SIST EN ISO 23088:2021
(Main)Gas cylinders - Periodic inspection and testing of welded steel pressure drums - Capacities up to 1 000 l (ISO 23088:2020)
Gas cylinders - Periodic inspection and testing of welded steel pressure drums - Capacities up to 1 000 l (ISO 23088:2020)
This document specifies the requirements for periodic inspection and testing of welded steel transportable pressure drums of water capacity from 150 l up to 1 000 l and up to 300 bar test pressure intended for compressed and liquefied gases.
Gasflaschen - Wiederkehrende Inspektion und Prüfung von geschweißten Druckfässern aus Stahl - Fassungsräume bis zu 1 000 l (ISO 23088:2020)
Dieses Dokument legt die Anforderungen an die wiederkehrende Inspektion und Prüfung von geschweißten, ortsbeweglichen Druckfässern aus Stahl mit einem Fassungsraum von 150 l bis 1 000 l und einem Prüfdruck von bis zu 300 bar fest, die für verdichtete und verflüssigte Gase vorgesehen sind.
ACHTUNG — Bei einigen der in diesem Dokument festgelegten Prüfungen werden Prozesse angewendet, die zu gefährlichen Situationen führen könnten.
Bouteilles à gaz - Contrôles et essais périodiques des fûts à pression soudés en acier - Capacité inférieure ou égale à 1 000 l (ISO 23088:2020)l
Le présent document spécifie les exigences relatives aux contrôles et essais périodiques des fûts à pression soudés en acier transportables d'une capacité de 150 l à 1 000 l et pour une pression d'épreuve maximale de 300 bar, destinés au transport des gaz comprimés et liquéfiés.
Plinske jeklenke - Periodični pregledi in preskušanje varjenih tlačnih sodov - Prostornina do 1000 l (ISO 23088:2020)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 23088:2021
01-februar-2021
Plinske jeklenke - Periodični pregledi in preskušanje varjenih tlačnih sodov -
Prostornina do 1000 l (ISO 23088:2020)
Gas cylinders - Periodic inspection and testing of welded steel pressure drums -
Capacities up to 1 000 l (ISO 23088:2020)
Gasflaschen - Wiederkehrende Inspektion und Prüfung von geschweißten Druckfässern
aus Stahl - Fassungsräume bis zu 1 000 l (ISO 23088:2020)
Bouteilles à gaz - Contrôles et essais périodiques des fûts à pression soudés en acier -
Capacité inférieure ou égale à 1 000 l (ISO 23088:2020)l
Ta slovenski standard je istoveten z: EN ISO 23088:2020
ICS:
23.020.35 Plinske jeklenke Gas cylinders
SIST EN ISO 23088:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 23088:2021
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SIST EN ISO 23088:2021
EN ISO 23088
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2020
EUROPÄISCHE NORM
ICS 23.020.35
English Version
Gas cylinders - Periodic inspection and testing of welded
steel pressure drums - Capacities up to 1 000 l (ISO
23088:2020)
Gasflaschen - Wiederkehrende Inspektion und Prüfung
von geschweißten Druckfässern aus Stahl -
Fassungsräume bis zu 1 000 l (ISO 23088:2020)
This European Standard was approved by CEN on 13 December 2020.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23088:2020 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 23088:2021
EN ISO 23088:2020 (E)
Contents Page
European foreword . 3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 23088:2021
EN ISO 23088:2020 (E)
European foreword
The text of ISO 23088:2020 has been prepared by Technical Committee ISO/TC 58 "Gas cylinders” of
the International Organization for Standardization (ISO) and has been taken over as EN ISO 23088:2020
by Technical Committee CEN/TC 23 “Transportable gas cylinders” the secretariat of which is held by
BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2021, and conflicting national standards shall be
withdrawn at the latest by June 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 23088:2020 has been approved by CEN as EN ISO 23088:2020 without any modification.
