This Part is the Part 8 of "Nondestructive Testing of Pressure Equipment" (NB/T 47013): Leak Testing
This Part is formulated according to the relevant requirements of Chapter 10, Volume V, "Boiler and Pressure Vessel Specifications" (ASME:2001) as well as the actual domestic conditions, thereof, Appendix G "Ammonia Leak Testing Technology" is formulated by reference to ASTM E1066.95R06 while Appendix H "Pipeline Acoustic Leak Testing Technology" is formulated by reference to the research achievements of "Research on the Leakage Point Location and Detection of Embedded Gas Piping and Relevant Equipment Development" of 11th Five-Year Plan undertaken by China Special Equipment Inspection and Research Institute.
Appendixes A~F of this Part is normative.
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).
Drafting organizations of this Part: China Special Equipment Inspection and Research Institute., Nanjing boiler and pressure vessel inspection institute, Hefei General Machinery Research Institute, Shanghai Research Institute of Materials Sinopec Engineering Incorporation, Aerosun Corporation, Sinopec Nanjing Chemical Industrial Co., Ltd. Chemical Machinery Works, Nanjing Baose Co., Ltd, Hebei Supervision and Inspection Institute of Boiler and Pressure Vessel and Pressure Vessel Inspection and Research Institute of Boiler and Pressure Vessel of Jiangxi Province.
Cheif drafting staff of this Part: Shen Gongtian, Jing Weike, Lin Shuqing, Ye Cheng, Tao Yuankong, Jin Yufei, Xu Feng, Wang Xiaomei, Chen Guozhu, Liu Hongyan, Zhou Qinming, Liu Canrong, Ma Jianyu, Xiao Zhongqun, Hu Bin, Qin Xianyong and Cui Qiang.
National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC:/TC 262) in charge of the explanation of this Part.
Nondestructive Testing of Pressure Equipment
Part 8: Leak Testing
規(guī)范承壓設(shè)備無(wú)損檢測(cè)
第8部分:泄漏檢測(cè)
1 Scope
This Part of NB/T 47013 specifies the leak testing method of pressure equipment.
This Part is applicable to the leak testing of pressure equipment in manufacturing and use to determine the leaking position and measure the leakage rate.
The testing methods and technical requirements specified in this Part are detailed in Appendixes.
2 Normative References
The following 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 11533 Standard Logarithmic Visual Acuity Charts
GB/T 12604.7 Terminology for Non-destructive Testing - Leak Testing
JB/T4730.1 Nondestructive Testing of Pressure Equipment - Part 1: General Requirements
NB/T 47013.7 Nondestructive Test of Pressure Equipment - Part 7: Visual Examination
3 Terms and Definitions
For the purposes of this standard, the terms and definitions given in GB/T 12604.7 apply.
4 General Requirements
4.1 General
The general requirements of leak testing shall not only in accordance with the relevant requirements of JB/T 4730.1, but also meet the requirements of Sections 4.2~4.4.
4.2 Testing personnel
The uncorrected or corrected near vision and distance vision of leak testing personnel shall not be less than 5.0 (the decimal record value is 1.0) and the testing method shall meet the requirements of GB 11533. The testing personnel shall receive vision inspection every 12 months to guarantee a normal or correct visual resolution in short distance.
4.3 Process specification
4.3.1 The process specification of leak testing shall be formulated in accordance with the requirements of JB/T 4730.1, and shall include the following contents at least:
a) application scope;
b) normative regulations and standards;
c) testing personnel qualification;
d) testing equipment and apparatus;
e) testing conditions (temperature, gas or concentration)
f) test pressure and pressure holding time;
g) tested surface preparation;
h) testing time;
i) testing process and technology;
j) evaluation of testing results;
k) testing record forms and their preservation;
l) formats and requirements of testing report;
m) developer, reviewer, and approver;
n) development date.
4.3.2 The process specification shall be verified; where the important factors specified in the Appendixes or that have a strong impact on the testing sensitivity are changed, the process specification shall be verified again.
4.4 Equipment and apparatus
4.4.1 Pressure gauge/vacuum gauge
4.4.1.1 Measuring range
Where the scale indication and record pressure gauge is adopted for leak testing, its measuring range shall be around 2 times as the maximum expected testing pressure with the testing pressure as 1.5~4 times the testing pressure. Such measuring range requirements are not applicable to the vacuum gauge, and other pressure gauges listed in the Appendixes of this Part shall meet the requirements of the corresponding Appendix.
4.4.1.2 Accuracy
Unless otherwise specified, the accuracy of pressure gauge used for leak testing shall not be less than Grade 1.6.
