NB/T 47059-2017Tank containers for refrigerated liquefied gas (English PDF)

Foreword

This document was issued on 15 November 2017 by the National Energy Administration of the PRC and takes effect on 1 March 2018.

It is a NB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

It is classified under ICS 23.020.01, Chinese classification J 74.

It replaces JB/T 4784-2007, which is superseded.

This standard has been drafted in accordance with the rules given in GB/T 1.1-2009, Directives for standardization - Part 1: Structure and drafting of standards.

This standard replaces JB/T 4784-2007, Tank containers for cryogenic liquid. Compared with JB/T 4784-2007, the main technical changes are as follows.

a) Title of the standard: the former title Tank containers for cryogenic liquid has been changed to Tank containers for refrigerated liquefied gas.

b) Scope: the range of non-application, the delimitation of the boundaries of the tank container and of the tank, and the delimitation of the main pressure-bearing components have been added.

c) Terms and definitions: sixteen terms and definitions, such as cryogenic liquid and insulation layer, have been deleted, while ten terms and definitions, such as high vacuum multilayer insulation and refrigerated liquefied gas, have been revised or added.

d) Qualification and responsibilities: the former clause Responsibilities has been changed to Qualification and responsibilities; the responsibilities of the user or of the party commissioning the design have been added, and the content of the requirements on the responsibilities of the design and manufacturing organizations has been revised and completed.

e) Materials: the requirements for steel plates, steel forgings, steel pipes and pipe fittings, welding consumables, insulating materials, adsorbent materials and interspace support materials used for the tank have been revised, and requirements for sealing gasket materials have been added.

f) Design: the design requirements for loads, design temperature, design pressure, frame, piping and so on have been revised, and requirements for the design by analysis method, the minimum design metal temperature, the minimum thickness of the tank and the maximum permissible filling quantity have been added.

g) Safety accessories, instruments and loading and unloading accessories: the types of safety accessories, instruments and loading and unloading accessories have been listed explicitly, and the related technical requirements have been revised.

h) Fabrication: the requirements for the classification of welded joints, re-inspection of materials, cold and hot forming, assembly, welding and non-destructive testing have been revised, and requirements for class E welded joints and for the coating of the tank have been added.

i) Test methods: the ammonia leak test, the halogen leak test and the helium leak test methods have been added.

j) Inspection rules: the requirements of the inspection rules have been revised, and a table of inspection items and technical requirements has been added.

k) Marks and markings: the specific requirements for marks and markings have been revised.

l) Annexes: the two annexes Statement of compliance with the standard and its revisions and Risk assessment report have been added; the three former annexes Test method for holding time, Format and content of the product quality certificate and Physical property parameters of common cryogenic liquids have been deleted; the former Annex A, Design calculation of the safety relief device, has been changed into Annex C, Calculation of the safety relief quantity of the tank and of the discharge capacity of the overpressure relief devices, and the content of the calculation of the safety relief quantity of the tank and of the discharge capacity of the overpressure relief devices has been revised.

This standard was proposed by and is under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262).

Attention is drawn to the possibility that some elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying such patent rights.

This standard was organized and drafted by the Subcommittee on Transportable Pressure Vessels of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262/SC4).

Drafting organizations of this standard: Nantong CIMC Energy Equipment Co., Ltd.; Shanghai Gas Industry Association; China Special Equipment Inspection and Research Institute; Shanghai Huayi Group Equipment Engineering Co., Ltd.; Zhangjiagang Branch of the Jiangsu Province Special Equipment Safety Supervision and Inspection Institute; Jiangxi Oxygen Plant Co., Ltd.; China Classification Society; Zhangjiagang CIMC Sanctum Cryogenic Equipment Co., Ltd.; Shanghai Special Equipment Supervision and Inspection Technical Institute; Shijiazhuang Enric Gas Equipment Co., Ltd.; Ningbo Mingxin Chemical Machinery Co., Ltd.; Zhangjiagang Hanzhong Deep Cooling Technology Co., Ltd.; Tieling Huanghai Special Purpose Vehicle Manufacturing Co., Ltd.

Main drafters of this standard: Yang Yang, Zhou Weiming, Luo Yongxin, Teng Junhua, Chen Zhaohui, Wang Fei, He Hua, Chen Yanshan, Lai Yongcai, Liu Gencang, Tang Xiaoying, Wang Hongxia, Wen Qing, Qin Feng and Chen Liyan.

The previous editions of the standard replaced by this standard are as follows: JB/T 4784-2007.

1 Scope

NB/T 47059-2017 covers tank containers for refrigerated liquefied gas, replacing JB/T 4784-2007. These are the ISO-framed vacuum-insulated tanks that move LNG, liquid oxygen, nitrogen, argon and ethylene by road, rail and sea: an inner vessel at cryogenic temperature, an outer jacket, and the vacuum and multilayer insulation between them, all inside a container frame that has to meet the handling and stacking loads of intermodal transport. The standard fixes the qualification and responsibilities of the designer, manufacturer and inspection body, then the materials permitted for the inner vessel, the outer jacket and the frame, with the low-temperature toughness required and the allowable stresses at service temperature. Design follows: the inner vessel for internal pressure and for the external pressure of the vacuum, the outer jacket for collapse, the supports that carry the inner vessel while conducting as little heat as possible, the frame for the transport load cases, and the sizing of the piping, valves, pressure relief and instrumentation. The insulation system, the vacuum and its measurement, and the evaporation rate that proves the insulation works are all specified. Fabrication and welding, non-destructive examination, pressure and leak testing, the thermal performance test, marking and the documentation delivered with the unit complete the standard. It applies to tank containers built in China for refrigerated liquefied gas service.

