excludes or removes moisture and
condensation to prevent malfunction of the pressure relief
device due to freezing or ice accumulation. [55:8.3.4]
Controls shall be provided to prevent
overfilling of stationary containers. [55:8.3.5]
Cryogenic containers and systems shall be
marked in accordance with nationally recognized standards
and in accordance with 63.4.4. [55:8.4.1]
Portable cryogenic containers shall be marked in
accordance with CGA C-7, Guide to the Preparation of Precautionary Labeling and Marking of Compressed Gas Containers.
[55:8.4.1.1.1]
Stationary tanks shall be marked
in accordance with NFPA 704. [55:8.4.1.2]
Visible hazard identification
signs shall be provided in accordance with NFPA 704 at entrances to buildings or areas in which cryogenic fluids are stored,
handled, or used. [55:8.4.1.3]
Stationary containers
shall be placarded with the identity of their contents to indicate
the name of the material contained. [55:8.4.2]
Stationary containers shall
be marked with the manufacturing specification and maximum
allowable working pressure on a permanent nameplate.
[55:8.4.3]
The nameplate shall be installed on the container
in an accessible location. [55:8.4.3.1]
The nameplate shall be marked in accordance with
nationally recognized standards. [55:8.4.3.2]
Container inlet and outlet connections, liquid-level
limit controls, valves, and pressure gauges shall be identified
using one of the methods prescribed by 63.4.4.4.1.1 through
63.4.4.4.1.2. [55:8.4.4.1]
They shall be marked with a permanent tag or
label identifying their function. [55:8.4.4.1.1]
When a schematic drawing is provided, it shall
be attached to the container and maintained in a legible condition. [55:8.4.4.1.2.1]
Emergency shutoff valves on stationary containers shall be identified,
visible, and indicated by means of a sign. [55:8.4.6]
Cryogenic containers and systems shall be
secured against accidental dislodgement and against access by
unauthorized personnel in accordance with 63.4.5. [55:8.5.1]
Areas used for the storage of
containers and systems shall be secured against unauthorized
entry. [55:8.5.2]
Administrative controls shall be allowed to be used
to control access to individual storage areas located in secure
facilities not accessible by the general public. [55:8.5.2.1]
Stationary containers shall
be secured to foundations in accordance with the building
code. [55:8.5.3]
Portable containers subject to shifting or upset shall
be secured. [55:8.5.3.1]
Nesting shall be permitted as a means of securing
portable containers. [55:8.5.3.2]
Vaporizers, heat exchangers,
and similar equipment shall be secured to foundations, and
their connecting piping shall be designed and constructed to
provide for the effects of expansion and contraction due to
temperature changes. [55:8.5.4]
Containers, piping, valves, pressure relief devices, regulating equipment, and other appurtenances shall be protected against physical damage and
tampering. [55:8.5.5]
Cryogenic containers and systems in storage
or use shall be separated from materials and conditions that
present exposure hazards to or from each other in accordance
with 63.4.6. [55:8.6.1]
Stationary containers located outdoors shall be separated from exposure hazards in accordance with the minimum separation distances indicated in Table 63.4.6.2. [55:8.6.2]
| Exposure |
Minimum Distance
|
|
|
ft
|
m
|
|
| (1) Buildings, regardless of construction type |
1
|
0.3
|
| (2) Wall openings |
1
|
0.3
|
| (3) Air intakes |
10
|
3.1
|
| (4) Property lines |
5
|
1.5
|
| (5) Places of public assembly (assembly occupancies) |
50
|
15
|
| (6) Nonambulatory patient areas |
50
|
15
|
| (7) Combustible materials, (e.g., paper, leaves, weeds, dry grass, debris) |
15
|
4.5
|
| (8) Incompatible hazardous materials |
20
|
6.1
|
| (9) Building exits |
10
|
3.1
|
[55: Table 8.6.2]