GB/T 5099.3-2017 English PDF (GBT5099.3-2017)

This Part of GB/T 5099 specifies the types and parameters, technical requirements, test methods, inspection rules, marks, coating, packaging, transportation, storage, product qualification certificate, batch inspection quality certificate of seamless steel gas cylinders, after normalizing or post-normalizing tempering treatment (hereinafter referred to as steel cylinder). This Part is applicable to the design and manufacture of refillable steel cylinders, which have a nominal working pressure not greater than 15 MPa, a nominal water volume of 0.5 L ~ 150 L, an ambient temperature of use at -20 ¡ãC ~ 60 ¡ãC, for holding compressed gas or high-pressure liquefied gas. This Part does not apply to vehicle gas cylinders and cylinder-type pressure vessels attached to machinery and equipment. Note: For steel seamless gas cylinders, which have a nominal water volume of less than 0.5 L, it can also be manufactured and inspected with reference to this Part.

GB/T 5099.3-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.020.30
J 74
Replacing GB/T 5099-1994
Seamless steel gas cylinders - Part 3: Normalized cylinders
(ISO 9809-3:2010, Gas cylinders - Refillable seamless steel gas cylinders - Design, construction and testing - Part 3: Normalized steel cylinders, NEQ)
ISSUED ON: DECEMBER 29, 2017
IMPLEMENTED ON: JANUARY 01, 2019
Issued by: General Administration of Quality Supervision, Inspection and Quarantine of PRC.
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions, symbols ... 6
4 Types and parameters ... 8
5 Technical requirements ... 10
6 Test method ... 16
7 Inspection rules ... 23
8 Marking, coating, packaging, transportation, storage ... 30
9 Product certificate and batch inspection quality certificate ... 32
Appendix A (Informative) Cylinder valve assembly torque ... 34
Appendix B (Normative) Ultrasonic testing ... 35
Appendix C (Normative) Magnetic particle testing ... 40
Appendix D (Normative) Flattening test method ... 43
Appendix E (Informative) Description and judgment of internal and external surface defects ... 47
Appendix F (Informative) Quality certificate for batch inspection of steel seamless gas cylinders ... 52
Seamless steel gas cylinders - Part 3: Normalized cylinders
1 Scope
This Part of GB/T 5099 specifies the types and parameters, technical requirements, test methods, inspection rules, marks, coating, packaging, transportation, storage, product qualification certificate, batch inspection quality certificate of seamless steel gas cylinders, after normalizing or post-normalizing tempering treatment (hereinafter referred to as steel cylinder).
This Part is applicable to the design and manufacture of refillable steel cylinders, which have a nominal working pressure not greater than 15 MPa, a nominal water volume of 0.5 L ~ 150 L, an ambient temperature of use at -20 °C ~ 60 °C, for holding compressed gas or high-pressure liquefied gas.
This Part does not apply to vehicle gas cylinders and cylinder-type pressure vessels attached to machinery and equipment.
Note: For steel seamless gas cylinders, which have a nominal water volume of less than 0.5 L, it can also be manufactured and inspected with reference to this Part.
2 Normative references
The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) is applicable to this standard.
GB/T 196 General purpose metric screw threads - Basic dimensions (ISO 724) GB/T 197 General purpose metric screw threads - Tolerances (ISO 965-1)
GB/T 222 Permissible tolerances for chemical composition of steel products GB/T 223 (all parts) Methods for chemical analysis of iron, steel and alloy GB/T 224 Determination of depth of decarburization of steels (ISO 3887) GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature (ISO 6892)
GB/T 229 Metallic materials - Charpy pendulum impact test method (ISO 148-1) When the steel cylinder is designed with a bottom ring structure, it shall be ensured that the bottom ring has sufficient strength, meanwhile the material of the bottom ring shall be compatible with the material of the cylinder body. The shape of the bottom ring shall be cylindrical, which can ensure the stability of the cylinder. The connection between the bottom ring and the cylinder body must not be welded; its structure must not cause water accumulation.
5.2.6 Neck ring design
When the steel cylinder is designed with a neck ring, it shall be ensured that the neck ring has sufficient strength, meanwhile the material of the neck ring shall be compatible with the material of the cylinder body. The connection between the neck ring and the cylinder body must not use welding methods. The axial pull-off force of the neck ring shall not be less than 10 times the weight of the empty cylinder AND not less than 1000 N; the anti-rotation torque shall not be less than 100 N·m.
