ISO 10460:2005

INTERNATIONAL ISO
STANDARD 10460
Second edition
2005-02-15


Gas cylinders — Welded carbon-steel gas
cylinders — Periodic inspection and
testing
Bouteilles à gaz — Bouteilles à gaz soudées en acier au carbone —
Contrôles et essais périodiques




Reference number
ISO 10460:2005(E)
©
ISO 2005

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ISO 10460:2005(E)
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ISO 10460:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Intervals between periodic inspections and tests. 1
4 List of procedures for periodic inspections and tests. 2
5 Identification of cylinder and preparation for inspections and tests . 2
6 Depressurization and de-valving procedures. 3
7 External visual inspection. 3
8 Internal visual inspection. 4
9 Supplementary tests. 4
10 Inspection of cylinder neck. 4
11 Pressure test . 5
12 Repair of cylinders. 6
13 Inspection of valve and other accessories. 6
14 Final operations . 6
15 Rejection and rendering cylinders unserviceable. 9
Annex A (informative) Intervals between periodic inspections and tests . 10
Annex B (informative) List of gases corrosive to cylinder material. 11
Annex C (normative) Description and evaluation of defects and conditions for rejection of welded
carbon-steel gas cylinders at time of visual inspection . 12
Annex D (normative) Procedure to be adopted when de-valving and/or when it is suspected that a
cylinder valve is obstructed. 16
Annex E (informative) Inspection and maintenance of valves and their junctions: recommended
procedures. 19
Annex F (informative) Test date rings for gas cylinders . 20
Bibliography . 21

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ISO 10460:2005(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 10460 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 4,
Operational requirements for gas cylinders.
This second edition cancels and replaces the first edition (ISO 10460:1993), which has been technically
revised.
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ISO 10460:2005(E)
Introduction
The principal aim of a periodic inspection and testing procedure is to be satisfied that at the completion of the
test the cylinders can be re-introduced into service for a further period of time.
The inspection and test are to be carried out only by persons who are authorized under the relevant
regulations and competent in the subject to assure all concerned that the cylinders are fit for continued safe
use.
Experience of inspection and testing of cylinders that are specified in this International Standard is an
important factor when determining whether a cylinder should be returned into service.

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INTERNATIONAL STANDARD ISO 10460:2005(E)

Gas cylinders — Welded carbon-steel gas cylinders — Periodic
inspection and testing
1 Scope
This International Standard deals with welded, carbon-steel, transportable gas cylinders intended for
compressed and liquefied gases under pressure, of water capacity from 0,5 l to 150 l; it also applies, as far as
practical, to cylinders of less than 0,5 l water capacity and greater than 150 l up to 450 l.
This International Standard specifies the requirements for periodic inspection and testing to verify the integrity
of such gas cylinders for further service.
This International Standard does not apply to the periodic inspection and testing of acetylene cylinders or
composite (fully wrapped or hoop-wrapped) cylinders.
This International Standard is primarily for industrial gases other than liquefied petroleum gas (LPG), but may
also be applied for LPG. For specific LPG applications, see ISO 10464.
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.
ISO 11621, Gas cylinders — Procedures for change of gas service
ISO 11114-2, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas
contents — Part 2: Non-metallic materials
ISO 13341, Transportable gas cylinders — Fitting of valves to gas cylinders
3 Intervals between periodic inspections and tests
A cylinder shall be due for a periodic inspection and test on its first receipt by a filler after the expiry of the
interval in accordance with the requirements of the United Nations Recommendations on the Transport of
Dangerous Goods, Model Regulations or as specified by national or international authorities (see examples in
Annex A).
Provided the cylinder has been subjected to normal conditions of use and has not been subjected to abusive
and abnormal conditions rendering the cylinder unsafe, there is no general requirement for the user to return a
gas cylinder before the contents have been used even though the periodic inspection and test interval may
have lapsed.
It is the responsibility of the owner or user to submit the cylinder for a periodic inspection and test within the
interval specified by national or international authorities, or as specified in the relevant cylinder design
standard if this is shorter.
