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GB/T 18442.4-2019 English PDF (GBT18442.4-2019)

GB/T 18442.4-2019 English PDF (GBT18442.4-2019)

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GB/T 18442.4-2019: Static vacuum insulated cryogenic pressure vessels -- Part 4: Fabrication

GB/T 18442.4-2019
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.020.40
J 76
Replacing GB/T 18442.4-2011
Static vacuum insulated cryogenic pressure vessels -
Part 4: Fabrication
ISSUED ON: DECEMBER 10, 2019
IMPLEMENTED ON: DECEMBER 10, 2019
Issued by: State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 3
1 Scope ... 6
2 Normative references ... 7
3 Terms and definitions ... 8
4 General requirements ... 8
5 Material re-inspection, division and mark transplantation ... 9
6 Cold and hot forming and assembly ... 9
7 Welding ... 12
8 Nondestructive testing ... 16
9 Heat treatment ... 19
10 Cleaning requirements ... 19
11 Assembly requirements ... 20
12 Installation of adsorbent ... 21
13 Pipeline fabrication ... 21
14 Helium mass spectrometer leak detection ... 22
15 Tank coating ... 22
16 Mark and identification ... 23
17 Exit-factory data ... 23
18 Sealing and shipping ... 25
Static vacuum insulated cryogenic pressure vessels -
Part 4: Fabrication
1 Scope
This Part of GB/T 18442 specifies the basic requirements, such as material re- inspection, machining and forming, welding, nondestructive testing, cleaning, assembly, mark and identification, and exit-factory data, in the fabrication of static vacuum insulated cryogenic pressure vessels (hereinafter referred to as cryogenic vessels).
This Part applies to cryogenic vessels, which simultaneously meet the following conditions:
a) The working pressure of the inner vessel is not less than 0.1 MPa;
b) The geometric volume is not less than 1 m3;
c) The insulation method is vacuum powder insulation, vacuum composite
insulation, or high vacuum multilayer insulation;
d) The storage medium is a refrigerated liquefied gas with a standard boiling point of not lower than -196 °C.
This Part does not apply to cryogenic vessels in the following scope:
a) The material of inner vessel and outer jacket is non-ferrous metal or non- metal;
b) HAVE a spherical structure;
c) Stacked insulation;
d) Mobile;
e) STORE refrigerated liquefied gas medium with standard boiling point
below -196 °C;
f) The storage medium is toxic gas according to GB 12268;
g) Those with special requirements such as national defense and military equipment.
NB/T 47013.14 Nondestructive testing of pressure equipments - Part 14: X- ray Computed radiographic testing
NB/T 47014 Welding procedure qualification for pressure equipment
NB/T 47016 Mechanical property tests of product welded test coupons for pressure equipments
NB/T 47041 Vertical vessels supported by skirt
NB/T 47065.1 Vessel support - Part 1: Saddle support
NB/T 47065.2 Vessel support - Part 2: Leg Support
NB/T 47065.4 Vessel support - Part 4: Bracket support
TSG 21 Supervision Regulation on Safety Technology for Stationary
Pressure Vessel
3 Terms and definitions
The terms and definitions defined in GB/T 150, GB/T 18442.1, GB/T 18442.3 apply to this document.
4 General requirements
4.1 The fabrication of cryogenic vessels shall comply with the requirements of TSG 21, GB/T 150.4, this Part, and the design documents approved by the prescribed procedures.
4.2 When the pressure components (heads, forgings, etc.) and safety
accessories, instruments, handling accessories, etc. are purchased and
outsourced parts, the fabrication organization of the cryogenic vessel shall ensure that, the quality of the purchased and outsourced parts meets the requirements of the design documents and this Part, and can be used only after passing the inspection.
4.3 The limit deviation of the linear dimension of the machined surface and non- machined surface is in accordance with the requirements of grade m and grade c in GB/T 1804-2000, respectively.
4.4 The connecting pipelines, parts, and accessories on the cryogenic vessel shall be firmly and reliably installed. The outer surface shall be flat and beautiful, without defects such as pressure injuries, cracks, welding slag, or paint peeling. Valves and instruments, etc. shall be installed in a position convenient for operation or observation.
polishing is 1 : 3. The depth of the polishing shall be no more than 5% of the thickness of the steel at that location, and no more than 2 mm; otherwise repair- welding shall be performed.