1.1 This standard specifies the requirements for the materials, design, fabrication, test methods, inspection rules, marks and markings, documents delivered with the product, storage and transport of tank containers for refrigerated liquefied gas (hereinafter referred to as tank containers).

1.2 This standard applies to tank containers in which the design pressure of the inner vessel of the tank is not less than 0.1 MPa, the geometric volume is not less than 1 cubic metre, a vacuum powder insulation structure or a high vacuum multilayer insulation structure is adopted, and the tank is permanently connected to the frame.

1.3 This standard does not apply to tank containers falling within the following ranges.

1.3 a) Tank containers whose tank material is a non-ferrous metal or a non-metallic material.

1.3 b) Tank containers filled with a refrigerated liquefied gas medium whose standard boiling point is lower than minus 196 degrees Celsius.

1.3 c) Tank containers filled with toxic media.

1.3 d) Tank containers with special requirements, such as those for national defence and military equipment.

1.4 Delimitation of the boundaries.

1.4.1 The tank containers covered by this standard include, within their boundaries, the tank, the piping, the safety accessories, the instruments, the loading and unloading accessories, the self-pressurizer, the frame, the supports and the operating box.

1.4.2 The boundaries of the tank are delimited as follows.

1.4.2 a) The bevelled end face of the first circumferential joint where the tank is welded to the external piping.

1.4.2 b) The end face of the first threaded joint where the tank is connected by threads to the external piping or to the safety accessories, and the first flange sealing face where the connection is flanged.

1.4.2 c) The end covers of the openings of the tank and their fasteners.

1.4.2 d) The connecting welds between the tank and the non-pressure-bearing components.

1.4.3 The piping includes all the pipes and pipe fittings connected to the tank.

1.4.4 The main pressure-bearing components include the shell and the heads of the inner vessel, as well as the pipes, pipe seats, flanges and flange cover plates in contact with the filling medium whose nominal diameter is not less than 15 mm.

1.5 The requirements set out in this standard are basic safety technical requirements; tank containers complying with this standard may be used for road, railway or waterway transport, as well as for the combined transport by these modes.

2 Normative references

The following documents are indispensable for the application 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 150.1, Pressure vessels - Part 1: General requirements.

GB/T 150.2, Pressure vessels - Part 2: Materials.

GB/T 150.3-2011, Pressure vessels - Part 3: Design.

GB/T 150.4-2011, Pressure vessels - Part 4: Fabrication, inspection and testing, and acceptance.

GB/T 567.1, Bursting disc safety devices - Part 1: Basic requirements.

GB/T 567.2, Bursting disc safety devices - Part 2: Application, selection and installation.

GB/T 567.3, Bursting disc safety devices - Part 3: Classification and installation dimensions.

GB/T 713, Steel plates for boilers and pressure vessels.

GB/T 1413, Series 1 freight containers - Classification, dimensions and ratings.

GB/T 1804-2000, General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications.

GB/T 1835, Series 1 freight containers - Corner fittings.

GB/T 1836, Freight containers - Coding, identification and marking.

GB/T 3531, Steel plates for low temperature pressure vessels.

GB/T 12241, Safety valves - General requirements.

GB/T 12243, Spring loaded (direct loaded) safety valves.

GB/T 13296, Seamless stainless steel tubes for boilers and heat exchangers.

GB/T 13550, 5A molecular sieve and its testing methods.

GB/T 14525, General specifications for corrugated metal hose.

GB/T 14976, Seamless stainless steel pipes for fluid transport.

GB/T 16563, Series 1 tank containers for liquids, gases and pressurized dry bulk - Technical requirements and test methods.

GB/T 17600 (all parts), Steel - Conversion of elongation values.

GB/T 18443 (all parts), Test methods for the performance of vacuum insulated cryogenic equipment.

GB/T 24511, Stainless steel plates and strips for pressure equipment.

GB/T 24918, Emergency shut-off valves for cryogenic media.

GB/T 25198, Heads for pressure vessels.

GB/T 26929, Terminology of pressure vessels.

GB/T 31480, High vacuum multilayer insulation materials for cryogenic vessels.

GB/T 31481, Guidelines for the determination of the compatibility between materials and gases for cryogenic vessels.

NB/T 47009, Low alloy steel forgings for low temperature pressure equipment.

NB/T 47010, Stainless steel and heat-resisting steel forgings for pressure equipment.

NB/T 47013.1, Non-destructive testing of pressure equipment - Part 1: General requirements.

NB/T 47013.2, Non-destructive testing of pressure equipment - Part 2: Radiographic testing.

