Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization—Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 20368-2012 Production, storage and handling of liquefied natural gas (LNG). In addition to structural adjustment and editorial changes, the following main technical changes have been made compared with GB/T 20368-2012:
a) The requirements of scope are modified (see Clause 1 hereof; Clause 1 of Edition 2012);
b) The normative references are modified (see Clause 2 hereof; Clause 2 of Edition 2012);
c) Terms and definitions such as "liquefied natural gas plant, sources of ignition, tank system, transfer systems, liquefied natural gas pressure tank, primary container, secondary container, vapor cloud, setback distance, automatic product retention valve, piping system, cryogenic pipe-in-pipe system" are added; terms and definitions such as "liquefied natural gas, noncombustible material, impounding area, impounding wall, single containment tank, double containment tank, full containment tank, membrane tank, vaporizer, ambient vaporizer, heated vaporizer, integral heated vaporizer, remote heated vaporizer, etc.” are modified, and terms and definitions such as “approved, bunkering, cargo tank vehicle, components, container, frozen ground container, pre-stressed concrete container, controllable emergency, design pressure, failsafe, fired equipment, flame spread index, hazardous fluid, LNG plant, maximum allowable working pressure, model, out-of-service, overfilling, transfer area, transition joint and water capacity” are deleted (see Clause 3 hereof; Clause 3 of Edition 2012);
d) The requirements for soil protection in cryogenic facilities (see 4.1 hereof, 5.5 of Edition 2012), snow and ice falling (see 4.2 hereof, 5.6 of Edition 2012) are modified; and requirements for corrosion control review (see 4.1 of Edition 2012) and record (see 4.4 of 2012 edition) are deleted;
e) The provisions of the country, industry, region, port planning and national industrial policy that the site selection shall comply with are added (see 5.1.2~5.1.3); the selection provisions on the utilization of port resources, the natural conditions of the land area and the surrounding supporting conditions are added (see 5.1.4~5.1.12); the impact assessment requirements of leakage consequence scenarios (combustible or toxic gas diffusion, fire and explosion) are summarized into normative Annex A; provisions are made on the determination of the distance between the plant and the peripheral facilities outside the battery limit, and the determination of the external safety protection distance of the plant; the content of site selection based on risk analysis is changed to “performance-based site selection of liquefied natural gas plant by quantitative risk analysis (QRA)", which was taken as a normative annex (see 5.1.12 and Annex B hereof, and Annex E of Edition 2012); provisions are made on how to carry out QRA for site selection; the requirements related to the division of impounding area, design of impounding area and LNG collection and discharge system in the original Clause 5 are separated into chapters, forming Clause 12 "Impounding area and discharge system" of this document; the general requirements for plane layout are added (see 5.2), and the spacing requirements of LNG tanks are modified (see 5.3.1 and 5.3.2 hereof, and 5.2.4.1 of Edition 2012); the provisions on the layout of double containment tank, full containment tank and membrane tank with adjacent single and double containment tanks are modified (see 5.3.3 hereof, 5.2.4.2 of Edition 2012); the provisions on the fire protection design of outer tank of concrete tank are added (see 5.3.3), the provisions on the spacing of vaporizers are modified (see 5.4 hereof, 5.2.5 of Edition 2012); the provisions on the spacing of combustible gas compressor room are added (see 5.5.2); the provisions on the heat flux in the impounding area are added (see 5.6.4); the provisions on the distance from buildings and structures to the LNG and other dangerous liquids are added (see 5.7 hereof, 5.3 of Edition 2012); and the provisions on the qualification of designers and manufacturers are deleted (see 5.4 of Edition 2012);
f) The content about vaporization facilities is moved to process equipment (see 6.3 hereof, Clause 8 of Edition 2012); the general requirements are added (see 6.1 hereof, and 6.1, 6.3, 6.4.1, 6.4.2 and 6.4.3 of Edition 2012); the provisions on the installation of internal combustion engines or gas turbines are deleted (see 6.4.4 of Edition 2012); the provisions for aluminum plate-fin heat exchanger are added (see 6.1.8); the provisions for setting shut-off valves at LNG inlet of vaporizer system are modified (see 6.3.6 hereof, and 8.3.1, 8.3.3 and 8.3.5.2 of Edition 2012); the provisions for unattended LNG plant installation are modified (see 6.3.7 hereof; 8.3.5, 8.3.5.1, 8.3.5.2, 8.3.6, 8.3.6.1 of Edition 2012); the provisions for the installation of attended LNG plants are modified (see 6.3.8 hereof, and 8.3.4, 8.3.5.3, 8.3.6.2 of Edition 2012); the content about LNG mobile equipment is moved to process equipment (see 6.4 hereof, and 5.8 of Edition 2012); the provisions for LNG mobile equipment are modified (see 6.4.1 hereof, and 5.8.1 of Edition 2012);
g) The provisions governing the qualifications of companies, inspectors and engineers are deleted; the inspection requirements are modified (see 7.3 hereof, and 7.1 of Edition 2012); general requirements, specifying the specifications to be met by several main tank types, are added (see 7.1); the definitions of operational benchmark earthquake (OBE) and safe shutdown earthquake (SSE) for seismic design of onshore tanks are adjusted, and the definition of aftershock level earthquake (ALE) is added (see 7.4.7.2 hereof, and 7.2.2 of Edition 2012); the seismic design of tanks manufactured in onshore factories is deleted (see 7.2.3 of Edition 2012); the flood load requirements are deleted (see 7.2.4 of Edition 2012); the provisions for liquefaction evaluation of tank sites are added (see 7.4.4.2); welding inspection requirements for metal tanks with design operating pressure greater than or equal to 100 kPa are added (see 7.4.5.2~7.4.5.5); the material requirements, and construction, inspection and test requirements for concrete, steel bars and pre-stressed steel bars in concrete tanks are deleted (see 7.4.1~7.4.3); the test of LNG tank is modified and the test requirements of membrane tank are added (see 7.4.8 hereof, and 7.6 of Edition 2012); other requirements for membrane tank are added (see 7.4.9); the provisions on LNG pressure tank type modified (see 7.5.1 hereof, and 7.3.2.1 of Edition 2012); the basic requirements for inner tanks of LNG double-wall tanks are modified (see 7.5.2 hereof, and 7.3.2.2 of Edition 2012); the basic requirements for outer tanks of LNG double-wall tanks are deleted (see 7.3.2.3 of Edition 2012); the basic requirements of LNG single-wall tank are added (see 7.5.3); the design requirements of the inner tank support system of LNG double-wall tanks are modified (see 7.5.9, 7.3.2.6 of Edition 2012); the basic requirements for seismic design of LNG pressure tanks are added (see 7.5.11); the provisions of the liquid level control equipment in LNG pressure tank are added (see 7.5.12); the basic requirements for LNG pressure tank test are added (see 7.5.13); the protection requirements for LNG pressure tanks during transportation are added (see 7.5.14);
h) The provisions for fire protection systems are added (see 8.1.1.3); provisions for power system are added (see 8.1.1.4); the earthquake category of LNG facility pipeline is deleted (see 9.1.2.1 of Edition 2012); the piping category (see 8.1.2.1, and 9.1.2.2 of Edition 2012); the maximum value of Category B piping response correction factor is modified (see 8.1.2.1, and 9.1.2.2 of Cotechini Edition 2012); the conditions that shall be met for thermal insulation materials in fire environment are added (see 8.1.4.4); the conditions that sealing is not required for threaded connections are added [see 8.3.1.4 d)]; the provisions for pipe joints (see 8.3.1.7); the disabled pipe connection mode is added (see 8.3.1.8); provisions for other pipe assemblies and flanged connections are added (see 8.3. 1.9); the lower limit of interface caliber is modified (see 8.3.2.5 hereof, and 9.3.2.5 of Edition 2012); the operating mechanism of the emergency shut-off valve is changed (see 8.3.2.7 hereof, and 9.3.2.7 of Edition 2012); the coating requirements for emergency shut-off valves are added (see 8.3.2.11); related contents of brazing (see 8.3.3.4); the content of pipe marking is added [see 8.3.4 d)]; the isolation of hazard sources is added (see 8.4); identification requirements for medium and flow direction are added (see 8.6.2); the setting of replacement nozzle is added (see 8.8.2); provisions for flare and vent pipe are added (see 8.10); the installation requirements of underground or submarine pipelines are added (see 8.12);
i) The design of plant facilities, including design classification, plant facilities design is added (see Clause 9), and the fire and explosion design for storage of LNG and flammable fluids is modified (see 9.5 hereof, and 5.3.2 of Edition 2012);