5.3 Manufacturing
5.3.1 General requirements
5.3.1.1 The manufacture of steel cylinders shall comply with the provisions of this Part, product drawings, relevant technical documents.
5.3.1.2 The cylinder body generally adopts the following manufacturing methods: a) Using steel billet as raw material, it is made by drawing, stretching, sealing, referred to as drawn cylinder;
b) It is made of seamless steel pipes after closing the bottom and mouth, referred to as pipe cylinders.
5.3.1.3 The chemical composition of the steel cylinder shall be analyzed and verified, according to the furnace number of the material, before manufacture. The analysis method shall be carried out, according to GB/T 223 or GB/T 4336; the result shall meet the requirements of 5.1.
5.3.1.4 Steel cylinders are not allowed to be welded. Defects such as cracks, inclusions, lack of fusion on the inner surface of the bottom of the pipe cylinder shall be removed, by mechanical milling or other methods.
5.3.1.5 It is allowed to use special tools for grinding the surface defects of the cylinder body; the grinding slope is not greater than 1:3.
5.3.2 Group batching
Manufacture shall be managed in batches; the quantity of each batch shall not exceed 500 plus the number of cylinders used for destructive tests.
5.3.3 Heat treatment
The body of the steel cylinder shall be heat treated as a whole; the heat treatment shall be carried out, according to the qualified normalizing or post-normalizing tempering. 5.3.4 Non-destructive testing
Non-destructive testing shall be carried out one by one, after the cylinder body is heat treated.
5.3.5 Hydrostatic test
The cylinder body shall be hydrostatically tested one by one; the inner surface shall be dried after the hydrostatic test; there shall be no residual water stains. 5.3.6 Cylinder mouth thread
The profile, size, tolerance of the cylinder mouth thread shall comply with the provisions of GB/T 8335 or relevant standards.
5.3.7 Accessories
5.3.7.1 Select and match the corresponding cylinder valves, according to the nature of the gas to be filled. For the control of assembly torque of tapered screw cylinder valves and common thread cylinder valves, refer to the requirements in Table A.1 and Table A.2 in Appendix A.
5.3.7.2 Steel cylinders shall generally be delivered with caps or shields. The caps or shields can be fixed or detachable. They can be made of metal or resin, which can resist the impact of external forces.
5.3.7.3 For accessories that use threaded connections, the profile, size, tolerance shall comply with the provisions of GB/T 8335 or relevant standards.
6 Test method
6.1 Wall thickness and manufacturing tolerances
6.1.1 The thickness of the cylinder body shall be measured by an ultrasonic thickness gauge.
6.1.2 The manufacturing tolerance of the cylinder is inspected by standard measuring tools or special measuring tools and templates. The inspection items include the average outer diameter, roundness, perpendicularity, straightness of the cylinder. 6.2 Bottom tightness test
Use an appropriate test device, to pressurize the central area of the inner surface of the bottom of the cylinder. The pressurized area shall be at least 1/16 of the bottom area of the cylinder; the diameter of the pressurized area shall be at least 20 mm. The test medium can be clean air or nitrogen. After pressurizing to the tightness test pressure, keep the pressure for at least 1 min. Observe whether there is any leakage, in the central area of the bottom of the cylinder, during the pressure keeping.
6.3 Inner and outer surfaces
For visual inspection, there shall be enough light for inner surface inspection; the inspection can be carried out, with the help of endoscope or appropriate tools. 6.4 Internal thread of cylinder mouth
Check visually and with a gauge. The tapered thread shall be inspected, according to GB/T 8335 and GB/T 8336 or relevant standards; the ordinary thread shall be inspected, according to GB/T 196 and GB/T 197 or relevant standards.
6.5 Non-destructive testing
Non-destructive testing can use online automatic ultrasonic testing or online automatic magnetic particle testing. Ultrasonic testing shall be carried out according to Appendix B; magnetic particle testing shall be carried out according to Appendix C. 6.6 Hydrostatic test
The hydrostatic test adopts the external measurement method for the volume deformation rate test, which is carried out according to GB/T 9251.
6.7 Air tightness test
The air tightness test shall be carried out, according to GB/T 12137.
6.8 Determination of various performance indicators of the cylinder body after heat treatment
6.8.1 Sampling
6.8.1.1 The cutting position of the specimen is as shown in Figure 4, wherein the tensile test specimen shall be cut at a 180° symmetrical position along the cylinder. 6.11.4 The assessment of banding texture and Widmanstatten texture shall be carried out, according to GB/T 13299.
