ISO 19880-9:2024

International
Standard
ISO 19880-9
First edition
Gaseous hydrogen — Fuelling
2024-07
stations —
Part 9:
Sampling for fuel quality analysis
Reference number
© ISO 2024
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms . 7
5 Sampling hydrogen at fuelling stations for hydrogen fuel quality analysis . 8
5.1 General .8
5.2 Sampling hydrogen at the dispenser for off-line hydrogen fuel quality .8
6 Safety for sampling hydrogen gas at the dispenser nozzle .10
6.1 General .10
6.2 Safety training .10
6.3 Operational safety during sample collection .11
6.4 Safe operation limits .11
6.5 Warning signs . .11
7 Hydrogen sampling apparatus – hardware .12
7.1 Sampling apparatus – design requirements . 12
7.1.1 General . 12
7.1.2 Maximum allowable working pressure for parts of a sampling system directly
connected to the dispenser nozzle . 13
7.1.3 Maximum allowable working pressure for parts of a sampling system
downstream of pressure regulation . 13
7.2 Gas sample containers to be used with HQSA . 13
7.3 Sampling apparatus technical documentation .14
7.4 Marking of sampling apparatus .14
8 Hydrogen sampling apparatus –operational requirements .15
8.1 General . 15
8.2 Inspection and maintenance of the sampling system . 15
8.3 Sampling equipment requiring the use of an FCEV . 15
8.4 Sampling with venting to atmosphere .16
8.5 Reporting .16
Annex A (informative) Hydrogen gas sampling — Method A . 17
Annex B (informative) Hydrogen gas sampling — Method B .23
Annex C (informative) Hydrogen gas sampling – Method C .25
Annex D (informative) Hydrogen particulate sampling – Method D .28
Annex E (informative) Hydrogen particulate sampling – Method E .31
Annex F (informative) Combining gas collection and particle collection with the same device .36
Annex G (informative) Sampling report example .37
Bibliography .38

iii
Foreword
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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 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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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 197, Hydrogen technologies.
A list of all parts in the ISO 19880 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.

iv
International Standard ISO 19880-9:2024(en)
Gaseous hydrogen — Fuelling stations —
Part 9:
Sampling for fuel quality analysis
WARNING — The use of sampling apparatuses, such as those described in the annexes to this
document, is associated with the safety risks associated with high pressure flammable gases. This
document explains the general concepts of how gaseous and particulate samples may be taken.
Sampling should be performed only by highly trained technicians experienced with the hazards of
high-pressure hydrogen.
1 Scope
This document outlines requirements for sampling from hydrogen fuelling stations for samples taken at the
dispenser. The document defines the best practice for sampling at the nozzle of a hydrogen fuelling station
as part of the fuelling station acceptance testing, and ongoing operation.
Further, the document describes the minimum safety requirements for sampling.
This document is targeted for the sampling from the hydrogen fuelling station dispenser. Many of the generic
requirements within this document are applicable to sampling at other locations within the hydrogen
fuelling station, which can be carried out for hydrogen quality assurance, see ISO 19880-8, however, further
specific requirements that can be necessary for safe sampling are not addressed in this document.
The intention of sampling hydrogen is to enable analysis against the requirements of ISO 14687, and by
analytical methods validated by protocols described in ISO 21087.
This document supersedes, and is an extension to, the guidance published in ISO 19880-1:2020, Annex K.
NOTE Analytical methods are divided into on-line analyses and off-line analyses. On-line analysis allows for real
time analysis at hydrogen stations and is not covered in this document.
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 14687, Hydrogen fuel quality — Product specification
ISO 21087, Gas analysis — Analytical methods for hydrogen fuel — Proton exchange membrane (PEM) fuel cell
applications for road vehicles
ISO 17268, Gaseous hydrogen land vehicle refuelling connection devices
ISO 19880-1, Gaseous hydrogen — Fuelling stations — Part 1: General requirements
ISO 19880-8, Gaseous hydrogen — Fuelling stations — Part 8: Hydrogen quality control
SAE J2600, Compressed Hydrogen Surface Vehicle Fuelling Connection Devices