NB/T 47013.3, Non-destructive testing of pressure equipment - Part 3: Ultrasonic testing.

NB/T 47013.4, Non-destructive testing of pressure equipment - Part 4: Magnetic particle testing.

NB/T 47013.5, Non-destructive testing of pressure equipment - Part 5: Penetrant testing.

NB/T 47013.10, Non-destructive testing of pressure equipment - Part 10: Time of flight diffraction ultrasonic testing.

NB/T 47013.11, Non-destructive testing of pressure equipment - Part 11: X-ray digital radiographic testing.

NB/T 47013.14, Non-destructive testing of pressure equipment - Part 14: X-ray computer-aided imaging testing.

NB/T 47014, Welding procedure qualification for pressure equipment.

NB/T 47016, Mechanical property tests of product welded test coupons for pressure equipment.

NB/T 47018.1, Technical conditions for the ordering of welding consumables for pressure equipment - Part 1: General rules for purchase.

NB/T 47018.2, Technical conditions for the ordering of welding consumables for pressure equipment - Part 2: Steel covered electrodes.

NB/T 47018.3, Technical conditions for the ordering of welding consumables for pressure equipment - Part 3: Steel wires and filler wires for gas shielded arc welding.

NB/T 47018.4, Technical conditions for the ordering of welding consumables for pressure equipment - Part 4: Steel wires and fluxes for submerged arc welding.

HG/T 2690, 13X molecular sieve.

JB/T 4711, Coating and transport packaging of pressure vessels.

JB 4732-1995, Steel pressure vessels - Design by analysis (confirmed in 2005).

JB/T 6804, Shock-resistant pressure gauges.

JB/T 6896, Air separation equipment - Surface cleanliness.

YS/T 599, Ultrafine palladium oxide powder.

TSG R0005, Supervision regulation on safety technology for transportable pressure vessels.

TSG Z6002, Assessment rules for welding operators of special equipment.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in GB/T 150.1, GB/T 150.4, GB/T 16563, GB/T 18443 and GB/T 26929, together with the following, apply.

3.1 refrigerated liquefied gas - A gas which, during transport, is partly in the liquid state because of its low temperature, and whose critical temperature is generally not higher than minus 50 degrees Celsius.

3.2 tank container for refrigerated liquefied gas - A tank container composed of a vacuum insulated tank, a frame and other parts, used for the filling of a refrigerated liquefied gas.

3.3 high vacuum multilayer insulation - An insulation method in which multiple heat radiation shields separated by insulating materials are arranged in the vacuum interspace of the tank and a high vacuum is drawn.

3.4 vacuum powder insulation - An insulation method in which the vacuum interspace of the tank is filled with porous particulate insulating material and a vacuum is drawn.

3.5 geometric volume - The internal volume of the inner vessel determined from the design geometric dimensions, deducting the volume occupied by the internal parts.

3.6 effective volume - The maximum volume of refrigerated liquefied gas in the liquid state which the inner vessel is permitted to contain under the service conditions.

3.7 equivalent pressure - The pressure borne by the tank arising from the action of the inertial force load of the medium under normal transport conditions.

3.8 filling rate - The ratio between the volume of the refrigerated liquefied gas in the liquid state filled into the tank container and the geometric volume of the inner vessel.

3.9 specified filling rate - The ratio between the volume of liquid corresponding to the highest liquid level laid down by the design, when the tank container is filled, and the geometric volume of the inner vessel.

3.10 rating mass R - The total mass of the tank container; it is the maximum value in service and the minimum value during testing.

3.11 reference steel - The reference material for which the specified lower limit value of the tensile strength (Rm) is set at 370 MPa and the elongation after fracture (A) at 27 per cent.

3.12 sealing-off vacuum degree - The vacuum degree of the interspace of the tank when, after the completion of the evacuation and sealing-off of the tank, the interspace pressure is relatively stable at ambient temperature.

4 Qualification and responsibilities

4.1 Qualification.

4.1.1 In addition to complying with the provisions of this standard, the design, fabrication, inspection and acceptance of the tank container shall comply with the relevant laws, regulations and safety technical regulations promulgated by the State.

4.1.2 The organizations designing and manufacturing the tank container shall obtain the corresponding special equipment design and manufacturing licences in accordance with the provisions of TSG R0005.

4.2 Responsibilities.

4.2.1 User or party commissioning the design. The user or the party commissioning the design shall submit the design conditions of the tank container to the design organization in a formal written form; the design conditions shall include at least the following content.

4.2.1 a) The main standards and safety technical regulations to be followed for the design and the fabrication.

4.2.1 b) The transport mode, including railway, road, waterway transport or the combined transport by these modes.

4.2.1 c) The working conditions, including the service ambient temperature, the working temperature range, the working pressure range, the loading and unloading conditions and method, the loading and unloading pressure and the additional loads.

4.2.1 d) The filling medium, including the number, name, category, composition, physical and chemical properties and hazardous characteristics of the medium, the content of harmful impurities and the corrosion rate of the medium on the materials of the tank.

4.2.1 e) The geometric volume or the effective volume of the inner vessel.

4.2.1 f) The dimensional specification of the freight container.

