GB 18442-2001 Cryogenic Insulated Pressure Vessels

This standard specifies the model compilation method and performance parameters, technical requirements, test methods, inspection rules, quality certificates, and marks for fixed high vacuum multilayer cryogenic insulation and vacuum powder cryogenic insulation pressure vessels. This standard is applicable to vacuum insulated cryogenic pressure vessels with low pressure, medium pressure, and vacuum interlayer. GB 18442-2001 Cryogenic Insulation Pressure Vessels GB18442-2001 Standard Download Decompression Password: www.bzxz.net

GB18442--2001
All technical contents of this standard are mandatory.
This standard and GB150 "Steel Pressure Vessels" belong to the same series of pressure vessel standards, and further regulations are made for low-temperature insulated pressure vessels.
Appendix A of this standard is a prompt appendix.
This standard is proposed and managed by the Boiler and Pressure Vessel Safety Supervision Bureau of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. This standard is drafted by the National Low Temperature Vessel Quality Supervision and Inspection Center and the Boiler and Pressure Vessel Safety Supervision Bureau of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China.
The main drafters of this standard are: Shi Baoyi, Chen Guangqi, Huang Hong, Liu Zhidong, Wu Yan, Gao Jixuan. This standard is entrusted to the National Low Temperature Vessel Quality Supervision and Inspection Center for interpretation. 684
1 Scope
National Standard of the People's Republic of China
Cryogenic Insulation Pressure Vessels
Cryo-insulation pressure vesselsGB18442---2001
This standard specifies the model compilation method and performance parameters, technical requirements, test methods, inspection rules, quality certificates, markings, etc. of fixed high vacuum multilayer cryogenic insulation and vacuum powder cryogenic insulation pressure vessels. This standard is applicable to vacuum insulated cryogenic pressure vessels with low pressure and medium pressure as the design pressure of the inner container and vacuum interlayer. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB150---1998 Steel pressure vessels
GI33198--1996 Pure aluminum foil for industrial use
GB/T9019--2001 Nominal diameter of pressure vesselsGB/T18443.12001 Test methods for cryogenic insulated pressure vessels Volume measurementGB/T18443.2--2001 Test methods for cryogenic insulated pressure vessels Vacuum measurement Test methods for cryogenic insulated pressure vessels Leakage rate measurementGB/T 18443.3--2001
GB/T 18443.4--2001 1
Test methods for cryogenic insulated pressure vessels Leakage and release rate measurement GB/T18443.5-2001 Test methods for cryogenic insulated pressure vessels Static evaporation rate measurement 3 General
3.1 The design, manufacture, inspection and acceptance of cryogenic insulated pressure vessels shall comply with relevant laws and regulations issued by the state in addition to complying with this standard.
3.2 Qualifications
3.2.1 Design qualifications
3.2.1.1 The design unit of cryogenic insulated pressure vessels must have a sound quality management system and hold the corresponding pressure vessel design unit approval certificate issued by the Boiler and Pressure Vessel Safety Supervision Bureau of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. 3.2.1.2 The design unit shall engage in product design within the corresponding qualification validity period specified in the approval certificate of the cryogenic insulated pressure vessel design unit. 3.2.1.3 The design of cryogenic insulated pressure vessels must be subject to the supervision of the boiler and pressure vessel safety supervision agencies of the quality and technical supervision bureaus at all levels. 3.2.2 Manufacturing Qualifications
3.2.2.1 The cryogenic insulated pressure vessel manufacturing unit must hold the corresponding pressure vessel manufacturing license issued by the Boiler and Pressure Vessel Safety Supervision Bureau of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, and have the corresponding professional and technical personnel, resources and a sound quality management system. 3.2.2.2 The vacuum leak detection personnel of the manufacturing unit shall pass the corresponding training and assessment, and take up their posts after passing the qualification. 3.2.2.3 The manufacturing unit must engage in the manufacture of products within the product range and validity period specified in the license. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on September 3, 2001, implemented on April 1, 2002
GB 18442—2001
3.2.2.4 The quality and safety of the manufacture, acceptance and use of cryogenic insulated pressure vessels must be subject to the supervision of the Boiler and Pressure Vessel Safety Supervision Bureau of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. 3.2.2.5 Low temperature insulated pressure vessel products shall be inspected and type tested by the national quality inspection agency designated by the Boiler and Pressure Vessel Safety Supervision Bureau of the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China.
3.3 Responsibilities
3.3.1 Responsibilities of the design unit
3.3.1.1 The design unit shall be responsible for the correctness and completeness of the design documents. 3.3.1.2 The design drawings, design calculations and other documents provided by the design unit to the manufacturing unit shall comply with the provisions of the "Regulations on Safety Technical Supervision of Pressure Vessels" (hereinafter referred to as the "Regulations"). 3.3.1.3 The design general drawing provided by the design unit shall be stamped with the design unit qualification seal in accordance with the provisions of the "Regulations". 3.3.2 Responsibilities of the manufacturing unit
3.3.2.1 The manufacturing unit must manufacture in accordance with the requirements of the design drawings. If the original design needs to be modified, the original design unit must be confirmed. 3.3.2.2 In addition to inspection and testing according to the requirements of the drawings, the product quality inspection department of the manufacturing unit shall also conduct inspection and testing according to the requirements of this standard and be responsible for the correctness and completeness of the inspection and test reports. 3.3.2.3 In the technical documents for each product manufactured by the manufacturing unit, in addition to the documents specified in GB150, the following documents shall be included and kept for at least 7 years.
a) Leak detection report of the inner container and overall leak detection report; b) Report on the measurement of the leakage and degassing rate of the vacuum interlayer; c) Records of vacuum pumping and sealing vacuum degree.
4 Definition
4.1 High vacuum multi-layer insulation High vacuum multi-layer insulation is an insulation method consisting of multiple layers of radiation protection materials in the interlayer space of a low-temperature insulated pressure vessel and pumped to a high vacuum (pressure less than 1.0×10-\Pa).
4.2 Vacuum powder insulation Vacuum powder insulation is an insulation method in which porous particulate insulation materials are filled in the interlayer space of the cryogenic insulation pressure vessel and evacuated to a specified vacuum. 4.3 Operation pressure The maximum operation pressure of the inner container should be less than the critical point pressure of the cryogenic medium contained, and the minimum operation pressure should be greater than the triple point pressure of the cryogenic medium contained.
