Detail of GB/T 20368-2006

Introduction of GB/T 20368-2006

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 national standard is identical to National Fire Protection Association (NFPA) 59A "Standard on production, storage and handling of liquefied natural gas (LNG)" (English edition 2001). This standard equals to the translation of NFPA 59A: 2001. Compared with that edition, editable changes have been made as follows: --Delete the word "Standard on" from the "Standard on production, storage and handling liquefied natural gas (LNG)"; --The "1.9" in the second row in Table 10.6.2 is wrong in the original text, and shall be changed into "3.8"; --The temperature unit " " shall be replaced by "K"; --Increase unit symbol and data of International System of Units in Table 10.6.3; --Increase outlines for all tables; --According to NFPA 59A Trail Revision TIA01 - 1 (NFPA 59A), the "50%" shall be replaced by "150%"; --According to NFPA 59A Trial Revision TIA02 - 1 (NFPA 59A), Article 2.2.3.4 shall be deleted, and the following Articles shall be renumbered; --According to correction table Errata No.: 59A - 01 - 1 issued by LNG technical commission of NFPA 59A, formula represented by unit of International System of Units shall be increased; --Delete the contents between the cover and contents; --Delete index; --Increase foreword; --The reference in Chapter 12 shall be merged into Annex E; --Increase unit conversion between English system and Metric system in Annex F. The asterisk (*) after the numbers or letter means that they are explained in Annex A. Except otherwise stated, the pressure used in this standard is gauge pressure. Annex A, B, C, D, E and F of this standard are informative. This national standard was proposed by and is under the jurisdiction of National Natural Gas Technical Committee for Standardization (CSBTS/TC 244). This standard is mainly drafted by: Investigation and Design Institute of China Petrochemical Group's Zhongyuan Petroleum Exploration Bureau Participating Development Organizations of this standard are: Qingdao Enpal Chemical Engineering Co., Ltd (original Qingdao Chemical Design Institute), and Henan Zhongyuan Green Energy Hi-Tech Co., Ltd. Main drafting staffs of this standard are: Yang Zhiyi, Zhao Baocai, Gao Aihua, Yang Hua, Shen Hancai, Zhang Kongming, Yang Sen, Zhang Xiuquan, Lian Jiaxiu, Xu Min and Zhang Xiaoping. This standard was first issued in January, 2006. Production, storage and handling liquefied natural gas (LNG) 1. General provisions 1.1 *Scope 1.1.1 This standard is applicable to a) Design; b) Location; c) Construction; d) Operation; e) Maintenance of storage, aerification, transportation, handling and truck transportation facilities liquefied natural gas (LNG) and natural gas liquefaction and personal training. 1.1.2 This standard is applicable to all kinds of LNG containers, including vacuum insulation system container. 1.1.3 This standard is not applicable to frozen ground container. 1.2 Equality This standard permits using system, method or device with quality, intensity, fire resistance, validity, viability and safeness equal to or exceed that stated in this standard. The technical documents shall be submitted to competent department for argumentation of their equality. The system, method or device that adopted shall be approved by competent department. 1.3 Traceability This standard reflects the unanimous opinion on taking necessary steps to guard against risks when the standard is issued. Unless otherwise defined, the provisions of this standard shall be not applicable to the establishment, equipment, structure or device which has been constructed or approved before the effect of this standard. If there are explanations, it shall trace back to the provisions of this standard. While the competent department determines that the existent situation has unacceptable risks, the competent department shall trace back to any part applicable to this standard. If the competent department considers there are unpractical parts in this standard, and the security reasonable scale has been unequivocally established, the requirement of traceability of this standard may be amended. 1.4 Personal training Personnel participating in LNG production, handling and storage shall join in the training at the aspects of LNG characteristics and risks. 1.5 System of units The Si units of this standard are determined according to ASTM E 380 "Normative usage of International System of Units (SI)". For the calculation of clear distance, it shall correct to 0.5m when the English units are reduced to SI units. In one project, it shall not use two kinds of Units systems, in order to reduce clear distance. 1.6 Reference standard This standard has reference to American and Canadian standards. While this standard is applied, it shall mention which America or Canadian standards are adopted. Without illustration, the user shall adopt United States Standards effective to all, or Canadian standards effective to all. If other standards are adopted, it shall give explanation. 