6.3 Groove
The surface quality of the groove shall comply with the provisions of GB/T 150.4. 6.4 Head
6.4.1 The head shall meet the requirements of GB/T 25198 and design
drawings.
6.4.2 The head forming should adopt integral forming and meet the following requirements:
a) The splicing welds of the first-spliced then-formed head are generally not more than 3. The width of the spliced plate shall not be less than 300 mm. The inner surface of the splicing weld, as well as the outer surface of the splicing weld that affects the forming quality, before forming, shall be polished to be flush with the base metal.
b) When using a full-size inner sample plate with gaps to check the shape deviation of the inner surface of the head (see Figure 1), the indent size is 3%Di~5%Di. The maximum shape deviation shall be no more than
1.25%Di for convexity and 0.625%Di for concavity. When checking, the
sample plate shall be perpendicular to the surface to be tested.
c) For the head of the inner vessel, it shall adopt proper forming process, to avoid cracks in the transition section and straight side section of the head. When using the warm forming process, it shall avoid the sensitization
temperature zone of austenitic stainless steel.
d) After the austenitic stainless steel head of inner vessel is formed, the measured ferrite value of its transition section and straight side section shall not be greater than 15%.
e) There shall be no longitudinal wrinkles on the straight side of the head. f) The welding between the inner vessel accessories and the inner vessel shall avoid type A and B welded joints on the inner vessel as far as
possible. The distance from the edge of the circumferential weld is not less than 100 mm. When crossing the longitudinal weld, slot shall be made to avoid.
6.5.5 After assembly welding of inner vessel and outer jacket is completed, according to the requirements of 6.5.10 and 6.5.11 in GB/T 150.4-2011,
respectively, the diameter and roundness of the shell shall be checked. 6.6 Other assembly requirements
6.6.1 The main geometric dimensions and nozzle orientation of the tank shall meet the requirements of the design drawings.
6.6.2 The fabrication and assembly requirements of leg supports are in
accordance with NB/T 47065.2.
6.6.3 The fabrication and assembly requirements of bracket supports are in accordance with NB/T 47065.4.
6.6.4 The fabrication and assembly requirements of saddle supports are in accordance with NB/T 47065.1.
6.6.5 The fabrication and assembly requirements of the skirt are in accordance with NB/T 47041.
7 Welding
7.1 Preparation before welding and welding environment
The preparation before welding and welding environment shall comply with the provisions in 7.1 of GB/T 150.4-2011.
7.2 Welding procedure
7.2.1 Cryogenic vessels shall, in accordance with NB/T 47014, be subjected to welding procedure qualification; and, meet the requirements of TSG 21 and GB/T 150.4.
7.2.2 When using materials of foreign designations (including filling materials) for the pressure components of the welded structure, before the first use, the fabrication organization shall conduct the welding procedure qualification according to NB/T 47014.
7.2.3 The welding procedure qualification shall include the low-temperature Charpy (V-notch) impact test of the weld and heat-affected zone. The sampling c) For tanks designed according to fatigue analysis, the surplus height of type A and B welds shall be removed, to make the weld surface flush with the base metal surface;
d) Other surface quality shall meet the requirements of the design drawing. 7.3.3 The welding of temporary accessories shall meet the following
requirements:
a) For temporary lifting lugs and tie bar base plates welded on the tank, it shall use materials with the same or similar mechanical properties and
welding performance as the tank; use the appropriate welding
consumables and welding procedure for welding.
b) After the temporary lifting lugs and tie bar base plates are cut off, the welding scars left shall be polished and smooth. According to the
provisions of the drawing, it shall conduct penetrant testing or magnetic particle testing. The surface shall be free of defects such as cracks. The thickness after grinding shall not be less than the design thickness of the location or the minimum forming thickness specified in the drawing.
7.4 Repair of welded joints and repair-welding of base metal defects
7.4.1 It shall analyze the causes of defects; propose the corresponding repair or repair-welding plan.
7.4.2 Repair and repair-welding of welded joints shall be subjected to welding procedure qualification or be supported by the welding procedure which passes the qualification. When welding, there shall be detailed records of repair or repair-welding.