4.4.1.3 Location
Where the pressure or vacuum leak testing is carried out on the tested piece, the scale indication pressure gauge shall be connected to the tested piece directly or from a remote position so that the testing personnel can observe the pressure gauge/vacuum gauge during the whole process. As for large container or tested system which requires one or more pressure gauge(s)/vacuum gauge(s), a record pressure gauge/vacuum gauge is recommended to replace one of the two or more indication pressure gauges/vacuum gauges.
4.4.1.4 Application
Where other pressure gauges/vacuum gauges are required by the normative appendixes, they may replace the scale indication or record pressure gauge/vacuum gauge or be used in combination with the latter.
4.4.1.5 Calibration
The calibration interval of the adopted indication and record pressure gauge/vacuum gauge shall not be greater than 12 months.
The accuracy of the results measured by the adopted pressure gauge/vacuum gauge shall meet relevant requirements; where there is any doubt, the pressure gauge shall be recalibrated.
Where any pressure gauge/vacuum gauge other than the scale indication or record pressure gauge/vacuum gauge is adopted according to the relevant requirements of this Part or normative Appendixes, such pressure gauge/vacuum gauge shall be calibrated according to relevant requirements.
4.4.2 Temperature measuring device
Where the temperature measurement is carried out according to the relevant requirements of this Part or normative Appendixes, the measuring device shall be calibrated according to relevant requirements.
4.4.3 Standard leak hole
a) Penetration standard leak hole: the penetration leak hole made of melt and calibrated glass or quartz and provided with helium leakage rate as 1×10-7(Pa·m3)/s~1×10-11(Pa·m3)/s.
b) Capillary standard leak hole: the calibrated capillary leak hole running through the pipe with the required leak rate equals to or smaller than the product of the required testing sensitivity and the actual tracer gas percentage concentration.
5 Testing
5.1 Testing equipment
5.1.1 Surface preparation
The surface of the tested piece shall be free from oil liquid, grease, paint and other potential contaminants which may impede the testing. If liquid is adopted to clean the workpiece or carry out pressure test before leak testing, the tested piece shall be fully dried before testing.
5.1.2 Sealing
Plug, cover plate, sealing wax, adhesive or other suitable materials easy to be fully removed shall be used to seal all holes; the sealing materials shall not affect the tracer gas concentration during the testing.
5.1.3 Testing temperature
The minimum temperature of the tested piece during testing shall meet the requirements of Appendixes and relevant test (like the pressure test) of the tested piece. During the testing, the maximum temperature shall not be greater than the permissible temperature determined by the adopted leak testing method or technical requirements.
5.1.4 Pressure/vacuum (pressure limit)
Unless otherwise specified in the Appendixes or relevant requirements of this Part, the pressure leak testing shall be carried out for workpiece, and the testing pressure shall not be greater than 1.15 times of the design pressure.
5.2 Pre-leak testing
Pre-leak testing may be carried out before adopting the highly sensitive testing method to detect and eliminate larger leak, and the potential leak on the tested piece shall not be blocked or covered.
5.3 Testing time
Unless otherwise specified, the leak testing shall be carried out before pressure test. The leak testing may be carried out again after pressure test as long as the acceptance party thinks it is necessary. Vacuum pumping shall not be carried out before the design calculation confirmation.
5.4 Testing
See corresponding Appendix of this Part for specific requirements.
6 Result Evaluation
Unless otherwise specified, the acceptance standard specified in each testing method or technology shall be adopted.
7 Records and Reports
7.1 Records
The testing data or information shall be recorded according to the requirements of testing process specification, and all records shall be preserved according to the requirement of relevant laws, regulations, standards and (or) contracts.
7.2 Reports
The testing report shall include the following contents at least:
a) entrusting organization;
b) testing date;
c) No. and edition of the process specification;
d) name, No., specification and material of the tested piece;
e) adopted method or technology;
f) schematic diagram for the testing method or technical scheme (if necessary);
g) testing instrument, standard leak hole and material identification number;
h) model, measuring range, accuracy and number of pressure gauge/vacuum gauge;
i) temperature measuring equipment and its number;
j) the working condition of testing, tracer gas and gas concentration;
k) testing pressure and pressure holding time;
1) testing data;
m) testing results;
n) signature and qualification certificate number of the testing personnel, report developer and reviewer;
o) testing date.
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 General Requirements
5 Testing
6 Result Evaluation
7 Records and Reports
Appendix A (Normative) Bubble Leak Testing - Direct Pressurization Technology
Appendix B (Normative) Bubble Leak Testing - Vacuum Cover Technology
Appendix C (Normative) Halogen Diode Leak Testing Technology
Appendix D (Normative) Helium Mass Spectrometer Leak Testing – Suction Gun Technology
Appendix E (Normative) Helium Mass Spectrometer Leak Testing - Tracer Probe Technology