j) Electrical, instrumentation and communication are separated into clauses (see Clauses 10 and 11 hereof; Clause 10 of Edition 2012); the provisions on power supply requirements are added (see 10.1); the general requirements for electrical equipment and wiring are deleted (see 10.9.1 of Edition 2012); the division requirements of electrical explosion hazardous areas are modified (see 10.2 hereof. and 10.6.2 of Edition 2012); the sealing requirements between combustible fluid system and electrical piping or wiring are deleted (see 10.6.3 of Edition 2012); other provisions for detecting combustible fluid leakage other than the main seal are deleted (see 10.6.4 of Edition 2012); the provisions on ventilation duct system when combustible gas air mixture is ignited are deleted (see 10.6.5 of Edition 2012); relevant provisions on power device design are added (see 10.3); relevant provisions on electrical lightning protection grounding and anti-static grounding are added (see 10.4); relevant provisions on lighting are added (see 10.5);
k) The general requirements for instrumentation and control systems are added (see 11.1.1); changes have been made to the level gauge settings, design, installation, alarm and interlocking requirements (see 11.1.2 hereof, and 10.1 of Edition 2012). The setting requirements of pressure instruments have been changed to distinguish the setting requirements of LNG tanks from those of non-LNG hazardous fluid tanks (see 11.1.3 hereof, and 10.2 of Edition 2012). The setting requirements of temperature instruments have been changed, and the setting requirements of temperature instruments for cryogenic piping have been added (see 11.1.5 hereof, and 10.4 of Edition 2012). The provisions for fail-safe design have been added (see 11.1.6). The setting requirements on emergency shutdown are deleted (see 10.5 of Edition 2012). The setting requirements of emergency stop system are modified (see 11.1.7 hereof, and 12.2 of Edition 2012). The setting requirements of fire and gas detection are modified, and the setting requirements of toxic gas and oxygen content detection are added (see 11.1.8 hereof, and 12.3 of Edition 2012); communication content is added (see 11.2);
l) The impounding area and discharge system are separated into clauses (see Clause 12);
m) The provisions on fire-fighting and fire prevention assessment are changed (see 13.1 hereof, and 12.1 of Edition 2012); the provisions on fire-fighting water system are modified (see 13.2 hereof, and 12.4 of Edition 2012); the provisions on mobile fire-fighting facilities are modified (see 13.3 hereof, 12.5 of Edition 2012); the provisions on personal protection is modified (see 13.4 hereof, and 12.7 of Edition 2012); the safety provisions are modified (see 13.5 hereof, and 12.8 of Edition 2012);
n) Anti corrosion provisions are added (see Clause 14);
o) The provisions on warning signs in the loading and unloading area are deleted (see 11.1.1 of Edition 2012); provisions on analysis of closing time of power shut-off valve are added (see 15.2.2 and 15.2.3); the provisions on berth design requirements are deleted (see 11.4.1 of Edition 2012); the provisions on fire source are deleted (see 11.4.2 of Edition 2012); the provisions on underwater pipeline are deleted (see 11.4.3.2 of Edition 2012); the provisions on tank car transportation and its approval are deleted (see 11.5.1 and 11.5.2 of Edition 2012); the provisions on discharge of loading and unloading pipelines are deleted (see 11.6.6 of Edition 2012); the provisions on hose design are deleted (see 11.7.2 of Edition 2012); the provisions on hose joint, icing and detection are deleted (see 11.7.3, 11.7.5 and 11.7.6 of Edition 2012); the provisions on loading and unloading ship operation test are deleted (see 11.7.7 of Edition 2012);
p) The provisions for small LNG facilities are added (see Clause 16);
q) Provisions on purging of LNG container are added (see 17.3.5); the commissioning requirements before equipment startup are added (see 17.4); provisions on inspection interval requirements of safety valve are added (see 17.7.3.5~17.7.3.9); and provisions on external surface inspection of LNG tank system are added (see 17.7.4).
This standard was proposed by and is under the jurisdiction of National Technical Committee on Petroleum and Natural Gas of Standardization Administration of China (SAT/TC 355).
This document was issued in 2006 as first edition, its first revision was issued in 2012, and this is the second revision.
Production, storage and handling of liquefied natural gas (LNG)
1 Scope
This document specifies the technical requirements for the design, construction, operation and maintenance of liquefied natural gas (LNG) plants.
This document is applicable to constructed, extended and renovated LNG plants on land.
This document is not applicable to permafrost containers, mobile storage tanks installed or used indoors, LNG filling vehicles and LNG fuel vehicles.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 150 (All parts) Pressure vessels
GB/T 151 Heat exchangers
GB 7956.1 Fire fighting vehicles—Part 1: General technical specifications
GB 7956.2 Fire fighting vehicles—Part 2: Water tank fire fighting vehicle
GB 7956.3 Fire fighting vehicles—Part 3: Foam fire fighting vehicle
GB/T 21246 Measurement method for cathodic protection parameters of buried steel pipelines
GB/T 21447 Specifications for steel pipeline external corrosion control
GB/T 21448 Specification of cathodic protection for underground steel pipelines
GB/T 23258 Standard practice controlling internal corrosion in steel pipelines
GB/T 26978 (All parts) Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of liquefied natural gases
GB/T 32270 Pressure piping code—Power piping
GB 36894 Risk criteria for hazardous chemicals production unit and storage installations
GB/T 37243-2019 Determination method of external safety distance for hazardous chemicals production units and storage installations
GB 50009 Load code for the design of building structures
GB 50010 Code for design of concrete structures
GB 50011 Code for seismic design of buildings
GB 50016 Code for fire protection design of buildings
GB 50019 Design code for heating ventilation and air conditioning of industrial buildings
GB 50034 Standard for lighting design of buildings
GB 50052 Code for design electric power supply systems
GB 50057 Code for design protection of structures against lightning
GB 50058 Code for design of electrical installations in explosive atmospheres
GB 50084 Code of design for sprinkler systems
GB 50093 Code for construction and quality acceptance of automation instrumentation engineering
GB 50116 Code for design of automatic fire alarm system
GB 50140 Code for design of extinguisher distribution in buildings
GB 50151 Code for design of foam extinguishing systems
GB 50160 Fire prevention code of petrochemical enterprise design
GB 50183 Code for fire protection design of petroleum and natural gas engineering
GB 50193 Code of design for carbon dioxide fire extinguishing systems
GB 50219 Technical code for water spray fire protection systems
GB 50235-2010 Code for construction of industrial metallic piping engineering
GB 50251 Code for design of gas transmission pipeline engineering
GB 50261 Code for installation and commissioning of sprinkler systems
GB 50264 Design code for insulation engineering of industrial equipment and pipe
GB 50316 Design code for industrial metallic piping
GB 50316-2000
(2008 Edition) Design code for industrial metallic piping
GB 50347 Code of design for powder extinguishing systems
GB 50370 Code for design of gas fire extinguishing systems
GB/T 50393 Technical standard for anti-corrosion engineering of steel petroleum storage tanks
GB 50493 Standard for design of combustible gas and toxic gas detection and alarm for petrochemical industry
GB 50650 Design code for lightning protection of petrochemical installations
GB/T 50698 Standard for AC interference mitigation of buried steel pipelines
GB 50779 Code for design of blast resistant control building in petrochemical industry
GB 50898 Technical code for water mist fire extinguishing system
GB 50974 Code of design on fire protection water supply and hydrant systems
GB/T 50991 Technical standard for DC interference mitigation of buried steel pipeline
GB 51081 Technical code for application of concrete under cryogenic circumstance
GB 51156 Code for design of liquefied natural gas receiving terminal
GB 51156-2015 Code for design of liquefied natural gas receiving terminal
GB/T 51257 Code for design of low temperature piping of liquefied natural gas
GB 51261 Standard for design of natural gas liquefaction plant
GB 51309 Technical standard for fire emergency lighting and evacuate indicating system
JT/T 617.7 Regulations concerning road transportation of dangerous goods—Part 7: Transport conditions and operational requirements
NB/T 47006 Aluminum plate-fin heat exchangers
SH 3009 Design specification for combustible gas discharge system in petrochemical industry
SH/T 3043 Specification of surface color and mark on equipment, piping and steel structure in petrochemical industry
SH/T 3073 Specification for design of piping support in petrochemical industry
SH/T 3097 Specification for design of static electricity earthing in petrochemical industry
SH/T 3192 Design specification for lighting in petrochemical plants
SY/T 0043 Code for painting colors of pipelines and equipments for petroleum and natural gas engineering
SY/T 6784 Standard of corrosion control for steel storage tank
SY/T 6964 Specification of cathodic protection for petroleum & gas station
SY/T 7036 Specification of external coating for piping and equipments in petroleum and gas stations
SY/T 7349 Specification for insulation and anti-corrosion of low temperature storage tank
SY/T 7350 Specification of coating and cold insulation for low temperature piping and equipment
SY/T 7419 Specification for insulation design, construction and acceptance of cryogenic piping
TSG 21 Supervision regulation on safety technology for stationary pressure vessel
XF 39 Fire fighting vehicles—Performance requirements and test methods
3 Terms and definitions
For the purposes of this document, the following term and definition apply.
