标准编号:	GB/T 18442.6-2019
中文名称:	固定式真空绝热深冷压力容器 第6部分：安全防护
英文名称:	Static vacuum insulated cryogenic pressure vessel—Part 6:Safety device requirements
行业分类:	GB    国家标准
发布机构:	国家市场监督管理总局 国家标准化管理委员会
发布日期:	2019-12-31
实施日期:	2019-12-31
标准状态:	现行
替代旧标准:	GB/T 18442.6-2011 固定式真空绝热深冷压力容器 第6部分:安全防护
翻译语言:	英文
文件格式:	PDF
中文字符数:	17000 字
翻译价格(元):	700.00 元
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 7 parts under the general title of Static vacuum insulated cryogenic pressure vessels:



——Part 1: General requirements;



——Part 2: Material;



——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 6 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 18442.6-2011 Static vacuum insulated cryogenic pressure vessel - Part 6: Safety device requirements. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 18442.6-2011:



—— general requirements are modified to add explosion-proof requirements for electrical control elements and connection requirements for safety valves, instruments, loading and unloading accessories and pipelines;



—— the setting requirements are modified for the overpressure relief device of the inner vessel, and the typical setting schematic diagram of the overpressure relief device is modified;



—— the design requirements are modified for the overpressure relief device;



—— the installation requirements for the overpressure relief device of the inner vessel, the type of explosion-proof device of the outer jacket and the requirements for its installation location are added;



—— the setting requirements of emergency cut-off valve, grounding resistance value of static conductive grounding device, requirements of liquid level measuring device and pressure measuring device, and requirements of loading and unloading accessories are modified.



—— relevant requirements are added for temperature measuring devices, vacuum degree measuring devices and measuring devices with sensors or electrical control elements;



—— the loading and unloading hose and its related requirements are deleted;



—— in Annex A, requirements are added for the calculation methods of safety relief volume of tanks storing non-flammable and non-explosive contents, and Formula (A.5) is modified.



In this part, the calculation of the safety relief volume of the tank and the discharge capacity of the overpressure relief device refers to ISO 21013-3: 2016 Cryogenic vessels - Pressure-relief accessories for cryogenic service - Part 3: Sizing and capacity determination.



This part was proposed by and is under the jurisdiction of the National Technical Committee 262 on Boilers and Pressure Vessels of Standardization Administration of China.



The previous editions replaced by this part are as follows:



—— GB/T 18442.6-2011;



—— GB 18442-2001.





Static vacuum insulated cryogenic pressure vessels - Part 6: Safety protection



1 Scope



This part of GB/T 18442 specifies the selection principles and setting requirements of safety accessories, instruments and loading and unloading accessories used in static vacuum insulated cryogenic pressure vessels (hereinafter referred to as "cryogenic vessels"), as well as the calculation of the safety relief volume of tanks and the discharge capacity of overpressure relief devices.



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 0.1 MPa;



b) cryogenic vessel with the geometric volume not less than 1 m3;



c) cryogenic vessel with the insulation mode of vacuum powder insulation, vacuum composite insulation or high vacuum multilayer insulation;



d) cryogenic vessel with storing refrigerated liquefied gas contents with standard boiling point not lower than -196℃.



This standard is not applicable to cryogenic vessels that meet the following conditions:



a) cryogenic vessel with the inner vessel and the outer jacket made of non-ferrous metals or non-metallic materials;



b) cryogenic vessel with spherical structure;



c) cryogenic vessel with stacked insulation;



d) transportable cryogenic vessel;



d) 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 (all parts) Pressure vessels

GB/T 567.1 Bursting disc safety devices - Part 1: Basic requirement

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

GB/T 567.3 Bursting disc safety devices - Part 3: Classification and mounting dimensions

GB/T 567.4 Bursting disc safety devices - Part 4: Type test

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 18442.5 Static vacuum insulated cryogenic pressure Vessels - Part 5: Inspection and testing

GB/T 24918 Cryogenic emergency shutoff valve

GB/T 29026 Spring loaded safety valve for cryogenic service

JB/T 6804 Shock-resistant pressure gauge

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, GB/T 18442.3, and GB/T 18442.5 apply.



4 Safety accessories, instruments and loading and unloading accessories



4.1 General requirements



4.1.1 The setting of safety accessories, instruments and loading and unloading accessories shall meet the requirements of design documents in addition to TSG 21 and this part.



4.1.2 Safety accessories include overpressure relief device (safety valve, bursting disc device), outer jacket explosion-proof device, emergency cut-off device, static conductive device, etc.