1.7 Terms and definitions 1.7.1 Approved It means approved by the competent department. 1.7.2 Authority haying jurisdiction It refers to the organization, office or individual who presides over the examination and approval of the equipment, device or program. 1.7.3 Barrel Volume units. A barrel equals to 42 US gal or 0.159m3 (5.615 ft3). 1.7.4 Bunkering It refers to bunkering for bunker or tank aboard for the use of power equipment or auxiliary equipment. 1.7.5 Tank vehicle It refers to the tanker or trailer used for carrying liquid cargo. 1.7.6 Components They refer to component or component system, whose functions equal to one unit of the LNG plant, including without limitation pipeline, process unit, container, control device, impoundment system, electrical system, safety devices, fire-protection equipment and communication equipment. 1.7.7 Container It refers to the vessel used to store liquefied natural gas. 1.7.7.1 Frozen ground container It is a container, whose maximal liquid level is lower than the natural floor elevation. it mainly is constructed by natural materials such as soil and stone, and frozen by water saturation earth material. It adopts proper method to keep tight or natural non-leakage. 1.7.7.2 Membrane container It is a container, whose membrane inter container is unable to support it self, and shall be supported by outer container through the thermal-protective coating. 1.7.7.3 Pre-stressed concrete container It is concrete container. The internal stress generated from different loads or combination of loads does not exceed the allowable stress stated in this standard. 1.7.8 Deriming Through heating, aerification, sublimation or dissolving, the ingredients of solid matter formed through accumulation in the process unit under low temperature such as water and carbon dioxide will be removed. 1.7.9 Design pressure It refers to the pressure in the design of equipment, container or vessel which is used to determine the minimal allowable thickness or the component's physical characteristics. The design pressure used to determine the thickness of any special component includes static head. 1.7.10 Dike It refers to the structure which is used to build impoundment region. 1.7.11 Fail safe If refers to the design characteristics of keeping safe operation state when the control equipment is mishandled or the power source is off. 1.7.12 Fired equipment It refers to the equipment burning fuels, such as fuel boiler, burning type heater, internal combustion engine, some integral heating gasifier, the heating system of the long-distance heating gasifier, gas oil atomizer, burning type regenerative heater and torch. 1.7.13 Fixed length dip tube It refers to the tube on certain elevation of the container and with fixed opening. 1.7.14 Flame spread rating The flame spread rating of the materials shall be determined according to NFPA 255 "Standard test method for surface burning characteristics of building materials" or ULC standard CAN 4 S102 "Surface burning characteristics of building materials and components"-Edition 1988. 1.7.15 G At sea level, G approximates 9.81 m/s2 (32.2 ft/s2). 1.7.16 Hazardous fluid It refers to liquid or gasses flammable, poisonous or corrosive. 1.7.17 Impounding area It refers to an area which is blocked out by fending groin or adaptation to the ground, in order to prevent LNG or flammable cryogen from spillage. 1.7.18 Liquefied natural gas It is a sort of liquid fluid, which is composed by methane in large amount, and ethane, propane, nitrogen or natural gas in small amount. 1.7.19 LNG plant It refers to the plants whose components are used to store and handle liquefied natural gas, and liquefied or gasified natural gas. 1.7.20 Maximum allowable working pressure It refers to the maximal gauge pressure allowed on the top of the equipment complex, container or vessel under design temperature. 1.7.21 Mathematical model It refers to the mathematical description used to forecast physical phenomenon. 1.7.22 Operating company It refers to the individual, co-partner, corporation, institution or other entities owning or operating the LNG plant. 1.7.23 Out-of-service It refers to the purposeful out of service of the components, including overhauling. 1.7.24 Process plant It refers to all the systems used to handle, liquefy and gasify the natural gases in the operating area in the applicability of this standard. 1.7.25 Shall It denotes mandatory requirement. 1.7.26 Should It denotes recommendation or suggestion, but not requirement. 1.7.27 Transfer area It refers to the part in the LNG plant equipped with pipeline system, where LNG, inflammable liquid or flammable cryogen is charged into the equipment or discharged from the equipment, for example car loading area or offloading area, or where the joints of pipeline system are regularly jointed or disconnected. The transfer area excludes product sampling unit or permanent plant pipeline system. 