7.4.3 The repair number of the same location of the weld should not exceed 2 times. If more than 2 times, before being repaired, it shall be approved by the technical director of the fabrication organization. The number, location, and status of the repair shall be recorded in the product quality certification document.
7.4.4 The repaired locations shall, according to the previous requirements, pass the testing.
7.4.5 For the repairs carried out after the pressure-tight test, if the repair depth is greater than 1/2 wall thickness, the pressure-tight test shall be repeated. 7.4.6 If it is necessary to repair after helium mass spectrometer leak detection, the repaired locations shall be tested as qualified by appropriate inspection methods; the helium mass spectrometer leak detection shall be carried out again.
requirements, the product represented by the test coupon shall be judged as unqualified.
8 Nondestructive testing
8.1 Nondestructive testing methods
8.1.1 Nondestructive testing methods include radiographic testing, ultrasonic testing, magnetic particle testing, and penetrant testing. Radiographic testing shall meet the requirements of NB/T 47013.2, NB/T 47013.11, or NB/T
47013.14. Ultrasonic testing shall meet the requirements of NB/T 47013.3 or NB/T 47013.10. Magnetic particle testing shall meet the requirements of NB/T 47013.4. Penetrant testing shall be in accordance with NB/T 47013.5.
8.1.2 The fabrication organization or nondestructive testing organization shall, in accordance with the requirements of the design drawings and the provisions of NB/T 47013.1, formulate the nondestructive testing process.
8.1.3 The selection of nondestructive testing methods shall meet the provisions of the corresponding nondestructive testing standards.
8.2 Selection of nondestructive testing methods
8.2.1 Type A and B welded joints of inner vessel and outer jacket (except for closed type B welded joints of craft manhole cylinder of inner vessel and of craft manhole head with the convex surface compressed, closed type B welded
joints of outer jacket), pipeline butt joints shall be subjected to radiographic testing or ultrasonic testing. Ultrasonic testing includes time-of-flight diffraction ultrasonic testing (TOFD), recordable pulse reflection ultrasonic testing, and non-recordable pulse reflection ultrasonic testing.
8.2.2 When the non-recordable pulse reflection ultrasonic testing is used, the radiographic testing or the time-of-flight diffraction ultrasonic testing shall be used as additional local testing.
8.2.3 For the nondestructive testing of the surface of the stainless steel welded joint of the tank, it shall adopt penetrant testing. For the nondestructive testing of the surface of carbon steel or low-alloy steel welded joints, it shall adopt magnetic particle testing or penetrant testing.
8.2.4 For the nondestructive testing of the surface of welded joints of the tank made of ferromagnetic materials, magnetic particle testing shall be used preferably.
8.3 Nondestructive testing ratio and technical requirements of inner
vessel
b) All welded joints covered by reinforcing rings, pads, supports, internals, etc.;
c) For the tube socket that meets 6.1.3 in GB/T 150.3-2011 without additional reinforcement, welded joints in the range with a length along the surface of the outer jacket from the center of the opening equal to 1.5 times the diameter of the opening.
8.4.3 All the spliced joints on the convex heads, which are first spliced and then formed, shall be subjected to 100% radiographic testing and 100% surface testing. The technical grade of radiographic testing shall not be lower than grade AB. The conformity level shall not be lower than level III. The conformity level of surface testing shall not be lower than level I.
8.4.4 Welding scars left after cutting and grinding the temporary lifting lugs and tie bar base plates on the outer jacket shall be surface-tested. The conformity level of surface testing shall not be lower than level I.
8.5 Nondestructive testing ratio and technical requirements of pipeline 8.5.1 For the pipelines inside and outside the vacuum annular space, according to NB/T 47013.2, the type B welded joints shall be 100% radiographically tested. The technical grade of radiographic testing shall not be lower than grade AB. The conformity level shall not be lower than level II.
8.5.2 For the pipelines inside and outside the vacuum annular space, in accordance with NB/T 47013.5, the type C and D welded joints shall be
subjected to 100% penetrant testing. The conformity level shall be level I. 8.6 Duplicate testing
8.6.1 If an unacceptable defect is found in a welded joint that has undergone nondestructive testing, after the defect is removed, repair-welding shall be carried out. The previous nondestructive testing method and conformity level shall be used for re-testing and assessment of the location.