4.4 Design pressure pressure of design The maximum pressure at the top of the inner container, together with the design temperature, is used as the design load condition, and its value is not less than the operating pressure. 4.5 Calculation pressure pressure of calculation The calculation pressure referred to in this standard has the following meanings: a) The maximum pressure of the inner container should be the sum of the design pressure, the static pressure of the liquid and the atmospheric pressure (the static pressure of the liquid shall be in accordance with GB150); b) The external pressure on the outer container should be equal to 0.1MPa. 4.6 Design temperature The design temperature referred to in this standard has the following meanings: a) Set the temperature that the inner container, internal components and components in contact with low-temperature media can withstand, which should be the boiling point of the low-temperature media contained; b) Set the lowest temperature of the outer container and external components under the operating environment; c) The components connecting the inner and outer containers, such as supports, inlet and outlet pipes, etc., should withstand the extreme temperatures at both ends. 686
4.7 Geometric volume
GB18442--2001
The volume of the inner container determined by the designed geometric dimensions, in m2. 4.8 Effective volume
The maximum liquid volume under working conditions, in m. 4.9 Static evaporation rate static evaporation When a cryogenic insulated pressure vessel is loaded with cryogenic liquid greater than 1/2 of its effective volume, after being left to stand to reach thermal equilibrium, the mass of cryogenic liquid lost by natural evaporation within 24 hours is the percentage of the mass of cryogenic liquid under the effective volume of the container, converted to the evaporation rate value under standard environment (20C, 101325Pa), unit is %/d.
4.10 Sealed-off vacuum degree sealed-off vacuum degree After the cryogenic insulated pressure vessel is evacuated and sealed, the interlayer vacuum degree when the interlayer pressure is relatively stable at room temperature, unit is Pa. 4.11 Vacuum interspace leakage rate vacuum interspace leakage rate The amount of gas leaking into the vacuum interlayer per unit time, unit is Pa·m/s. 4.12 Vacuum interspace outguessing rate vacuum interspace outgassing rate The amount of gas released from the insulation material, vessel wall surface, etc. in the vacuum interlayer per unit time, unit is Pa·m\/s. 4.13 Vacuum interspace outguessing and leak rate The sum of the vacuum interspace outguessing and leak rate of the cryogenic insulation pressure vessel, in Pa·m\/s. 5 Model compilation method and performance parameters
5.1 The product model compilation method is as follows:
Use numbers to indicate the maximum working pressure, unit: MPa-Use numbers to indicate the effective volume, unit: m2-Type: L-vertical; W-horizontal; Q-spherical Insulation method: D-high vacuum multi-layer insulation; F-vacuum powder insulation C-represents cryogenic insulation pressure vessel (storage tank) For example: CF1.-20/0.8: represents a vertical 20m vacuum powder cryogenic insulation pressure vessel, with a maximum working pressure of 0.8MPa. CDW-50/1.6: represents a horizontal 50m high vacuum multi-layer cryogenic insulation pressure vessel, with a maximum working pressure of 1.6MPa. 5.2 Product specifications and main performance parameters
5.2.1 The static evaporation rate of vertical and horizontal high vacuum multilayer cryogenic insulation pressure vessels shall comply with the provisions of Table 1. 5.2.2 The static evaporation rate of vertical and horizontal vacuum powder cryogenic insulation pressure vessels shall comply with the provisions of Table 2. 5.2.3 The static evaporation rate index of spherical cryogenic insulation pressure vessels with the same insulation method is 0.6 times that in Table 1 and Table 2. 5.2.4 The static evaporation rate in Table 1 and Table 2 refers to the index of the product when it leaves the factory. 5.2.5 The static pressure rise method can be used to test the insulation performance of liquid carbon dioxide cryogenic insulation pressure vessels. At an ambient temperature of (20 ± 5) ℃, the pressure rise value per 24 hours for an effective volume of less than 50m2 should be less than 35kPa; for an effective volume of 50~~100m2, the pressure rise value per 24 hours should be less than 20kPa.
5.2.6 Liquid nitrogen may be used as a substitute medium to test the static evaporation rate index of flammable or toxic cryogenic liquids, and its value shall comply with the index specified in Table 1 and Table 2.
Effective volume V
Effective volume
Static evaporation rate index of vertical and horizontal high vacuum multilayer cryogenic insulation pressure vessels Table 1
Evaporation rate (upper limit)/%·d-1
Static evaporation rate index of vertical and horizontal vacuum powder cryogenic insulation pressure vessels Evaporation rate (upper limit)/%·d-1
Effective volume V
Technical requirements
—General requirements
GB 18442—2001
Table 2 (end)
Evaporation rate (upper limit)/%·d-
6.1.1 Product drawings and technical documents shall be designed, reviewed, approved and used in accordance with the prescribed procedures. Liquid Hydrogen
6.1.2 In addition to complying with this standard, the design and manufacture of the product shall also comply with the "Container Regulations" promulgated by the State Administration of Quality and Technical Supervision and the provisions of GB150.
6.1.3 The liquid discharge capacity of the product shall comply with the design drawings or meet the requirements of the contract. 6.1.4 The pipe joints, valves, instruments and other devices used for operation or monitoring on the product shall be reasonably arranged and relatively concentrated to facilitate operation, inspection and maintenance. If necessary, a protective cover or operating room may be set up. 6.1.5 The inner surface, pipes, joints, valves, instruments and other components of the product that come into contact with liquid oxygen or gaseous oxygen must be strictly oil-free. 6.2 Environmental requirements
6.2.1 The product shall be designed according to environmental conditions and use requirements, and ensure that the product can work normally. 6.2.2 For products used to fill inert cryogenic liquids, ventilation and air flow requirements shall be put forward for the use environment. 6.2.3 For products used to fill flammable cryogenic liquids, fire prevention and explosion prevention requirements shall be put forward. 6.2.4 For products filled with toxic cryogenic liquids, preventive measures should be taken for the environment and users. 6.3 Design requirements
6.3.1 Structural calculation
Based on the type of cryogenic liquid contained, select the manufacturing material and insulation structure, and perform strength and heat transfer calculations. The calculation results should meet the requirements of GB150 and this standard.
