标准编号:	GB/T 18442.4-2019
中文名称:	固定式真空绝热深冷压力容器　第4部分：制造
英文名称:	Static vacuum insulated cryogenic pressure vessels—Part 4:Fabrication
行业分类:	GB    国家标准
ICS分类:	23.020.40 23.020.40    低温容器 23.020.40
发布机构:	中华人民共和国国家市场监督管理总局 中国国家标准化管理委员会
发布日期:	2019-12-10
实施日期:	2019-12-10
标准状态:	valid
替代旧标准:	GB/T 18442.4-2011 固定式真空绝热深冷压力容器 第4部分:制造
翻译语言:	英文
文件格式:	PDF
中文字符数:	15000 字
翻译价格(元):	520.0
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. GB/T 18442 consists of the following seven parts under the general title Static vacuum insulated cryogenic pressure vessels: ——Part 1: General requirements; ——Part 2: Materials; ——Part 3: Design; ——Part 4: Fabrication; ——Part 5: Inspection and testing; ——Part 6: Safety protection; ——Part 7: Rules of pressure strengthening for inner vessels. This is Part 4 of GB/T 18442. This part is developed in accordance with the rules given in GB/T 1.1-2009. This part replaces GB/T 18442.4-2011 Static vacuum insulated cryogenic pressure vessel - Part 4: Fabrication. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 18442.4-2011: ——the general requirements are modified; ——the classification of welded joints is deleted and included in Part 1 of GB/T 18442. ——the material re-inspection is added; ——the calculation equation for the processing deformation rate of cold-formed steel plates is deleted and replaced by direct reference to GB/T 150.4; ——the measured ferrite content index of cold-formed austenitic stainless steel pipe is added; ——the technical requirements for fabrication, such as defect grinding, repair welding and seal head, are modified; ——the requirements for measured ferrite content in formed austenitic stainless steel seal head of inner vessel are added; ——the requirements for misalignment, corner angle and roundness of the jacket of Classes A and B welded joints are simplified, and replaced by direct reference to GB/T 150.4; ——the assembly requirements for tanks and supports are added; ——the fabrication requirements for welded joints between cylinder and tank are modified; ——the welding requirements are modified, and the requirements for weld reinforcement of Classes A and B welded joints are specified as directly referred from GB/T 150.4; ——the preparation requirements for welded test pieces of products are modified; ——the selection of non-destructive testing methods and testing methods such as CR, DR and TOFD are added; the technical requirements for non-destructive testing of inner vessel and outer jacket are improved, and the requirements for non-destructive testing record, data and report are added; ——the heat treatment requirements are added; ——the cleaning requirements and