4.1.3 Instruments include pressure measuring device, liquid level measuring device, vacuum degree measuring device, etc.



4.1.4 Loading and unloading accessories include loading and unloading valves, loading and unloading joints, etc.



4.1.5 The selected safety accessories, instruments and loading and unloading accessories shall be suitable for the storage contents.



4.1.6 The manufacturing license and type test of safety accessories and loading and unloading accessories shall meet the requirements of corresponding safety technical specifications.



4.1.7 Safety accessories, instruments and loading and unloading accessories shall meet the requirements of relevant safety technical specifications and product standards, and shall have product quality certificates.



4.1.8 Cryogenic vessels storing flammable and explosive contents shall meet the requirements of relevant standards for explosion-proof design of electrical elements when safety accessories, instruments and loading and unloading accessories with electrical control elements are used.



4.1.9 Before installing, the safety valve and pressure gauge shall be checked and verified, and shall be subjected to lead seal after passing the check and verification.



4.1.10 The connection between safety accessories, instruments and pipelines may be welded, flanged or threaded.



4.1.11 The connection between loading and unloading accessories and pipelines shall be welded or flanged as far as possible.



4.2 Overpressure relief device of inner vessel



4.2.1 Setting requirements for overpressure relief device of inner vessel



4.2.1.1 Inner vessel shall be provided with at least two sets of independent overpressure relief devices. In any case, at least one set of overpressure relief device shall be kept in connection with the inner vessel. In order to meet the requirements of safety relief, each set of overpressure relief device shall be provided with a full lift spring safety valve as the main relief device and a full lift spring safety valve or rupture disk in parallel as the auxiliary relief device. For the inner vessel filled with flammable and explosive contents, safety valve shall be selected as the auxiliary relief device.



4.2.1.2 If the inner vessel is provided with overpressure relief device according to Figure 1 or Figure 2, the following requirements shall be met:



a) the set pressure of the main safety valve shall not be greater than the design pressure of the inner vessel, and the re-seating pressure shall not be less than 0.90 times the set pressure;



b) the operating pressure of the auxiliary relief device shall not be less than the set pressure of the main safety valve and not greater than 1.1 times the design pressure of the inner vessel;



c) the discharge capacity of the main safety valve shall ensure that the pressure of the inner vessel under non-fire conditions does not exceed 1.1 times of its design pressure, and the total discharge capacity of each group of overpressure relief devices shall ensure that the pressure of the inner vessel under fire conditions does not exceed 1.21 times of its design pressure;



d) the discharge capacity of each safety valve or rupture disk device shall meet the safety relief requirements of the inner vessel when considering non-fire conditions, and the discharge capacity of each group of overpressure discharge devices shall meet the safety relief requirements of the inner vessel when considering fire conditions.







Key:



1—— switching valve;

2—— safety valve;

3—— safety valve;



Figure 1 Schematic diagram for combination of safety valves







Key:



1—— switching valve;

2—— safety valve;

3—— bursting disc device;



Figure 2 Schematic diagram for combination of safety valve and bursting disc



4.2.1.3 The design of overpressure relief device of inner vessel shall meet the following requirements:



a) the safety valve shall meet the requirements of GB/T 29026;



b) the bursting disc device shall meet the requirements of GB/T 567.1, GB/T 567.2, GB/T 567.3, and GB/T 567.4;



c) the inlet pipe design of overpressure relief device shall meet the requirements of GB/T 18442.3;



d) when filling with flammable, explosive contents, a relief pipe shall be installed at the outlet of overpressure relief device to discharge the contents to a safe place;



e) the selected bursting disc shall not generate fragments, falling off and sparks during bursting, and reverse arch groove type bursting disc should be adopted;



f) the discharge of gas shall be unblocked, and the gas discharged from pressure relief shall not directly impact the vessel and main stressed structural members;



g) the device can withstand the pressure inside the vessel, possible overpressure and dynamic load including liquid impact force;



h) the outlet shall prevent rainwater and sundries from accumulating and prevent foreign matters from entering;



i) the influence of inlet pressure drop and outlet back pressure of overpressure relief device shall be considered.