3
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SIST EN ISO 23088:2021
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SIST EN ISO 23088:2021
INTERNATIONAL ISO
STANDARD 23088
First edition
2020-02
Gas cylinders — Periodic inspection
and testing of welded steel pressure
drums — Capacities up to 1 000 l
Reference number
ISO 23088:2020(E)
©
ISO 2020
---------------------- Page: 7 ----------------------
SIST EN ISO 23088:2021
ISO 23088:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 23088:2021
ISO 23088:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Intervals between periodic inspections and tests . 2
5 List of procedures for periodic inspection and test . 2
6 Identification of pressure drum . 3
7 Preparation for inspection and testing . 3
7.1 General . 3
7.2 Depressurization . 3
7.3 Devalving and flange removal . 3
8 External visual inspection . 3
8.1 Preparation . 3
8.2 Procedure . 4
9 Internal visual inspection . 4
10 Supplementary tests . 4
11 Inspection of openings and fittings . 4
11.1 Internal threads . 4
11.2 Damaged internal threads . 5
11.3 Flanged openings and retaining assemblies . 5
11.4 Damaged flanged openings and/or retaining assemblies . 5
12 Pressure test . 6
12.1 General . 6
12.2 Proof pressure test . 6
12.3 Test procedures . 6
12.3.1 Hydraulic test . 6
12.3.2 Pneumatic test . 7
12.4 Acceptance criteria . 7
13 Repair of pressure drums . 8
13.1 Welds . 8
13.2 Other repairs . 8
13.3 Requirements for repair . 8
14 Inspection of valves . 8
15 Final operations . 8
15.1 Drying and cleaning . 8
15.2 Painting . 9
15.3 Fitting valves . 9
15.4 Fitting of flanges . 9
15.5 Verification of tare. 9
15.6 Retest marking . 9
15.7 Reference to the next test date .10
15.8 Records .10
16 Rejection and rendering unserviceable .10
Annex A (informative) Periodic inspection and test periods .12
© ISO 2020 – All rights reserved iii
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SIST EN ISO 23088:2021
ISO 23088:2020(E)
Annex B (normative) Description, evaluation of defects and conditions for rejection of
pressure drums at the time of visual inspection.13
Bibliography .19
iv © ISO 2020 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 23088:2021
ISO 23088:2020(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 4,
Operational requirements for gas cylinders.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 23088:2021
ISO 23088:2020(E)
Introduction
This document provides information and procedures for the periodic inspection and testing of
pressure drums and the condition of the test equipment. It addresses requirements that reflect current
practice and experience. The principal aim of a periodic inspection and testing procedure is that at the
satisfactory completion of the inspection the pressure drums can be reintroduced into service for a
further period of time.
[7]
This document has been written so that it is suitable to be referenced in the UN Model Regulations .
vi © ISO 2020 – All rights reserved
---------------------- Page: 12 ----------------------
SIST EN ISO 23088:2021
INTERNATIONAL STANDARD ISO 23088:2020(E)
Gas cylinders — Periodic inspection and testing of welded
steel pressure drums — Capacities up to 1 000 l
CAUTION — Some of the tests specified in this document involve the use of processes that could
lead to a hazardous situation.
1 Scope
This document specifies the requirements for periodic inspection and testing of welded steel
transportable pressure drums of water capacity from 150 l up to 1 000 l and up to 300 bar test pressure
intended for compressed and liquefied gases.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 10286, Gas cylinders — Terminology
ISO 11114-1, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 1:
Metallic materials
ISO 11114-2, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 2:
Non-metallic materials
ISO 13341, Gas cylinders — Fitting of valves to gas cylinders
ISO 13769, Gas cylinders — Stamp marking
ISO 21172-1, Gas cylinders — Welded steel pressure drums up to 3 000 litres capacity for the transport of
gases — Design and construction — Part 1: Capacities up to 1 000 litres
ISO 22434, Transportable gas cylinders — Inspection and maintenance of cylinder valves
ISO 25760, Gas cylinders — Operational procedures for the safe removal of valves from gas cylinders
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10286 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
pressure drum
welded transportable pressure receptacle of a water capacity exceeding 150 l and of not more than 1 000 l
EXAMPLE Cylindrical receptacles equipped with rolling hoops, spheres on skids.
[SOURCE: UN Model Regulations, as amended]
© ISO 2020 – All rights reserved 1
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SIST EN ISO 23088:2021
ISO 23088:2020(E)
3.2
rejected pressure drum
pressure drum (3.1) not fit for service without further evaluation
3.3
minimum design wall thickness
thickness of the pressure drum (3.1) wall calculated from the design standard, taking into account the
material properties and dimensions at time of manufacture
[SOURCE: ISO 18119:2018, 3.4, modified — "cylinder" replaced by "pressure drum".]
4 Intervals between periodic inspections and tests
A pressure drum shall be due for periodic inspection and testing on its first receipt by a filler following
the expiry of the established interval or, in the absence of regulations, in accordance with the UN Model
Regulations (see Annex A). The expiry date is based on the last test date shown on the pressure drum.