assembly requirements are detailed; ——the installation requirements for adsorbents are added; ——the design requirements such as welding structure of pipelines in pipeline fabrication are deleted and included in Part 3 of GB/T 18442; ——the requirements for non-destructive testing and pressure test for external pipelines are added; ——the installation requirements for safety accessories are deleted and included in Part 6 of GB/T 18442; ——the requirements for marking and identification, ex-factory documents, sealed storage and shipment are modified. This part was proposed by and is under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262). The previous editions of this part are as follows: ——GB/T 18442.4-2011; ——GB 18442-2001. 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, processing and forming, welding, non-destructive testing, cleaning, assembly, marking and identification and ex-factory documents in the fabrication of static vacuum insulated cryogenic pressure vessels (hereinafter referred to as “cryogenic vessels”). This part is applicable to cryogenic vessels that simultaneously meet the following conditions: a) cryogenic vessel with the working pressure of inner vessel not less than 0.1MPa; b) cryogenic vessel with the geometric volume not less than 1m3; c) cryogenic vessel with the insulation mode of vacuum powder insulation, vacuum composite insulation or high vacuum multilayer insulation; d) cryogenic vessel storing refrigerated liquefied gas contents with standard boiling point not lower than -196℃. This part is not applicable to cryogenic vessels that meet the following conditions: a) cryogenic vessel with the inner vessel and outer jacket made of non-ferrous metal or non-metallic materials; b) cryogenic vessel with spherical structure; c) cryogenic vessel with stacked insulation; d) transportable cryogenic vessel; e) cryogenic vessel storing refrigerated liquefied gas contents with standard boiling point lower than -196℃; f) cryogenic vessel storing toxic gas as specified in GB 12268; g) cryogenic vessel with special requirements such as national defense military equipment. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 150-2011 (All parts) Pressure vessels GB/T 1804-2000 General tolerances－Tolerances for linear and angular dimensions without individual tolerance indications GB/T 9969 General principles for preparation of instructions for use of industrial products GB/T 18442.1 Static vacuum insulated cryogenic pressure vessels - Part 1: General requirements GB/T 18442.3 Static vacuum insulated cryogenic pressure vessels - Part 3: Design GB/T 25198 Heads for pressure vessels