6.12 Fatigue test
6.12.1 The fatigue test shall be carried out according to GB/T 9252.
6.12.2 The upper limit of the cycle pressure shall not be lower than the hydrostatic test pressure ph of the cylinder; the lower limit of the cycle pressure shall not be higher than 2 MPa; the pressure cycle rate shall not exceed 10 times per minute.
6.12.3 For the specimen cylinder used in the fatigue test, it shall select the steel cylinder whose actual bottom thickness is close to the minimum design thickness; the bottom thickness shall not exceed 1.15 times the minimum design bottom thickness. 6.13 Neck ring assembly inspection
6.13.1 Fix the gas cylinder. Carry out an axial pull-off test, on the neck ring using a pulling force 10 times the weight of the empty gas cylinder and not less than 1000 N. 6.13.2 Fix the gas cylinder. Apply a torque of 100 N·m to the neck ring, to carry out the rotation test.
7 Inspection rules
7.1 Judgement basis for test and inspection
7.1.1 Wall thickness and manufacturing tolerances
7.1.1.1 The wall thickness of the cylinder shall not be less than the design wall thickness. 7.1.1.2 The average outer diameter of the cylinder shall not exceed ±1% of the nominal outer diameter D.
7.1.1.3 For the roundness of the cylinder, the difference between the maximum and minimum outer diameter measured on the same section, shall not exceed 2% of the average outer diameter of the section.
7.1.1.4 For vertical steel cylinders, the perpendicularity of the cylinder shall not exceed 1% of the length l of the cylinder (see Figure 9).
7.1.1.5 The straightness of the cylinder shall not exceed 0.3% of the length l of the cylinder (see Figure 9).
can be evaluated, with reference to Appendix E.
7.1.3.2 The transition -- between the end of the steel cylinder and the cylinder body -- shall be smooth; grooves are not allowed on the shoulder.
7.1.4 Cylinder thread
7.1.4.1 The profile, size, tolerance of tapered threads shall comply with the provisions of GB/T 8335 or relevant standards.
7.1.4.2 The axial variation of the taper thread's base surface position shall not exceed +1.5 mm.
7.1.4.3 The dimensions and tolerances of ordinary threads shall meet the requirements of GB/T 196 and GB/T 197 or relevant standards; the number of effective threads shall meet the design requirements.
7.1.5 Non-destructive testing
Ultrasonic testing results shall meet the requirements of Appendix B; magnetic particle testing shall meet the requirements of Appendix C.
7.1.6 Hydrostatic test
7.1.6.1 Under the pressure ph of the hydrostatic test, the pressure holding time shall not be less than 30 s; the pointer of the pressure gauge shall not fall back; the cylinder shall not leak or be obviously deformed. The volume residual deformation rate shall not be greater than 5%.
7.1.6.2 The hydrostatic test report shall include the measured water volume and mass of the cylinder; the water volume and mass shall retain three significant figures and at least one decimal. The rounding principle of water volume and mass is to round off the mantissa of water volume and round up the mantissa of mass.
For example: The measured value of water volume or mass is 40.675; the water volume shall be expressed as 40.6; the mass shall be expressed as 40.7.
7.1.7 Air tightness test
The steel cylinders with cylinder valves and the steel cylinders filled with flammable and toxic media shall be tested for air tightness. The airtightness test pressure shall be the nominal working pressure pw; the pressure shall be held for at least 1 minute. The cylinder body, cylinder valve and the joint of the cylinder body and cylinder valve shall not leak. Leakage caused by assembly is allowed to be retested, after repair. 7.1.8 Determination of various performance indicators of the cylinder body after heat treatment
The neck ring does not fall off during the axial pull-off test; the neck ring does not loosen, when the torque is applied for the rotation test.
7.2 Type test
7.2.1 Each newly designed steel cylinder shall be subject to a type test. If the type test fails, it shall not be put into mass production or put into use. Steel cylinders with one of the following conditions can be identified as newly designed steel cylinders: a) When using different manufacturing methods (see 5.3.1.2);
b) When using different designations of steel to manufacture;
c) When using different heat treatment methods;
d) When different nominal outer diameters are used;
e) When different design wall thicknesses are used;
f) When different bottom structures are used;
g) When the length of the cylinder increases by more than 50%;
h) When using different guaranteed values of tensile strength or yield stress heat treatment.
7.2.2 The manufacturer shall produce at least 50 steel cylinders, that can represent the new design, for type test selection.