Provided the pressure drum has not been subjected to abusive and abnormal conditions such as being
involved in an accident, heat exposure or other severe conditions that would render the pressure drum
unsafe, there is no requirement for the user to return a pressure drum before the contents have been
used even though the periodic inspection and test interval has lapsed. However, pressure drums,
particularly those containing corrosive gases, should be retested within a period not exceeding twice
the periodic inspection and test interval of the applicable regulations.
5 List of procedures for periodic inspection and test
Each pressure drum shall be submitted to a periodic inspection and test. The following procedures
form the requirements for such inspection and testing, and are explained more fully in later clauses:
a) identification of pressure drum (see Clause 6);
b) preparation for inspection and testing (see Clause 7);
c) depressurization (see 7.2);
d) devalving and flange removal (see 7.3);
e) external visual inspection (see Clause 8);
f) internal visual inspection (see Clause 9);
g) supplementary tests (see Clause 10);
h) inspection of openings and fittings (see Clause 11);
i) pressure test (see Clause 12);
j) repair of pressure drums (see Clause 13);
k) inspection of valves (see Clause 14);
l) final operations (see Clause 15);
m) rejection and rendering unserviceable (see Clause 16).
These procedures should be performed in the sequence listed in order to improve the safety of the
operation and to detect potential harmful damage.
When a pressure drum passes the above listed procedures, but the condition of the pressure drum
remains in doubt, additional, supplementary tests shall be performed to confirm its suitability for
continued service or the pressure drum shall be rejected (see Clause 16).
2 © ISO 2020 – All rights reserved
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SIST EN ISO 23088:2021
ISO 23088:2020(E)
Pressure drums that fail an inspection or test shall be rejected (see Clause 16).
Depending on the reason for rejection, some pressure drums may be returned to service after further
evaluation. The requirements for returning a rejected pressure drum to service are provided in
Clause 16 and Annex B.
The eyesight acuity of operators is critical and should be checked by an optician on a yearly basis.
6 Identification of pressure drum
The labelling and permanent marks on the pressure drum shall be checked and the information
recorded before carrying out any further work. Pressure drums with incorrect or illegible marks shall
be set aside for further evaluation.
Pressure drums with contents that are unknown shall also be set aside for further evaluation.
7 Preparation for inspection and testing
7.1 General
Pressure drums shall be made safe before carrying out any further inspections. This can include
purging or other operations depending upon the gas service involved. Pressure drums that cannot be
safely emptied of product shall be set aside for further evaluation.
Particular attention shall be paid to pressure drums that have contained flammable, oxidizing or toxic
gases to eliminate risks during the internal visual inspection. Additionally, as some liquefied products
cannot be removed from the pressure drum by only venting, an additional check such as weighing the
pressure drum and comparing this value to its tare may be required.
7.2 Depressurization
Before removing the valve, a check shall be performed to ensure that the pressure drum does not
contain any gas under pressure.
A check shall be performed to establish that the valve is not obstructed or inoperable in accordance
with ISO 25760.
7.3 Devalving and flange removal
WARNING — The uncontrolled opening of the valve and/or the removal of the valve and flange
from a pressure drum can lead to injury, death and/or property damage.
The valve may be removed only after the pressure drum has been depressurized and it has been
established that there is no obstruction to gas flow in the pressure drum's valve. Devalving shall be
performed in accordance with ISO 25760.
The flange(s) shall only be removed after the pressure drum has been devalved in accordance with
ISO 25760.
8 External visual inspection
8.1 Preparation
Each pressure drum shall be cleaned and have all labels, loose coatings, corrosion products, tar, oil or
other foreign matter removed from its external surface, e.g. by brushing, shot blasting (under controlled
conditions), water jet abrasive cleaning, chemical cleaning or other methods. Care shall be taken to
ensure that the integrity of the pressure drum is not compromised by the cleaning process.
© ISO 2020 – All rights reserved 3
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SIST EN ISO 23088:2021
ISO 23088:2020(E)
8.2 Procedure
The external surface of each pressure drum shall undergo a thorough visual inspection for:
— dents, cuts, gouges, bulges, cracks, laminations or excessive wear;
— heat damage, torch or electric arc burns (as identified in Table B.1);
— corrosion (as defined in Table B.2) — attention shall be given to areas where water can be trapped;
— defects to welds, welded attachments and the areas adjacent to them;
— other defects such as illegible or unauthorized stamp marks, unauthorized additions or modifications;
— integrity of all permanent attachments, e.g. shrouds, lifting points, lifting pockets; and
— damage to rolling bands.
