About this chapter: Chapter 55 regulates the hazards associated with the storage, use and handling of cryogenic fluids through regulation of such things as pressure relief mechanisms and proper container storage. These hazards are in addition to the code requirements that address the other hazards of cryogenic fluids such as flammability and toxicity. These other characteristics are dealt with in Chapter 50 and other chapters, such as Chapter 58 and its content about flammable gases. Cryogens are hazardous because they are held at extremely low temperatures and high pressures. Many cryogenic fluids, however, are actually inert gases and would not be regulated elsewhere in this code. Cryogens are used for many applications but specifically have had widespread use in the biomedical field and in space programs.
Storage, use and handling of cryogenic fluids shall comply with this chapter and NFPA 55. Cryogenic fluids classified as hazardous materials shall also comply with the general requirements of Chapter 50. Partially full containers containing residual cryogenic fluids shall be considered as full for the purposes of the controls required.
- Fluids used as refrigerants in refrigeration systems (see Section 605).
- Liquefied natural gas (LNG), which shall comply with NFPA 59A.
Oxidizing cryogenic fluids, including oxygen, shall comply with Chapter 63, as applicable.
Flammable cryogenic fluids, including hydrogen, methane and carbon monoxide, shall comply with Chapters 23 and 58, as applicable.
Inert cryogenic fluids, including argon, helium and nitrogen, shall comply with ANSI/CGA P-18.
The following terms are defined in Chapter 2.
Containers employed for storage or use of cryogenic fluids shall comply with Sections 5503.1.1 through 5503.1.3.2 and Chapter 50.
Containers, equipment and devices that are not in compliance with recognized standards for design and construction shall be approved upon presentation of satisfactory evidence that they are designed and constructed for safe operation.
The following data shall be submitted to the fire code official with reference to the deviation from the recognized 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.
- Other data requested by the fire code official.
Concrete containers shall be built in accordance with the International Building Code. Barrier materials and membranes used in connection with concrete, but not functioning structurally, shall be compatible with the materials contained.
Containers shall be provided with substantial concrete or masonry foundations, or structural steel supports on firm concrete or masonry foundations. Containers shall be supported to prevent the concentration of excessive loads on the supporting portion of the shell. Foundations for horizontal containers shall be constructed to accommodate expansion and contraction of the container. Foundations shall be provided to support the weight of vaporizers or heat exchangers.
Where container foundations or supports are subject to exposure to temperatures below -130°F (-90°C), the foundations or supports shall be constructed of materials to withstand the low-temperature effects of cryogenic fluid spillage.
Portions of containers in contact with foundations or saddles shall be painted to protect against corrosion.
Pressure relief devices shall be provided in accordance with Sections 5503.2.1 through 5503.2.7 to protect containers and systems containing cryogenic fluids from rupture in the event of overpressure. Pressure relief devices shall be designed in accordance with CGA S-1.1, CGA S-1.2 and CGA S-1.3.
Containers shall be provided with pressure relief devices.
Heat exchangers, vaporizers, insulation casings surrounding containers, vessels and coaxial piping systems in which liquefied cryogenic fluids could be trapped because of leakage from the primary container shall be provided with a pressure relief device.
Pressure relief devices shall be sized in accordance with the specifications to which the container was fabricated. The relief device shall have sufficient capacity to prevent the maximum design pressure of the container or system from being exceeded.
Pressure relief devices shall be located such that they are provided with ready access for inspection and repair.
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 to enter enclosed spaces.
Exception: DOTn-specified containers with an internal volume of 2 cubic feet (0.057 m3) or less.
Shutoff valves shall not be installed between pressure relief devices and containers.
- A shutoff valve is allowed on containers equipped with multiple pressure relief device installations where the arrangement of the valves provides the full required flow through the minimum number of required relief devices at all times.
- A locking-type shutoff valve is allowed to be used upstream of the pressure relief device for service-related work performed by the supplier when in accordance with the requirements of the ASME Boiler and Pressure Vessel Code.
Pressure relief devices shall not be subjected to cryogenic fluid temperatures except when operating.
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.
Pressure relief device vent piping and drains in vent lines shall be arranged so that escaping gas will discharge unobstructed to the open air and not impinge on personnel, containers, equipment and adjacent structures or enter enclosed spaces. Pressure relief device vent lines shall be installed in such a manner to exclude or remove moisture and condensation and prevent malfunction of the pressure relief device because of freezing or ice accumulation.
Cryogenic containers and systems shall be marked in accordance with Sections 5503.4.1 through 5503.4.6.
Visible hazard identification signs in accordance with NFPA 704 shall be provided at entrances to buildings or areas in which cryogenic fluids are stored, handled or used.
