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GB/T 5099.3-2017 English PDF (GB/T5099.3-2017)
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GB/T 5099.3-2017: Seamless steel gas cylinders -- Part 3: Normalized cylinders
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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 ...
Delivery: 9 seconds. Download (& Email) true-PDF + Invoice.
Get Quotation: Click GB/T 5099.3-2017 (Self-service in 1-minute)
Historical versions (Master-website): GB/T 5099.3-2017
Preview True-PDF (Reload/Scroll-down if blank)
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 ...
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