6.3.2 Structural design
6.3.2.1 The diameter of the product cylinder should generally comply with the provisions of GB/T9019, and the effective volume shall not exceed 95% of the geometric volume. 6.3.2.2 Stress concentration should be minimized in structural design. 6.3.2.3 The connection between the inner and outer walls of the product should be as simple and firm as possible. 6.3.3 Additional amount of wall thickness
Additional amount of wall thickness is calculated according to the formula specified in 3.5.5 of GB150---1998. For stainless steel inner wall and when the low-temperature medium loaded is non-corrosive, the corrosion allowance C is equal to zero; the corrosion allowance of other materials is not less than 1mm; for corrosive low-temperature liquids such as liquid fluorine, the corrosion allowance should be determined based on the design life of the container and the corrosion rate of the material. 6.3.4 Welded structure
6.3.4.1 According to the temperature and load conditions of the low-temperature medium to which the component is subjected, the design of the welded structure should avoid excessive stress concentration and obvious deformation. Appendix A (suggested appendix) provides optional welded structures. For welding structures without vacuum requirements at room temperature, please refer to Appendix J of GB150-1998.
6.3.4.2 Welding structures in vacuum areas should avoid "vacuum blind areas" as much as possible. Note: "Vacuum blind areas" refer to dead spaces in the vacuum chamber that are closed at one end and are not conducive to vacuuming and leak detection. 6.3.5 Leak rate requirements
According to the leak rate indicators of this standard, the leak rate requirements of the main components should be proposed. 6.3.6 Design pressure
The design pressure of the inner container shall comply with the provisions of Appendix B of GB150-1998. 6.3.7 Design temperature
6.3.7.1 When designing the temperature that the inner container, internal components and components in contact with low-temperature media can withstand, the maximum temperature to which the container is subjected during vacuum baking to the boiling point of the low-temperature medium contained should be considered. 6.3.7.2 The design temperature of the outer container shall comply with the provisions of Section 1 of the "Container Regulations". 35 provisions. 6.3.8 The design of the pipeline leading from the inner container through the interlayer shall meet the following requirements: a) good low-temperature toughness and low thermal conductivity; www.bzxz.net
b) the temperature difference stress caused by the temperature changes of the inner and outer containers during the manufacturing and use process shall be fully considered, and a temperature compensation structure shall be provided when necessary;
c) the pipe connections in the interlayer must be connected by welding joints. 6.3.9 The gas discharge outlet of flammable cryogenic liquids shall be equipped with a flame arrester. 6.4 Vacuum performance requirements
6.4.1. The leakage rate of the vacuum interlayer shall comply with the provisions of Table 3. 6.4.2 The leakage and degassing rate of the vacuum interlayer shall comply with the provisions of Table 4. 6.4.3 The pressure of the vacuum interlayer after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 1.5 ×10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulated pressure vessel is filled with cryogenic liquid, the tank body shall not show "sweating" phenomenon. 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the stored cryogenic liquid and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in high vacuum multi-layer insulation shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
101 The static evaporation rate of vertical and horizontal high vacuum multilayer cryogenic insulation pressure vessels shall comply with the provisions of Table 1. 5.2.2 The static evaporation rate of vertical and horizontal vacuum powder cryogenic insulation pressure vessels shall comply with the provisions of Table 2. 5.2.3 The static evaporation rate index of spherical cryogenic insulation pressure vessels with the same insulation method is 0.6 times that in Table 1 and Table 2. 5.2.4 The static evaporation rate in Table 1 and Table 2 refers to the index of the product when it leaves the factory. 5.2.5 The static pressure rise method can be used to test the insulation performance of liquid carbon dioxide cryogenic insulation pressure vessels. At an ambient temperature of (20 ± 5) ° C, the pressure rise value per 24 hours for an effective volume of less than 50m2 should be less than 35kPa; for an effective volume of 50~~100m2, the pressure rise value per 24 hours should be less than 20kPa.
5.2.6 Liquid nitrogen can be used as a substitute medium to test the static evaporation rate index of flammable or toxic cryogenic liquids, and its value should comply with the index specified in Table 1 and Table 2.
Effective volume V
Effective volume
Static evaporation rate index of vertical and horizontal high vacuum multilayer cryogenic insulation pressure vessels Table 1
Evaporation rate (upper limit)/%·d-1
Static evaporation rate index of vertical and horizontal vacuum powder cryogenic insulation pressure vessels Evaporation rate (upper limit)/%·d-1
Effective volume V
Technical requirements
—General requirements
GB 18442—2001
Table 2 (end)
Evaporation rate (upper limit)/%·d-
6.1.1 Product drawings and technical documents shall be designed, reviewed, approved and used in accordance with the prescribed procedures. Liquid hydrogen
6.1.2 In addition to complying with this standard, the design and manufacture of products shall also comply with the "Container Regulations" promulgated by the State Administration of Quality and Technical Supervision and the provisions of GB150.
6.1.3 The drainage capacity of the product shall comply with the design drawings or meet the requirements of the contract. 6.1.4 The pipe joints, valves, instruments and other devices used for operation or monitoring on the product shall be reasonably arranged and relatively concentrated to facilitate operation, inspection and maintenance. Protective covers or operating rooms may be set up when necessary. 6.1.5 The inner surfaces, pipes, joints, valves, instruments and other components of the product that come into contact with liquid oxygen or gaseous oxygen must be strictly oil-free. 6.2 Environmental requirements
6.2.1 The product shall be designed according to environmental conditions and use requirements, and ensure that the product can work normally. 6.2.2 For products used to fill inert cryogenic liquids, ventilation, air flow and other requirements shall be put forward for the use environment. 6.2.3 For products used to fill flammable cryogenic liquids, fire prevention and explosion prevention requirements shall be put forward. 6.2.4 For products used to fill toxic cryogenic liquids, preventive measures shall be taken for the environment and users. 6.3 Design requirements
6.3.1 Structural calculation
Based on the type of cryogenic liquid contained, select the manufacturing material and insulation structure, and perform strength and heat transfer calculations. The calculation results should meet the requirements of GB150 and this standard.
6.3.2 Structural design
6.3.2.1 The diameter of the product cylinder should generally comply with the provisions of GB/T9019, and the effective volume shall not exceed 95% of the geometric volume. 6.3.2.2 Stress concentration should be minimized in structural design. 6.3.2.3 The connection between the inner and outer walls of the product should be as simple and firm as possible. 6.3.3 Additional amount of wall thickness
Additional amount of wall thickness is calculated according to the formula specified in 3.5.5 of GB150---1998. For stainless steel inner wall and when the low-temperature medium loaded is non-corrosive, the corrosion allowance C is equal to zero; the corrosion allowance of other materials is not less than 1mm; for corrosive low-temperature liquids such as liquid fluorine, the corrosion allowance should be determined based on the design life of the container and the corrosion rate of the material. 6.3.4 Welded structure
6.3.4.1 According to the temperature and load conditions of the low-temperature medium to which the component is subjected, the design of the welded structure should avoid excessive stress concentration and obvious deformation. Appendix A (suggested appendix) provides optional welded structures. For welding structures without vacuum requirements at room temperature, please refer to Appendix J of GB150-1998.