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ISO 10460:2005(E)
4 List of procedures for periodic inspections and tests
Each cylinder shall be submitted to periodic inspections and tests. The following procedures, where applicable,
form the requirements for such inspections and tests and are explained more fully in later clauses:
a) identification of cylinder and preparation for inspections and tests (Clause 5);
b) depressurization and de-valving procedures (Clause 6);
c) external visual inspection (Clause 7);
d) internal visual inspection (Clause 8);
e) supplementary tests (Clause 9);
f) inspection of cylinder neck (Clause 10);
g) pressure test (Clause 11);
h) repair of cylinders (Clause 12);
i) inspection of valve and other accessories (Clause 13);
j) final operations (Clause 14);
k) rejection and rendering cylinders unserviceable (Clause 15).
It is recommended that the previously listed tests be performed in the suggested sequence. In particular the
internal visual inspection (Clause 8) should be carried out before the pressure test (Clause 11).
Cylinders that fail an inspection or tests shall be rejected (see Clause 15). Where a cylinder passes the above
procedures, but when the condition of the cylinder remains in doubt, additional tests shall be performed to
confirm its suitability for continued service or the cylinder shall be rendered unserviceable.
Depending on the reason for the rejection, some cylinders may be recovered (see Clause 8, 10.3 and
Annex C).
The inspections and tests shall be carried out only by persons who are competent in the subject and
authorized under relevant regulations.
Mechanical properties of steel cylinders can be affected by heat. Therefore, the maximum temperature for any
operation shall be limited according to the manufacturer's recommendations.
5 Identification of cylinder and preparation for inspections and tests
Before any work is carried out, the relevant cylinder data (e.g. see ISO 13769) and its contents and ownership
shall be identified. Cylinders with incorrect or illegible markings, unknown gas contents or those that cannot be
safely emptied of gas shall be set aside for special handling.
If contents are identified as hydrogen or other embrittling gases, only those cylinders manufactured or
qualified as hydrogen cylinders shall be used for that service. It shall be checked that the cylinder is
compatible for hydrogen service, i.e. with respect to the maximum tensile strength and internal surface
condition. For example, cylinders according to ISO 13769 are stamped “H”. All other cylinders shall be
withdrawn from hydrogen service and their suitability checked for their new intended service.
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ISO 10460:2005(E)
6 Depressurization and de-valving procedures
The cylinders shall be depressurized and emptied in a safe, controlled manner before proceeding. Particular
attention shall be given to cylinders containing flammable, oxidizing or toxic gases to eliminate risks at the
internal inspection stage.
Before removing any pressure-retaining accessory (valve, flange, etc.), a positive check shall be performed to
ensure that the cylinder does not contain any gas under pressure. This can be performed as described in
Annex D using a device such as shown in Figure D.1.
Cylinders with inoperative or blocked valves shall be treated as outlined in Annex D.
Provided the requirements previously stated have been complied with, the cylinder shall be depressurized
safely and the valve shall be removed.
7 External visual inspection
7.1 Preparation for external visual inspection
When necessary, each cylinder shall be cleaned and have all loose coatings, corrosion products, tar, oil or
other foreign matter removed from its external surface by a suitable method, e.g. brushing, shot-blasting
(under closely controlled conditions), water jet abrasive cleaning, chemical cleaning or other suitable methods.
The method used to clean the cylinder shall be a validated, controlled process. Care shall be taken at all times
to avoid damaging the cylinder or removing excess amounts of cylinder wall (see Annex C).
If fused nylon, polyethylene or a similar coating has been applied and the coating is seen to be damaged or
prevents a proper inspection, then the coating shall be stripped. If the coating has been removed by the
application of heat, in no case shall the temperature of the cylinder have exceeded 300 °C.
