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 designati...