JB/T 4711 Coating and packing for pressure vessels transport JB/T 6896 Surface cleanliness of air separation plants NB/T 47013.1 Nondestructive testing of pressure equipment - Part 1: General requirements NB/T 47013.2 Nondestructive testing of pressure equipment - Part 2: Radiographic testing NB/T 47013.3 Nondestructive testing of pressure equipment - Part 3: Ultrasonic testing NB/T 47013.4 Nondestructive testing of pressure equipment - Part 4: Magnetic particle testing NB/T 47013.5 Nondestructive testing of pressure equipment - Part 5: Penetrant testing NB/T 47013.10 Nondestructive testing of pressure equipment - Part 10: Ultrasonic time of flight diffraction technique NB/T 47013.11 Nondestructive testing of pressure equipment - Part 11: Standard practice for X-ray digital radiography NB/T 47013.14 Nondestructive testing of pressure equipment - 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 equipment NB/T 47041 Vertical vessels supported by skirt NB/T 47065.1 Vessel supports - Part 1: Saddle support NB/T 47065.2 Vessel supports - Part 2: Leg support NB/T 47065.4 Vessel supports - Part 4: Bracket support TSG 21 Supervision regulation on safety technology for stationary pressure vessel 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 150, GB/T 18442.1 and GB/T 18442.3 apply. 4 General requirements 4.1 Cryogenic vessels shall be fabricated in accordance with TSG 21, GB/T 150.4, this part and the design documents approved by the established procedures. 4.2 Where pressure elements (seal heads, forgings, etc.) and safety accessories, instruments, handling accessories, etc. are purchased or outsourced, the cryogenic vessel fabrication unit shall ensure that the quality of these elements meets the requirements of the design documents and this part, and may not be used before passing the inspection. 4.3 The limit deviation of linear dimension for machined and non-machined surfaces shall respectively meet the requirements of Grade m and Grade c in GB/T 1804-2000. 4.4 The installation of all connecting pipelines, parts, components and accessories on cryogenic vessels shall be firm and reliable, and the outer surfaces thereof shall be smooth and beautiful, free from defects such as crushing, cracking, welding slag or paint layer peeling off. Valves and instruments shall be installed at positions convenient for operation or observation. 5 Material re-inspection, cutting and mark transplantation 5.1 The material re-inspection shall meet the requirements of TSG 21, GB/T 150.4 and design documents. 