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
bleed
intentional expiration of a fluid from a fluid system
3.2
building
structure, usually enclosed by walls and a roof, constructed to provide support or shelter for intended
occupancy
3.3
canopy
roof, overhead shelter, or hood which affords a degree of weather protection
3.4
compressed hydrogen storage system
CHSS
hydrogen storage on-board vehicle
3.5
component pressure rating
maximum pressure at which it is permissible to operate a component as specified by the manufacturer at a
specified temperature
Note 1 to entry: See ISO 19880-1 for further details.
3.6
connector
matching parts (such as male and female parts) that can be put together to form a "connection" which
permits the transfer of fluids, electric power, or control signals
Note 1 to entry: Fitting (3.12) are a type of connector used in piping systems.
Note 2 to entry: Examples of connectors commonly used in hydrogen systems are as follows:
a) The fuelling nozzle (3.28) “connector” mates with the receptacle (3.36) “connector” on the vehicle to form the
connection for transfer of compressed hydrogen between the dispenser (3.7) and the vehicle, as defined in
ISO 17268 for this specific application;
b) The hose assemblies have connectors on each end that allow coupling to the hoses and connection to the piping
system, e.g. hose breakaway device or fuelling nozzle;
c) Control systems often use electrical connectors to allow rapid and secure assembly or replacement.
3.7
dispenser
equipment in the dispensing system (3.9), including the dispenser cabinet(s) (3.8) and support structure, that
is physically located in the fuelling area
Note 1 to entry: The hydrogen dispenser typically includes, as a minimum, the fuelling assembly (3.14), required
temperature and pressure instrumentation, filters, and the user interface to conduct vehicle fuelling.
Note 2 to entry: The manufacturer of the hydrogen dispenser can elect to include additional equipment in the
dispenser, including the possibility of all equipment in the dispensing system.

3.8
dispenser cabinet
protective housing (3.21) that encloses process piping and can also enclose measurement, control and
ancillary dispenser (3.7) equipment
3.9
dispensing system
system downstream of the hydrogen supply system comprising all equipment necessary to carry out the
vehicle fuelling operation, through which the compressed hydrogen is supplied to the vehicle
3.10
enclosure
structure, protective housing (3.21), container, machine cabinet, etc. which encloses or partially encloses
equipment of a station that can have access for maintenance but is not intended to be occupied
Note 1 to entry: The use of an enclosure can be to protect equipment from the environment, provide noise attenuation,
or provide safety (3.40) to the areas surrounding the equipment.
Note 2 to entry: A canopy (3.3) without walls is not regarded as an enclosure in this context.
3.11
explosive gas atmosphere
mixture with air, under atmospheric conditions, of flammable substances in the form of gas or vapour,
which, after ignition, permits self-sustaining flame propagation
Note 1 to entry: Although a mixture which has a concentration above the upper flammable limit (UFL) is not an
explosive gas atmosphere, it can readily become so and, generally for area classification purposes, it is advisable to
consider it as an explosive gas atmosphere.
[SOURCE: IEC 60079-10-1:2015, 3.2]
3.12
fitting
part or design feature on a component used to join (i.e. connect) any pressure retaining components in the system
3.13
forecourt
surfaced area where vehicle dispensing operations are conducted including the fuelling pad (3.15) and any
area underneath a canopy (3.3)
3.14
fuelling assembly
assembly consisting of a hose breakaway device, a hose(s), a nozzle (3.28) and connections between these
components that is part of the dispenser (3.7) providing the interface between the hydrogen fuelling station
(3.16) and the vehicle
Note 1 to entry: The fuelling assembly can include, or not, a nozzle vent line (with hose breakaway device and hose)
depending on the type of nozzle, and communications, if used.
3.15
fuelling pad
area with special construction requirements adjacent to the hydrogen dispensers (3.7), where customers
park their vehicles during fuelling
3.16
hydrogen fuelling station
HRS
fuelling station
hydrogen refuelling station
hydrogen filling station
facility for the dispensing of compressed hydrogen vehicle fuel, including the supply of hydrogen, and
hydrogen compression, storage, and dispensing systems (3.9)