3.1 General
3.1.1
liquefied natural gas; LNG
a low-temperature liquid fluid which is mainly composed of methane and may contain small amounts of ethane, propane, nitrogen, or other components commonly found in natural gas
[Source: GB 51261-2019, 2.0.1]
3.1.2
liquefied natural gas plant
LNG plant
plant with natural gas purification and liquefaction, LNG storage and shipment, LNG loading and unloading and regasification functions
Note: For example: basic load natural gas liquefaction plant, peak shaving liquefaction plant, LNG receiving station and LNG satellite station.
3.1.3
sources of ignition
energy source that can make combustibles react with combustion-supporting substances
Note: This kind of energy may be heat energy, light energy, electric energy, chemical energy and mechanical energy.
3.1.4
noncombustible material
construction material used under expected conditions, which do not catch fire, burn, support combustion or release combustible vapor in case of fire and heat, and whose combustion performance grade is Grade A
3.1.5
impounding area
area delineated by means of an impounding wall or topographic conditions for accommodating accidental spills or leaks of liquefied natural gas or other dangerous liquids
3.1.6
impounding wall
structure for preventing overflow of liquefied natural gas or spread of fire in case of a leakage accident of LNG storage tank
[Source: GB 51156-2015, 2.0.16]
3.1.7
vapor cloud
mixed gas cloud formed by cooling and condensation of water vapor in the atmospheric environment when LNG leaks or overflows to the atmospheric environment
[Source: GB/T 8423.3-2018, 5.2.5]
3.1.8
setback distance
minimum distance from the automatic product retention valve on the maximum liquid pipeline of LNG container to the building outside the plant or building boundary
3.1.9
transfer systems
system in an LNG yard for transferring LNG or other hazardous media between storage containers or tanks and loading and unloading points or loading points by means of pipelines, tank car, tankers, tank containers or ships
3.2 Vaporization facilities
3.2.1
vaporizer
device that introduces heat in a controlled way to change a liquid into a vapor or gaseous state
3.2.2
ambient vaporizer
device that the main heat source of the vaporizer is not separated from the actual vaporization heat exchanger, and the main heat sources are environment, seawater or geothermal water, etc.
Note: Including air temperature vaporizer.
[Source: GB 51261-2019, 2.0.16, modified]
3.2.3
heated vaporizer
device that the main heat source of the vaporizer comes from fuel combustion, electric heating or waste heat (such as waste heat of boiler or internal combustion engine)
[Source: GB 51261-2019, 2.0.13, modified]
3.2.4
integral heated vaporizer
heated vaporizer integrating the main heat source and the vaporizer heat exchanger
Note: Including submerged combustion vaporizer.
[Source: GB 51261-2019, 2.0.14, modified]
3.2.5
remote heated vaporizer
heated vaporizer in which the main heat source is separated from the actual vaporization heat exchanger and the intermediate medium (such as water, isopentane and ethylene glycol) is used as the heating transmission medium
Note: Including open shelf vaporizer and intermediate medium vaporizer.
[Source: GB 51261-2019, 2.0.15, modified]
3.3 Storage facilities
3.3.1
tank system
low-pressure (operating pressure less than 100kPa) field-assembled, vertical, cylindrical, flat-bottomed equipment for storage of LNG or other hazardous liquids
Note: Including one or more containers, as well as various accessories, appendages and thermal insulation materials.
3.3.2
primary container
container used for holding cryogenic liquids and in direct contact with cryogenic liquids
[Source: GB/T 8423.3-2018, 5.2.24]
3.3.3
secondary container
container that is generally located outside the primary container, contains cryogenic liquid when leaking, and does not contact with cryogenic liquid under normal operating conditions
[Source: GB/T 8423.3-2018, 5.2.25]
3.3.4
single containment tank
tank that has only one self-supporting steel storage tank for cryogenic liquids, which can be composed of single-wall or double-wall structures with insulation, and has liquid tightness and air tightness
[Source: GB/T 8423.3-2018, 5.2.26]
3.3.5
double containment tank
tank composed of a liquid-tight secondary container and a single containment tank built in the secondary container, in which the horizontal distance between the secondary container and the primary container is no more than 6m, and the top is open to the atmosphere
[Source: GB/T 8423.3-2018, 5.2.27]
3.3.6
full containment tank
tank composed of a secondary container with liquid tightness and air tightness and a primary container built in the secondary container, in which the secondary container is an independent self-supporting closed structure with vault
[Source: GB/T 8423.3-2018, 5.2.28]
3.3.7
membrane tank
composite structure for cryogenic liquid storage consisting of a thin steel primary container (i.e. membrane), thermal insulation and pre-stressed concrete tank
[Source: GB/T 8423.3-2018, 5.2.31]
3.3.8
liquefied natural gas pressure tank
LNG pressure tank
Factory-manufactured steel container for the storage of liquefied natural gas with an operating pressure greater than or equal to 100kPa
3.4 Piping system and piping component
3.4.1
piping system
a group of pipes formed by connecting a plurality of pipes divided according to fluid and design conditions
[Source: GB 50316-2000 (Edition 2008), 2.1.7]
3.4.2
cryogenic pipe-in-pipe system
cryogenic jacket system consisting of an inner pipe and an outer pipe
Note: The inner pipe is used to transport cryogenic medium, while the outer pipe is serviced as a protection mean.
3.4.3
automatic product retention valve
valve that can automatically enter the safe state when an accident occurs in LNG tank
4 Basic requirements
4.1 Soil protection in cryogenic facilities
During the design and construction of the foundations of LNG tanks, cold boxes, pipes and pipe racks and other cryogenic facilities, measures shall be taken to prevent the destructive force caused by soil freezing or frost heaving.
4.2 Snow and ice falling
For the accumulated ice and snow on the top of tall facilities, effective measures shall be taken to prevent personnel injury and equipment damage caused by falling ice and snow.