Stationary and portable containers shall be marked with the name of the gas contained. Stationary above-ground containers shall be placarded in accordance with Sections 5003.5 and 5003.6. Portable containers shall be identified in accordance with CGA C-7.
Stationary containers shall be identified with the manufacturing specification and maximum allowable working pressure with a permanent nameplate. The nameplate shall be installed on the container in a location provided with ready access. The nameplate shall be marked in accordance with the ASME Boiler and Pressure Vessel Code or DOTn 49 CFR Parts 100—185.
Container inlet and outlet connections, liquid-level limit controls, valves and pressure gauges shall be identified with one of the following:
- A permanent tag or label identifying the function.
- A schematic drawing that portrays the function and designates whether the connection is to the vapor or liquid space of the container.
Where a schematic drawing is provided, it shall be attached to the container and maintained in a legible condition.
Piping systems shall be identified in accordance with ASME A13.1.
Emergency shutoff valves shall be identified and the location shall be clearly visible and indicated by means of a sign.
Cryogenic containers and systems shall be secured against accidental dislodgement and against access by unauthorized personnel in accordance with Sections 5503.5.1 through 5503.5.4.
Containers and systems shall be secured against unauthorized entry and safeguarded in an approved manner.
Stationary containers shall be secured to foundations in accordance with the International Building Code. Portable containers subject to shifting or upset shall be secured. Nesting shall be an acceptable means of securing containers.
Vaporizers, heat exchangers and similar equipment shall be anchored to a suitable foundation and its connecting piping shall be sufficiently flexible to provide for the effects of expansion and contraction due to temperature changes.
Containers, piping, valves, pressure relief devices, regulating equipment and other appurtenances shall be protected against physical damage and tampering.
Containers and systems shall not be located where they could become part of an electrical circuit.
Containers and systems shall not be used for electrical grounding. Where electrical grounding and bonding is required, the system shall comply with NFPA 70. The grounding system shall be protected against corrosion, including corrosion caused by stray electric currents.
Service, repair, modification or removal of valves, pressure relief devices or other container appurtenances shall comply with Sections 5503.7.1 and 5503.7.2 and the ASME Boiler and Pressure Vessel Code, Section VIII or DOTn 49 CFR Parts 100—185.
Containers that have been removed from service shall be handled in an approved manner.
Service and repair of systems shall be performed by trained personnel.
Containers shall not be used for any purpose other than to serve as a vessel for containing the product that it is designed to contain.
Leaking, damaged or corroded containers shall be removed from service. Leaking, damaged or corroded systems shall be replaced, repaired or removed in accordance with Section 5503.7.
Where required, lighting, including emergency lighting, shall be provided for fire appliances and operating facilities such as walkways, control valves and gates ancillary to stationary containers.
Storage of containers shall comply with this section.
Indoor storage of containers shall be in accordance with Sections 5504.2.1 through 5504.2.2.3.
Stationary containers shall be installed in accordance with the provisions applicable to the type of fluid stored and this section.
Stationary containers shall comply with Section 5503.1.
Cryogenic fluids in stationary containers stored indoors shall be located in buildings, rooms or areas constructed in accordance with the International Building Code.
Storage areas for stationary containers shall be ventilated in accordance with the International Mechanical Code.
Indoor storage of portable containers shall comply with the provisions applicable to the type of fluid stored and Sections 5504.2.2.1 through 5504.2.2.3.
Portable containers shall comply with Section 5503.1.
Cryogenic fluids in portable containers stored indoors shall be stored in buildings, rooms or areas constructed in accordance with the International Building Code.
Storage areas shall be ventilated in accordance with the International Mechanical Code.
Outdoor storage of containers shall be in accordance with Sections 5504.3.1 through 5504.3.1.2.3.
Cryogenic containers and systems in outdoor storage shall be separated from materials and conditions that pose exposure hazards to or from each other in accordance with Sections 5504.3.1.1 through 5504.3.1.1.5.
Stationary containers shall be separated from exposure hazards in accordance with the provisions applicable to the type of fluid contained and the minimum separation distances indicated in Table 5504.3.1.1.
SEPARATION OF STATIONARY CONTAINERS FROM EXPOSURE HAZARDS
|Buildings, regardless of construction type||1|
|Places of public assembly||50|
|Nonambulatory patient areas||50|
|Combustible materials such as paper, leaves, weeds, dry grass or debris||15|
|Other hazardous materials||In accordance with Chapter 50|
For SI: 1 foot = 304.8 mm.
Remote transfer points and fill connection points shall not be positioned closer to exposures than the minimum distances required for stationary containers.
Containers shall be placed on surfaces that are compatible with the fluid in the container.
Containers of cryogenic fluids shall not be located within diked areas containing other hazardous materials.
Stationary containers located in areas subject to flooding shall be securely anchored or elevated to prevent the containers from separating from foundations or supports.