3.17
harm
physical injury or damage to the health of people, or damage to property or the environment
[SOURCE: ISO/IEC Guide 51:2014, 3.1, modified — The word "physical" has been added.]
3.18
hazard
potential source of harm (3.17)
[SOURCE: ISO/IEC Guide 51: 2014, 3.2]
3.19
hazardous area
classified area
area in which an explosive gas atmosphere (3.11) is present or can be expected
to be present, in quantities such as to require special precautions for the construction, installation and use
of equipment
Note 1 to entry: The interior of many items of process equipment are commonly considered as a hazardous area
even though a flammable atmosphere may not normally be present to account for the possibility of air entering the
equipment. Where specific controls such as inerting are used the interior of process equipment may not need to be
classified as a hazardous area.
[SOURCE: IEC 60079-10-1:2015, 3.3.1, modified — The alternative preferred term "classified area" has
been added.]
3.20
hose assembly
assembly which includes the hose and end connections, including any necessary fittings (3.12), bend
restrictors, and appropriate markings.
3.21
housing
guard or enclosure (3.10) for operating parts, control mechanisms, or other components, that need not be
accessible during normal operation.
3.22
hydrogen service level
HSL
pressure level in MPa used to characterize the hydrogen service of the dispensing system (3.9) based on the
NWP (3.27) of the vehicle.
Note 1 to entry: The numerical value of HSL also matches the number after the “H” in the pressure class (3.32) (see
Table 1).
Note 2 to entry: See ISO 19880-1: 2020, Annex E for application of pressure terminology to hydrogen dispensing
systems and vehicles.
3.23
incident
any unplanned event that resulted in injury or ill health of people, or damage or loss to property, plant,
materials or the environment or a loss of business opportunity
Note 1 to entry: The use of the term incident is intended to include the term accident.

3.24
maximum allowable working pressure
MAWP
maximum pressure permissible in a system at the temperature specified for the pressure
Note 1 to entry: The maximum allowable working pressure can also be defined as the design pressure, the maximum
allowable operating pressure, the maximum permissible working pressure, or the maximum allowable pressure for
the rating of pressure vessels and equipment manufactured in accordance with national pressure vessel codes.
Note 2 to entry: See Annex E for discussion of pressure terminology and its application to dispensing systems (3.9) and
fuelling stations (3.16) in general.
3.25
maximum fuelling pressure
MFP
maximum pressure expected during a normal (fault-free) vehicle fuelling
Note 1 to entry: Per the UN GTR No. 13, the maximum fuelling pressure is 125 % NWP (3.27).
Note 2 to entry: Also referred to as Maximum Fill Pressure.
Note 3 to entry: See Annex E for discussion of pressure terminology and its application to dispensing systems (3.9) and
fuelling stations (3.16) in general.
3.26
maximum operating pressure
MOP
highest pressure that is expected for a component or system during normal operation including anticipated
transients
Note 1 to entry: In the case of the dispensing system (3.9), the MOP is equivalent to the maximum fuelling pressure
(3.26) of the vehicle.
Note 2 to entry: See Annex E for discussion of pressure terminology and its application to dispensing systems and
fuelling stations (3.16) in general.
3.27
nominal working pressure
NWP
pressure of a vehicle CHSS (3.4) at 100 % state of charge (SOC) at a gas temperature of 15 ºC
Note 1 to entry: See UN GTR No. 13 clause II-3.37, on page 54.
Note 2 to entry: For road vehicles, this is typically 35 MPa or 70 MPa.
Note 3 to entry: See Annex E for discussion of pressure terminology and the correspondence between vehicle
terminology and dispensing systems (3.9).
Note 4 to entry: Also known as “settled pressure” in ISO 10286.
3.28
nozzle
device connected to a fuel dispensing system (3.9), which permits the quick connect and disconnect of fuel
supply to the vehicle storage system
[SOURCE: ISO 17268:2012, 3.8]
3.29
particle
small piece of matter or oil
3.30
particulate
one or more solid or liquid particles suspended in hydrogen