4.2.1 g) The expected service life of the tank container and the service life of the interspace vacuum.

4.2.1 h) The required holding time.

4.2.1 i) The number of pressure cycles corresponding to the fluctuating pressure.

4.2.1 j) The main dimensional requirements and the orientation of the nozzles.

4.2.1 k) Other necessary conditions required for the design, such as the selection of the materials of the tank, corrosion protection, surface treatment and special tests.

4.2.2 Design organization.

4.2.2.1 The design organization shall complete the overall design of the tank container on the basis of the content of the risk assessment report, and shall be responsible for the correctness and completeness of the design documents.

4.2.2.2 The management and use of the special design stamp shall satisfy the requirements of TSG R0005.

4.2.2.3 The design organization shall preserve all the design documents throughout the design service life of the tank container.

4.2.3 Manufacturing organization.

4.2.3.1 The tank container shall be manufactured as a complete unit, and the manufacturing organization shall be responsible for the manufacturing quality of the tank container.

4.2.3.2 The manufacturing organization shall manufacture according to the requirements of the design documents; where the original design is modified, written evidential documents showing the consent of the original design organization to the modification shall be obtained, and a detailed record shall be made of the modified parts.

4.2.3.3 Before manufacture, the manufacturing organization shall draw up a quality plan, whose content shall include at least the manufacturing process control points, the inspection items and the acceptance requirements for the tank container.

4.2.3.4 During manufacture and after completion, the inspection department of the manufacturing organization shall carry out the various inspections and tests in accordance with the provisions of this standard, of the design drawings, of the design documents and of the quality plan, shall issue the corresponding reports, and shall be responsible for the correctness and completeness of those reports.

4.2.3.5 After each tank container has passed the inspection, the manufacturing organization shall issue a product certificate of conformity.

4.2.3.6 The manufacturing organization shall accept the supervisory inspection of its manufacturing process by the special equipment inspection and testing body, and shall obtain the Special equipment manufacturing supervisory inspection certificate issued by the supervisory inspection body.

4.2.3.7 The tank container shall undergo, by type, the prototype container type test and the low temperature performance type test, and shall obtain the certificates of conformity recognized by the competent authority.

4.2.3.8 For each tank container it manufactures, the manufacturing organization shall preserve at least the following technical documents for verification throughout its design service life: a) the manufacturing process drawing or manufacturing process card; b) the welding procedure and heat treatment procedure documents of the tank; c) the records of the inspection and test items specified by the standard; d) the records of the checks, inspections and tests carried out during manufacture and after completion; e) the documents delivered with the product (complying with the provisions of Clause 12); f) the original design documents.

5 Materials

5.1 General requirements.

5.1.1 The selection of the materials shall take into account the mechanical properties, the physical properties, the technological properties of the materials and their compatibility with the medium.

5.1.2 For materials which may come into contact with oxygen or with an oxygen-enriched environment, their compatibility with oxygen shall comply with the provisions of GB/T 31481.

5.1.3 The materials of the non-pressure-bearing components welded to pressure-bearing components shall have good toughness and weldability and shall match the pressure-bearing components to which they are welded.

5.1.4 The material manufacturer shall make clear and firm factory steel stamp marks, or use other traceable marks, on a conspicuous part of the material.

5.1.5 The material manufacturer shall provide the manufacturer of the tank container with the material quality certificate; the content of the material quality certificate shall be complete and clear, and shall bear a printed traceable information mark and the quality inspection stamp.

5.1.6 Where the manufacturing organization obtains the materials for the tank from an organization other than the material manufacturer, it shall obtain the original of the material quality certificate issued by the material manufacturer, or a copy bearing the official stamp of the material distributor and the stamp of the responsible person handling the matter.

5.1.7 The manufacturing organization shall be responsible for the authenticity and consistency of the quality certificates of the materials for the tank and of the bought-out parts which it obtains.

5.2 Materials of the tank.

5.2.1 The materials selected for the tank shall comply with GB/T 150.2 and with the corresponding national and industry standards. When selecting the materials of the pressure-bearing components of the tank, the service conditions (such as design temperature, design pressure, characteristics of the medium and operating features), the properties of the materials (mechanical, technological, chemical and physical properties), the manufacturing technology of the tank and the economic rationality shall be taken into account.

5.2.2 The use of foreign grade materials and of new materials shall comply with the relevant provisions of TSG R0005.

5.2.3 Inner vessel.

5.2.3.1 The materials of the pressure-bearing components of the inner vessel shall comply with the corresponding material standards and with the provisions of the design drawings.

5.2.3.2 The steel used for the pressure-bearing components of the inner vessel shall generally be an austenitic stainless steel material.

5.2.3.3 The mechanical properties of the materials used for the inner vessel shall satisfy the following requirements: a) the steel used for the pressure-bearing components of the inner vessel shall have good plasticity, its specified value of the yield strength at room temperature (or the 0.2 per cent proof plastic extension strength) shall be not greater than 460 MPa and the specified upper limit value of the tensile strength shall be not greater than 725 MPa; b) the ratio between the room temperature yield strength (or the 0.2 per cent proof plastic extension strength) and the room temperature tensile strength stated in the material quality certificate shall be not greater than 0.85; c) the elongation after fracture of the steel plates shall be not less than 10 000 divided by Rm (per cent), and the elongation after fracture of austenitic stainless steels shall be not less than 40 per cent; where elongation after fracture values obtained on test pieces of different sizes are used, they shall be converted in accordance with GB/T 17600 and the converted values shall comply with the requirements of this subclause.