5.2 Materials for fabricating pressure elements shall be provided with traceable marks. In the fabrication process, if the original mark is cut off or the material is cut, the fabrication unit shall transplant the logo before material cutting. 5.3 Cold cutting, thermal cutting or other appropriate method may be adopted for material cutting. Where thermal cutting is adopted, the surface slag and surface layer affecting the fabrication quality shall be removed. 5.4 The hard printing shall not be used for transplanted marks, welder marks and other marks for pressure elements of inner vessels. 6 Cold/thermal forming and assembly 6.1 Forming 6.1.1 The cylinder and seal head may be processed into required shapes by cold/thermal forming. 6.1.2 Where the deformation rate of cold formed austenitic stainless steel cylinder and seal head exceeds the control index specified in GB/T 150.4, solution treatment shall be carried out according to the corresponding material standards. 6.1.3 For cold-formed austenitic stainless steel pipes exposed to cryogenic contents, the measured ferrite content after forming shall not be greater than 15%. 6.1.4 The fabrication unit shall determine the machining allowance according to the fabrication process, and the thickness of formed pressure elements shall not be less than the minimum forming thickness indicated in design drawings. 6.2 Surface grinding Mechanical damage on the steel plate surface shall be avoided during fabrication. Defects such as sharp scars as well as local scars and notches on the stainless steel surface shall be ground with the maximum inclination of 1:3. The grinding depth shall not be greater than 5% the thickness of steel at this position, and not be greater than 2mm, otherwise repair welding shall be carried out. 6.3 Groove The groove surface quality shall meet the requirements of GB/T 150.4. 6.4 Seal head 6.4.1 The seal head shall meet the requirements of GB/T 25198 and the design drawings. 6.4.2 The seal head should be integrally formed and meet the following requirements: a) for the seal head which is formed after plate splicing, the number of splicing welds is generally not greater than three, and the width of the splicing plate shall not be less than 300mm. The internal surface of splicing weld and the external surface of splicing weld that affects the forming quality shall be polished until they are flush with the base metal before forming. b) when checking the shape deviation of the internal surface of the seal head with a full-size internal template with clearance (see Figure 1), the indent dimension is 3％Di~5％Di, the maximum shape deviation for convex shall not be greater than 1.25%Di, and that for concave shall not be greater than 0.625%Di. During