3.31
pre-cooling
process of cooling hydrogen fuel temperature prior to dispensing
3.32
pressure class
non-dimensional rating of components designed to dispense hydrogen to road vehicles at the required
pressure and temperature
Note 1 to entry: The numbers following ‘H’ in the pressure class are numerically the same as HSL (3.22), but the HSL
identifies only the level of the dispensing service whereas the pressure class designation shows the component are fully
capable of meeting the pressure and temperature requirements for dispensing hydrogen at the indicated service level.
Note 2 to entry: See Annex E for discussion of pressure terminology and its application to dispensing systems (3.9) and
fuelling stations (3.16) in general.
Note 3 to entry: Additional examples of pressure class come from ISO 15649; e.g. "600", "3000" or "6000".
3.33
pressure relief device
PRD
safety (3.40) device that releases gases or liquids above a specified pressure value in cases of emergency or
abnormal conditions
Note 1 to entry: PRDs can be activated by pressure or another parameter, such as temperature, and can be either
re-closing devices (such as valves) or non-re-closing devices (such as rupture disks and fusible plugs). Common
designations for these specific types of PRDs are as follows:
— pressure safety valve (PSV) — pressure activated valve that opens at specified set point to protect a system from
rupture and re-closes when the pressure falls below the set point. Requirements for PSVs used in dispensing systems
(3.9) can be found in 19880-1:2020. PSVs protecting the dispensing system can reclose above the MOP (3.26);
— thermally-activated pressure relief device (TPRD) — a PRD that opens at a specified temperature to protect a
system from rupture and remains open.
Note 2 to entry: See Annex E for discussion of pressure terminology and its application to pressure protection of the
dispensing system and fuelling stations (3.16) in general.
3.34
probability
expression of the chance (likelihood) that a considered event will take place to property, system, business or
to the environment
3.35
qualified personnel
personnel with knowledge or abilities, gained through training and/or experience as measured against
established requirements, standards or tests, that enable the individual to perform a required function
[SOURCE: ISO 10417:2004, 3.13, modified — The word "characteristics" has been replaced with "knowledge".]
3.36
receptacle
device connected to a vehicle storage system which receives the nozzle (3.28)
Note 1 to entry: This can also be referred to as a fuelling inlet or gas filling port in other documents.
[SOURCE: ISO 17268:2020, 3.11]

3.37
risk
combination of the probability (3.34) of occurrence of harm (3.17) and the severity of that harm;
encompassing both the uncertainty about and severity of the harm
[SOURCE: ISO/IEC Guide 51:2014, 3.9, modified — The part “encompassing both the uncertainty about and
severity of the harm” has been added.]
3.38
risk assessment
determination of quantitative or qualitative value of risk related to a specific situation and a recognised
threat (also called hazard (3.18))
Note 1 to entry: Based on national requirements, a review of a risk analysis or a safety (3.40) concept by third party is
sometimes required.
3.39
risk level
assessed magnitude of the risk
3.40
safety
freedom from unacceptable risk
[SOURCE: ISO/IEC Guide 51:2014, 3.14]
3.41
safety distance
separation distance
safe distance
setback distance
distance to acceptable risk level (3.39) or minimum risk-informed distance between a hazard (3.18) source
and a target (human, equipment or environment), which will mitigate the effect of a likely foreseeable
incident (3.23) and prevent a minor incident escalating into a larger incident
Note 1 to entry: Safety distances can be split into restriction distances, clearance distances, installation layout
distances, protection distances and external risk zone.
3.42
safety perimeter
area around the location of the sampling activity where people not involved in the sampling activity are
prevented from entering, the extent of which is based on the appropriate safety distance (3.41)
4 Abbreviated terms
APRR average pressure ramp rate
ERP emergency response plan
FCEV fuel cell electric vehicle
H35 indication for 35 MPa NWP hydrogen fuelling as defined in ISO 17268
H70 indication for 70 MPa NWP hydrogen fuelling as defined in ISO 17268
HAZOP hazard and operability study
HPSA hydrogen particle sampling apparatus
HQSA hydrogen quality sampling apparatus