5.2.4 Outer shell.

5.2.4.1 Melting method.

5.2.4.1.1 The steel used for the outer shell shall be killed steel.

5.2.4.1.2 Low temperature steel plates and low temperature steel forgings used at design temperatures below minus 20 degrees Celsius shall in addition be produced with a secondary refining (out-of-furnace refining) process.

5.2.4.2 Chemical composition (heat analysis).

5.2.4.2.1 For low alloy steels used for welding, the carbon content shall be not greater than 0.250 per cent, the phosphorus content not greater than 0.035 per cent and the sulphur content not greater than 0.035 per cent.

5.2.4.2.2 For low alloy steel products (steel plates and steel forgings), the phosphorus and sulphur contents shall comply with the following: a) phosphorus content not greater than 0.030 per cent and sulphur content not greater than 0.020 per cent; b) for steels used at design temperatures below minus 20 degrees Celsius and whose specified lower limit value of the tensile strength is not greater than 540 MPa, the phosphorus content shall be not greater than 0.025 per cent and the sulphur content not greater than 0.012 per cent.

5.2.4.3 Mechanical properties.

5.2.4.3.1 For the low alloy steel products used for the outer shell, the specified value of the yield strength at room temperature shall be not greater than 460 MPa and the specified upper limit value of the tensile strength not greater than 725 MPa; they shall be able to withstand the environmental conditions met by the tank container during transport and service and shall comply with the requirements of the design drawings.

5.2.4.3.2 For the low alloy steel products used for the outer shell, the ratio between the yield strength and the tensile strength at room temperature stated in the material quality certificate shall be not greater than 0.85.

5.2.4.3.3 The impact test on the low alloy steel plates and steel forgings used for the outer shell shall comply with the following: a) the impact test temperature shall follow the requirements of the design documents; b) the minimum value of the Charpy V-notch impact absorbed energy (KV2) shall comply with the provisions of Table 1; c) where the impact absorbed energy values specified in the steel product standard are higher than those laid down in Table 1, the provisions of the corresponding steel product standard shall also be satisfied; d) steel plates with a thickness of less than 6 mm may be exempted from the impact test.

Table 1 - Impact absorbed energy of low alloy steel plates and steel forgings, row 1: specified lower limit value of the tensile strength Rm not greater than 510 MPa; average impact absorbed energy KV2 of three standard test pieces not less than 27 J.

Table 1 - Impact absorbed energy of low alloy steel plates and steel forgings, row 2: specified lower limit value of the tensile strength Rm greater than 510 MPa and up to 540 MPa; average impact absorbed energy KV2 of three standard test pieces not less than 34 J.

Table 1, note: for steels whose Rm decreases as the thickness increases, the impact absorbed energy requirement shall be determined from the Rm corresponding to the minimum thickness range of that steel.

5.2.4.3.4 The sampling position and the orientation of the Charpy impact test pieces shall comply with the provisions of the corresponding steel product standard. For each group of impact tests three standard test pieces (width 10 mm) shall be taken; the impact absorbed energy value of one test piece is permitted to be lower than the value specified in Table 1, but not lower than 70 per cent of that value. Where the dimensions of the steel product do not allow standard test pieces to be prepared, small size impact test pieces of width 7.5 mm or 5 mm shall be prepared in that order, and their impact absorbed energy requirements shall be, respectively, 75 per cent or 50 per cent of the requirement for the standard test piece.

5.2.4.3.5 The elongation after fracture (A) shall comply with the following: a) the elongation after fracture (A) of the steel plates used for the heads and the shell of the outer shell shall be not less than 10 000 divided by Rm (per cent) and not less than 20 per cent; b) where the elongation after fracture (A) specified in the corresponding steel plate standard is higher than that required in a), the provisions of the steel plate standard shall also be satisfied; c) the elongation after fracture (A) of the steel plates, steel pipes and steel forgings used for the outer shell and for the other pressure-bearing components shall comply with the provisions of the corresponding steel product standards; d) where elongation after fracture values obtained on test pieces of different sizes are used, they shall be converted in accordance with GB/T 17600 and the converted values shall comply with the provisions of a), b) and c).

5.2.5 Steel plates.

5.2.5.1 Steel plates for the inner vessel.

5.2.5.1.1 Austenitic stainless steel plates shall comply with the provisions of GB/T 24511 and shall be delivered in the solution treated condition. The surface finish type of hot rolled steel plates shall be not lower than grade 1D, and that of cold rolled steel plates not lower than grade 2B.

5.2.5.1.2 The mechanical property requirements for the steel plate materials commonly used for the inner vessel shall follow the provisions of Table 2.

5.2.5.1.3 Where steel plates other than those of Table 2 are used, they shall comply with this standard and with the provisions of the corresponding material standards.