7.2 Inspection procedure
The external surface of each cylinder shall then be inspected for
a) dents, cuts, gouges, bulges, cracks, laminations or excessive base wear;
b) heat damage, torch or electric-arc burns (as specified in Table C.1);
c) corrosion (as defined in Table C.2);
d) other defects such as illegible, incorrect or unauthorized stamp markings, or unauthorized additions or
modifications;
e) integrity of all permanent attachments (see C.2); and
f) vertical stability, if relevant (see Table C.1).
When inspecting for corrosion [see c)], special attention shall be given to areas where water could be trapped.
These include the entire base area, the junction between the body and the foot-ring and the junction between
body and the shroud.
For rejection criteria, see Annex C. Cylinders no longer suitable for future service shall be rendered
unserviceable (see Clause 15).
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ISO 10460:2005(E)
8 Internal visual inspection
Each cylinder shall be inspected internally using adequate illumination to identify any defects similar to those
listed in 7.2 a) and 7.2 c). Precautions shall be taken to ensure that the method of illumination presents no
risks to the tester while performing the operation. Any internal liner or coating that may obstruct optimum
internal visual inspection shall be removed. Any cylinder showing presence of foreign matter or signs of more
than light surface corrosion shall be cleaned internally under closely controlled conditions by shot-blasting,
water jet abrasive cleaning, flailing, steam jet, hot water jet, rumbling, chemical cleaning or other suitable
method. The method used to clean the cylinder shall be a validated, controlled process. Care shall be taken at
all times to avoid damaging the cylinder or removing excess amounts of cylinder wall (see Annex C). If
cleaning is required, the cylinder shall be reinspected after the cleaning operation.
9 Supplementary tests
Where there is doubt concerning the type and/or severity of a defect found on visual inspection, additional
tests or methods of examination shall be applied, e.g. ultrasonic techniques, check weighing or other non-
destructive tests.
10 Inspection of cylinder neck
10.1 Cylinder to valve threads
When the valve is removed, the cylinder to valve threads shall be examined to identify the type of thread
(e.g. 25E) and to ensure that they are
 clean and of full form,
 free of damage,
 free of burrs,
 free of cracks, and
 free of other imperfections.
10.2 Other neck surfaces
Other surfaces of the neck shall also be examined to ensure they are free of cracks or other defects (see
Annex C).
10.3 Damaged internal neck threads
Where necessary and where the manufacturer or the competent design authority confirms that the design of
the neck permits, threads may be re-tapped or the thread type changed to provide the appropriate number of
effective threads. After re-tapping or changing the thread form, the threads shall be checked with the
appropriate thread gauge, e.g. ISO 11191 for 25E threads.
10.4 Neck ring and collar attachment
When a neck ring/collar is attached, an examination shall be carried out to ensure it is secure and to inspect
for thread damage. A neck ring shall only be changed using an approved procedure. If it is found that any
significant damage to cylinder material has occurred by replacement of the neck ring/collar, the cylinder shall
be rendered unserviceable (see Clause 15).
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ISO 10460:2005(E)
11 Pressure test
11.1 General
Each cylinder shall be subjected to a hydraulic or pneumatic pressure test.
WARNING — Appropriate measures shall be taken to ensure safe operation and to contain any energy
that could be released. It should be noted that pneumatic pressure tests require more precautions than
hydraulic pressure tests since, regardless of the size of the container, any error in carrying out this
test is highly likely to lead to a rupture under gas pressure. Therefore, these tests shall be carried out
only after ensuring that the safety measures satisfy the safety requirements.
Each cylinder subjected to a hydraulic pressure test shall use a suitable fluid, normally water, as the test
medium. The test pressure shall be established from the stamping on the cylinder.
This test requires that the pressure in the cylinder be increased gradually until the test pressure is reached.
The cylinder test pressure shall be held for at least 30 s with the cylinder isolated from the pressure source,
during which time there shall be no decrease in the recorded pressure or any evidence of leakage. Adequate
safety precautions shall be taken during the test.
The following proposes a typical method for carrying out the test. Any cylinder failing to comply with the
requirements of a hydraulic proof pressure test shall be rendered unserviceable.