HSG health and safety guidance
HSTA hydrogen station test apparatus
IrDA Infrared Data Association
LFL lower flammability limit
P&ID piping and instrumentation diagram
PPE personal protective equipment
PSV pressure safety valve
QRA quantitative risk assessment
SAE SAE International formerly known as Society of automotive engineers
TPRD temperature-activated pressure relief device
5 Sampling hydrogen at fuelling stations for hydrogen fuel quality analysis
5.1 General
Analytical methods are divided into on-line analyses and off-line analyses. On-line analysis allows for real
time analysis at hydrogen stations and is not covered in this document. For off-line analysis of samples, the
analytical methods used shall be validated by protocols described in ISO 21087.
Sampling is used to perform an accurate and comprehensive analysis of impurities, which is done externally,
typically at a laboratory.
Sampling of hydrogen involves collecting a sample of the fuel from the dispenser in a gas container or in the
case of particulate matter on a filter. Sampling can be performed at maximum operating pressure, but very
often require pressure reduction for sample collection into gas containers.
The sample should be:
— representative of a normal fuelling sequence;
— collected at a pressure that ensures the sample is representative of dispensed hydrogen;
— collected at a flow that ensures the sample is representative of dispensed hydrogen.
Gas phase impurities in the dispensed hydrogen may be captured with a sampling apparatus and taken off
site in a dedicated sample vessel for laboratory analysis. A representative sample from multiple fuelling
station hydrogen storage banks should be taken to confirm that all storage banks have been cleaned and
purged properly.
5.2 Sampling hydrogen at the dispenser for off-line hydrogen fuel quality
To enable off-line analysis of hydrogen as dispensed from hydrogen fuelling stations, samples of hydrogen
are typically taken from the hydrogen dispenser fuelling nozzle. Figure 1 shows the general concept of
sampling for off-line analysis.

Figure 1 — Schematic of hydrogen sampling to analytical methods
The annexes to this document describe examples of different methodologies that can be followed in order
to collect samples from the dispenser nozzle. There are three different methodologies for hydrogen gas
sampling and two methods for particulate sample collection described in these annexes.
NOTE Samples can be taken for analysis from other points of the station for hydrogen quality assurance, see
ISO 19880-8, however the requirements for this are not included in this document.
The characteristics of the different example methodologies are listed in Table 1.
NOTE Depending upon equipment availability and local regulations, certain methods can be desirable over
others, i.e. the option of HRS manual dispensing (safety override) and availability of fuel cell electric vehicles (FCEVs).
Table 1 — Characteristics of different example sampling strategies
Sample Annex con-
HRS Reference
Sample container taining fur-
Method Sampling time fuelling Sink sample pres-
Type volume ther details
override sure
(example)
a
Method A Gas ~3 min No FCEV or test ≤10 L <16 MPa A
CHSS
Method B Gas <1 minute per Yes Vent system ≤2 L <7 MPa B
container
Method C Gas <20 min Yes Vent system ≤47 L <12 MPa C
Method D Particulate < 10 min Yes Vent system Not Average pres- D
applicable sure ramp
rate (APRR)
according to
b
SAE J 2601
a
Method E Particulate ~3 min No FCEV or test Not APRR accord- E
CHSS applicable ing to SAE J
b
a
Sampling while fuelling into a CHSS (instead of venting).
b
Representative fuel passing the filter should be of a minimum 2,5 kg hydrogen.
It is important that the sample for gas and particulates is collected safely and that the sample is representative
of the dispensed hydrogen.
The hydrogen quality sampling apparatus (HQSA) described in this document can be subject to conventional
hydrogen fuelling parameters such as the 87,5 MPa (1,25 × nominal working pressure (NWP)) test pulse for
H70 fuelling when methods not applying HRS fuelling override (e.g. Methods A, E).