7.2.3 The type test items shall be in accordance with the provisions in Table 5. Except for the items inspected one by one, the following quantity of steel cylinders shall be randomly selected for type test:
a) Determination of various performance indicators (including tensile test, impact test, cold bending or flattening test) of the two steel cylinders, after the heat treatment of the cylinder body;
b) Carry out a hydraulic burst test on two steel cylinders;
c) Carry out metallographic inspection on the two steel cylinders (can be carried out on the cylinder body for measuring various performance indicators, after heat treatment);
d) Carry out fatigue test on 3 steel cylinders;
e) For pipe cylinders, take 2 for bottom cutting (it can use the cylinder body after heat treatment to measure various performance indicators).
Appendix B
(Normative)
Ultrasonic testing
B.1 Scope
This Appendix specifies the ultrasonic testing methods for steel cylinders. B.2 General requirements
B.2.1 Ultrasonic testing equipment shall be able to conduct online automatic testing of steel cylinders, at least be able to detect the artificial defects of the comparison sample tube specified in B.4; it shall be able to work normally and ensure its accuracy, according to the process requirements. Ultrasonic testing equipment shall meet the requirements of the evaluation standards; it shall have a quality certificate or a verification certificate.
B.2.2 All personnel engaged in ultrasonic testing shall obtain the qualification for ultrasonic testing of special equipment; the operators of ultrasonic testing equipment shall have at least the qualification certificate for ultrasonic testing of grade I (primary). The personnel who issue the testing report shall at least have the qualification certificate for ultrasonic testing of grade II (medium).
B.2.3 The inner and outer surfaces of the steel cylinders to be tested shall meet the conditions for accurate ultrasonic testing and repeatable testing.
B.2.4 The pulse reflection ultrasonic testing shall be adopted; the coupling method may be the contact method or the immersion method.
B.3 Detection method
B.3.1 Generally, the ultrasonic testing probe shall be used to scan the steel cylinder in a spiral manner. The scanning movement rate of the probe shall be uniform; the variation shall be within ±10%. The helical pitch shall be smaller than the scanning width of the probe (there shall be at least 10% overlap), to ensure 100% detection during the helical scanning process.
B.3.2 Both the longitudinal and transverse defects of the cylinder wall shall be inspected. When detecting longitudinal defects, the sound beam propagates along the circumferential direction in the cylinder wall; when detecting transverse defects, the sound beam propagates along the axial direction in the cylinder wall. The detection in both longitudinal and transverse detections shall be carried out in two directions of the cylinder wall.
Appendix C
(Normative)
Magnetic particle testing
C.1 Scope
This Appendix specifies the magnetic particle testing methods for steel cylinders. C.2 General requirements
C.2.1 Magnetic particle testing equipment shall at least be able to magnetize and demagnetize steel cylinders, in the circumferential direction and longitudinal direction; use continuous method for testing; display magnetic marks in all directions; be able to work normally and ensure its accuracy, according to the process requirements. The equipment shall have a quality certificate or a verification certificate. C.2.2 All personnel engaged in magnetic particle testing shall obtain special equipment's magnetic particle testing qualifications; operators of magnetic particle testing equipment shall have at least grade I (primary) magnetic particle testing qualifications; personnel who issue test reports shall have at least grade II (medium) magnetic particle testing qualifications.
C.2.3 Continuous method shall be used for magnetic particle testing. When using fluorescent magnetic particle testing, the black light irradiance of the black light, which is used on the cylinder surface, shall be greater than or equal to 1000 μW/cm2; the wavelength of the black light shall be 320 mm ~ 400 mm.
C.2.4 Magnetic particle testing can use oil-based magnetic suspension or water-based magnetic suspension. The concentration of the magnetic suspension shall be determined according to the type of magnetic powder, particle size, application method, time. Generally, the concentration of non-fluorescent magnetic powder is 10 g/L ~ 25 g/L; the concentration of fluorescent magnetic powder is 0.5 g/L ~ 3 g/L.
C.2.5 Before the magnetic particle testing, the surface of the inspected cylinder shall be thoroughly cleaned; there shall be no oil stain, burrs, loose scale, etc. on the surface of the cylinder.
C.2.6 Before the cylinder body is electro-magnetized, any non-conductive substances, in the contact area of the cylinder body with the electrodes, shall be removed. C.3 Testing method
C.3.1 The magnetic particle testing of steel seamless gas cylinders shall be carried out by wet method. The magnetic suspension liquid shall be applied at the same time as the electricity is applied. The duration of each power-on, in the magnetization process, is 1.5 s ~ 3 s. Magnetization ca...