the check, the template shall be perpendicular to the surface to be tested. c) proper forming process shall be adopted for the seal head of inner vessel to avoid cracks in the transition section and straight section of the seal head. Where warm forming process is adopted, the sensitive temperature zone of austenitic stainless steel shall be bypassed. d) for the formed austenitic stainless steel seal heads of inner vessels, the measured ferrite content of transition section and straight section shall not be greater than 15%.

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 General requirements 5 Material re-inspection, cutting and mark transplantation 6 Cold/thermal forming and assembly 7 Welding 8 Non-destructive testing 9 Heat treatment 10 Cleaning requirements 11 Assembling requirements 12 Adsorbent installation 13 Pipeline fabrication 14 Helium mass spectrometer leak detection 15 Tank coating 16 Marking and identification 17 Ex-factory documents 18 Sealed storage and shipment

固定式真空绝热深冷压力容器 第4部分：制造 1 范围 GB/T 18442的本部分规定了固定式真空绝热深冷压力容器(以下简称深冷容器)制造中的材料复验、加工成型、焊接、无损检测、清洁、组装、标志标识、出厂资料等基本要求。 本部分适用于同时满足以下条件的深冷容器： a)内容器工作压力不小于0.1 MPa； b)几何容积不小于1 m3； c)绝热方式为真空粉末绝热、真空复合绝热或高真空多层绝热； d)储存介质为标准沸点不低于-196℃的冷冻液化气体。 本部分不适用于下列范围的深冷容器： a)内容器和外壳材料为有色金属或非金属的； b)球形结构的； c)堆积绝热方式的； d)移动式的； e)储存标准沸点低于-196℃冷冻液化气体介质的； f)储存介质按GB 12268规定为毒性气体的； g)国防军事装备等有特殊要求的。 2规范性引用文件 下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。 GB/T 150—2011(所有部分)压力容器 GB/T 1804—2000一般公差 未注公差的线性和角度尺寸的公差 GB/T 9969 工业产品使用说明书 总则 GB/T 18442.1 固定式真空绝热深冷压力容器 第1部分：总则 GB/T 18442.3 固定式真空绝热深冷压力容器 第3部分：设计 GB/T 25198 压力容器封头 JB/T 4711压力容器涂敷与运输包装 JB/T 6896 空气分离设备表面清洁度 NB/T 47013.1 承压设备无损检测 第1部分：通用要求 NB/T 47013.2 承压设备无损检测 第2部分：射线检测 NB/T 47013.3 承压设备无损检测 第3部分：超声检测 NB/T 47013.4 承压设备无损检测 第4部分：磁粉检测 NB/T 47013.5 承压设备无损检测 第5部分：渗透检测 NB/T 47013.10 承压设备无损检测 第10部分：衍射时差法超声检测 NB/T 47013.11 承压设备无损检测 第11部分：X射线数字成像检测 NB/T 47013.14承压设备无损检测 第14部分：X射线计算机辅助成像检测 NB/T 47014 承压设备焊接工艺评定 NB/T 47016 承压设备产品焊接试件的力学性能检验 NB/T 47041 塔式容器 NB/T 47065.1容器支座 第1部分：鞍式支座 NB/T 47065.2容器支座 第2部分：腿式支座 NB/T 47065.4容器支座 第4部分：支承式支座 TSG 21 固定式压力容器安全技术监察规程 3术语和定义 GB/T 150、GB/T 18442.1、GB/T 18442.3界定的术语和定义适用于本文件。 4 一般要求 4.1 深冷容器的制造应符合TSG 21、GB/T 150.4、本部分以及经规定程序批准的设计文件的要求。 4.2受压元件(封头、锻件等)以及安全附件、仪表、装卸附件等为外购、外协件时，深冷容器制造单位应保证外购、外协件的质量满足设计文件及本部分的要求，且经检验合格后方可使用。 4.3机械加工表面和非机械加工表面的线性尺寸的极限偏差，分别按GB/T 1804—2000中的m级和c级的要求。 4.4深冷容器上的各连接管路、零部件和附件安装应牢固可靠，外表面应平整美观，无压伤、裂纹、焊渣或漆层脱落等缺陷。阀门和仪表等应安装在便于操作或观察的位置。 5材料复验、分割与标志移植 5.1材料的复验应符合TSG 21、GB/T 150.4和设计文件的规定。 5.2制造受压元件的材料应有可追溯的标志。在制造过程中，如原有标志被裁掉或材料分割时，制造单位应在材料分割前完成标志移植。 5.3材料分割可采用冷切割、热切割或其他适当的方法。当采用热切割方法分割材料时，应清除表面熔渣和影响制造质量的表面层。 5.4 内容器受压元件不应采用硬印作为材料移植标记、焊工标记及其他标记。 