If the results of the external visual inspection are in doubt, see Clause 10.
For rejection criteria, see Annex B. Pressure drums no longer suitable for continued service shall be
rendered unserviceable as defined in Clause 16.
9 Internal visual inspection
Once the requirements of Clause 7 have been met, each pressure drum shall be inspected internally to
identify defects such as those listed in 8.2. Flange(s), if present, shall be removed in accordance with 7.3
to facilitate the internal inspection of the pressure drum.
Precautions shall be taken to ensure that the method of illumination used for the internal visual
inspection presents no hazard to the person carrying out the inspection. Any internal lining or coating
that can prevent a thorough examination shall be removed.
Any pressure drum showing the presence of foreign matter or signs of corrosion shall be cleaned under
closely controlled conditions by a method such as shot blasting, water jet abrasive cleaning, flailing,
steam jet, hot water jet, chemical cleaning or other approved method. Care shall be taken to avoid
damage to the pressure drum. The pressure drum shall be re-inspected after the cleaning process.
10 Supplementary tests
Where there is doubt concerning the type and severity of a defect found on visual inspection (see
Clauses 8 and 9), or when the cleaning processes might have reduced the wall thickness, additional
tests or methods of examination may be performed. These additional tests or methods of examination
include ultrasonic examination (UT), checking the weight of the pressure drum or other non-destructive
testing such as x-ray or dye-penetrant to investigate the presence of surface imperfections.
Only when doubt is eliminated may the drum be further processed (see Annex B).
11 Inspection of openings and fittings
11.1 Internal threads
The internal threaded openings shall be visually examined to ensure they are:
— clean and of full form;
— free of damage;
— free of burrs;
4 © ISO 2020 – All rights reserved
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SIST EN ISO 23088:2021
ISO 23088:2020(E)
— free of cracks; and
— free of other imperfections.
Where there is any doubt as to the condition of the threaded openings and the threads of the fittings of
pressure drums, the threads shall be checked using a thread gauge.
Threaded openings and the threads of the fittings of pressure drums used in toxic, flammable or
corrosive service shall be examined using an appropriate thread gauge or gauges.
For examples on the use of thread gauges, see ISO 11363-2. In all cases, the threads s
...
SLOVENSKI STANDARD
oSIST prEN ISO 23088:2020
01-september-2020
Plinske jeklenke - Periodični pregledi in preskušanje varjenih tlačnih sodov -
Prostornina do 1000 l (ISO 23088:2020)
Gas cylinders - Periodic inspection and testing of welded steel pressure drums -
Capacities up to 1 000 l (ISO 23088:2020)
Ta slovenski standard je istoveten z: prEN ISO 23088
ICS:
23.020.35 Plinske jeklenke Gas cylinders
oSIST prEN ISO 23088:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 23088:2020
---------------------- Page: 2 ----------------------
oSIST prEN ISO 23088:2020
INTERNATIONAL ISO
STANDARD 23088
First edition
2020-02
Gas cylinders — Periodic inspection
and testing of welded steel pressure
drums — Capacities up to 1 000 l
Reference number
ISO 23088:2020(E)
©
ISO 2020
---------------------- Page: 3 ----------------------
oSIST prEN ISO 23088:2020
ISO 23088:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 23088:2020
ISO 23088:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Intervals between periodic inspections and tests . 2
5 List of procedures for periodic inspection and test . 2
6 Identification of pressure drum . 3
7 Preparation for inspection and testing . 3
7.1 General . 3
7.2 Depressurization . 3
7.3 Devalving and flange removal . 3
8 External visual inspection . 3
8.1 Preparation . 3
8.2 Procedure . 4
9 Internal visual inspection . 4
10 Supplementary tests . 4
11 Inspection of openings and fittings . 4
11.1 Internal threads . 4
11.2 Damaged internal threads . 5
11.3 Flanged openings and retaining assemblies . 5
11.4 Damaged flanged openings and/or retaining assemblies . 5
12 Pressure test . 6
12.1 General . 6
12.2 Proof pressure test . 6
12.3 Test procedures . 6
12.3.1 Hydraulic test . 6
12.3.2 Pneumatic test . 7
12.4 Acceptance criteria . 7
13 Repair of pressure drums . 8
13.1 Welds . 8
13.2 Other repairs . 8
13.3 Requirements for repair . 8
14 Inspection of valves . 8