6.3.4.2 Welding structures in vacuum areas should avoid "vacuum blind areas" as much as possible. Note: "Vacuum blind areas" refer to dead spaces in the vacuum chamber that are closed at one end and are not conducive to vacuuming and leak detection. 6.3.5 Leak rate requirements
According to the leak rate indicators of this standard, the leak rate requirements of the main components should be proposed. 6.3.6 Design pressure
The design pressure of the inner container shall comply with the provisions of Appendix B of GB150-1998. 6.3.7 Design temperature
6.3.7.1 When designing the temperature that the inner container, internal components and components in contact with low-temperature media can withstand, the maximum temperature to which the container is subjected during vacuum baking to the boiling point of the low-temperature medium contained should be considered. 6.3.7.2 The design temperature of the outer container shall comply with the provisions of Section 1 of the "Container Regulations". 35 provisions. 6.3.8 The design of the pipeline leading from the inner container through the interlayer shall meet the following requirements: a) good low-temperature toughness and low thermal conductivity;
b) the temperature difference stress caused by the temperature changes of the inner and outer containers during the manufacturing and use process shall be fully considered, and a temperature compensation structure shall be provided when necessary;
c) the pipe connections in the interlayer must be connected by welding joints. 6.3.9 The gas discharge outlet of flammable cryogenic liquids shall be equipped with a flame arrester. 6.4 Vacuum performance requirements
6.4.1. The leakage rate of the vacuum interlayer shall comply with the provisions of Table 3. 6.4.2 The leakage and degassing rate of the vacuum interlayer shall comply with the provisions of Table 4. 6.4.3 The pressure of the vacuum interlayer after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 1.5 ×10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulated pressure vessel is filled with cryogenic liquid, the tank body shall not show "sweating" phenomenon. 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the stored cryogenic liquid and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in high vacuum multi-layer insulation shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
101 The static evaporation rate of vertical and horizontal high vacuum multilayer cryogenic insulation pressure vessels shall comply with the provisions of Table 1. 5.2.2 The static evaporation rate of vertical and horizontal vacuum powder cryogenic insulation pressure vessels shall comply with the provisions of Table 2. 5.2.3 The static evaporation rate index of spherical cryogenic insulation pressure vessels with the same insulation method is 0.6 times that in Table 1 and Table 2. 5.2.4 The static evaporation rate in Table 1 and Table 2 refers to the index of the product when it leaves the factory. 5.2.5 The static pressure rise method can be used to test the insulation performance of liquid carbon dioxide cryogenic insulation pressure vessels. At an ambient temperature of (20 ± 5) ° C, the pressure rise value per 24 hours for an effective volume of less than 50m2 should be less than 35kPa; for an effective volume of 50~~100m2, the pressure rise value per 24 hours should be less than 20kPa.
5.2.6 Liquid nitrogen can be used as a substitute medium to test the static evaporation rate index of flammable or toxic cryogenic liquids, and its value should comply with the index specified in Table 1 and Table 2.
Effective volume V
Effective volume
Static evaporation rate index of vertical and horizontal high vacuum multilayer cryogenic insulation pressure vessels Table 1
Evaporation rate (upper limit)/%·d-1
Static evaporation rate index of vertical and horizontal vacuum powder cryogenic insulation pressure vessels Evaporation rate (upper limit)/%·d-1
Effective volume V
Technical requirements
—General requirements
GB 18442—2001
Table 2 (end)
Evaporation rate (upper limit)/%·d-
6.1.1 Product drawings and technical documents shall be designed, reviewed, approved and used in accordance with the prescribed procedures. Liquid hydrogen
6.1.2 In addition to complying with this standard, the design and manufacture of products shall also comply with the "Container Regulations" promulgated by the State Administration of Quality and Technical Supervision and the provisions of GB150.
6.1.3 The drainage capacity of the product shall comply with the design drawings or meet the requirements of the contract. 6.1.4 The pipe joints, valves, instruments and other devices used for operation or monitoring on the product shall be reasonably arranged and relatively concentrated to facilitate operation, inspection and maintenance. Protective covers or operating rooms may be set up when necessary. 6.1.5 The inner surfaces, pipes, joints, valves, instruments and other components of the product that come into contact with liquid oxygen or gaseous oxygen must be strictly oil-free. 6.2 Environmental requirements
6.2.1 The product shall be designed according to environmental conditions and use requirements, and ensure that the product can work normally. 6.2.2 For products used to fill inert cryogenic liquids, ventilation, air flow and other requirements shall be put forward for the use environment. 6.2.3 For products used to fill flammable cryogenic liquids, fire prevention and explosion prevention requirements shall be put forward. 6.2.4 For products used to fill toxic cryogenic liquids, preventive measures shall be taken for the environment and users. 6.3 Design requirements
6.3.1 Structural calculation
Based on the type of cryogenic liquid contained, select the manufacturing material and insulation structure, and perform strength and heat transfer calculations. The calculation results should meet the requirements of GB150 and this standard.
6.3.2 Structural design
6.3.2.1 The diameter of the product cylinder should generally comply with the provisions of GB/T9019, and the effective volume shall not exceed 95% of the geometric volume. 6.3.2.2 Stress concentration should be minimized in structural design. 6.3.2.3 The connection between the inner and outer walls of the product should be as simple and firm as possible. 6.3.3 Additional amount of wall thickness
Additional amount of wall thickness is calculated according to the formula specified in 3.5.5 of GB150---1998. For stainless steel inner wall and when the low-temperature medium loaded is non-corrosive, the corrosion allowance C is equal to zero; the corrosion allowance of other materials is not less than 1mm; for corrosive low-temperature liquids such as liquid fluorine, the corrosion allowance should be determined based on the design life of the container and the corrosion rate of the material. 6.3.4 Welded structure
6.3.4.1 According to the temperature and load conditions of the low-temperature medium to which the component is subjected, the design of the welded structure should avoid excessive stress concentration and obvious deformation. Appendix A (suggested appendix) provides optional welded structures. For welding structures without vacuum requirements at room temperature, please refer to Appendix J of GB150-1998.