Table 2 - Mechanical property requirements for the steel plates commonly used for the inner vessel, row 1: steel grade S30408, steel plate standard GB/T 24511, delivery condition solution treated, thickness 3 mm to 25 mm, Rp0.2 not less than 220 MPa, Rp1.0 not less than 250 MPa, Rm not less than 520 MPa, elongation after fracture A not less than 40 per cent.

Table 2, row 2: steel grade S30403, steel plate standard GB/T 24511, delivery condition solution treated, thickness 3 mm to 25 mm, Rp0.2 not less than 210 MPa, Rp1.0 not less than 230 MPa, Rm not less than 490 MPa, elongation after fracture A not less than 40 per cent.

Table 2, row 3: steel grade S31608, steel plate standard GB/T 24511, delivery condition solution treated, thickness 3 mm to 25 mm, Rp0.2 not less than 220 MPa, Rp1.0 not less than 260 MPa, Rm not less than 520 MPa, elongation after fracture A not less than 40 per cent.

Table 2, row 4: steel grade S31603, steel plate standard GB/T 24511, delivery condition solution treated, thickness 3 mm to 25 mm, Rp0.2 not less than 210 MPa, Rp1.0 not less than 260 MPa, Rm not less than 490 MPa, elongation after fracture A not less than 40 per cent.

5.2.5.2 Steel plates for the outer shell.

5.2.5.2.1 The steel plates shall have good weldability, sufficient strength and impact toughness, and account shall also be taken of the corrosive action of the external environment. Where low alloy steel plates are selected, they shall comply with the provisions of GB/T 713 or GB/T 3531; where austenitic stainless steel plates are selected, they shall comply with the provisions of GB/T 24511.

5.2.5.2.2 The mechanical property requirements for the steel plate materials commonly used for the outer shell shall follow the provisions of Table 3.

5.2.5.2.3 Where steel plates other than those of Table 3 are used, they shall comply with this standard and with the provisions of the corresponding material standards.

Table 3 - Mechanical property requirements for the steel plate materials commonly used for the outer shell, row 1: steel grade Q245R, steel plate standard GB/T 713, delivery condition hot rolled, controlled rolled or normalized, thickness 3 mm to 16 mm, ReL (Rp0.2) not less than 245 MPa, Rm from 400 MPa to 520 MPa, elongation after fracture A not less than 25 per cent.

Table 3, row 2: steel grade Q345R, steel plate standard GB/T 713, delivery condition hot rolled, controlled rolled or normalized, thickness 3 mm to 16 mm, ReL (Rp0.2) not less than 345 MPa, Rm from 510 MPa to 640 MPa, elongation after fracture A not less than 21 per cent.

Table 3, row 3: steel grade 16MnDR, steel plate standard GB/T 3531, delivery condition normalized or normalized and tempered, thickness 6 mm to 16 mm, ReL (Rp0.2) not less than 315 MPa, Rm from 490 MPa to 620 MPa, elongation after fracture A not less than 21 per cent.

Table 3, row 4: steel grade S30408, steel plate standard GB/T 24511, delivery condition solution treated, thickness 3 mm to 25 mm, Rp0.2 not less than 220 MPa, Rm not less than 520 MPa, elongation after fracture A not less than 40 per cent.

Table 3, row 5: steel grade S30403, steel plate standard GB/T 24511, delivery condition solution treated, thickness 3 mm to 25 mm, Rp0.2 not less than 210 MPa, Rm not less than 490 MPa, elongation after fracture A not less than 40 per cent.

5.2.6 Steel forgings.

5.2.6.1 The stainless steel forgings used for the inner vessel shall comply with the provisions of NB/T 47010, and the forging grade shall be not lower than grade III.

5.2.6.2 The low alloy steel forgings and the stainless steel forgings used for the outer shell shall comply with the provisions of NB/T 47009 and NB/T 47010 respectively; the grade of the forgings in contact with the medium inside the tank shall be not lower than grade III, and that of the remaining forgings not lower than grade II.

5.2.7 Steel pipes and pipe fittings.

5.2.7.1 The materials of the steel pipes shall comply with GB/T 150.2 and with the provisions of the design drawings, and shall comply with the provisions of GB/T 13296 or GB/T 14976.

5.2.7.2 The pipe fittings shall comply with the provisions of the corresponding standards; where the pipe fittings are made of steel forgings, they shall comply with the provisions of 5.2.6.

5.2.7.3 Where the pipe fittings are formed by cold forming, the measured ferrite value after forming shall be not greater than 15 per cent.

5.2.8 Insulating materials.

5.2.8.1 The expanded perlite used for vacuum powder insulation shall satisfy the following: a) particle size from 0.1 mm to 1.2 mm; b) bulk density from 30 kg per cubic metre to 60 kg per cubic metre; c) moisture content not greater than 0.3 per cent (by mass); d) thermal conductivity (average value at atmospheric pressure and at temperatures from 77 K to 310 K) not greater than 0.03 W per metre kelvin.

5.2.8.2 The opacifier shall have good chemical stability.

5.2.8.3 The high vacuum multilayer insulation materials shall comply with the provisions of GB/T 31480, and materials with low thermal conductivity and low outgassing rate, such as degreased fibre cloth or degreased fibre paper, shall be used.