15 Final operations . 8
15.1 Drying and cleaning . 8
15.2 Painting . 9
15.3 Fitting valves . 9
15.4 Fitting of flanges . 9
15.5 Verification of tare. 9
15.6 Retest marking . 9
15.7 Reference to the next test date .10
15.8 Records .10
16 Rejection and rendering unserviceable .10
Annex A (informative) Periodic inspection and test periods .12
© ISO 2020 – All rights reserved iii
---------------------- Page: 5 ----------------------
oSIST prEN ISO 23088:2020
ISO 23088:2020(E)
Annex B (normative) Description, evaluation of defects and conditions for rejection of
pressure drums at the time of visual inspection.13
Bibliography .19
iv © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST prEN ISO 23088:2020
ISO 23088:2020(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 4,
Operational requirements for gas cylinders.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST prEN ISO 23088:2020
ISO 23088:2020(E)
Introduction
This document provides information and procedures for the periodic inspection and testing of
pressure drums and the condition of the test equipment. It addresses requirements that reflect current
practice and experience. The principal aim of a periodic inspection and testing procedure is that at the
satisfactory completion of the inspection the pressure drums can be reintroduced into service for a
further period of time.
[7]
This document has been written so that it is suitable to be referenced in the UN Model Regulations .
vi © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
oSIST prEN ISO 23088:2020
INTERNATIONAL STANDARD ISO 23088:2020(E)
Gas cylinders — Periodic inspection and testing of welded
steel pressure drums — Capacities up to 1 000 l
CAUTION — Some of the tests specified in this document involve the use of processes that could
lead to a hazardous situation.
1 Scope
This document specifies the requirements for periodic inspection and testing of welded steel
transportable pressure drums of water capacity from 150 l up to 1 000 l and up to 300 bar test pressure
intended for compressed and liquefied gases.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 10286, Gas cylinders — Terminology
ISO 11114-1, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 1:
Metallic materials
ISO 11114-2, Gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 2:
Non-metallic materials
ISO 13341, Gas cylinders — Fitting of valves to gas cylinders
ISO 13769, Gas cylinders — Stamp marking
ISO 21172-1, Gas cylinders — Welded steel pressure drums up to 3 000 litres capacity for the transport of
gases — Design and construction — Part 1: Capacities up to 1 000 litres
ISO 22434, Transportable gas cylinders — Inspection and maintenance of cylinder valves
ISO 25760, Gas cylinders — Operational procedures for the safe removal of valves from gas cylinders
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10286 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
pressure drum
welded transportable pressure receptacle of a water capacity exceeding 150 l and of not more than 1 000 l
EXAMPLE Cylindrical receptacles equipped with rolling hoops, spheres on skids.
[SOURCE: UN Model Regulations, as amended]
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3.2
rejected pressure drum
pressure drum (3.1) not fit for service without further evaluation
3.3
minimum design wall thickness
thickness of the pressure drum (3.1) wall calculated from the design standard, taking into account the
material properties and dimensions at time of manufacture
[SOURCE: ISO 18119:2018, 3.4, modified — "cylinder" replaced by "pressure drum".]
4 Intervals between periodic inspections and tests
A pressure drum shall be due for periodic inspection and testing on its first receipt by a filler following
the expiry of the established interval or, in the absence of regulations, in accordance with the UN Model
Regulations (see Annex A). The expiry date is based on the last test date shown on the pressure drum.
Provided the pressure drum has not been subjected to abusive and abnormal conditions such as being
involved in an accident, heat exposure or other severe conditions that would render the pressure drum
unsafe, there is no requirement for the user to return a pressure drum before the contents have been
used even though the periodic inspection and test interval has lapsed. However, pressure drums,
particularly those containing corrosive gases, should be retested within a period not exceeding twice
the periodic inspection and test interval of the applicable regulations.