4.3 Concrete structure design and materials
4.3.1 Concrete structures in long-term or periodic contact with LNG shall be able to withstand design loads, in particular the effects of extreme temperatures. Such structures shall include, but are not limited to, foundations of cryogenic equipment and shall be made of materials in accordance with GB 51081. Materials and design of structures other than LNG containers meet the requirements of GB 50010.
4.3.2 Concrete in contact with LNG under accident shall be inspected and tested immediately after it returns to atmospheric temperature, and repaired if necessary.
4.4 Control room
4.4.1 LNG plant shall be equipped with control rooms, which shall be set according to the scale and characteristics of the plant and in combination with different requirements of management and production modes. The control room shall mainly have the functions of production operation, process control, safety protection, instrument maintenance, etc.
4.4.2 The setting of control room shall meet the following requirements:
a) The central control room shall be manned for operation control;
b) The unattended control room shall have sound and light alarm function to remind operators;
c) When multiple control rooms are set up in LNG plant, standby communication mode shall be set between central control room and other control rooms;
d) In case of emergency, the control room shall be able to start audible and visual alarm in all occupied areas.
5 Site selection and layout of plant
5.1 Site selection
5.1.1 For the site selection of liquefied natural gas plant, comprehensive evaluation shall be conducted on the specific sites that can be selected in terms of technology, economy, safety, environment, land acquisition, demolition, management and other aspects according to the topography, geology, hydrology, meteorology, transportation, fire protection, water supply and drainage, power supply, communication, available land and social life of the area to select the optimal site.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 3.1 General 3.2 Vaporization facilities 3.3 Storage facilities 3.4 Piping system and piping component 4 Basic requirements 4.1 Soil protection in cryogenic facilities 4.2 Snow and ice falling 4.3 Concrete structure design and materials 4.4 Control room 5 Site selection and layout of plant 5.1 Site selection 5.2 Layout 5.3 Tank spacing 5.4 Vaporizer spacing 5.5 Process equipment spacing 5.6 Loading and unloading equipment spacing 5.7 Buildings and structures 5.8 Spacing of impounding facilities 6 Process equipment 6.1 General requirements 6.2 Pumps and compressors 6.3 Vaporization facilities 6.4 LNG mobile equipment 7 LNG tanks 7.1 General requirements 7.2 Design requirements 7.3 Inspection 7.4 Liquefied natural gas (LNG) tank system 7.5 Liquefied natural gas pressure tank 8 Piping system and piping component 8.1 General requirements 8.2 Piping system material 8.3 Installation 8.4 Isolation of hazardous medium 8.5 Pipe support 8.6 Pipe identification 8.7 Inspection, examination and test of pipe 8.8 Replacement of piping system 8.9 Safety relief valve 8.10 Flare and vent pipe 8.11 Cryogenic pipe-in-pipe system 8.12 Installation of underground or submarine pipelines 9 Plant facilities 9.1 Design classification 9.2 Factory facilities 9.3 Liquefied natural gas (LNG) tank 9.4 Structures 9.5 Fire and explosion control 9.6 Ventilation 9.7 Combustible gas or evaporative gas control 9.8 Personnel protection 10 Electrical equipment 10.1 Power load classification 10.2 Division of explosive hazardous areas 10.3 Design of electrical device 10.4 Lightning protection and static protection design 10.5 Lighting 11 Instrument and communications 11.1 Instrument and control system 11.2 Communication 12 Impounding area and discharge system 12.1 General requirements 12.2 Impounding area volume 12.3 Cofferdam and impounding wall 12.4 Cofferdams, impounding walls and drainage ditches 12.5 Cold insulation 12.6 Height of impounding wall and distance to tank 12.7 Drainage 13 Fire-fighting and safety 13.1 Fire-fighting and fire prevention assessment 13.2 Fire-fighting water system 13.3 Mobile fire-fighting facilities 13.4 Personal protection 13.5 Safety 14 Anti-corrosion 14.1 General requirements 14.2 Corrosion control of pipeline and equipment in atmospheric environment 14.3 Corrosion control of buried or underwater pipelines and equipment 14.4 Internal corrosion control of pipeline and equipment 14.5 Stray current interference corrosion control 14.6 Corrosion control monitoring 14.7 Repair measures 15 Transfer systems 15.1 General requirements 15.2 Pumps and compressors 15.3 Loading and unloading arm 15.4 Loading/unloading pipeline 15.5 Ship loading and unloading facilities 15.6 Tank car, tanker and tank loading and unloading facilities 15.7 Communication 16 Small LNG facilities 16.1 General requirements 16.2 Control room 16.3 Site selection of plant 16.4 Plant layout 16.5 Process equipment 16.6 LNG tanks 16.7 Piping system and pipeline component 16.8 Instrument, communication and electrical equipment 16.9 Plant facilities 16.10 Impounding area and discharge system 16.11 Transfer systems 16.12 Fire-fighting and safety 16.13 Operation and maintenance 17 Operation and maintenance 17.1 Operation procedure manual 17.2 Emergency procedures 17.3 Operation monitoring 17.4 Test run 17.5 Transport of LNG and flammable liquids 17.6 Maintenance manual 17.7 Maintenance items Annex A (Normative) Analysis of leakage consequences scenario A.1 Determination of leak consequence scenarios A.2 Design leakage A.3 Selection of calculation model A.4 Meteorological data A.5 Diffusion of combustible gases or vapors A.6 Diffusion of toxic gases or vapors A.7 Vapor cloud explosion A.8 Fire Annex B (Normative) Performance-based site selection of liquefied natural gas plant by quantitative risk analysis (QRA) B.1 General B.2 Basis of risk calculation and assessment B.3 Leakage scenarios of liquefied natural gas and other hazardous materials B.4 Leakage frequency and conditional frequency B.5 Modeling conditions and frequency B.6 Hazard and consequence assessment B.7 Risk outcome B.8 Risk datum B.9 Safety improvement measures Annex C (Normative) Seismic design C.1 General C.2 Operational benchmark earthquake (OBE) C.3 Safe shutdown earthquake (SSE) C.4 Aftershock level earthquake (ALE) C.5 Designed response spectrum C.6 Other seismic load Annex D (Normative) Explosive hazardous area division Annex E (Normative) Fire prevention assessment E.1 Basis for design, installation and testing of fire prevention and fire-fighting facilities E.2 Main contents of fire prevention assessment Bibliography Figure 1 Distance from cofferdam or impounding wall to tank Figure D.1 Cofferdam height less than the distance from the tank to the cofferdam (H is less than L) Figure D.2 Cofferdam height higher than the distance from the tank to the cofferdam (H is less than L) Figure D.3 Liquid level in the tank below the ground or the top of cofferdam Figure D.4 Full containment tank and membrane tank system Figure D.5 Division of places for LNG shipment at shipping termination Table 1 Fire separation distance for tanks with operating pressure less than 100kPa Table 2 Fire separation distance layout of aboveground tanks Table 3 Fire separation distance layout of buried tanks with operating pressure greater than or equal to 100kPa Table 4 Environmental factors Table 5 Calculation coefficient of setback distance Table A.1 Concentration limits of toxic substances in plant boundary areas and occupied places Table A.2 Explosion overpressure limit in plant boundary areas and occupied places Table B.1 Failure frequency database Table B.2 Endpoint of vapor diffusion consequences Table B.3 Endpoint of heat radiation consequence Table B.4 Overpressure consequence limit
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization—Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 20368-2012 Production, storage and handling of liquefied natural gas (LNG). In addition to structural adjustment and editorial changes, the following main technical changes have been made compared with GB/T 20368-2012:
a) The requirements of scope are modified (see Clause 1 hereof; Clause 1 of Edition 2012);
b) The normative references are modified (see Clause 2 hereof; Clause 2 of Edition 2012);
c) Terms and definitions such as "liquefied natural gas plant, sources of ignition, tank system, transfer systems, liquefied natural gas pressure tank, primary container, secondary container, vapor cloud, setback distance, automatic product retention valve, piping system, cryogenic pipe-in-pipe system" are added; terms and definitions such as "liquefied natural gas, noncombustible material, impounding area, impounding wall, single containment tank, double containment tank, full containment tank, membrane tank, vaporizer, ambient vaporizer, heated vaporizer, integral heated vaporizer, remote heated vaporizer, etc.” are modified, and terms and definitions such as “approved, bunkering, cargo tank vehicle, components, container, frozen ground container, pre-stressed concrete container, controllable emergency, design pressure, failsafe, fired equipment, flame spread index, hazardous fluid, LNG plant, maximum allowable working pressure, model, out-of-service, overfilling, transfer area, transition joint and water capacity” are deleted (see Clause 3 hereof; Clause 3 of Edition 2012);