6冷、热加工成型与组装 6.1 成型 6.1.1 筒体和封头可采用冷、热成型方法加工成所需形状。 6.1.2奥氏体不锈钢筒体和封头，采用冷加工成型后变形率超过GB/T 150.4规定的控制指标时，应按照相应的材料标准进行固溶处理。 6.1.3与深冷介质接触的冷弯成型的奥氏体不锈钢管子，其成型后的铁素体测量值应不大于15％。 6.1.4制造单位应根据制造工艺确定加工余量，受压元件成型后的厚度应不小于设计图样标注的最小成型厚度。 6.2 表面修磨 制造过程中应避免钢板表面的机械损伤。对于尖锐伤痕以及不锈钢表面的局部伤痕、刻槽等缺陷应予以修磨，修磨的斜度最大为1：3。修磨的深度应不大于该部位钢材厚度的5％，且不大于2 mm，否则应予补焊。 6.3 坡口 坡口表面质量应符合GB/T 150.4的规定。 6.4 封头 6.4.1 封头应符合GB/T 25198和设计图样的规定。 6.4.2 封头成型宜采用整体成型，并符合下列规定： a)先拼板后成型封头的拼接焊缝一般不超过3条，拼板的宽度应不小于300 mm。拼接焊缝的内表面以及影响成型质量的拼接焊缝的外表面，应在成型前打磨至与母材齐平。 b)用带间隙的全尺寸的内样板检查封头内表面的形状偏差时(见图1)，缩进尺寸为3％Di～5％Di，其最大形状偏差外凸应不大于1.25％Di，内凹应不大于0.625％Di。检查时应使样板垂直于待测表面。 c)内容器封头应采用适当的成型工艺，避免封头过渡段和直边段出现裂纹。当采用温成型工艺时，应避开奥氏体型不锈钢的敏化温度区。 d)内容器奥氏体不锈钢封头成型后其过渡段和直边段的铁素体测量值应不大于15％。 e)封头直边部分应不存在纵向皱折。 间隙样板 缩进尺寸(视封头大小而定) 间隙样板轮廓测量基准线 封头 图1 凸形封头的形状偏差检查 6.5圆筒与罐体 6.5.1 A、B类焊接接头对口错边量以及在焊接接头环向、轴向形成的棱角应符合GB/T 150.4的规定。 6.5.2不等厚钢材的B类焊接接头以及圆筒与球形封头相连的A类焊接接头的对接要求应符合GB/T 150.4的规定。 6.5.3 圆筒直线度允差应符合GB/T 150.4的规定。 6.5.4组装时，罐体上焊接接头的布置应满足下列要求： a)组装圆筒中，任何单个筒节的长度应不小于300 mm，环向拼板长度应不小于500 mm； b)相邻筒节A类接头间外圆弧长应大于钢材厚度的3倍，且不小于200 mm； c)封头A类拼接接头、与封头相邻筒节的A类接头相互间的外圆弧长均应大于钢材厚度的3倍，且不小于200 mm； d)不应采用十字焊缝，焊接接头宜避开开孔位置； e)罐体上凡被补强圈、垫板等覆盖的焊缝，均应在覆盖前打磨至与母材齐平； f)内容器附件和内容器间的焊接应尽量避开内容器上的A、B类焊接接头，且距离环焊缝边缘不小于100 mm；当与纵焊缝交叉时，应开槽避让。 6.5.5 内容器、外壳组焊完成后，应分别按GB/T 150.4—2011中6.5.10和6.5.11的要求检查壳体的直径和圆度。 6.6其他组装要求 6.6.1 罐体的主要几何尺寸、管口方位应符合设计图样的要求。 6.6.2 腿式支座的制造和装配要求按照NB/T 47065.2的规定。 6.6.3 支承式支座的制造和装配要求按照NB/T 47065.4的规定。 6.6.4 鞍式支座的制造和装配要求按照NB/T 47065.1的规定。 6.6.5裙座的制造和装配要求按照NB/T 47041的规定。 7 焊接 7.1 焊前准备和施焊环境 焊前准备和施焊环境应符合GB/T 150.4—2011中7.1的规定。 7.2 焊接工艺 7.2.1 深冷容器应按NB/T 47014进行焊接工艺评定，且符合TSG 21和GB/T 150.4的规定。 7.2.2 当焊接结构受压元件用境外牌号材料(含填充材料)时，制造单位在首次使用前应按NB/T 47014进行焊接工艺评定。 7.2.3焊接工艺评定应包括焊缝和热影响区的低温夏比(V形缺口)冲击试验。冲击试验的取样方法，按NB/T 47014的要求确定。冲击试验温度应不高于设计图样要求的试验温度。当焊缝两侧母材具有不同冲击试验要求时，低温冲击吸收能量按两侧母材抗拉强度的较低者符合GB/T 150.2或设计图样的要求。接头的拉伸和弯曲性能按两侧母材中要求的较低者。 7.2.4受压元件之间或受压元件与非受压元件组装时的定位焊，若保留成焊缝金属的一部分，应按受压元件的焊缝要求施焊。 7.2.5罐体的焊接应严格控制线能量。在焊接工艺评定所确认的范围内，宜选用较小的焊接线能量，以多道施焊为宜。 7.2.6 内容器主要受压元件焊缝应在含焊缝布置图的焊接记录中记录焊工代号。 7.2.7焊接工艺评定技术档案应保存至该工艺评定失效为止，焊接工艺评定试样保存期不少于5年。 7.3 罐体焊缝表面的形状尺寸及外观要求 7.3.1 焊缝表面的形状尺寸应符合下列规定： a)A、B类焊接接头的焊缝余高应符合GB/T 150.4的规定。 b)C、D、E类接头的焊脚尺寸，在图样无规定时，取焊件中较薄者的厚度。当补强圈的厚度不小于8 mm时，其焊脚尺寸等于补强圈厚度的70％，且不小于8 mm。 7.3.2焊接接头表面质量应符合下列规定： a)不应有表面裂纹、未焊透、未熔合、咬边、表面气孔、弧坑、未填满、夹渣和飞溅物等缺陷； b)焊缝与母材应圆滑过渡，角焊缝的外形应凹形圆滑过渡； c)按照疲劳分析设计的罐体，应去除A、B类焊缝的余高，使焊缝表面与母材表面平齐； d)其他表面质量应符合设计图样的规定。 7.3.3 临时附件的焊接应符合下列规定： a)罐体上焊接的临时吊耳和拉筋的垫板等，应采用力学性能和焊接性能与罐体相同或相近的材料，并用相适应的焊材及焊接工艺进行焊接。 b)临时吊耳和拉筋的垫板割除后，留下的焊疤应打磨光滑，并按图样规定进行渗透检测或磁粉检测，表面应无裂纹等缺陷。打磨后的厚度应不小于该部位的设计厚度或图样规定的最小成型厚度。 7.4 焊接接头返修及母材缺陷补焊 7.4.1 应分析缺陷产生的原因，提出相应的返修或补焊方案。 7.4.2焊接接头的返修和补焊都应进行焊接工艺评定或具有经评定合格的焊接工艺支持，施焊时应有详尽的返修或补焊记录。 7.4.3焊缝同一部位的返修次数不宜超过2次。