4.2.1.4 The installation of overpressure relief device of inner vessel shall meet the following requirements:



a) the safety valve shall be vertically installed;



b) shut-off valve should not be installed between overpressure relief device and tank. In order to facilitate the verification, maintenance and replacement of the overpressure relief device, the shut-off valve may only be installed between the overpressure relief device and the tank after the approval of the person in charge of safety technology of the pressure vessel of the user unit and the adoption of reliable preventive measures. During the normal use and operation of cryogenic vessels, the shut-off valve shall be fully opened (sealed with lead or locked), and its structure and size shall not affect the safe release of overpressure relief device.



4.2.1.5 The overpressure relief device of inner vessel shall be clearly and permanently marked, and the marked content shall at least include:



a) operating pressure of overpressure relief device;



b) rated discharge capacity or minimum relief area;



c) manufacturing license No. and marking;



d) manufacturer name or trademark.



4.2.2 Safety relief volume of inner vessel



4.2.2.1 The discharge capacity of the overpressure relief device of the inner vessel shall not be less than the safety relief volume required by the inner vessel. The calculation method for the safety relief volume required by the inner vessel and the discharge capacity of the overpressure relief device shall be as specified in Annex A.



4.2.2.2 When calculating the safety relief volume required by the inner vessel, at least the following conditions and possible combinations shall be considered:



a) the thermal insulation system is intact and in a normal vacuum state under the ambient temperature, and the temperature of the inner vessel is the saturation temperature of the stored contents under the relief pressure;



b) the insulation system is intact and in a normal vacuum state under the ambient temperature, the temperature of the inner vessel is the saturation temperature of the stored contents under the relief pressure, and the pressurization system is in a fully open working state;



c) the insulation system is intact, with the annular space not in a vacuum state, under the ambient temperature and the temperature of the inner vessel is the saturation temperature of the stored contents under the relief pressure.



d) the thermal insulation system of the cryogenic vessel is intact or partially intact, with the annular space not in a vacuum state, and is exposed to fire or high temperature of 922 K or above;



e) the thermal insulation system structure of the cryogenic vessel is completely damaged, and the jacket is exposed to fire or high temperature of 922 K or above;



f) the flow capacity of other valves in the pipeline connecting the high pressure source and the inner vessel;



g) effect of recycling of possible combinations of pumps;



h) filling the storage tank at the working temperature with flash gas with liquid at the maximum possible flow rate.



4.2.2.3 Design personnel shall identify various possible conditions according to actual conditions, including the conditions listed in items a) to h) of 4.2.2.2 and possible combination conditions.



4.2.2.4 Annex A does not specify the calculation method for conditions of items f), g) and h) in 4.2.2.2. The design personnel shall identify whether these conditions exist according to actual conditions. If these conditions exist, the maximum possible impact of these

conditions shall be fully estimated according to the method of thermodynamic basic theory.



4.2.2.5 The discharge capacity of the overpressure relief device of the inner vessel shall meet the safety relief requirements if several conditions of items a) to d), f), g), and h) in 4.2.2.2 may occur simultaneously, but the possibility of occurrence of extreme conditions of item e) in 4.2.2.2 shall also be fully studied.

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Safety accessories, instruments and loading and unloading accessories
Annex A (Normative) Calculation of safety relief volume of tank and capacity of overpressure relief device
Bibliography