6.3.4.2 Welding structures in vacuum areas should avoid "vacuum blind areas" as much as possible. Note: "Vacuum blind areas" refer to dead spaces in the vacuum chamber that are closed at one end and are not conducive to vacuuming and leak detection. 6.3.5 Leak rate requirements
According to the leak rate indicators of this standard, the leak rate requirements of the main components should be proposed. 6.3.6 Design pressure
The design pressure of the inner container shall comply with the provisions of Appendix B of GB150-1998. 6.3.7 Design temperature
6.3.7.1 When designing the temperature that the inner container, internal components and components in contact with low-temperature media can withstand, the maximum temperature to which the container is subjected during vacuum baking to the boiling point of the low-temperature medium contained should be considered. 6.3.7.2 The design temperature of the outer container shall comply with the provisions of Section 1 of the "Container Regulations". 35 provisions. 6.3.8 The design of the pipeline leading from the inner container through the interlayer shall meet the following requirements: a) good low-temperature toughness and low thermal conductivity;
b) the temperature difference stress caused by the temperature changes of the inner and outer containers during the manufacturing and use process shall be fully considered, and a temperature compensation structure shall be provided when necessary;
c) the pipe connections in the interlayer must be connected by welding joints. 6.3.9 The gas discharge outlet of flammable cryogenic liquids shall be equipped with a flame arrester. 6.4 Vacuum performance requirements
6.4.1. The leakage rate of the vacuum interlayer shall comply with the provisions of Table 3. 6.4.2 The leakage and degassing rate of the vacuum interlayer shall comply with the provisions of Table 4. 6.4.3 The pressure of the vacuum interlayer after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not exceed 1.5 ×10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulated pressure vessel is filled with cryogenic liquid, the tank body shall not show "sweating" phenomenon. 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the stored cryogenic liquid and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in high vacuum multi-layer insulation shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
103 The drainage capacity of the product shall comply with the design drawings or meet the requirements of the contract. 6.1.4 The pipe joints, valves, instruments and other devices used for operation or monitoring on the product shall be reasonably arranged and relatively concentrated to facilitate operation, inspection and maintenance. Protective covers or operating rooms may be set up when necessary. 6.1.5 The inner surfaces, pipes, joints, valves, instruments and other components of products that come into contact with liquid oxygen or gaseous oxygen must be strictly oil-free. 6.2 Environmental requirements
6.2.1 The product shall be designed according to environmental conditions and use requirements, and ensure that the product can work normally. 6.2.2 Products used to fill inert cryogenic liquids shall have ventilation, air flow and other requirements for the use environment. 6.2.3 Products used to fill flammable cryogenic liquids shall have fire prevention, explosion prevention and other requirements. 6.2.4 Products used to fill toxic cryogenic liquids shall take preventive measures for the environment and users. 6.3 Design requirements
6.3.1 Structural calculation
Based on the type of cryogenic liquid contained, select the manufacturing material and insulation structure, and perform strength and heat transfer calculations. The calculation results should meet the requirements of GB150 and this standard.
6.3.2 Structural design
6.3.2.1 The diameter of the product cylinder should generally comply with the provisions of GB/T9019, and the effective volume shall not exceed 95% of the geometric volume. 6.3.2.2 Stress concentration should be minimized in structural design. 6.3.2.3 The connection between the inner and outer walls of the product should be as simple and firm as possible. 6.3.3 Additional amount of wall thickness
Additional amount of wall thickness is calculated according to the formula specified in 3.5.5 of GB150---1998. For stainless steel inner wall and when the low-temperature medium loaded is non-corrosive, the corrosion allowance C is equal to zero; the corrosion allowance of other materials is not less than 1mm; for corrosive low-temperature liquids such as liquid fluorine, the corrosion allowance should be determined based on the design life of the container and the corrosion rate of the material. 6.3.4 Welded structure
6.3.4.1 According to the temperature and load conditions of the low-temperature medium to which the component is subjected, the design of the welded structure should avoid excessive stress concentration and obvious deformation. Appendix A (suggested appendix) provides optional welded structures. For welding structures without vacuum requirements at room temperature, please refer to Appendix J of GB150-1998.
6.3.4.2 Welding structures in vacuum areas should avoid "vacuum blind areas" as much as possible. Note: "Vacuum blind areas" refer to dead spaces in the vacuum chamber that are closed at one end and are not conducive to vacuuming and leak detection. 6.3.5 Leak rate requirements
According to the leak rate indicators of this standard, the leak rate requirements of the main components should be proposed. 6.3.6 Design pressure
The design pressure of the inner container shall comply with the provisions of Appendix B of GB150-1998. 6.3.7 Design temperature
6.3.7.1 When designing the temperature that the inner container, internal components and components in contact with low-temperature media can withstand, the maximum temperature to which the container is subjected during vacuum baking to the boiling point of the low-temperature medium contained should be considered. 6.3.7.2 The design temperature of the outer container shall comply with the provisions of Section 1 of the "Container Regulations". 35 provisions. 6.3.8 The design of the pipeline leading from the inner container through the interlayer shall meet the following requirements: a) good low-temperature toughness and low thermal conductivity;
b) the temperature difference stress caused by the temperature changes of the inner and outer containers during the manufacturing and use process shall be fully considered, and a temperature compensation structure shall be provided when necessary;
c) the pipe connections in the interlayer must be connected by welding joints. 6.3.9 The gas discharge outlet of flammable cryogenic liquids shall be equipped with a flame arrester. 6.4 Vacuum performance requirements
6.4.1. The leakage rate of the vacuum interlayer shall comply with the provisions of Table 3. 6.4.2 The leakage and degassing rate of the vacuum interlayer shall comply with the provisions of Table 4. 6.4.3 The pressure of the vacuum interlayer after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 1.5 ×10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulated pressure vessel is filled with cryogenic liquid, the tank body shall not show "sweating" phenomenon. 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the stored cryogenic liquid and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in high vacuum multi-layer insulation shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
103 The drainage capacity of the product shall comply with the design drawings or meet the requirements of the contract. 6.1.4 The pipe joints, valves, instruments and other devices used for operation or monitoring on the product shall be reasonably arranged and relatively concentrated to facilitate operation, inspection and maintenance. Protective covers or operating rooms may be set up when necessary. 6.1.5 The inner surfaces, pipes, joints, valves, instruments and other components of products that come into contact with liquid oxygen or gaseous oxygen must be strictly oil-free. 6.2 Environmental requirements
6.2.1 The product shall be designed according to environmental conditions and use requirements, and ensure that the product can work normally. 6.2.2 Products used to fill inert cryogenic liquids shall have ventilation, air flow and other requirements for the use environment. 6.2.3 Products used to fill flammable cryogenic liquids shall have fire prevention, explosion prevention and other requirements. 6.2.4 Products used to fill toxic cryogenic liquids shall take preventive measures for the environment and users. 6.3 Design requirements
6.3.1 Structural calculation
Based on the type of cryogenic liquid contained, select the manufacturing material and insulation structure, and perform strength and heat transfer calculations. The calculation results should meet the requirements of GB150 and this standard.