11.2 Test equipment
11.2.1 All rigid pipe work, flexible tubing, valves, fittings and components forming the pressure system of the
test equipment shall be designed to withstand a pressure at least 1,5 times the maximum test pressure of any
cylinder that could be tested.
11.2.2 Pressure gauges shall be to Industrial Class 1 (± 1 % deviation from the end value) with a scale
appropriate to the test pressure (e.g. EN 837-1 or EN 837-3). They shall be checked for accuracy against a
calibrated master gauge at regular intervals and in any case not less than once a month. The master gauge
shall be calibrated in accordance with national requirements. The pressure gauge shall be chosen so that the
test pressure is between approximately one-third and two-thirds of the value capable of being measured on
the pressure gauge.
11.2.3 The design and installation of the equipment, the connection of the cylinders and the operating
procedures shall be such as to avoid trapping air in the system when a liquid medium is used.
11.2.4 All joints within the system shall be leak tight.
11.2.5 A suitable system control device shall be fitted to the test equipment to ensure that no cylinder is
subjected to a pressure in excess of its test pressure by more than the tolerances specified in 11.3.3.
11.3 Test criteria
11.3.1 More than one cylinder may be tested at a time provided that they all have the same test pressure. If
individual test points are not used, then in case of leakage all cylinders being tested shall be individually re-
tested.
11.3.2 Before applying pressure, the external surface of the cylinder shall be dry.
11.3.3 The pressure applied shall not be below the test pressure and shall not exceed the test pressure by
3 % or 10 bar, whichever is lower.
11.3.4 On attaining the test pressure, the cylinder shall be isolated from the pump and the pressure held for
a minimum period of 30 s.
11.3.5 If there is a leakage in the pressure system, it shall be corrected and the cylinders retested.
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ISO 10460:2005(E)
11.4 Acceptance criteria
During the 30 s hold period, the pressure as registered on the test gauge shall remain constant.
There shall be absence of visible leakage on the entire surface of the cylinder. This check can be made during
the 30 s hold. There shall be no visible permanent deformation.
12 Repair of cylinders
12.1 Repair of pinholes
If during the pressure test or external visual inspections pinhole leaks are detected in a weld, the cylinder shall
be made unserviceable or repaired by welding (see 12.3.1). No other repair to pressure containing welds shall
be undertaken.
12.2 Other repairs
Any other major repairs, including removal of dents and replacement of foot-rings and shrouds, can be carried
out provided this repair will not impair the integrity of the cylinder. All corrosion product shall be removed prior
to repair.
12.3 Requirements for repair
12.3.1 Repairs as defined in 12.1 and 12.2 shall be performed to the original manufacturer's heat treatment
procedure by a competent/authorized reconditioner following an approved procedure and taking into account
the fabrication and testing requirements of the cylinder design standard. After such repairs, a stress
relief/normalizing heat treatment shall be performed. The cylinder shall finally be hydraulically tested in
accordance with Clause 11 and inspected as necessary for the intended gas service.
12.3.2 Minor repairs such as reforming damaged shrouds, carrying handles, etc., not involving welding or
hot-work on pressure containing parts may be carried out as long as the integrity of the cylinder is not
impaired.
12.3.3 Any operation that could result in loss of wall thickness to below minimum guaranteed wall thickness
shall be completed before the inspection and testing procedures (see Annex C).
13 Inspection of valve and other accessories
If a valve or any other accessory is to be reintroduced into service, it shall be inspected and maintained to
ensure that it will perform satisfactorily in service and meet the requirements of gas tightness from the valve
manufacturing standards, e.g. ISO 10297. An example of a suitable method is given in Annex E.
14 Final operations
14.1 Drying, cleaning, painting and coating
14.1.1 Drying and cleaning
The interior of each cylinder shall be thoroughly dried by a suitable method at a temperature not exceeding
300 °C immediately after hydraulic pressure testing, such that there is no trace of free water. The interior of
the cylinder shall be inspected to ensure that it is dry and free from other contaminants.