5 List of procedures for periodic inspection and test
Each pressure drum shall be submitted to a periodic inspection and test. The following procedures
form the requirements for such inspection and testing, and are explained more fully in later clauses:
a) identification of pressure drum (see Clause 6);
b) preparation for inspection and testing (see Clause 7);
c) depressurization (see 7.2);
d) devalving and flange removal (see 7.3);
e) external visual inspection (see Clause 8);
f) internal visual inspection (see Clause 9);
g) supplementary tests (see Clause 10);
h) inspection of openings and fittings (see Clause 11);
i) pressure test (see Clause 12);
j) repair of pressure drums (see Clause 13);
k) inspection of valves (see Clause 14);
l) final operations (see Clause 15);
m) rejection and rendering unserviceable (see Clause 16).
These procedures should be performed in the sequence listed in order to improve the safety of the
operation and to detect potential harmful damage.
When a pressure drum passes the above listed procedures, but the condition of the pressure drum
remains in doubt, additional, supplementary tests shall be performed to confirm its suitability for
continued service or the pressure drum shall be rejected (see Clause 16).
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Pressure drums that fail an inspection or test shall be rejected (see Clause 16).
Depending on the reason for rejection, some pressure drums may be returned to service after further
evaluation. The requirements for returning a rejected pressure drum to service are provided in
Clause 16 and Annex B.
The eyesight acuity of operators is critical and should be checked by an optician on a yearly basis.
6 Identification of pressure drum
The labelling and permanent marks on the pressure drum shall be checked and the information
recorded before carrying out any further work. Pressure drums with incorrect or illegible marks shall
be set aside for further evaluation.
Pressure drums with contents that are unknown shall also be set aside for further evaluation.
7 Preparation for inspection and testing
7.1 General
Pressure drums shall be made safe before carrying out any further inspections. This can include
purging or other operations depending upon the gas service involved. Pressure drums that cannot be
safely emptied of product shall be set aside for further evaluation.
Particular attention shall be paid to pressure drums that have contained flammable, oxidizing or toxic
gases to eliminate risks during the internal visual inspection. Additionally, as some liquefied products
cannot be removed from the pressure drum by only venting, an additional check such as weighing the
pressure drum and comparing this value to its tare may be required.
7.2 Depressurization
Before removing the valve, a check shall be performed to ensure that the pressure drum does not
contain any gas under pressure.
A check shall be performed to establish that the valve is not obstructed or inoperable in accordance
with ISO 25760.
7.3 Devalving and flange removal
WARNING — The uncontrolled opening of the valve and/or the removal of the valve and flange
from a pressure drum can lead to injury, death and/or property damage.
The valve may be removed only after the pressure drum has been depressurized and it has been
established that there is no obstruction to gas flow in the pressure drum's valve. Devalving shall be
performed in accordance with ISO 25760.
The flange(s) shall only be removed after the pressure drum has been devalved in accordance with
ISO 25760.
8 External visual inspection
8.1 Preparation
Each pressure drum shall be cleaned and have all labels, loose coatings, corrosion products, tar, oil or
other foreign matter removed from its external surface, e.g. by brushing, shot blasting (under controlled
conditions), water jet abrasive cleaning, chemical cleaning or other methods. Care shall be taken to
ensure that the integrity of the pressure drum is not compromised by the cleaning process.
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8.2 Procedure
The external surface of each pressure drum shall undergo a thorough visual inspection for:
— dents, cuts, gouges, bulges, cracks, laminations or excessive wear;
— heat damage, torch or electric arc burns (as identified in Table B.1);
— corrosion (as defined in Table B.2) — attention shall be given to areas where water can be trapped;
— defects to welds, welded attachments and the areas adjacent to them;
— other defects such as illegible or unauthorized stamp marks, unauthorized additions or modifications;
— integrity of all permanent attachments, e.g. shrouds, lifting points, lifting pockets; and
— damage to rolling bands.
If the results of the external visual inspection are in doubt, see Clause 10.
For rejection criteria, see Annex B. Pressure drums no longer suitable for continued service shall be
rendered unserviceable as defined in Clause 16.
9 Internal visual inspection
Once the requirements of Clause 7 have been met, each pressure drum shall be inspected internally to
identify defects such as those listed in 8.2. Flange(s), if present, shall be removed in accordance with 7.3
to facilitate the internal inspection of the pressure drum.
Precautions shall be taken to ensure that the method of illumination used for the internal visual
inspection presents no hazard to the person carrying out the inspection. Any internal lining or coating
that can prevent a thorough examination shall be removed.
Any pressure drum showing the presence of foreign matter or signs of corrosion shall be cleaned under
closely controlled conditions by a method such as shot blasting, water jet abrasive cleaning, flailing,
steam jet, hot water jet, chemical cleaning or other approved method. Care shall be taken to avoid
damage to the pressure drum. The pressure drum shall be re-inspected after the cleaning process.