d) The requirements for soil protection in cryogenic facilities (see 4.1 hereof, 5.5 of Edition 2012), snow and ice falling (see 4.2 hereof, 5.6 of Edition 2012) are modified; and requirements for corrosion control review (see 4.1 of Edition 2012) and record (see 4.4 of 2012 edition) are deleted;
e) The provisions of the country, industry, region, port planning and national industrial policy that the site selection shall comply with are added (see 5.1.2~5.1.3); the selection provisions on the utilization of port resources, the natural conditions of the land area and the surrounding supporting conditions are added (see 5.1.4~5.1.12); the impact assessment requirements of leakage consequence scenarios (combustible or toxic gas diffusion, fire and explosion) are summarized into normative Annex A; provisions are made on the determination of the distance between the plant and the peripheral facilities outside the battery limit, and the determination of the external safety protection distance of the plant; the content of site selection based on risk analysis is changed to “performance-based site selection of liquefied natural gas plant by quantitative risk analysis (QRA)", which was taken as a normative annex (see 5.1.12 and Annex B hereof, and Annex E of Edition 2012); provisions are made on how to carry out QRA for site selection; the requirements related to the division of impounding area, design of impounding area and LNG collection and discharge system in the original Clause 5 are separated into chapters, forming Clause 12 "Impounding area and discharge system" of this document; the general requirements for plane layout are added (see 5.2), and the spacing requirements of LNG tanks are modified (see 5.3.1 and 5.3.2 hereof, and 5.2.4.1 of Edition 2012); the provisions on the layout of double containment tank, full containment tank and membrane tank with adjacent single and double containment tanks are modified (see 5.3.3 hereof, 5.2.4.2 of Edition 2012); the provisions on the fire protection design of outer tank of concrete tank are added (see 5.3.3), the provisions on the spacing of vaporizers are modified (see 5.4 hereof, 5.2.5 of Edition 2012); the provisions on the spacing of combustible gas compressor room are added (see 5.5.2); the provisions on the heat flux in the impounding area are added (see 5.6.4); the provisions on the distance from buildings and structures to the LNG and other dangerous liquids are added (see 5.7 hereof, 5.3 of Edition 2012); and the provisions on the qualification of designers and manufacturers are deleted (see 5.4 of Edition 2012);
f) The content about vaporization facilities is moved to process equipment (see 6.3 hereof, Clause 8 of Edition 2012); the general requirements are added (see 6.1 hereof, and 6.1, 6.3, 6.4.1, 6.4.2 and 6.4.3 of Edition 2012); the provisions on the installation of internal combustion engines or gas turbines are deleted (see 6.4.4 of Edition 2012); the provisions for aluminum plate-fin heat exchanger are added (see 6.1.8); the provisions for setting shut-off valves at LNG inlet of vaporizer system are modified (see 6.3.6 hereof, and 8.3.1, 8.3.3 and 8.3.5.2 of Edition 2012); the provisions for unattended LNG plant installation are modified (see 6.3.7 hereof; 8.3.5, 8.3.5.1, 8.3.5.2, 8.3.6, 8.3.6.1 of Edition 2012); the provisions for the installation of attended LNG plants are modified (see 6.3.8 hereof, and 8.3.4, 8.3.5.3, 8.3.6.2 of Edition 2012); the content about LNG mobile equipment is moved to process equipment (see 6.4 hereof, and 5.8 of Edition 2012); the provisions for LNG mobile equipment are modified (see 6.4.1 hereof, and 5.8.1 of Edition 2012);
g) The provisions governing the qualifications of companies, inspectors and engineers are deleted; the inspection requirements are modified (see 7.3 hereof, and 7.1 of Edition 2012); general requirements, specifying the specifications to be met by several main tank types, are added (see 7.1); the definitions of operational benchmark earthquake (OBE) and safe shutdown earthquake (SSE) for seismic design of onshore tanks are adjusted, and the definition of aftershock level earthquake (ALE) is added (see 7.4.7.2 hereof, and 7.2.2 of Edition 2012); the seismic design of tanks manufactured in onshore factories is deleted (see 7.2.3 of Edition 2012); the flood load requirements are deleted (see 7.2.4 of Edition 2012); the provisions for liquefaction evaluation of tank sites are added (see 7.4.4.2); welding inspection requirements for metal tanks with design operating pressure greater than or equal to 100 kPa are added (see 7.4.5.2~7.4.5.5); the material requirements, and construction, inspection and test requirements for concrete, steel bars and pre-stressed steel bars in concrete tanks are deleted (see 7.4.1~7.4.3); the test of LNG tank is modified and the test requirements of membrane tank are added (see 7.4.8 hereof, and 7.6 of Edition 2012); other requirements for membrane tank are added (see 7.4.9); the provisions on LNG pressure tank type modified (see 7.5.1 hereof, and 7.3.2.1 of Edition 2012); the basic requirements for inner tanks of LNG double-wall tanks are modified (see 7.5.2 hereof, and 7.3.2.2 of Edition 2012); the basic requirements for outer tanks of LNG double-wall tanks are deleted (see 7.3.2.3 of Edition 2012); the basic requirements of LNG single-wall tank are added (see 7.5.3); the design requirements of the inner tank support system of LNG double-wall tanks are modified (see 7.5.9, 7.3.2.6 of Edition 2012); the basic requirements for seismic design of LNG pressure tanks are added (see 7.5.11); the provisions of the liquid level control equipment in LNG pressure tank are added (see 7.5.12); the basic requirements for LNG pressure tank test are added (see 7.5.13); the protection requirements for LNG pressure tanks during transportation are added (see 7.5.14);
h) The provisions for fire protection systems are added (see 8.1.1.3); provisions for power system are added (see 8.1.1.4); the earthquake category of LNG facility pipeline is deleted (see 9.1.2.1 of Edition 2012); the piping category (see 8.1.2.1, and 9.1.2.2 of Edition 2012); the maximum value of Category B piping response correction factor is modified (see 8.1.2.1, and 9.1.2.2 of Cotechini Edition 2012); the conditions that shall be met for thermal insulation materials in fire environment are added (see 8.1.4.4); the conditions that sealing is not required for threaded connections are added [see 8.3.1.4 d)]; the provisions for pipe joints (see 8.3.1.7); the disabled pipe connection mode is added (see 8.3.1.8); provisions for other pipe assemblies and flanged connections are added (see 8.3. 1.9); the lower limit of interface caliber is modified (see 8.3.2.5 hereof, and 9.3.2.5 of Edition 2012); the operating mechanism of the emergency shut-off valve is changed (see 8.3.2.7 hereof, and 9.3.2.7 of Edition 2012); the coating requirements for emergency shut-off valves are added (see 8.3.2.11); related contents of brazing (see 8.3.3.4); the content of pipe marking is added [see 8.3.4 d)]; the isolation of hazard sources is added (see 8.4); identification requirements for medium and flow direction are added (see 8.6.2); the setting of replacement nozzle is added (see 8.8.2); provisions for flare and vent pipe are added (see 8.10); the installation requirements of underground or submarine pipelines are added (see 8.12);
i) The design of plant facilities, including design classification, plant facilities design is added (see Clause 9), and the fire and explosion design for storage of LNG and flammable fluids is modified (see 9.5 hereof, and 5.3.2 of Edition 2012);
j) Electrical, instrumentation and communication are separated into clauses (see Clauses 10 and 11 hereof; Clause 10 of Edition 2012); the provisions on power supply requirements are added (see 10.1); the general requirements for electrical equipment and wiring are deleted (see 10.9.1 of Edition 2012); the division requirements of electrical explosion hazardous areas are modified (see 10.2 hereof. and 10.6.2 of Edition 2012); the sealing requirements between combustible fluid system and electrical piping or wiring are deleted (see 10.6.3 of Edition 2012); other provisions for detecting combustible fluid leakage other than the main seal are deleted (see 10.6.4 of Edition 2012); the provisions on ventilation duct system when combustible gas air mixture is ignited are deleted (see 10.6.5 of Edition 2012); relevant provisions on power device design are added (see 10.3); relevant provisions on electrical lightning protection grounding and anti-static grounding are added (see 10.4); relevant provisions on lighting are added (see 10.5);
