ISO/TR 19884-3

ISO/TC 197
ISO/CD TRDTR 19884-3(en)
ISO/TC 197
Secretariat:  SCC
Date: 2026-02-02
Gaseous hydrogen — Pressure vessels for stationary storage —
Part 3:
Pressure cycle test data to demonstrate shallow pressure cycle
estimation methods
ISO/CD TRDTR 19884-3:20252026(en)
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ISO/CD TRDTR 19884-3:20252026(en)
Contents
Foreword . iii
Introduction . iii
Scope . iii
Normative references . iii
Terms and definitions . iii
Goodman diagram based method . iii
S-N diagram . iii
Equivalent pressure cycling . iii
Goodman diagram . iii
Exponential formula based method . iii
Formula of cycle life extension by partial pressure cycle . iii
Pressure-cycle test data to determine index . iii
Bibliography . iii
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Goodman diagram based method . 2
4.1 S-N diagram . 2
4.2 Equivalent pressure cycling . 4
4.3 Goodman diagram . 5
5 Exponential formula based method . 7
5.1 Formula of cycle life extension by partial pressure cycle . 7
5.2 Pressure-cycle test data to determine index . 7
Bibliography . 14

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ISO/CD TRDTR 19884-3:20252026(en)
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
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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 1Part 1. In particular, the different approval criteria needed for the different
types of ISO document 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).IEC Directives, Part 2 (see
www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO [had/had not] received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that this
may not represent the latest information, which may be obtained from the patent database available at
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This document was prepared by Technical Committee 197, Hydrogen technologies.
A list of all parts in the ISO 19884 series can be found on the ISO website.
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.www.iso.org/members.html.
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ISO/CD TRDTR 19884-3:20252026(en)
Introduction
A much higher level of long-term reliability is required for a pressure vessel in stationary use compared to on-
board use, as the risk of a serious incident in the event of a vessel rupture is significantly higher. Reliability is
ensured through full-pressure cycle testing in accordance with the performance-based standard, Error!
Reference source not found.0 . One of the primary objectives of utilizing stationary vessels is to accumulate
hydrogen pressure quickly prior to refuelling vehicles. That is why the pressure of a stationary vessel never
decreases to zero in actual use. The expected pressurizing time-history is between the design pressureError!
Reference source not found. and 70% of the design pressureError! Reference source not found. , that is,
a partial pressure cycleError! Reference source not found. , for which a longer cycle life is expected than the
full pressure cycle life .Error! Reference source not found. . The cycle life extension by the partial pressure
cycleError! Reference source not found. seems applicable to other high-pressure hydrogen equipment, such
as tubes. Cycle life extension is rather a matter of maintenance for reliable performance. The authority with
jurisdiction needs to be convinced that the vessel can be relied upon for a period longer than the nameplate
life. This document presents candidate methods for estimating cycle life extension through partial pressure
cycling for authorities and users, enabling hydrogen stations to be operated and managed efficiently and
safely. This document presents the currently available methods and the test data to support them. Still,
itHowever, this document does is not intended to inhibit the advancement of new technologies that are
presently being developed or used in the market, or those yet to emerge. As these new technologies mature,
they will be added in future revisions of this International Technical Report. As these emerging technologies
are developing rapidly, ISO Technical Committee 197 Hydrogen Technologies will monitor the technology
trend to prepare for further revisionsdocument.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights other than those in the patent database. ISO [and/or] IEC shall not be held responsible for identifying
any or all such patent rights.
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ISO/CD TRDTR 19884-3:20252026(en)
Gaseous hydrogen — Pressure vessels for stationary storage —
Part 3:
Pressure cycle test data to demonstrate shallow pressure cycle
estimation methods
1 Scope
Two methods for evaluating cycle life extension by partial pressure cycles based on the Goodman diagram and
1)
exponential formula are presented in ISO 19884-1:—, Annex E of the proposed draft of ISO DIS19884-1. .
These methods do not rely on fracture mechanical methodology but on pressurizing cycle test data, since the
framework of ISO DIS1988419884-1 is constructed on performance demonstrated by pressurizing cycle test
data in hydrogen. DetailedThis document describes detailed methods with necessary conditions are described
in this document, with example data of their application.

2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminologicalterminology databases for use in standardization at the following
addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obphttps://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
Class A material
materialsmaterial known to have no significant or unanticipated changes in theirits performance or
mechanical properties when exposed to gaseous hydrogen under the listed service conditions
3.2
design pressure
pressure used in the design of the vessel for the purposes of establishing the minimum thickness of the
pressure shell for the stated cycle life and service conditions
3.3
full pressure cycle
cycle of pressure amplitude greater than 100% of the design pressure (3.2) to less than 10% of the design
pressure (3.2)
1)
Under preparation. Stage at the time of publication: ISO/DIS 19884-1:2026.

ISO/CD TRDTR 19884-3:20252026(en)
3.4
full pressure cycle life
maximum number of full pressure cycles in hydrogen service that the pressure vessel is designed to withstand
in service
3.5
mean stress
average of the maximum value and the minimum value of repeated stress
3.6
partial pressure cycle
cycle of pressure amplitude smaller than full pressure cycle (3.3) keeping the maximum pressure lower than
or equal to the design pressure (3.2)
3.7
partial pressure cycle life
maximum number of partial pressure cycles that the pressure vessel is designed to withstand in hydrogen
service
3.8
pressure differential
difference between the maximum value and the minimum value of repeated pressure
3.9
stress amplitude
half (1/2) of the difference between the maximum value and the minimum value of repeated stress
4 Goodman diagram based method

4.1 S-N diagram
The S-N diagram has been commonly used for the prediction of fatigue life of metallic specimens. The
Goodman diagram has also been employed to take into account the effect of the mean stressError! Reference
source not found. of the stress cycle on the fatigue life of the specimen. The Minor’s rule has been regarded
as valid for the fatigue life prediction of the specimen in the case of variational stress amplitude .Error!
Reference source not found. . These methods have been developed in the research of fatigue life of metals,
especially of steel. In line with the research and development history of fatigue life, these methods seem fit for
Type 1 pressure vessels , Type 2 pressure vessels , and Type 3 pressure vessels, where the critical failure
modes are fatigue crack penetration in the metallic shell. The merit of these methods can be applied to Type 4
pressure vessels , which consist of a metallic boss, a plastic liner, and a composite.
The pressure vessel manufacturer is responsible for developing the S-N diagram using the same materials and
manufacturing approach used for the Type 4 pressure vessels to be developed. As this is an S-N diagram to
evaluate fatigue characteristics of the composite, the failure mode needs to be consistent, e.g. always
composite failure for a Type 4 pressure vessel (i.e. burst, not liner leakage).
The following steps are requiredmust be used for a Type 4 vessel:
a) Establish the mean burst pressure of a vessel for which an S­-N diagram is to be developed. A minimum
of 4 units of the vessel is required to achieve this. Plot this point as 100 % stress, 1 cycle on the S-N
diagram.
ISO/CD TRDTR 19884-3:20252026(en)
b) Cycle a minimum of 4 units from no more than 10 % of the design pressureError! Reference source not
found. to a first specified pressure level for which the stress is known. Plot this point on the S-N diagram.
The S value will be a stress relative to the
...