6.3.2 Structural design
6.3.2.1 The diameter of the product cylinder should generally comply with the provisions of GB/T9019, and the effective volume shall not exceed 95% of the geometric volume. 6.3.2.2 Stress concentration should be minimized in structural design. 6.3.2.3 The connection between the inner and outer walls of the product should be as simple and firm as possible. 6.3.3 Additional amount of wall thickness
Additional amount of wall thickness is calculated according to the formula specified in 3.5.5 of GB150---1998. For stainless steel inner wall and when the low-temperature medium loaded is non-corrosive, the corrosion allowance C is equal to zero; the corrosion allowance of other materials is not less than 1mm; for corrosive low-temperature liquids such as liquid fluorine, the corrosion allowance should be determined based on the design life of the container and the corrosion rate of the material. 6.3.4 Welded structure
6.3.4.1 According to the temperature and load conditions of the low-temperature medium to which the component is subjected, the design of the welded structure should avoid excessive stress concentration and obvious deformation. Appendix A (suggested appendix) provides optional welded structures. For welding structures without vacuum requirements at room temperature, please refer to Appendix J of GB150-1998.
6.3.4.2 Welding structures in vacuum areas should avoid "vacuum blind areas" as much as possible. Note: "Vacuum blind areas" refer to dead spaces in the vacuum chamber that are closed at one end and are not conducive to vacuuming and leak detection. 6.3.5 Leak rate requirements
According to the leak rate indicators of this standard, the leak rate requirements of the main components should be proposed. 6.3.6 Design pressure
The design pressure of the inner container shall comply with the provisions of Appendix B of GB150-1998. 6.3.7 Design temperature
6.3.7.1 When designing the temperature that the inner container, internal components and components in contact with low-temperature media can withstand, the maximum temperature to which the container is subjected during vacuum baking to the boiling point of the low-temperature medium contained should be considered. 6.3.7.2 The design temperature of the outer container shall comply with the provisions of Section 1 of the "Container Regulations". 35 provisions. 6.3.8 The design of the pipeline leading from the inner container through the interlayer shall meet the following requirements: a) good low-temperature toughness and low thermal conductivity;
b) the temperature difference stress caused by the temperature changes of the inner and outer containers during the manufacturing and use process shall be fully considered, and a temperature compensation structure shall be provided when necessary;
c) the pipe connections in the interlayer must be connected by welding joints. 6.3.9 The gas discharge outlet of flammable cryogenic liquids shall be equipped with a flame arrester. 6.4 Vacuum performance requirements
6.4.1. The leakage rate of the vacuum interlayer shall comply with the provisions of Table 3. 6.4.2 The leakage and degassing rate of the vacuum interlayer shall comply with the provisions of Table 4. 6.4.3 The pressure of the vacuum interlayer after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 1.5 ×10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulated pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulated pressure vessel is filled with cryogenic liquid, the tank body shall not show "sweating" phenomenon. 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the stored cryogenic liquid and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in high vacuum multi-layer insulation shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
103 The vacuum interlayer pressure after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulation pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 1.5 × 10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulation pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulation pressure vessel is filled with cryogenic liquid, the tank body should not "sweat". 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the cryogenic liquid stored and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in the high vacuum multi-layer insulation body shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
103 The vacuum interlayer pressure after sealing shall comply with the provisions of Table 5. 6.4.4 During use, after the high vacuum multi-layer cryogenic insulation pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 1.5 × 10\2Pa.
6.4.5 During use, after the vacuum powder cryogenic insulation pressure vessel is filled with cryogenic liquid, the pressure of the vacuum interlayer shall not be higher than 5 X10° 'Pa.
6.4.6 During the warranty period, after the cryogenic insulation pressure vessel is filled with cryogenic liquid, the tank body should not "sweat". 6.5 Material requirements
6.5.1 The inner container shall be made of materials that are compatible with the cryogenic liquid stored and have good low-temperature toughness. 6.5.2 The aluminum foil or double-sided aluminum-plated polyester film used in the high vacuum multi-layer insulation body shall comply with the provisions of GB3198. Table 3 Vacuum interlayer leakage rate
Effective volume V/m2
1V≤10
10V≤100
100V≤1 000
V>1 000
High vacuum multilayer insulation
2×107
6×10-7
≤2×10-6
≤6×106
Leakage rate/Pa·m2·s-1
Vacuum powder insulation
≤6×10-?