k) The general requirements for instrumentation and control systems are added (see 11.1.1); changes have been made to the level gauge settings, design, installation, alarm and interlocking requirements (see 11.1.2 hereof, and 10.1 of Edition 2012). The setting requirements of pressure instruments have been changed to distinguish the setting requirements of LNG tanks from those of non-LNG hazardous fluid tanks (see 11.1.3 hereof, and 10.2 of Edition 2012). The setting requirements of temperature instruments have been changed, and the setting requirements of temperature instruments for cryogenic piping have been added (see 11.1.5 hereof, and 10.4 of Edition 2012). The provisions for fail-safe design have been added (see 11.1.6). The setting requirements on emergency shutdown are deleted (see 10.5 of Edition 2012). The setting requirements of emergency stop system are modified (see 11.1.7 hereof, and 12.2 of Edition 2012). The setting requirements of fire and gas detection are modified, and the setting requirements of toxic gas and oxygen content detection are added (see 11.1.8 hereof, and 12.3 of Edition 2012); communication content is added (see 11.2);
l) The impounding area and discharge system are separated into clauses (see Clause 12);
m) The provisions on fire-fighting and fire prevention assessment are changed (see 13.1 hereof, and 12.1 of Edition 2012); the provisions on fire-fighting water system are modified (see 13.2 hereof, and 12.4 of Edition 2012); the provisions on mobile fire-fighting facilities are modified (see 13.3 hereof, 12.5 of Edition 2012); the provisions on personal protection is modified (see 13.4 hereof, and 12.7 of Edition 2012); the safety provisions are modified (see 13.5 hereof, and 12.8 of Edition 2012);
n) Anti corrosion provisions are added (see Clause 14);
o) The provisions on warning signs in the loading and unloading area are deleted (see 11.1.1 of Edition 2012); provisions on analysis of closing time of power shut-off valve are added (see 15.2.2 and 15.2.3); the provisions on berth design requirements are deleted (see 11.4.1 of Edition 2012); the provisions on fire source are deleted (see 11.4.2 of Edition 2012); the provisions on underwater pipeline are deleted (see 11.4.3.2 of Edition 2012); the provisions on tank car transportation and its approval are deleted (see 11.5.1 and 11.5.2 of Edition 2012); the provisions on discharge of loading and unloading pipelines are deleted (see 11.6.6 of Edition 2012); the provisions on hose design are deleted (see 11.7.2 of Edition 2012); the provisions on hose joint, icing and detection are deleted (see 11.7.3, 11.7.5 and 11.7.6 of Edition 2012); the provisions on loading and unloading ship operation test are deleted (see 11.7.7 of Edition 2012);
p) The provisions for small LNG facilities are added (see Clause 16);
q) Provisions on purging of LNG container are added (see 17.3.5); the commissioning requirements before equipment startup are added (see 17.4); provisions on inspection interval requirements of safety valve are added (see 17.7.3.5~17.7.3.9); and provisions on external surface inspection of LNG tank system are added (see 17.7.4).
This standard was proposed by and is under the jurisdiction of National Technical Committee on Petroleum and Natural Gas of Standardization Administration of China (SAT/TC 355).
This document was issued in 2006 as first edition, its first revision was issued in 2012, and this is the second revision.
Production, storage and handling of liquefied natural gas (LNG)
1 Scope
This document specifies the technical requirements for the design, construction, operation and maintenance of liquefied natural gas (LNG) plants.
This document is applicable to constructed, extended and renovated LNG plants on land.
This document is not applicable to permafrost containers, mobile storage tanks installed or used indoors, LNG filling vehicles and LNG fuel vehicles.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 150 (All parts) Pressure vessels
GB/T 151 Heat exchangers
GB 7956.1 Fire fighting vehicles—Part 1: General technical specifications
GB 7956.2 Fire fighting vehicles—Part 2: Water tank fire fighting vehicle
GB 7956.3 Fire fighting vehicles—Part 3: Foam fire fighting vehicle
GB/T 16507 (All parts) Water-tube Boilers
GB/T 16508 (All parts) Shell boilers
GB/T 18442 (All parts) Static vacuum insulated cryogenic pressure vessels
GB/T 20173 Petroleum and natural gas industries—Pipeline transportation systems—Pipeline valves
GB/T 20801 Pressure piping code—Industrial piping
GB/T 20801.2 Pressure piping code—Industrial piping—Part 2: Materials
GB/T 20801.3 Pressure piping code—Industrial piping—Part 3: Design and calculation
GB/T 20801.3-2020 Pressure piping code—Industrial piping—Part 3: Design and calculation
GB/T 20801.6 Pressure piping code—Industrial piping—Part 6: Safeguarding
GB/T 21246 Measurement method for cathodic protection parameters of buried steel pipelines
GB/T 21447 Specifications for steel pipeline external corrosion control
GB/T 21448 Specification of cathodic protection for underground steel pipelines
GB/T 23258 Standard practice controlling internal corrosion in steel pipelines
GB/T 26978 (All parts) Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for the storage of liquefied natural gases
GB/T 32270 Pressure piping code—Power piping
GB 36894 Risk criteria for hazardous chemicals production unit and storage installations
GB/T 37243-2019 Determination method of external safety distance for hazardous chemicals production units and storage installations
GB 50009 Load code for the design of building structures
GB 50010 Code for design of concrete structures
GB 50011 Code for seismic design of buildings
GB 50016 Code for fire protection design of buildings
GB 50019 Design code for heating ventilation and air conditioning of industrial buildings
GB 50034 Standard for lighting design of buildings
GB 50052 Code for design electric power supply systems
GB 50057 Code for design protection of structures against lightning
GB 50058 Code for design of electrical installations in explosive atmospheres
GB 50084 Code of design for sprinkler systems
GB 50093 Code for construction and quality acceptance of automation instrumentation engineering
GB 50116 Code for design of automatic fire alarm system
GB 50140 Code for design of extinguisher distribution in buildings
GB 50151 Code for design of foam extinguishing systems
GB 50160 Fire prevention code of petrochemical enterprise design
GB 50183 Code for fire protection design of petroleum and natural gas engineering
GB 50193 Code of design for carbon dioxide fire extinguishing systems
GB 50219 Technical code for water spray fire protection systems
GB 50235-2010 Code for construction of industrial metallic piping engineering
GB 50251 Code for design of gas transmission pipeline engineering
GB 50261 Code for installation and commissioning of sprinkler systems
GB 50264 Design code for insulation engineering of industrial equipment and pipe
GB 50316 Design code for industrial metallic piping
GB 50316-2000
(2008 Edition) Design code for industrial metallic piping
GB 50347 Code of design for powder extinguishing systems
GB 50370 Code for design of gas fire extinguishing systems
GB/T 50393 Technical standard for anti-corrosion engineering of steel petroleum storage tanks
GB 50493 Standard for design of combustible gas and toxic gas detection and alarm for petrochemical industry
GB 50650 Design code for lightning protection of petrochemical installations
GB/T 50698 Standard for AC interference mitigation of buried steel pipelines
GB 50779 Code for design of blast resistant control building in petrochemical industry
GB 50898 Technical code for water mist fire extinguishing system
GB 50974 Code of design on fire protection water supply and hydrant systems
GB/T 50991 Technical standard for DC interference mitigation of buried steel pipeline
GB 51081 Technical code for application of concrete under cryogenic circumstance
GB 51156 Code for design of liquefied natural gas receiving terminal
GB 51156-2015 Code for design of liquefied natural gas receiving terminal
GB/T 51257 Code for design of low temperature piping of liquefied natural gas
GB 51261 Standard for design of natural gas liquefaction plant
GB 51309 Technical standard for fire emergency lighting and evacuate indicating system
JT/T 617.7 Regulations concerning road transportation of dangerous goods—Part 7: Transport conditions and operational requirements
NB/T 47006 Aluminum plate-fin heat exchangers
SH 3009 Design specification for combustible gas discharge system in petrochemical industry
SH/T 3043 Specification of surface color and mark on equipment, piping and steel structure in petrochemical industry
SH/T 3073 Specification for design of piping support in petrochemical industry
SH/T 3097 Specification for design of static electricity earthing in petrochemical industry
SH/T 3192 Design specification for lighting in petrochemical plants
SY/T 0043 Code for painting colors of pipelines and equipments for petroleum and natural gas engineering
SY/T 6784 Standard of corrosion control for steel storage tank
SY/T 6964 Specification of cathodic protection for petroleum & gas station
SY/T 7036 Specification of external coating for piping and equipments in petroleum and gas stations
SY/T 7349 Specification for insulation and anti-corrosion of low temperature storage tank
SY/T 7350 Specification of coating and cold insulation for low temperature piping and equipment
SY/T 7419 Specification for insulation design, construction and acceptance of cryogenic piping
TSG 21 Supervision regulation on safety technology for stationary pressure vessel
TSG G0001 Boiler safety technical supervision administration regulation
XF 39 Fire fighting vehicles—Performance requirements and test methods
3 Terms and definitions
For the purposes of this document, the following term and definition apply.