1.7.28 Transition joint It refers to a joint made up of two or more kings of metallic materials, which is used to effectively connect two pipe sections of two different materials which are not suitable to welding. 2 Plant location and layout 2.1 Principle of plant location 2.1.1 The plant location shall take into consideration of the following factors: a) It shall take into consideration of the provision in this standard on the minimal clear spacing between the LNG container, flammable cryogen container, flammable liquid container, structures, plant equipment and plant's property line. b) Except the personal safety and fire-fighting provision in Chapter 9 shall be executed, the emergency evacuation passage and fire passage shall be clear all day. c) It shall take into consideration of the capacity of the plant resisting natural forces in the practical limitation. d) It shall take into consideration of other factors which may impact the security of the plant personnel and around public and concern with the specific positions. When these factors are assessed, the possibility of accidents and the safety precautions adopted in design or operation shall be considered to make integral assessment. 2.1.2 The field preparation of plant shall include measures of preventing spilled LNG, inflammable cryogen and flammable liquid form out-flowing the plant, and measures of surface drainage. 2.1.3 It shall specify the maximum allowable working pressure for all components. 2.1.4 It shall conduct field soil survey to determine the design basis data of the equipment. 2.2 The major principles of spillage and leakage control 2.2.1 Basic requirements 2.2.1.1 In order to reduce the LNG accidental release form container, which may endanger the safety of the neighborhood property or important process plant and structures, or the feasibility of discharging in the drain, any one of the following methods shall be adopted: a) According to the provisions stated in 2.2.2 and 2.2.3, utilizing the natural cover, fending groin, impounding wall or their combination to form a impounding area surrounding the container. b) According to the provisions stated in 2.2.2 and 2.2.3, utilizing the natural cover, fending groin, impounding wall or their combination to form a impounding area surrounding the container. According to provisions stated in 2.2.2 and 2.2.3, natural or artificial drainage system shall be built around the container. c) If the container is underground type or half- underground type, according to provisions stated in 2.2.2 and 2.2.3, utilizing the dike to form an impounding area. 2.2.1.2 In order to minimize the feasibility of the accidental spillage and leakage endangering important structures, equipment or neighboring property or entering into the drain, the following areas shall be leveled off, drained or built with impoundment establishment. a) Process area b) Gasification area c) Transfer area of LNG, inflammable cryogen and inflammable liquid d) Area around the inflammable cryogen and flammable liquid container If the requirements on impounding area in 2.1.2 shall be met, the provisions in 2.2.2 and 2.2.3 shall be executed. 2.2.1.3 For some device area, the provisions on neighboring property or drain in 2.1.2.2, 2.1.1 and 2.2.1.2, the alteration shall be approved by authority having jurisdiction. The alteration shall not constitute overt harm to the life and property, or breach the national, provincial and local provisions. 2.2.1.4 The inflammable liquid and flammable cryogen container shall not be mounted in the impounding area of LNG container. 2.2.2 The capacity of impounding area and design of drainage system 2.2.2.1 The minimal capacity of LNG container impounding area V includes the dischargeable capacity of the drainage area, and leaves space for snow retention, other container and equipment. It shall be determined according to the following provisions: a) For impounding area with single container, V equals to the total volume of the container. b) For impounding area with multiple containers, due to low temperature or one container leakage on fire causing others on fire, and with preventive measures taken, V equals to the total volume of the largest container in the impounding area. c) For the impounding area with multiple containers, the measures under 2.2.2.1 b) are not taken, V equals to the total volume of all the containers. 2.2.2.2 For the impounding area of gasification area, process area or LNG transfer area, the minimal capacity shall equal to maximum volume of the LNG, inflammable cryogen and inflammable liquid may discharged into the impounding area from any source of leaks with in 10min or even short periods of time stated by the surveillance and parking approved by the authority having jurisdiction. 