2×10-6
6×10:6
2×105
Effective volume V/m2
V≤10
101000
Effective volume V/m
50AVN100
100V≤500
GB 18442—2001
Table 4 Leakage and degassing rate of vacuum interlayer
Leakage and degassing rate/Pa·m2·s
High vacuum multilayer insulation
2×10-6
6×106
2×10
6X10-5
Table 5 Vacuum degree after sealing
Vacuum degree/Pa
High vacuum multilayer insulation
≤3×10-1
Vacuum powder insulation
≤2×10-5
≤6×10°5
≤2×104
6×10-4
Vacuum powder insulation
6.5.3 The insulation material in high vacuum multilayer insulation should be degreased glass fiber cloth, plant fiber paper or nylon net with small thermal conductivity and low degassing rate. The fat content of glass fiber cloth should not be greater than 0.1% (weight ratio), otherwise it should be degreased. 6.5.4 The expanded perlite (pearl sand) insulation material used in vacuum powder insulation should meet the following requirements: a) Particle size: 0.1~1.2mm;
b) Bulk density: 30~60kg/m;
c) Moisture content after drying: less than 0.3% (weight ratio); d) Thermal conductivity (average value at 77~310K under normal pressure): ≤0.03W/(m·k). 6.5.5 When using vacuum powder insulation, light-blocking agents can be added to the powder, and the light-blocking agents should have good chemical stability. It is prohibited to use flammable light-blocking agents, such as aluminum powder, in liquid oxygen storage containers. 6.5.6 The low-temperature adsorbent placed in the vacuum interlayer should be a molecular sieve (5A, 13X, etc.) or activated carbon with good adsorption performance under low temperature and vacuum conditions. It is prohibited to use activated carbon as a low-temperature adsorbent in liquid oxygen containers. 6.6 Manufacturing requirements
6.6.1 Welding requirements
6.6.1.1 Welding process assessment should be carried out before welding. 6.6.1.2 The quality of the weld of the inner container should comply with the relevant provisions of the "Container Regulations". 6.6.1.3 The leakage rate of the outer shell weld should comply with the technical requirements specified in the drawings. 6.6.1.4 The welding structure should be in accordance with the design drawings. Adsorbent placement and multi-layer insulation winding
The low-temperature adsorbent should be activated before placement, and the placement amount should meet the requirements of the interlayer vacuum degree during use. 6.6.2.1
6. 6. 2. 2
When winding multi-layer insulation, direct contact between radiation protection films should be avoided. The layer density of multi-layer insulation should comply with the requirements of the design drawings, and the insulation layer is not allowed to fall off. Anti-settling measures should be taken before filling the vacuum powder insulation material. 6.6.2.4
6.6.3 Assembly requirements
6.6.3.1 Before assembly, the inner container shall be subjected to pressure test in accordance with the provisions of GB150. Before assembly, the outer surface of the inner container shall be degreased, derusted, degreased, cleaned, dried, etc., and protective measures shall be taken to ensure that there shall be no impurities such as oil, dust, etc. inside the vacuum layer after assembly. 6.6.3.2
GB18442--2001
6.6.3.3 Before assembly, the inner surface of the outer shell shall be degreased, derusted, degreased, cleaned, dried, etc., and protective measures shall be taken to ensure that there shall be no impurities such as oil, dust, etc. inside the vacuum interlayer after assembly. 6.6.4 Vacuum valve or vacuum joint
6.6.4.1 The leakage rate of the vacuum valve or vacuum joint shall meet the specified indicators. 6.6.4.2 The vacuum valve or vacuum joint shall be equipped with a protective device and shall be sealed after factory inspection and acceptance. 6.7 Safety devices and accessories
6.7.1 Interlayer vacuum monitoring device
6.7.1.1 Interlayer vacuum monitoring device should be installed on the evacuation valve or tank body. 6.7.1.2 Vacuum gauges used in flammable low-temperature insulated pressure vessels must not produce open flames and be equipped with protective covers. 6.7.1.3 Vacuum gauges should have a calibration certificate and indicate the measurement and adjustment parameters. 6.7.2 Safety valve
6.7.2.1 The maximum discharge volume and opening pressure of the safety valve used should comply with the relevant provisions of Article B6 in Appendix B of GB150--1998. 6.7.2.2 Safety valves should be installed vertically on the gas discharge pipeline for easy observation and maintenance, and at least two should be installed in parallel. 6.7.2.3 Safety valves should have a product certificate or quality certificate, and can only be installed after calibration and lead sealing. 6.7.3 Bursting disc device (except liquid CO2 container) 6.7.3.1 The bursting disc device of the inner container shall comply with the relevant provisions of Article B7 in Appendix B of GB150--1998, and at least two shall be installed in parallel.
The combination of the bursting disc device and the safety valve shall comply with the relevant provisions of Article B8 in Appendix B of GB1501998. 6.7.3.2
6.7.3.3 The materials used in the bursting disc device of the flammable low-temperature insulated pressure vessel shall not produce sparks and metal fragments when bursting. 6.7.3.4 The bursting disc device shall be equipped with a safety protection cover. 6.7.3.5 The bursting disc used must be a qualified product produced by a qualified manufacturer and have corresponding qualification certification documents. 6.7.4 Vacuum interlayer safety relief device
6.7.4.1 The design pressure of the vacuum interlayer relief device shall be less than 0.1MPa. 6.7.4.2 The vacuum interlayer safety relief device shall be equipped with a safety protection cover. 6.7.5 Evaporative gas discharge device
6.7.5.1 An automatic safety discharge device shall be installed for flammable low-temperature insulated pressure vessels. 6.7.5.2 When the automatic discharge device is activated, it shall be able to ensure that the concentration of the discharged flammable evaporative gas is lower than the lower limit of the volume concentration of the gas explosion.
6.7.5.3 The gas discharge pipe of the liquid hydrogen container shall be located at the top of the container, and the flow rate of the discharged hydrogen gas shall not exceed 16m/s to prevent static electricity explosion. 6.7.6 Liquid level gauge
6.7.6.1 The product shall be equipped with a liquid level gauge with good stability, safety and reliability. 6.7.6.2 The liquid level indication of the liquid level gauge shall be intuitive. When a scale conversion liquid level gauge is used, the filling amount and scale conversion table shall be marked in an obvious position.
6.7.6.3 The installation position of the liquid level gauge shall be convenient for operators to observe and repair. 6.7.7 Pressure gauge
6.7.7.1 A monitoring pressure gauge should be installed on the inner container. 6.7.7.2 The accuracy level of the pressure gauge should not be lower than level 1.5, the range of the pressure gauge should be 1.5~~2.0 times the maximum working pressure of the inner container, and the dial diameter should not be less than 100mm.
6.7.7.3 The pressure gauge should have a product certificate and a calibration date, and can only be installed after being calibrated and sealed. 6.7.7.4 The installation position of the pressure gauge should be convenient for operators to observe and repair. 6.7.8 Cryogenic valve
6.7.8.1 The basic parameters of the cryogenic valve used should match the working temperature, type of cryogenic liquid, working pressure, and pipeline diameter. 692
GB18442--2001
6.7.8.2.1 When the operating temperature is very low (when storing liquid hydrogen or liquid nitrogen), a cryogenic valve with a vacuum insulation structure should be used. 6.7.8.3 The cryogenic valve should have good sealing performance and open flexibly at low temperatures. 6.7.8.4 The cryogenic valve used should have a product certificate and comply with the requirements of the drawings or technical documents. 6.7.9 Filtering device for flammable cryogenic liquids
6.7.9.1 A liquid filter should be installed on the liquid phase pipeline of the flammable cryogenic insulated pressure vessel to prevent solid particles or other solid impurities from entering the interior.