固定式真空绝热深冷压力容器
第6部分：安全防护
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”)使用的安全附件、仪表、装卸附件的选用原则、设置要求以及罐体安全泄放量和超压泄放装置排放能力的计算。
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(所有部分)压力容器
GB/T 567.1 爆破片安全装置 第1部分：基本要求
GB/T 567.2 爆破片安全装置 第2部分：应用、选择与安装
GB/T 567.3 爆破片安全装置 第3部分：分类及安装尺寸
GB/T 567.4爆破片安全装置 第4部分：型式试验
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 18442.5 固定式真空绝热深冷压力容器 第5部分：检验与试验
GB/T 24918 低温介质用紧急切断阀
GB/T 29026低温介质用弹簧直接载荷式安全阀
JB/T 6804抗震压力表
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、GB/T 18442.5界定的术语和定义适用于本文件。
4安全附件、仪表和装卸附件
4.1 一般要求
4.1.1安全附件、仪表和装卸附件的设置，除应符合TSG 21和本部分的规定外，还应满足设计文件的要求。
4.1.2安全附件包括超压泄放装置(安全阀、爆破片装置)、外壳防爆装置、紧急切断装置以及导静电装置等。
4.1.3仪表包括压力测量装置、液位测量装置、真空度测量装置等。
4.1.4装卸附件包括装卸阀门、装卸接头等。
4.1.5选用的安全附件、仪表和装卸附件应与储存介质相适应。
4.1.6安全附件和装卸附件的制造许可和型式试验应符合相应安全技术规范的要求。
4.1.7安全附件、仪表和装卸附件应符合相应安全技术规范和产品标准的规定，且有产品质量证明书或产品质量合格证。
4.1.8储存易燃、易爆介质的深冷容器，采用带电气控制元件的安全附件、仪表和装卸附件时，应符合电气元件防爆设计的相关标准的要求。
4.1.9安全阀、压力表安装前，应进行校验和检定，合格后应重新铅封。
4.1.10安全附件、仪表与管路之间的连接可采用焊接连接、法兰连接或螺纹连接等方式。
4.1.11 装卸附件与管路之间的连接应尽量采用焊接连接或法兰连接。
4.2 内容器超压泄放装置
4.2.1 内容器超压泄放装置的设置要求
4.2.1.1 内容器应至少设置两组相互独立的超压泄放装置，任何情况下应保证至少有一组超压泄放装置与内容器保持连通。为满足安全泄放的要求，每一组超压泄放装置应设置一个全启式弹簧安全阀作为主泄放装置，且并联一个全启式弹簧安全阀或爆破片作为辅助泄放装置。充装易燃、易爆介质的内容器，辅助泄放装置应选用安全阀。
4.2.1.2 内容器按图1或图2设置超压泄放装置时，应满足下列要求：
a)主安全阀的整定压力应不大于内容器设计压力，回座压力应不低于整定压力的0.90倍；
b)辅助泄放装置的动作压力应不小于主安全阀的整定压力，且不大于内容器设计压力的1.1倍；
c)主安全阀的排放能力应保证内容器在非火灾条件下的压力不超过其设计压力的1.1倍，每组超压泄放装置的总排放能力应保证内容器在火灾条件下的压力不超过其设计压力的1.21倍；
d)每一个安全阀或爆破片装置的排放能力均应满足按非火灾条件考虑时内容器的安全泄放要求，每一组超压泄放装置的排放能力均应满足按火灾条件考虑时内容器的安全泄放要求。