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ISO 10460:2005(E)
14.1.2 Painting and coating
Cylinders are sometimes repainted using paints that require stoving. Plastic coatings may also be reapplied.
Painting or coating shall be applied so that all the markings stamped on the cylinder remain legible.
In no case shall the temperature of the cylinder exceed 300 °C since overheating could change the
mechanical properties of the cylinder.
14.2 Re-valving of the cylinder
Before re-valving the cylinder, the thread type shall be identified. The appropriate valve shall be fitted in
accordance with ISO 13341.
The torque applied shall take into consideration the size and form of the threads, the material of the valve, and
the type of sealing material used according to the manufacturer's recommendations. Where the use of
lubricants/sealing material is permitted, only those approved for the gas service shall be used, taking
particular care for oxygen service in accordance with ISO 11114-2.
14.3 Check on cylinder tare
The requirement shall apply only to cylinders for liquefied gases. The tare of the cylinders shall be obtained by
weighing on a scale calibrated with traceability to national or international standards. The weigh scale shall be
checked for accuracy on a daily basis. The capacity of the weighing scale shall be suitable for the tare weight
of the appropriate cylinders.
The tare shall include the mass of the cylinder, valve(s) and all permanent fittings. If the tare of the cylinder
differs from the stamped tare by more than the value shown in Table 1 and is not due to damage, the original
tare shall be cancelled. For welded steel cylinders, particular attention shall be paid to the tare weight when
replacing any valves, dip tubes, guards/shrouds and foot-rings. The new correct tare shall be marked in a
durable and legible fashion (see ISO 13769).
Table 1 — Permissible deviation in tare
Cylinder water capacity, V Maximum permissible deviation in tare
l g
0,5 u V < 5,0
± 50
5,0 u V u 20 ± 200
V > 20 ± 400

14.4 Retest marking
14.4.1 General
After satisfactory completion of the periodic inspection and test, each cylinder shall be permanently marked
according to the relevant standard or regulation, e.g. ISO 13769, with
a) the symbol of the inspection body or test station, followed by
b) the present test date.
14.4.2 Retester symbol and retest date
The retester symbol is the symbol of the inspection body or test station. The retest date is the date of the
present test, which shall be indicated by the year and month.
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ISO 10460:2005(E)
14.4.3 Stamping
These marks shall be in accordance with the relevant standard or regulations, e.g. ISO 13769.
14.5 Reference to next inspection and test date
When regulations require, the next inspection and test date shall be shown by an appropriate method such as
a disc fitted between the valve and the cylinder indicating the date (year) of the next periodic inspections
and/or tests. Annex F provides one example of an existing system for indicating retest dates. Other systems
are in use.
14.6 Identification of contents
Before the cylinder is reintroduced into service, the intended contents shall be identified. This need not be part
of the periodic inspection and test procedure. As an example, use ISO 7225 and ISO 32. If painting is required,
care shall be exercised in accordance with 14.1.2. If a change of gas service is involved, care shall be taken
to follow the requirements of ISO 11621.
14.7 Records
A cylinder retest shall be recorded by the test station and the following information shall be available:
a) owner's name;
b) manufacturer's or owner's serial number;
c) cylinder mass (empty weight), or tare, where applicable;
d) type of test performed;
e) test pressure;
f) result of test (pass or fail);
g) present retest date — year/month/day;
h) identification symbol of the retest body or the test station;
i) identification of retester;
j) details of any repairs as described in Annex C made to the cylinder.
Additionally, it shall be possible to obtain the following items of information from records, which need not
necessarily be kept on a single file, but will enable a particular cylinder to be uniquely traced:
k) cylinder manufacturer's name;
l) manufacturer's serial number;
m) manufacturing design specification;
n) water capacity/size; and
o) manufacturing test date.
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ISO 10460:2005(E)
15 Rejection and rendering cylinders unserviceable
The decision to reject a cylinder may be taken at any stage during the inspection and test procedure. If it is
impossible to recover a rejected cylinder, it shall, af
...