6.7.9.2 The equivalent aperture of the liquid hydrogen filter screen should be less than 40um. 6.7.9.3 The screen of other flammable cryogenic liquid filters should comply with the requirements of the drawings or technical documents. 6.7.10 The grounding resistance of the anti-static grounding device of the flammable low-temperature insulated pressure vessel shall be less than 102. 6.7.11 The circuit system used in the flammable low-temperature insulated pressure vessel shall be designed according to the explosion-proof requirements. 6.8 Appearance quality
6.8.1 The external surface marking shall comply with the requirements of this standard. 6.8.2 The external surface shall be free of bruises, cracks, welding slag, burrs, and unevenness. 6.8.3 Metal parts shall have no obvious corrosion. 7 Test method
7.1 Appearance quality inspection
Appearance quality shall be inspected visually.
7.2 Volume measurement
The measurement of geometric volume, effective volume and interlayer volume shall be in accordance with GB/T18443.1. 7.3 Interlayer vacuum degree measurement
The measurement of sealing vacuum degree, interlayer vacuum degree at room temperature and interlayer vacuum degree at low temperature shall be in accordance with GB/T18443.2. 7.4 Leakage rate measurement
The type test of leakage rate and component leakage rate shall be in accordance with GB/T18443.3. 7.5 Leakage and degassing rate measurement
The measurement of leakage and degassing rate of vacuum interlayer shall be in accordance with GB/T18443.4. 7.6 Static evaporation rate measurement
The measurement of static evaporation rate shall be in accordance with GB/T18443.5.8 Inspection rules
8.1 In addition to the inspection items specified in the "Container Regulations", low-temperature insulated pressure vessels shall also be inspected according to the requirements of this standard. 8.2 Factory inspection
8.2.1 Inspection items and methods
8.2.1.1 Check the integrity of the quality certification documents specified in this standard. 8.2.1.2 The inspection items shall be as specified in Table 6.
8.2.2 Judgment rules
8.2.2.1 Classification of non-conforming items
a) Static evaporation rate, leakage rate, sealing vacuum degree, and leakage and degassing rate are Class A non-conforming items; b) Appearance quality is (Class C non-conforming items.
8.2.2.2 Non-conforming treatment
a) When the product has - Class A non-conforming items, it shall be reworked. b) When there are Class C non-conforming items, the manufacturer shall make repairs. 8.3 Type test
Inspection items
Appearance quality
Sealing vacuum
Leakage rate
Static evaporation rate
2—2001
GB18442
Table 6 Factory inspection items and methods
Technical requirements (according to the items of this standard)
Test methods (according to the items of this standard)
Note: Static evaporation rate factory inspection: For effective volume less than 5m2, one out of every five units shall be tested, and less than five units shall be counted as five units. For more than or equal to 5m2, it shall be carried out according to the contract requirements.
8.3.1 In any of the following cases, a type test must be conducted: a) To obtain product manufacturing qualification;
b) Having obtained product manufacturing qualification, completing new product trial production, and preparing for mass production; c) After formal production, if there are major changes in structure, materials or processes that may affect product performance; d) Production is resumed after more than one year of suspension;
e) New product finalization and appraisal.
8.3.2 Type test is conducted on 1 to 2 products of the same model being manufactured. 8.3.3 Inspection items and methods
8.3.3.1 Check the integrity of the quality certification documents specified in this standard. 8.3.3.2 Inspection items are as specified in Table 7.
8.3.4 Judgment rules
If there are unqualified items in Table 7, they should be repaired within a time limit and re-inspected. If the re-inspection still fails to meet the requirements, it is determined that the type test has not been passed.
Type test inspection items and methods
Quality certificate, mark
Inspection items
Effective volume
Sealing vacuum
Interlayer vacuum at low temperature
Leakage and degassing rate
Static evaporation rate
Technical requirements (according to the items of this standard)
6.4.4 and 6.4.5
Test method (according to the items of this standard)
9.1The quality certification documents for the product leaving the factory shall include the product certificate, quality certificate and product manual. The product shall also have the product completion drawing when leaving the factory. 9.21
9.3In addition to complying with the "Container Regulations", the quality certificate shall at least include the following contents: a) Sealing vacuum;
b) Vacuum interlayer leakage and degassing rate inspection report; c) Static evaporation rate.
9.4 The product manual shall at least include the following contents: a) product model and technical performance indicators specified in the standard; 694
b) product characteristics and instructions for use;
GB 18442—2001
c) product flow chart and necessary structural flow description; d) installation instructions;
e) when using a differential pressure liquid level gauge, there shall be a conversion table for cryogenic liquid filling volume and scale; f) spare parts list.
9.5 Nameplate
9.5.1 The product nameplate shall be firmly fixed in a conspicuous position. 9.5.2 The nameplate shall comply with the provisions of the "Container Regulations".
9.5.3 In order to facilitate operation, a work flow sign shall be provided at the corresponding position. 9.5.4 When using a differential pressure liquid level gauge, there shall be a conversion table for cryogenic liquid filling volume and scale at the corresponding position. 9.6 Safety Signs
9.6.1 The words "No Fireworks" and the name of the medium contained shall be clearly marked on the outside of flammable low-temperature insulated pressure vessels, with the height of the words not less than 200mm.
9.6.2 The words "Toxic Liquid" and the name of the medium contained shall be clearly marked on the outside of toxic low-temperature insulated pressure vessels, with the height of the words not less than 200mm.
9.6.3 The color of the text shall comply with the provisions of Table 8. Table 8 Text Color
Cryogenic Liquid Type
Flammable Type
Toxic Type
Text Color2 The words "toxic liquid" and the name of the medium contained shall be clearly marked on the outside of the toxic low-temperature insulated pressure vessel, with the height of the words not less than 200mm.
9.6.3 The color of the text shall comply with the provisions of Table 8. Table 8 Text Color
Cryogenic Liquid Type
Flammable
Text Color2 The words "toxic liquid" and the name of the medium contained shall be clearly marked on the outside of the toxic low-temperature insulated pressure vessel, with the height of the words not less than 200mm.
9.6.3 The color of the text shall comply with the provisions of Table 8. Table 8 Text Color
Cryogenic Liquid Type
Flammable
Text Color
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