如超过2次，返修前应经制造单位技术负责人批准，且应将返修的次数、部位和返修情况记入产品质量证明文件。 7.4.4返修部位应按原要求经检测合格。 7.4.5耐压试验后进行的返修，如返修深度大于1/2壁厚，应重新进行耐压试验。 7.4.6氦质谱检漏后需返修的，返修部位应采用合适的检验方法检测合格，且重新进行氦质谱检漏。 7.5产品焊接试件与试样 7.5.1 凡符合以下条件之一的、有A类纵向焊接接头的内容器，应逐台制备产品焊接试件： a)需经过热处理改善或恢复材料力学性能的内容器； b)设计图样要求制备产品焊接试件的内容器。 7.5.2 制备产品焊接试件与试样应符合下列规定： a)产品焊接试件应在内容器筒节A类纵向焊缝的延长部位与筒节同时施焊。 b)试件应取合格的原材料，且与内容器用材料具有相同标准、相同牌号、相同厚度和相同热处理状态。 c)试件应由施焊内容器的焊工，采用与施焊内容器相同的条件、过程与焊接工艺施焊。有热处理要求的内容器或部件，试件一般应随内容器或部件一起热处理。 d)试件的尺寸和试样的截取应符合NB/T 47016的规定。 7.5.3试样的力学性能检验与评定应符合下列规定： a)力学性能检验的试验方法、合格指标及复验要求，应符合NB/T 47016的规定； b)夏比(V形缺口)冲击试验应包括焊缝金属和热影响区，试验温度为受压元件的设计温度或设计图样规定的温度； c)当产品焊接试样评定结果被判为不合格时，应分析原因，采取相应措施，允许按NB/T 47016的要求重新取样进行复验。当复验结果仍达不到要求时，则该试件所代表的产品应判为不合格。 8 无损检测 8.1无损检测方法 8.1.1 无损检测方法包括射线检测、超声检测、磁粉检测和渗透检测。射线检测应符合NB/T 47013.2、NB/T 47013.11或NB/T 47013.14的规定；超声检测应符合NB/T 47013.3或NB/T 47013.10的规定；磁粉检测应符合NB/T 47013.4的规定；渗透检测应按NB/T 47013.5的规定。 8.1.2 制造单位或无损检测机构应按设计图样要求和NB/T 47013.1的规定制定无损检测工艺。 8.1.3无损检测方法的选择应满足相应的无损检测标准的规定。 8.2无损检测方法的选择 8.2.1 内容器及外壳的A、B类焊接接头(内容器工艺人孔筒体与凸面受压的工艺人孔封头的合拢B类焊接接头和外壳的合拢B类焊接接头除外)、管路对接接头，应进行射线检测或超声检测。超声检测包括衍射时差法超声检测(TOFD)、可记录的脉冲反射法超声检测和不可记录的脉冲反射法超声检测。 8.2.2 当采用不可记录的脉冲反射法超声检测时，应采用射线检测或衍射时差法超声检测作为附加局部检测。 8.2.3罐体的不锈钢焊接接头表面无损检测应采用渗透检测，碳钢或低合金钢焊接接头的表面无损检测应采用磁粉检测或渗透检测。 8.2.4 铁磁性材料制罐体焊接接头的表面无损检测应优先采用磁粉检测。 8.3 内容器无损检测比例及技术要求 8.3.1 A、B类焊接接头应进行100％射线检测或超声检测。 8.3.2工艺人孔筒体与凸面受压的工艺人孔封头的合拢B类焊接接头无损检测的检测方法和要求应符合设计图样的规定。 8.3.3 先拼板后成型的凸形封头上所有拼接接头还应进行100％表面检测。 8.3.4 内容器上D、E类焊接接头应进行100％表面检测。 8.3.5 内容器上临时吊耳和拉筋垫板割除并修磨后留下的焊疤，应进行表面检测。 8.3.6 内容器无损检测的技术要求应符合下列规定： a)射线检测技术等级应不低于相应检测方法的AB级，其合格级别应不低于Ⅱ级； b)脉冲反射法超声检测技术等级应不低于B级，合格级别应不低于工级； c)渗透检测合格级别应不低于I级。 8.4 外壳无损检测比例及技术要求 8.4.1 A、B类焊接接头(外壳的合拢B类焊接接头除外)应进行局部射线检测，检测长度不小于各条焊接接头长度的20％，且均不得小于250 mm，其射线检测技术等级应不低于相应检测方法的AB级，合格级别不低于Ⅲ级。 8.4.2外壳的合拢B类焊接接头以及下列项目的焊缝应经无损检测，检测方法和要求应符合设计图样的规定，其检测长度可计入外壳的局部检测长度： a)先拼板后成型凸形封头上的所有拼接接头； b)凡被补强圈、垫板、支座、内件等覆盖的焊接接头； c)对于满足GB/T 150.3—2011中6.1.3不另行补强的管座，自开孔中心、沿外壳表面的长度等于1.5倍开孔直径的范围内的焊接接头。 8.4.3 先拼板后成型的凸形封头上所有拼接接头应进行100％射线检测及100％表面检测，其射线检测技术等级应不低于AB级，合格级别应不低于Ⅲ级，表面检测的合格级别应不低于I级。 8.4.4外壳上临时吊耳和拉筋垫板割除并修磨后留下的焊疤，应进行表面检测，表面检测的合格级别应不低于I级。 8.5 管路无损检测比例及技术要求 8.5.1 真空夹层内及外部的管路，其B类焊接接头应按NB/T 47013.2进行100％射线检测，射线检测技术等级应不低于AB级，其合格级别应不低于Ⅱ级。 8.5.2真空夹层内及外部的管路，其C、D类焊接接头应按NB/T 47013.5进行100％渗透检测，合格级别应为I级。 8.6 重复检测 8.6.1 经无损检测的焊接接头，发现不准许的缺陷时，应在缺陷清除干净后进行补焊，并对该部位采用原无损检测方法和合格级别进行重新检测和评定。 8.6.2进行局部无损检测的焊接接头，发现不准许的缺陷时，应在该缺陷两端的延伸部位增加检测长度，增加的长度为该焊接接头长度的10％，且两侧均不小于250 mm。若仍有不准许的缺陷，则对该条焊接接头进行100％无损检测。 8.6.3渗透与磁粉检测发现不准许的缺陷时，应进行修磨及必要的补焊，并对该部位采用原无损检测方法重新检测。 8.7无损检测的实施时机 8.7.1 焊接接头的无损检测，应在形状尺寸和外观质量检查合格后进行。 8.7.2拼接封头应在成型后进行无损检测。若成型前已进行无损检测，则成型后还应对圆弧过渡区至直边段进行无损检测。 8.8 无损检测记录、资料和报告 制造单位应如实填写无损检测记录，正确签发无损检测报告，妥善保管射线底片和超声检测数据等检测资料(含缺陷返修前记录)，并建立无损检测档案，其保存期限应不少于深冷容器的设计使用年限。