2.2.2.3 Close type LNG drain shall be prohibited. Exception: For the container leak-off pipe used to lead quickly the spilled LNG out of the critical area, it its dimension is determined according to anticipated liquid capacity and gasification rate, it shall be allowed to seal. 2.2.2.4 The fending groin, impounding wall and drainage system in the LNG and flammable cryogen container area shall be constructed with compacted soil, concrete, metal or other materials. These structures is allowed to lie against the container or not, and allowed to integrate with container. The design of these structures and any penetrated structures shall be able to endure all the hydrostatic head of the LNG or inflammable cryogen impounded, be able to endure the impact causing by temperature quenching to the temperature of the impounded liquid, and shall take into consideration of preventing fire and the impact of natural forces, such as earthquake, blowing and rain. If the double wall container's crust is able to satisfy these requirements, it may be seen as impounding area. Hereby the space of location area in 2.2.3 may be determined. If the air-tightness of the crust may be impacted by the inter tank accident, it shall construct additional impounding area according to requirements in 2.2.1.1. 2.2.2.5 The fending groin, impounding wall and drain in flammable liquid container area shall meet the requirement stated in NFPA 30 "Flammable and combustible liquids code". 2.2.2.6 The height of the dike or impounding wall and the distance between it and container with operating pressure equaling to or less than 100 kPa (15 lbf/in2) shall be determined according to Figure 2.2.2.6. Figure 2.2.2.6 The distance between dike or impounding wall and container Explanation: dimension "X" shall equal to or be greater than dimension "Y" charging level of vapor pressure's LNG equivalent indenter. Exception: while the height of fending groin or impounding wall reaches or exceeds the maximal liquid level, "X" may take arbitrary value. Dimension "X" is the distance between the container’s inner wall to fending groin or impounding wall's nearest facing. Dimension "Y" is the distance between the maximal liquid level of the container and the fending groin or impounding wall's top. 2.2.2.7 Drain measures of water and other water in the impounding area shall be established. The auto-control draining pump is allowed to use, but the automatic knock-off block shall avoid exposing to the LNG temperature. The liquid may flow out of the impounding area when the pipe, valve and pipe fittings go out of order, it shall be able to continue working under LNG temperature conditions. If the free drainage is adopted, measures shall be adopted to prevent LNG from out-flowing through the drainage system. 2.2.2.8 The heat(thermal)insulation system used on the impounding surface shall be incombustible after installation, and shall fit for its usage, while considering the expectant heat stress, mechanical stress and load. If floating problem appears, it shall adopt braking measure. 2.2.3 The location of impounding area 2.2.2.1 The provision in 2.2.3 is not applicable to the impounding area of the terminal transfer area on the sea. 2.2.3.2 It shall adopt measures according to the following requirements to minimize the hazard caused by fire spreading beyond property line: a) Measures shall be adopted to prevent fire calorific radiation when exceeding the following limits under the atmospheric conditions of Grade 0, temperature 21℃ (70 ) and relative humidity 50%; 1) On the property line, due to the spillage on fire, the design radiant heat flux is 5000 W/m2 (1600 Btu/(h·ft2)); 2) Beyond the plant property line, the nearest location of outdoors meeting point of fifty persons, due to LNG burning in the impounding area (LNG capacity V is determined according to 2.2.2.1), the radiant heat flux is 5000 W/m2 (1600 Btu/(h·ft2)); 3) Beyond the plant property line, for the closest point of the plant, school, hospital, lockup and prison or residential area building or structures according to NFPA 101 "Life Safety Code" when the plant location is determined, due to the LNG burning in the impounding area (the LNG capacity V is determined according to 2.2.2.1), the radiant heat flux generated is 9000 W/m2 (3000 Btu/(h·ft2)); 4) On the property line, due to the LNG burning in the impounding area(the LNG capacity V is determined according to 2.2.2.1), the radiant heat flux generated is 30000 W/m2 (10000 Btu/(h·ft2)). b) Heat distance shall be calculated according to the following methods: 1) The Gas Research Institute's GRI Report 0176, "LNGFIRE: A Thermal Radiation Model for LNG Fires" Exception: it is allowed to use the model meeting the following criteria to calculate the distance: Ⅰ) The shape of the impounding area, wind speed, wind direction, humidity and air temperature are considered. Ⅱ) Test data suitable to assessing the risk scale and condition has been demonstrated. Ⅲ) It has been approved by the authority having jurisdiction. 