5.2.9 Adsorbent materials.

5.2.9.1 The 5A molecular sieve shall comply with the provisions of GB/T 13550 and the 13X molecular sieve with the provisions of HG/T 2690.

5.2.9.2 The palladium oxide shall comply with the provisions of YS/T 599.

5.2.10 Welding consumables.

5.2.10.1 The welding consumables used for the tank shall comply with the provisions of NB/T 47018.1 to NB/T 47018.4 and shall bear clear and firm marks.

5.2.10.2 The selection of the welding consumables shall take into account the matching between the mechanical properties of the welded joint and the parent material of the tank. The tensile strength of the weld metal shall be not lower than the lower limit value specified in the standard for the parent material, and the impact absorbed energy of the welding consumables for low alloy steels shall comply with the provisions of Table 1. Where necessary, the other properties shall also be not lower than the corresponding requirements for the parent material.

5.2.10.3 The welding consumables shall undergo welding procedure qualification in accordance with the requirements of NB/T 47014 and may be used only after the qualification has been passed.

5.2.11 Interspace support materials.

5.2.11.1 The non-metallic support materials shall be materials with low thermal conductivity, low surface outgassing rate under vacuum and good low temperature impact toughness, and their service temperature shall lie within the temperature range permitted for the material.

5.2.11.2 The metallic support materials shall be materials with low thermal conductivity and good low temperature impact toughness; their service temperature shall lie within the temperature range permitted for the material and they shall comply with the standard requirements for the corresponding materials.

5.2.12 Frame materials.

5.2.12.1 The steel plates and sections used for the corner posts, end rails, side rails and supports shall have good weldability, sufficient strength and impact toughness, and shall comply with the provisions of the corresponding material standards.

5.2.12.2 The main load-bearing members of the frame, such as the corner posts, the end rails and the side rails, shall possess sufficient impact toughness at minus 20 degrees Celsius. When the Charpy V-notch impact test is carried out, the test temperature shall be minus 20 degrees Celsius and the average impact absorbed energy (KV2) of three standard test pieces shall be not less than 27 J.

5.2.12.3 The materials of the frame, of the supports and of other parts shall take into account the corrosive action of the external environment and the influence of the ambient temperature.

5.2.13 Other materials.

5.2.13.1 The bought-out parts shall comply with the provisions of the corresponding national or industry standards and shall be accompanied by quality certification documents or by a product certificate of conformity.

5.2.13.2 Imported pressure piping components shall comply with the relevant provisions of the General Administration of Quality Supervision, Inspection and Quarantine.

5.2.13.3 The fasteners shall comply with the provisions of the corresponding national or industry standards.

5.2.13.4 The corner fittings shall comply with the provisions of GB/T 1835.

5.2.13.5 The sealing gaskets shall be correctly selected according to the filling medium, the working pressure and the temperature, and shall comply with the provisions of the corresponding standards. Where polytetrafluoroethylene gaskets are used, expanded or filled modified polytetrafluoroethylene gaskets shall be selected.

5.2.13.6 The materials of the supports shall have sufficient strength and impact toughness.

5.2.13.7 The other materials used for the tank container shall comply with the requirements of the design drawings.

6 Design

6.1 General requirements.

6.1.1 In addition to satisfying the requirements of this standard, the design of the tank container shall comply with the provisions of the relevant laws and regulations, safety technical regulations, national standards and industry standards.

6.1.2 The arrangement of the tank, the piping, the safety accessories, the instruments and the loading and unloading accessories shall satisfy the requirements of use and of safety.

6.1.3 The design loads borne by the tank container shall be confirmed by calculation or by testing.

6.1.4 Tank containers for international combined transport shall comply with the provisions of the relevant international conventions.

6.1.5 When the tank container is designed, consideration shall be given to the adoption of appropriate protective measures, in order to prevent the damage or the leakage of the filling medium caused by an impact in the longitudinal or transverse direction or by overturning.

6.1.6 For tank containers used for railway transport, the structural strength and stiffness of the prototype container shall be able to withstand the impact force, not less than four times the rating mass multiplied by the acceleration of gravity, produced by the typical mechanical vibrations undergone during railway transport when fully loaded.

6.1.7 The design service life of the tank container shall be not less than 15 years.

6.2 Design documents.

6.2.1 The design documents of the tank container shall include at least the following documents.

6.2.1 a) The risk assessment report, including the main failure modes and the risk control measures for the design, fabrication and service stages; its basic content shall comply with the provisions of Annex B.

6.2.1 b) The design specification, including the main physical and chemical properties of the filling medium (number, name, category, and the saturated vapour pressure and density corresponding to the working temperature), the hazardous characteristics, the limiting composition of mixed media and the limiting content requirements for harmful impurities, the compatibility with the materials of the tank, and also an explanation of the choice of the design codes and standards, of the principles for determining the main design structures, of the principles for determining the main design parameters, of the selection of the materials, of the selection of the safety accessories and of the selection of the instruments and of the loading and unloading accessories.