10 Supplementary tests
Where there is doubt concerning the type and severity of a defect found on visual inspection (see
Clauses 8 and 9), or when the cleaning processes might have reduced the wall thickness, additional
tests or methods of examination may be performed. These additional tests or methods of examination
include ultrasonic examination (UT), checking the weight of the pressure drum or other non-destructive
testing such as x-ray or dye-penetrant to investigate the presence of surface imperfections.
Only when doubt is eliminated may the drum be further processed (see Annex B).
11 Inspection of openings and fittings
11.1 Internal threads
The internal threaded openings shall be visually examined to ensure they are:
— clean and of full form;
— free of damage;
— free of burrs;
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— free of cracks; and
— free of other imperfections.
Where there is any doubt as to the condition of the threaded openings and the threads of the fittings of
pressure drums, the threads shall be checked using a thread gauge.
Threaded openings and the threads of the fittings of pressure drums used in toxic, flammable or
corrosive service shall be examined using an appropriate thread gauge or gauges.
For examples on the use of thread gauges, see ISO 11363-2. In all cases, the threads shall be checked by
a person trained in gauging threads.
11.2 Damaged internal threads
When necessary, threads may be re-tapped to clean and rectify the appropriate number of
effective threads. After re-tapping, the threads shall be checked using the applicable thread gauge
(e.g. ISO 11363-2).
11.3 Flanged openings and retaining assemblies
If the pressure drum is fitted with flanged openings, they shall be inspected to ensure that they are:
— clean faced;
— free of damage to the mating surfaces; and
— free of cuts or gouges.
For retaining assemblies, including bolts/studs, ensure that:
— the profile conforms to the required specification;
— is free from all surface defects; and
— the materials are compatible with the intended gas service, even those that are not in the gas stream
(see ISO 11114-1).
11.4 Damaged flanged openings and/or retaining assemblies
If the design permits, damaged flange faces on both the pressure drum and the flange may be re-
machined to enable a pressure seal to be made on re-assembly.
When retaining assemblies have been replaced, ensure that they are compatible with the intended gas
service (see ISO 11114-1 or ISO 11114-2, as applicable).
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12 Pressure test
12.1 General
Each pressure drum shall be subjected to a proof pressure test (see 12.2).
12.2 Proof pressure test
WARNING — Appropriate measures shall be taken to ensure safe operation and to contain any
energy that might be released. It should be noted that pneumatic proof pressure tests require
more precautions than hydraulic proof pressure tests, regardless of the size of the pressure
drum. 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 adopted
satisfy the safety requirements.
The hydraulic proof pressure test shall use a fluid, usually water, as the test medium. The test procedure
shall be performed in accordance with 12.3 as appropriate to the design of the pressure drum. The test
pressure shall be in accordance with the stamp mark of the pressure drum.
A pneumatic pressure test may be substituted for the hydraulic proof pressure test provided that a risk
assessment has been carried out. Personnel using pneumatic testing need to ensure that precautions
are taken to contain any energy released if a pressure drum fails. The energy required to conduct a
pneumatic pressure test is considerably more than that required for a hydraulic pressure test and can
cause extensive damage in the event of failure if adequate precautions have not been taken.
When using air as the medium for the pneumatic pressure test, care shall be taken due to the oxidizing
potential of high pressure air. At 300 bar, the partial pressure of oxygen is approximately 60 bar.
Pressure drums that have internal flammable materials (e.g. coatings containing hydrocarbons) shall
not undergo a pneumatic pressure test that uses high pressure air.
Care shall be taken during the periodic inspection and testing of pressure drums that have been used in
flammable gas service.
12.3 Test procedures
12.3.1 Hydraulic test
12.3.1.1 General
The pressure in the pressure drum shall be increased gradually until the test pressure is reached. The
pressure shall be held for a minimum of 10 min with the pressure drum isolated from the pressure
source. During the test period, there shall be no decrease in the recorded pressure or evidence of any
leakage. Safety precautions shall be taken, even for a hydraulic test, due to the considerable stored
energy in a pressure drum.
12.3.1.2 Test equipment
12.3.1.2.1 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 1,5 times the maximum test
pressure of the pressure drum that is to be tested. Flexible tubing shall have sufficient wall thickness to
prevent kinking.
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