2) If the maximal and minimal size ratio of the impounding area does not exceed 2, the following formula is allowed to use: Where: d--The distance away from the side of the LNG impounding area, m (ft); A--Surface area of impounding LNG, m2 (ft2); F--Heat flux correlation coefficient and it shall adopt the following values: 3.0 used for 5000 W/m2 (1600 Btu/(h·ft2)); 2.0 used for 9000 W/m2 (3000 Btu/(h·ft2)); 0.8 used for 30000 W/m2 (10000 Btu/(h·ft2)). 2.2.3.3 For the distance between the impounding area of LNG container and property line, when the LNG spillage described in 2.2.3.4 occurs, it shall guarantee that the average concentration of methane in the air beyond the property line shall not exceed 50% of the lower explosive limit. Its calculation shall apply one of the following models: a) Dispersion Model in "LNG Vapor Dispersion Prediction with the DEGADIS Dense Gas" of Gas Research Institute's report 0242. b) Gas Research Institute GRI–96/0396.5 "Evaluation of Mitigation Methods for Accidental LNG Releases, Volume 5: Using FEM3A for LNG Accident Consequence Analyses". c) Model combining the following contents: 1) Considering the physical factors that impact the LNG vapor diffusion, including but not limited to gravitation spread, heat transfer, humidity, wind speed, wind direction, atmosphere stability, buoyancy and surface irregularity. 2) Test data suitable to assessing the risk scale and condition has been demonstrated. 3) It has been approved by the authority having jurisdiction. The calculation distance shall be determined based on one of the following conditions: --The wind speed and atmosphere stability happen simultaneously, and the longest downwind diffusion distance is caused, but the extra distance is less than 10% of the time required by diffusion. --Pascal atmosphere stability, Grade F, wind speed is 2 (4.5 mile/h). The calculation distance is based on the physical characteristics of the liquid and the maximal vapor rate of flow from the vessel (the vapor gasification rate plus replacement rate of the liquid flow). In the calculation approved by the authority having jurisdiction, it is allowed to consider the effect of checking the vapor and depressing the combustible vapor (such as impounding the surface heat(thermal)insulation, adding water curtain or other proper measures). 2.2.3.4 The design spillage shall be determined according to Table 2.2.3.4.

Contents of GB/T 20368-2006

Foreword IV 1. General provisions 1.1 *Scope 1.2 Equality 1.3 Traceability 1.4 Personal training 1.5 System of units 1.6 Reference standard 1.7 Terms and definitions 2 Plant location and layout 2.1 Principle of plant location 2.2 The major principles of spillage and leakage control 2.3 Buildings and structures 2.4 Designer and manufacturer qualification 2.5 The soil protection of cryogenic equipment 2.6 Snow and ice falling 2.7 Concrete material 3 Process plant 3.1 Basic requirements of installation 3.2 Basic requirements of equipment 3.3 Storage of inflammable cryogen and inflammable liquid 3.4 Process plant 4 Stationary LNG containers 4.1 Basic requirements 4.2 Metal container 4.3 Concrete container 4.4 Marking of LNG container 4.5 LNG container test 4.6 Displacement and cooling of container 4.7 Release device 5 Gasification facilities 5.1 Classifications of gasifiers 5.2 Material for design and construction 5.3 Gasifier piping, heating medium fluid piping and storage 5.4 Release device of gasifier 5.5 The air supply of flaming 5.6 Flaming outcome 6 Piping system and subassembly 6.1 Basic requirement 6.2 Construction material 6.3 Installation 6.4 Pipe support 6.5 *Pipeline identification 6.6 Pipeline examination and experimentation 6.7 Piping system displacement 6.8 Safety and pressure relief valve 6.9 Corrosion control 7 Instruments and Electric Installation 7.1 Liquid meter 7.2 Pressure gauge 7.3 Vacuum gauge 7.4 Temperature indicator 7.5 Emergency switching-off 7.6 Electric installation 7.7 Earthing and containment shell 8 Transfer of LNG and cryogen 8.1 Basic requirements 8.2 Piping system 8.3 Control of pump and compressor 8.4 Stevedoring 8.5 Handling facilities of tank vehicle 8.6 Pipeline handling 8.7 Hose and loading arm 8.8 Communication and illumination 9 Fire Prevention, safety and security 9.1 Basic requirements 9.2 Emergency shutdown system 9.3 Fire protection and leakage protection 9.4 Firemain system 9.5 Fire-extinguishing equipments and other fire-fighting equipments 9.6 Maintenance of fire-fighting equipments 9.7 Personal security 9.8 *Security 9.9 Other operations 10 Requirements on selection of fixed ASME container 10.1 Scope 10.2 Basic requirements 10.3 Containers 10.4 Container filling 10.5 Container's foundation and bearing 10.6 Container installation 10.7 Product storage valve 10.8 Containment of leaking LNG 10.9 Inspection 10.10 Test of LNG container 10.11 Pipelines 10.12 Container apparatus 10.13 Fire protection and security 10.14 Fuel gas detector 10.15 Operation and maintenance 11 Operation, Maintenance and Personnel Training 11.1 General provisions * 11.2 Basic requirements 11.3 Operational procedure documents 11.4 Stevedoring 11.5 Maintenance 11.6 Training Annex A Annex B Annex C Annex D Annex E Annex F