6.2.1 c) The design calculation sheet, including the calculations of the strength, stiffness, external pressure stability, volume, heat transfer, safety relief quantity, discharge capacity of the overpressure relief devices and strength of the internal and external support structures of the tank and, where necessary, also the stress check at the connection between the tank and the frame.

6.2.1 d) The design drawings, including the general drawing, the drawings of the tank and of its parts, the piping system and the flow diagrams.

6.2.1 e) The technical conditions for fabrication, including the main manufacturing process requirements and the inspection and test methods.

6.2.1 f) The instructions for use, including the main technical performance parameters, the applicable media, the specifications and connection methods of the safety accessories, instruments and loading and unloading accessories, the operating instructions, the precautions for use, the necessary warning requirements and the emergency measures.

6.2.1 g) The test programme for the prototype container, including the main test methods and the acceptance requirements.

6.2.2 The general design drawing, the drawing of the tank, the risk assessment report and the design calculation sheet shall be signed at the three levels of design, checking and review, and shall be approved by the technical manager of the design organization or by the person authorized by him.

6.2.3 The general design drawing shall state at least the following content.

6.2.3 a) The product name, the model and the main safety technical regulations and standards on which the design and the fabrication are based.

6.2.3 b) The transport mode, including the applicable railway, road or waterway transport modes or the combined transport by these modes.

6.2.3 c) The working conditions, including the service ambient temperature, the working temperature, the working pressure and the characteristics of the medium (such as the degree of explosion hazard).

6.2.3 d) The design conditions, including the design temperature, the minimum design metal temperature, the design loads (including the pressure load and the other necessary loads), the medium (composition) and the corrosion allowance; where the medium has a tendency to cause stress corrosion, the limiting content of the corrosive medium shall be stated.

6.2.3 e) The main characteristic parameters, including the rating mass of the tank container, the tare mass, the geometric volume of the inner vessel and of the vacuum interspace, the specified filling rate and the maximum permissible filling quantity.

6.2.3 f) The design service life.

6.2.3 g) The special manufacturing requirements (such as the requirements for purging with nitrogen or with inert gas).

6.2.3 h) The requirements for the pressure test.

6.2.3 i) The requirements for the leak test.

6.2.3 j) The type of vacuum insulation of the tank, the vacuum performance requirements, the vacuum insulation performance requirements and the design service life of the vacuum.

6.2.3 k) The corrosion protection requirements (where necessary).

6.2.3 l) The specifications, performance parameters and connection methods of the safety accessories, of the instruments and of the loading and unloading accessories.

6.2.3 m) The orientation and specification of the loading and unloading nozzles, the standards of the connecting flanges, and so on.

6.2.3 n) The requirements for gas protection during transport (such as the limitation of the sealed tank pressure with nitrogen or with another insoluble gas).

6.2.3 o) The permissible stacking mass.

6.2.3 p) The position of the nameplate.

6.2.3 q) The other relevant requirements laid down by the competent railway, road and waterway authorities.

6.2.4 The design drawing of the tank shall state at least the following content.

6.2.4 a) The material grade, specification, standard and requirements of the main pressure-bearing components.

6.2.4 b) The main design parameters, including the design temperature, the design pressure, the minimum design metal temperature, the corrosion allowance, the density of the medium, the specified filling rate, the maximum permissible filling quantity, the filling medium and its hazardousness, the geometric volume of the inner vessel and of the vacuum interspace and the welded joint coefficient; where the medium has a tendency to cause stress corrosion, the limiting content of the corrosive medium shall also be stated.

6.2.4 c) The calculated thickness, the nominal thickness and the minimum formed thickness of the shell and of the heads of the inner vessel and of the outer shell.

6.2.4 d) The non-destructive testing requirements.

6.2.4 e) The heat treatment requirements (where necessary).

6.2.4 f) The requirements for the pressure test.

6.2.4 g) The type of vacuum insulation of the tank, the vacuum performance requirements, the vacuum insulation performance requirements and the design service life of the vacuum.

6.2.4 h) The corrosion protection requirements (where necessary).

6.2.4 i) The design service life of the tank (for fatigue-loaded tanks, the number of cycles shall be stated).

6.3 Dimensions, tolerances and rating mass.

6.3.1 The external dimensions and the tolerances of the tank container shall comply with the provisions of GB/T 1413; for the models 1AX, 1BX, 1CX and 1DX, the height of the tank container may be reduced. Tank containers whose external dimensions exceed those laid down in GB/T 1413 (for example over-length or over-width) shall be designed, manufactured, inspected and accepted in accordance with the standards recognized by the competent authority, and shall be marked accordingly.

6.3.2 No part of the tank container and none of its accessories shall project beyond the specified external dimensions.

6.3.3 The rating mass of the tank container shall comply with the provisions of GB/T 1413. Where tank containers of the types 1EEE, 1EE, 1AAA, 1AA, 1A, 1BBB, 1BB, 1B, 1CC and 1C are designed and tested according to the rating mass, their rating mass is permitted to exceed the value laid down in GB/T 1413. Tank containers whose rating mass exceeds the value laid down in GB/T 1413 shall be designed, inspected, tested and marked according to that rating mass value, and shall bear the overweight marking.