说明：
1——切换阀；
2——安全阀；
3——安全阀。
图1 安全阀与安全阀组合设置示意

说明：
1——切换阀；
2——安全阀；
3——爆破片装置。
图2 安全阀与爆破片组合设置示意
4.2.1.3 内容器超压泄放装置的设计应符合下列要求：
a)安全阀应符合GB/T 29026的规定；
b)爆破片装置应符合GB/T 567.1、GB/T 567.2、GB/T 567.3、GB/T 567.4的规定；
c)超压泄放装置的入口管设计应符合GB/T 18442.3的规定；
d)储存易燃、易爆介质时，超压泄放装置的出口应装设泄放管，将排放介质引至安全地点；
e)选用的爆破片在爆破时不应产生碎片、脱落和火花，宜采用反拱刻槽型爆破片；
f)气体的排放应畅通无阻，泄压排出的气体不应直接冲击容器和主要受力结构件；
g)能承受容器内部的压力、可能出现的超压及包括液体冲击力在内的动载荷；
h)出口处应防止雨水和杂物的积聚，并防止任何异物的进入；
i)应考虑超压泄放装置的入口压降和出口背压的影响。
4.2.1.4 内容器超压泄放装置的安装应符合下列要求：
a)安全阀安装时应铅直安装；
b)超压泄放装置与罐体之间不宜安装截止阀门。为便于超压泄放装置的校验、维修与更换，经使用单位主管压力容器安全技术负责人批准，且采取可靠的防范措施，方可在超压泄放装置与罐体之间安装截止阀门。在深冷容器正常使用和运行期间，截止阀门应保证处于全开状态(加铅封或锁定)，且其结构和通径应不影响超压泄放装置的安全泄放。
4.2.1.5 内容器超压泄放装置应有清晰、永久的标记，标记内容应至少包括：
a)超压泄放装置动作压力；
b)额定的排气能力或最小泄放面积；
c)制造许可证编号及标志；
d)制造单位名称或标识商标。
4.2.2 内容器安全泄放量
4.2.2.1 内容器超压泄放装置的排放能力应不小于内容器需要的安全泄放量。内容器需要的安全泄放量及超压泄放装置的排放能力计算方法按附录A的规定。
4.2.2.2进行内容器需要的安全泄放量计算时，至少应考虑到下列工况及可能的组合：
a)绝热系统结构完好且处于正常的真空状态下，外部为环境温度，内容器的温度为泄放压力下所储存介质的饱和温度；
b)绝热系统结构完好且处于正常的真空状态下，外部为环境温度，内容器的温度为泄放压力下所储存介质的饱和温度，且增压系统处于全开工作状态；
c)绝热系统结构完好，但夹层已丧失真空的状态下，外部温度为环境温度，内容器的温度为泄放压力下所储存介质的饱和温度；
d)深冷容器的绝热系统结构完好或部分完好，但夹层真空已丧失，且外部遭遇火灾或遭遇922 K及以上高温；
e)深冷容器的绝热系统结构完全损坏，且夹套外部遭遇火灾或遭遇922 K及以上高温；
f)连接高压源与内容器的管路中的其他阀的流通能力；
g)泵的可能组合的循环使用的影响；
h)以可能的最大流量对工作温度下的储罐加注带液闪蒸气体。
4.2.2.3设计人员应根据实际条件判明可能发生的各种工况，包括4.2.2.2列出的a)～h)的工况及可能的组合工况。
4.2.2.4 附录A未规定针对4.2.2.2中的工况f)、g)和h)的计算方法，设计人员应根据实际条件判明是否存在这些工况。存在这些工况时应按热力学基本理论的方法，充分估计这些工况可能产生的最大影响。
4.2.2.5 内容器超压泄放装置的排放能力应满足4.2.2.2中的a)～d)、f)、g)、h)中可能有几种工况同时发生时的安全泄放要求，但也应充分研究发生4.2.2.2中极端工况e)的可能。
4.3外壳防爆装置
4.3.1 外壳防爆装置的设置要求
4.3.1.1 外壳应设置防爆装置，其泄放压力应不大于0.05 MPa，其排放能力足以使夹层的压力限制在不超过0.1 MPa。
4.3.1.2 防爆装置应能耐大气腐蚀，材料应与环境温度相适应。
4.3.1.3 防爆装置应能防止绝热材料的堵塞。防爆装置应尽可能设置在外壳顶部位置。
4.3.1.4外壳防爆装置可采用自紧式防爆装置或焊接式爆破片装置。自紧式防爆装置的盖板应有相应的保护措施。采用焊接式爆破片装置时，与外壳本体连接也应采用焊接型式，并应有防雨、防尘等保护措施。
4.3.2外壳防爆装置的排放面积
外壳防爆装置的排放面积一般不小于内容器几何容积(m3)与340 mm2/m3的乘积，但不必超过5 000 mm2。
4.4紧急切断装置
4.4.1 紧急切断装置的设置要求
4.4.1.1储存易燃、易爆介质的深冷容器，应按如下要求设置紧急切断装置，但确认在工程系统中已设置紧急切断装置或类似的能防大量泄漏的其他紧急闭止装置时除外：
a)应在液相进出管线上尽量靠近罐体的位置设置紧急切断装置。
b)紧急切断装置一般由紧急切断阀、远程控制系统以及易熔合金塞组成。紧急切断装置应动作灵活、性能可靠、便于检修，且不应兼作他用。
c)紧急切断阀应符合GB/T 24918的规定，且阀体不应采用铸铁或非金属材料制造，紧急切断阀的上阀杆不应安装手轮。
4.4.1.2 在遭遇火灾或充装、排液过程中发生意外泄漏时，紧急切断装置应能自动关闭，且该装置应能进行远程控制。