3.1 General
3.1.1
liquefied natural gas; LNG
a low-temperature liquid fluid which is mainly composed of methane and may contain small amounts of ethane, propane, nitrogen, or other components commonly found in natural gas
[Source: GB 51261-2019, 2.0.1]
3.1.2
liquefied natural gas plant
LNG plant
plant with natural gas purification and liquefaction, LNG storage and shipment, LNG loading and unloading and regasification functions
Note: For example: basic load natural gas liquefaction plant, peak shaving liquefaction plant, LNG receiving station and LNG satellite station.
3.1.3
sources of ignition
energy source that can make combustibles react with combustion-supporting substances
Note: This kind of energy may be heat energy, light energy, electric energy, chemical energy and mechanical energy.
3.1.4
noncombustible material
construction material used under expected conditions, which do not catch fire, burn, support combustion or release combustible vapor in case of fire and heat, and whose combustion performance grade is Grade A
3.1.5
impounding area
area delineated by means of an impounding wall or topographic conditions for accommodating accidental spills or leaks of liquefied natural gas or other dangerous liquids
3.1.6
impounding wall
structure for preventing overflow of liquefied natural gas or spread of fire in case of a leakage accident of LNG storage tank
[Source: GB 51156-2015, 2.0.16]
3.1.7
vapor cloud
mixed gas cloud formed by cooling and condensation of water vapor in the atmospheric environment when LNG leaks or overflows to the atmospheric environment
[Source: GB/T 8423.3-2018, 5.2.5]
3.1.8
setback distance
minimum distance from the automatic product retention valve on the maximum liquid pipeline of LNG container to the building outside the plant or building boundary
3.1.9
transfer systems
system in an LNG yard for transferring LNG or other hazardous media between storage containers or tanks and loading and unloading points or loading points by means of pipelines, tank car, tankers, tank containers or ships
3.2 Vaporization facilities
3.2.1
vaporizer
device that introduces heat in a controlled way to change a liquid into a vapor or gaseous state
3.2.2
ambient vaporizer
device that the main heat source of the vaporizer is not separated from the actual vaporization heat exchanger, and the main heat sources are environment, seawater or geothermal water, etc.
Note: Including air temperature vaporizer.
[Source: GB 51261-2019, 2.0.16, modified]
3.2.3
heated vaporizer
device that the main heat source of the vaporizer comes from fuel combustion, electric heating or waste heat (such as waste heat of boiler or internal combustion engine)
[Source: GB 51261-2019, 2.0.13, modified]
3.2.4
integral heated vaporizer
heated vaporizer integrating the main heat source and the vaporizer heat exchanger
Note: Including submerged combustion vaporizer.
[Source: GB 51261-2019, 2.0.14, modified]
3.2.5
remote heated vaporizer
heated vaporizer in which the main heat source is separated from the actual vaporization heat exchanger and the intermediate medium (such as water, isopentane and ethylene glycol) is used as the heating transmission medium
Note: Including open shelf vaporizer and intermediate medium vaporizer.
[Source: GB 51261-2019, 2.0.15, modified]
3.3 Storage facilities
3.3.1
tank system
low-pressure (operating pressure less than 100kPa) field-assembled, vertical, cylindrical, flat-bottomed equipment for storage of LNG or other hazardous liquids
Note: Including one or more containers, as well as various accessories, appendages and thermal insulation materials.
3.3.2
primary container
container used for holding cryogenic liquids and in direct contact with cryogenic liquids
[Source: GB/T 8423.3-2018, 5.2.24]
3.3.3
secondary container
container that is generally located outside the primary container, contains cryogenic liquid when leaking, and does not contact with cryogenic liquid under normal operating conditions
[Source: GB/T 8423.3-2018, 5.2.25]
3.3.4
single containment tank
tank that has only one self-supporting steel storage tank for cryogenic liquids, which can be composed of single-wall or double-wall structures with insulation, and has liquid tightness and air tightness
[Source: GB/T 8423.3-2018, 5.2.26]
3.3.5
double containment tank
tank composed of a liquid-tight secondary container and a single containment tank built in the secondary container, in which the horizontal distance between the secondary container and the primary container is no more than 6m, and the top is open to the atmosphere
[Source: GB/T 8423.3-2018, 5.2.27]
3.3.6
full containment tank
tank composed of a secondary container with liquid tightness and air tightness and a primary container built in the secondary container, in which the secondary container is an independent self-supporting closed structure with vault
[Source: GB/T 8423.3-2018, 5.2.28]
3.3.7
membrane tank
composite structure for cryogenic liquid storage consisting of a thin steel primary container (i.e. membrane), thermal insulation and pre-stressed concrete tank
[Source: GB/T 8423.3-2018, 5.2.31]
3.3.8
liquefied natural gas pressure tank
LNG pressure tank
Factory-manufactured steel container for the storage of liquefied natural gas with an operating pressure greater than or equal to 100kPa
3.4 Piping system and piping component
3.4.1
piping system
a group of pipes formed by connecting a plurality of pipes divided according to fluid and design conditions
[Source: GB 50316-2000 (Edition 2008), 2.1.7]
3.4.2
cryogenic pipe-in-pipe system
cryogenic jacket system consisting of an inner pipe and an outer pipe
Note: The inner pipe is used to transport cryogenic medium, while the outer pipe is serviced as a protection mean.
3.4.3
automatic product retention valve
valve that can automatically enter the safe state when an accident occurs in LNG tank
4 Basic requirements
4.1 Soil protection in cryogenic facilities
During the design and construction of the foundations of LNG tanks, cold boxes, pipes and pipe racks and other cryogenic facilities, measures shall be taken to prevent the destructive force caused by soil freezing or frost heaving.