The area surrounding stationary containers shall be provided with a means to prevent accidental discharge of fluids from endangering personnel, containers, equipment and adjacent structures or to enter enclosed spaces. The stationary container shall not be placed where spilled or discharged fluids will be retained around the container.
Exception: These provisions shall not apply where it is determined by the fire code official that the container does not constitute a hazard, after consideration of special features such as crushed rock utilized as a heat sink, topographical conditions, nature of occupancy, proximity to structures on the same or adjacent property, and the capacity and construction of containers and character of fluids to be stored.
Outdoor storage of portable containers shall comply with Section 5503 and Sections 5504.3.1.2.1 through 5504.3.1.2.3.
Portable containers in outdoor storage shall be separated from exposure hazards in accordance with Table 5504.3.1.2.1.
SEPARATION OF PORTABLE CONTAINERS FROM EXPOSURE HAZARDS
|Combustible materials such as paper, leaves, weeds, dry grass or debris||15|
|Other hazardous materials||In accordance with Chapter 50|
For SI: 1 foot = 304.8 mm.
The surface of the area on which stationary containers are placed, including the surface of the area located below the point where connections are made for the purpose of filling such containers, shall be compatible with the fluid in the container.
The area surrounding portable containers shall be provided with a means to prevent accidental discharge of fluids from endangering adjacent containers, buildings, equipment or adjoining property.
Exception: These provisions shall not apply where it is determined by the fire code official that the container does not constitute a hazard.
Use and handling of cryogenic fluid containers and systems shall comply with Sections 5505.1.1 through 5505.5.2.
Cryogenic fluid systems shall be suitable for the use intended and designed by persons competent in such design. Equipment, machinery and processes shall be listed or approved.
Piping, tubing, valves and joints and fittings conveying cryogenic fluids shall be installed in accordance with the material-specific provisions of Section 5501.1 and Sections 5505.1.2.1 through 5505.1.2.6.
Joints on container piping and tubing shall be threaded, welded, silver brazed or flanged.
Valves and accessory equipment shall be suitable for the intended use at the temperatures of the application and shall be designed and constructed to withstand the maximum pressure at the minimum temperature to which they will be subjected.
Shutoff valves shall be installed in piping containing cryogenic fluids where needed to limit the volume of liquid discharged in the event of piping or equipment failure. Pressure relief valves shall be installed where liquid is capable of being trapped between shutoff valves in the piping system (see Section 5503.2).
Piping systems shall be supported and protected from physical damage. Piping passing through walls shall be protected from mechanical damage.
Piping systems shall be tested and proven free of leaks after installation as required by the standards to which they were designed and constructed. Test pressures shall be not less than 150 percent of the maximum allowable working pressure where hydraulic testing is conducted or 110 percent where testing is conducted pneumatically.
Indoor use of cryogenic fluids shall comply with the material-specific provisions of Section 5501.1.
Outdoor use of cryogenic fluids shall comply with the material specific provisions of Sections 5501.1, 5505.3.1 and 5505.3.2.
Distances from lot lines, buildings and exposure hazards shall comply with Section 5504.3 and the material-specific provisions of Section 5501.1.
Manual or automatic emergency shutoff valves shall be provided to shut off the cryogenic fluid supply in case of emergency. An emergency shutoff valve shall be located at the source of supply and at the point where the system enters the building.
Filling and dispensing of cryogenic fluids shall comply with Sections 5505.4.1 through 5505.4.3.
Dispensing of cryogenic fluids with physical or health hazards shall be conducted in approved locations. Dispensing indoors shall be conducted in areas constructed in accordance with the International Building Code.
Indoor areas where cryogenic fluids are dispensed shall be ventilated in accordance with the requirements of the International Mechanical Code in a manner that captures any vapor at the point of generation.
Exception: Cryogenic fluids that can be demonstrated not to create harmful vapors.
Piping systems utilized for filling or dispensing of cryogenic fluids shall be designed and constructed in accordance with Section 5505.1.2.
Loading or unloading areas shall be conducted in an approved manner in accordance with the standards referenced in Section 5501.1.
Limit controls shall be provided to prevent overfilling of stationary containers during filling operations.
Handling of cryogenic containers shall comply with Sections 5505.5.1 and 5505.5.2.
Cryogenic containers shall be moved using an approved method. Where cryogenic containers are moved by hand cart, hand truck or other mobile device, such carts, trucks or devices shall be designed for the secure movement of the container.
Carts and trucks used to transport cryogenic containers shall be designed to provide a stable base for the commodities to be transported and shall have a means of restraining containers to prevent accidental dislodgement.
Pressurized containers shall be transported in a closed condition. Containers designed for use at atmospheric conditions shall be transported with appropriate loose-fitting covers in place to prevent spillage.