4.4.1.3当远程控制系统采用气动控制系统时，所用气体宜采用外置式压缩空气源，且满足下列要求：
a)压缩空气应无油且洁净、干燥；
b)压缩空气的压力应与紧急切断阀的操作压力相匹配，且保持稳定；
c)气动控制系统的管路一般采用不锈钢材料。
4.4.1.4设有远程控制接口，便于远程控制系统关闭操作的装置，应设置在工程系统中人员易于到达的位置。
4.4.1.5 紧急切断阀与罐体液相口、气相口、增压器口的连接可以采用法兰或焊接的连接方式。
4.4.2 紧急切断装置的性能要求
4.4.2.1 易熔塞应选用易熔合金材料，并应能在70℃±5℃时熔融。
4.4.2.2 紧急切断装置应经耐压试验和气密性试验检验合格。
4.5导静电接地装置
4.5.1 储存易爆介质的深冷容器，其罐体、管道、阀门和支座等连接处的导电性应良好，并设置可靠的导静电连接端子。
4.5.2罐体金属与接地导线末端之间的电阻值应不大于5 Ω。
4.6液位测量装置
4.6.1 深冷容器应设置一个或多个液位测量装置，如机械指针式液位计(以下简称“液位计”)、数字式液位显示仪器等，用于罐体液位测量和充装量的辅助测量。
4.6.2 液位测量装置的选用和设置应符合以下要求：
a)应根据充装介质、设计压力和设计温度等设计参数正确选用；
b)指示应灵敏准确，安装结构牢固；
c)精度等级不低于2.5级；
d)对易燃、易爆介质，应采用防爆型液位测量装置，且有防止泄漏的保护装置；
e)应设置在便于观察和操作的位置，其允许的最高安全液位应做出明显的标志；
f)液位计应附有罐内介质密度的上限和下限、液位指示刻度与容积的对照表。
4.7压力测量装置
4.7.1 深冷容器应设置一个或多个压力测量装置，如机械指针式压力表(以下简称“压力表”)或数字式压力显示仪器，用以显示罐体内的工作压力。
4.7.2压力测量装置的选用和设置应符合以下要求：
a)应与罐体内的介质相适应，且满足使用工况要求；
b)应符合相应国家标准或行业标准规定的规定；
c)压力表应符合JB/T 6804的规定，且表盘直径不小于100 mm、精度等级不低于1.6级、表盘刻度极限值应为工作压力的1.5倍～3.0倍；
d)安装位置应便于操作人员观察和清洗，且应避免受到辐射热、冻结或震动等不利因素的影响；
e)安装结构应牢固可靠，防止其脱落；
f)压力测量装置与罐体之间应装设针形阀或其他切断阀门。针形阀或切断阀门上应有开启标记和锁紧装置，并且不得连接其他用途的配件或接管。
4.7.3 压力测量装置检定应符合以下要求：
a)压力测量装置应按照国家计量部门的有关规定进行定期检定；
b)压力测量装置安装前应进行检定，检定合格后应加铅封锁定；
c)压力表应在刻度盘上画出指示工作压力的红线，并注明下次检定日期。
4.8温度测量装置
4.8.1 深冷容器应按照设计文件的要求设置温度测量装置，如机械指针式温度计或数字式温度显示仪器等。
4.8.2温度测量装置的测量范围应与充装介质的工作温度相适应。
4.8.3 温度测量装置应按照国家计量部门的有关规定进行定期检定。
4.9真空度测量装置
4.9.1 真空度测量装置一般由真空隔离阀和真空规管组成，并与配套的真空计组合使用。罐体真空夹层应至少设置一套真空度测量装置。
4.9.2 真空度测量装置的选用和设置应满足以下要求：
a)真空度测量装置的整体漏气速率和漏放气速率，应优于真空夹层的漏气速率和漏放气速率；
b)真空规管以及配套的真空计的测量范围应满足产品制造、使用和定期检验的测量要求；
c)用于充装液氧或易燃、易爆介质的深冷容器，真空规管应满足防爆要求；
d)真空度测量装置的安装结构应牢固可靠、便于测量，并且设置安全保护装置。
4.10 带传感器或电气控制元件的测量装置
4.10.1带传感器或电气控制元件的测量装置，是为满足罐体内温度、压力、液位等参数的实时测量，用相应的传感器采集信号并转化为数据显示，必要时能实现远程传输功能的测量装置。
4.10.2测量装置的测量范围以及精度等级应满足设计文件的要求。
4.10.3测量装置的安装结构应牢固、可靠，其连接导线、导管等不应与相邻零部件干涉。
4.10.4选用带有电气控制元件的机械指针或数字式仪表，应选用符合电气元件防护设计标准规定的产品，其中充装易燃、易爆介质的深冷容器，还应选用符合电气元件防爆设计标准规定的产品。
4.11 装卸附件
4.11.1 阀门材料应与介质相容，阀体不得选用铸铁或非金属材料制造。
4.11.2 装卸阀门的公称压力应不低于管路的设计压力，其耐压试验和气密性试验压力应满足以下要求：
a)耐压试验压力为阀门公称压力的1.5倍；
b)气密性试验压力为阀门公称压力，阀门应在全开和全闭工作状态下进行气密性试验合格。
4.11.3 手动阀门应在阀门承受气密性试验压力下能够全开、全闭操作自如，且不应有异常阻力、空转等。
4.11.4 装卸接头应符合下列要求：
a)应符合相应的产品标准或设计图样的规定，且应有产品质量证明文件；
b)表面应无油污、杂物等；
c)应能够防止介质错装；
d)应在产品的明显部位进行标识。