4.2 Snow and ice falling
For the accumulated ice and snow on the top of tall facilities, effective measures shall be taken to prevent personnel injury and equipment damage caused by falling ice and snow.
4.3 Concrete structure design and materials
4.3.1 Concrete structures in long-term or periodic contact with LNG shall be able to withstand design loads, in particular the effects of extreme temperatures. Such structures shall include, but are not limited to, foundations of cryogenic equipment and shall be made of materials in accordance with GB 51081. Materials and design of structures other than LNG containers meet the requirements of GB 50010.
4.3.2 Concrete in contact with LNG under accident shall be inspected and tested immediately after it returns to atmospheric temperature, and repaired if necessary.
4.4 Control room
4.4.1 LNG plant shall be equipped with control rooms, which shall be set according to the scale and characteristics of the plant and in combination with different requirements of management and production modes. The control room shall mainly have the functions of production operation, process control, safety protection, instrument maintenance, etc.
4.4.2 The setting of control room shall meet the following requirements:
a) The central control room shall be manned for operation control;
b) The unattended control room shall have sound and light alarm function to remind operators;
c) When multiple control rooms are set up in LNG plant, standby communication mode shall be set between central control room and other control rooms;
d) In case of emergency, the control room shall be able to start audible and visual alarm in all occupied areas.
5 Site selection and layout of plant
5.1 Site selection
5.1.1 For the site selection of liquefied natural gas plant, comprehensive evaluation shall be conducted on the specific sites that can be selected in terms of technology, economy, safety, environment, land acquisition, demolition, management and other aspects according to the topography, geology, hydrology, meteorology, transportation, fire protection, water supply and drainage, power supply, communication, available land and social life of the area to select the optimal site.
Contents of GB/T 20368-2021
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
3.1 General
3.2 Vaporization facilities
3.3 Storage facilities
3.4 Piping system and piping component
4 Basic requirements
4.1 Soil protection in cryogenic facilities
4.2 Snow and ice falling
4.3 Concrete structure design and materials
4.4 Control room
5 Site selection and layout of plant
5.1 Site selection
5.2 Layout
5.3 Tank spacing
5.4 Vaporizer spacing
5.5 Process equipment spacing
5.6 Loading and unloading equipment spacing
5.7 Buildings and structures
5.8 Spacing of impounding facilities
6 Process equipment
6.1 General requirements
6.2 Pumps and compressors
6.3 Vaporization facilities
6.4 LNG mobile equipment
7 LNG tanks
7.1 General requirements
7.2 Design requirements
7.3 Inspection
7.4 Liquefied natural gas (LNG) tank system
7.5 Liquefied natural gas pressure tank
8 Piping system and piping component
8.1 General requirements
8.2 Piping system material
8.3 Installation
8.4 Isolation of hazardous medium
8.5 Pipe support
8.6 Pipe identification
8.7 Inspection, examination and test of pipe
8.8 Replacement of piping system
8.9 Safety relief valve
8.10 Flare and vent pipe
8.11 Cryogenic pipe-in-pipe system
8.12 Installation of underground or submarine pipelines
9 Plant facilities
9.1 Design classification
9.2 Factory facilities
9.3 Liquefied natural gas (LNG) tank
9.4 Structures
9.5 Fire and explosion control
9.6 Ventilation
9.7 Combustible gas or evaporative gas control
9.8 Personnel protection
10 Electrical equipment
10.1 Power load classification
10.2 Division of explosive hazardous areas
10.3 Design of electrical device
10.4 Lightning protection and static protection design
10.5 Lighting
11 Instrument and communications
11.1 Instrument and control system
11.2 Communication
12 Impounding area and discharge system
12.1 General requirements
12.2 Impounding area volume
12.3 Cofferdam and impounding wall
12.4 Cofferdams, impounding walls and drainage ditches
12.5 Cold insulation
12.6 Height of impounding wall and distance to tank
12.7 Drainage
13 Fire-fighting and safety
13.1 Fire-fighting and fire prevention assessment
13.2 Fire-fighting water system
13.3 Mobile fire-fighting facilities
13.4 Personal protection
13.5 Safety
14 Anti-corrosion
14.1 General requirements
14.2 Corrosion control of pipeline and equipment in atmospheric environment
14.3 Corrosion control of buried or underwater pipelines and equipment
14.4 Internal corrosion control of pipeline and equipment
14.5 Stray current interference corrosion control
14.6 Corrosion control monitoring
14.7 Repair measures
15 Transfer systems
15.1 General requirements
15.2 Pumps and compressors
15.3 Loading and unloading arm
15.4 Loading/unloading pipeline
15.5 Ship loading and unloading facilities
15.6 Tank car, tanker and tank loading and unloading facilities
15.7 Communication
16 Small LNG facilities
16.1 General requirements
16.2 Control room
16.3 Site selection of plant
16.4 Plant layout
16.5 Process equipment
16.6 LNG tanks
16.7 Piping system and pipeline component
16.8 Instrument, communication and electrical equipment
16.9 Plant facilities
16.10 Impounding area and discharge system
16.11 Transfer systems
16.12 Fire-fighting and safety
16.13 Operation and maintenance
17 Operation and maintenance
17.1 Operation procedure manual
17.2 Emergency procedures
17.3 Operation monitoring
17.4 Test run
17.5 Transport of LNG and flammable liquids
17.6 Maintenance manual
17.7 Maintenance items
Annex A (Normative) Analysis of leakage consequences scenario
A.1 Determination of leak consequence scenarios
A.2 Design leakage
A.3 Selection of calculation model
A.4 Meteorological data
A.5 Diffusion of combustible gases or vapors
A.6 Diffusion of toxic gases or vapors
A.7 Vapor cloud explosion
A.8 Fire
Annex B (Normative) Performance-based site selection of liquefied natural gas plant by quantitative risk analysis (QRA)
B.1 General
B.2 Basis of risk calculation and assessment
B.3 Leakage scenarios of liquefied natural gas and other hazardous materials
B.4 Leakage frequency and conditional frequency
B.5 Modeling conditions and frequency
B.6 Hazard and consequence assessment
B.7 Risk outcome
B.8 Risk datum
B.9 Safety improvement measures
Annex C (Normative) Seismic design
C.1 General
C.2 Operational benchmark earthquake (OBE)
C.3 Safe shutdown earthquake (SSE)
C.4 Aftershock level earthquake (ALE)
C.5 Designed response spectrum
C.6 Other seismic load
Annex D (Normative) Explosive hazardous area division
Annex E (Normative) Fire prevention assessment
E.1 Basis for design, installation and testing of fire prevention and fire-fighting facilities
E.2 Main contents of fire prevention assessment
Bibliography
Figure 1 Distance from cofferdam or impounding wall to tank
Figure D.1 Cofferdam height less than the distance from the tank to the cofferdam (H is less than L)
Figure D.2 Cofferdam height higher than the distance from the tank to the cofferdam (H is less than L)
Figure D.3 Liquid level in the tank below the ground or the top of cofferdam
Figure D.4 Full containment tank and membrane tank system
Figure D.5 Division of places for LNG shipment at shipping termination
Table 1 Fire separation distance for tanks with operating pressure less than 100kPa
Table 2 Fire separation distance layout of aboveground tanks
Table 3 Fire separation distance layout of buried tanks with operating pressure greater than or equal to 100kPa
Table 4 Environmental factors
Table 5 Calculation coefficient of setback distance
Table A.1 Concentration limits of toxic substances in plant boundary areas and occupied places
Table A.2 Explosion overpressure limit in plant boundary areas and occupied places
Table B.1 Failure frequency database
Table B.2 Endpoint of vapor diffusion consequences
Table B.3 Endpoint of heat radiation consequence
Table B.4 Overpressure consequence limit