8.6.2 For welded joints subjected to local nondestructive testing, when unacceptable defects are found, the testing length shall be increased at the extensions of the two ends of the defect. The increased length is 10% of the length of the welded joint; both sides are not less than 250 mm. If there are still unacceptable defects, 100% nondestructive testing is performed on the welded joint.
8.6.3 When the unacceptable defects are found by penetrant and magnetic particle testing, polishing and necessary repair-welding shall be carried out. Moreover, the previous nondestructive testing method shall be used to re-test this location.
11 Assembly requirements
11.1 After passing the pressure-tight test, the inner vessel can be assembled with the outer jacket and shall meet the following requirements:
a) After the insulation material is wrapped, the inner vessel of high vacuum multilayer insulation shall be set with the outer jacket as soon as possible, to prevent the insulation material from moisture and pollution;
b) When fitting, the annular space shall be clean. It shall prevent damage to the outer surface of the multilayer insulation material, annular space
pipeline, and inner vessel;
c) When fitting, the coaxiality deviation between the inner vessel and the outer jacket shall be reduced as much as possible.
11.2 Before the inner vessel and outer jacket are assembled, the high vacuum multilayer insulation layer shall be installed and shall meet the following requirements:
a) Multilayer insulation material shall be dried;
b) The number of layers and layer density shall meet the requirements of the design drawings;
c) The reflective screen and the spacer material shall be closed to each other; d) Try to avoid the phenomenon of direct contact (short-circuit) between the reflective screens and local absence of reflective screens;
e) The outermost layer shall have corresponding measures to prevent the insulation layer from loosening and falling off.
11.3 After the assembly of the inner vessel and the outer jacket is completed, the filling of vacuum powder insulation material shall be carried out and shall meet the following requirements:
a) Powder insulation material shall be dried;
b) When filling, it shall control the filling density of powder insulation material; c) Take measures as far as possible, to prevent the settlement of powder insulation material;
d) When filling powder insulation material under pressure, there shall be corresponding measures preventing the inner vessel from destabilizing;
13.5 When the pipeline assembly is intermittently constructed, the open nozzle shall be closed in time.
13.6 For the valve, the installation direction shall be determined according to the design flow chart. The screw-type globe valve shall be closed when turning clockwise.
13.7 On the pipeline, it shall clearly mark the purpose of each interface and accessory. The pipeline valve shall be indicated with the flow direction of the medium. The globe valve shall be indicated with the opening and closing directions.
13.8 Safety valves and pressure gauges can only be installed and used after they pass the verification.
13.9 The pipeline should be fixed with pipe clamps. The fixation of pipe clamps shall not limit the thermal expansion and cold contraction of the pipeline. 13.10 For the equipment with static conductive grounding requirements, the sections of pipes shall be electrically conductive. When the resistance value between each pair of flanges or threaded joints exceeds 0.03 Ω, wire jumpers shall be provided.
13.11 The external pipeline shall be subjected to pressure-tight test and airtightness test.
14 Helium mass spectrometer leak detection
14.1 After the inner vessel and the outer jacket are assembled, the vacuum annular space shall be subjected to helium mass spectrometer leak detection. The leak rate index shall comply with the provisions of GB/T 18442.3 and the design drawings.
14.2 Leakage location shall be repaired according to the welding repair process. After it is tested as qualified according to the previous nondestructive testing requirements, the helium mass spectrometer leak detection shall be repeated. 15 Tank coating
The coating of the tank shall meet the requirements of JB/T 4711 and design documents.
c) Special equipment manufacturing supervision and inspection certificate; d) Risk assessment report;
e) Strength calculation sheets;
f) Stress analysis report (when required);
g) Calculation sheets of safety discharge quantity of tank, flow capacity of safety valve, discharge area of bursting disc, and discharge area of the explosion-proof device of outer jacket;
h) Installation, use and maintenance instructions;
i) List of spare parts and accessories and corresponding quality qualification certificates;
j) Electrical and instrument explosion-proof certificates (when required). 17.2 The product quality certification document shall have at least the following contents:
a) Bill of materials;
b) Material quality certificate of main pressure components;
c) Quality plan;
d) Product quality certification documents when pressure components
(heads, forgings, etc.) are p...

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