Station side bank shifting can impact representative sample collection. Sampling strategies presented in the
annexes of this document do not ensure that sample is collected from all banks.
The hydrogen particulate sampling methods described in this document can be used to check the technical
cleanliness (particulates) according to ISO 14687 of the fuel in 70 MPa hydrogen fuelling stations at fuel
delivery flow rates up to 60 grams per second.
HQSA and hydrogen particle sampling apparatus (HPSA) devices may relay IrDA communications (such as
described in SAE J2799).
6 Safety for sampling hydrogen gas at the dispenser nozzle
6.1 General
Gas sample collection and particulate collection sampling system design, setup, and sampling procedure
should be based on a risk assessment. Collection shall be suitable for hydrogen service as defined in
Clause 7, under the process conditions defined in 7.1.2, unless other safety precautions have been taken.
Piping systems and other equipment comprising the hydrogen sampling apparatus shall comply with the
requirements in 7.2.
Hydrogen sampling at the dispenser requires gas flow, vent or sink. This document assumes that one or
more of the following will be available:
a) a dedicated fixed vent port and line at the hydrogen station (this is preferred) for hydrogen venting/
purging during sampling (see 8.4);
b) a temporary vent stack located in an area away from adjacent hazards. Ensure adequate separation from
ignition sources, and people/objects that would be affected by both unignited and ignited hydrogen
releases;
c) a vehicle CHSS: FCEV (see 8.3), hydrogen station test apparatus (HSTA), or test tank system.
The general guidance from this document should be observed. In addition, specific guidance based on the
hydrogen sampling methodology is found in the annexes to this document.
In order to conduct gas sampling, the safety regulations relevant to the dispenser and fuelling station where
sampling is to be conducted should be taken into consideration.
Where sampling equipment uses the dispenser vent line for purging or relief venting, this shall be in
accordance with guidelines given in Clause 8.
Personal safety equipment, e.g. safety glasses, fire resistant clothing, gloves and hearing protection, should
be worn at all times when sampling of hydrogen is conducted.
NOTE Further guidance on vent system design can be found in EIGA Doc 211/17 and CGA G-5.5.
6.2 Safety training
Safety precautions should be taken when sampling hydrogen gas and particulates at a hydrogen fuelling
station.
Sampling operators shall be trained in the operations of the sampling apparatus and the necessary
procedures at HRS for dispensing the sample gas, including the station emergency response plan. For
sampling of hydrogen, it is important to understand that the hydrogen provided by the station is at a very
high pressure.
6.3 Operational safety during sample collection
A safety perimeter should be established preventing public access to the HRS sampling device and the
vent system assembly. The safety perimeter should be established from HRS or sampling apparatus
documentation safety requirements or per risk assessment.
Smoking or use of ignition sources should be prevented within this perimeter.
High-pressure hydrogen releases have the potential to ignite. Discharges can originate from the high velocity
flow over surfaces. Arcing can also originate from mechanical operations, therefore, non-sparking tools (e.g.
brass spanners) should be used.
All hose assemblies should be attached to a suitable anchor point using an anti-whip during sampling to
prevent the hose from whipping should the connection become uncoupled.
Electrical grounding of the sampling device to the dispenser’s earth ground should be ensured.
Pressure release from bleed valves should be performed with caution as fast pressure release can ignite the
hydrogen released.
To counteract the temperature increase by hydrogen fuelling, hydrogen is often pre-cooled down to −40 °C
in order to achieve fast fuelling rates. Issues such as “freeze on” of the fuelling nozzle to the HQSA or HPSA
while sampling hydrogen can occur.
Low temperatures can also affect the functionality of connections (quick connects and nozzle adapters).
Appropriate protective gloves should be worn by operators of the sampling instrumentation.
Leak detection should be performed prior to sampling with a portable hydrogen detector to assist in
confirming proper connection integrity. Leak detection using soap bubbles, or any liquid shall not be used in
order to avoid contamination of the sample.
6.4 Safe operation limits
During sample collection the device operator should take care to not allow the sample container to exceed
operational limits.
a) exceeding the maximum fuelling pressure:
Monitor the pressure and the ramp rate of the sample container during sampling. If pressure falls or
rises outside operational limits, then terminate the sampling;
b) exceeding the fuelling gas temperature:
Check the temperature of the sample container while sampling, and suspend the fuelling immediately if
it is outside operational limits.
6.5 Warning signs
Warning signs shall be placed to warn public/people not involved in the sampling about hazards identified,
for example including (but not limited to) the following types of hazards:
— flammable, pressurized hydrogen;
— hazardous areas, where flammable, potentially explosive gas atmospheres may be present;
— no smoking, open flames, or other ignition sources;
— authorized access only.
Warning signs should be of sufficient durability to withstand the physical environment involved, including
the effects of weather.
7 Hydrogen sampling apparatus – hardware
7.1 Sampling apparatus – design requirements
7.1.1 General
The sampling equipment may have different requirements. The sampling system should consider the
requirement for sampling container (flow and pressure requirements), the type of material used, the HRS
requirements (flow, pressure and filling protocol), and the process (pressure pulse, venting).
It is important to differentiate the section, flow, and pressure requirements to ensure the system is safe
and fit for service. There is a section of the sampling system that will be in contact with HRS nozzle (need to
comply with HRS requirements) and a section of the sampling system that may be in contact with reduced
flow and pressure (after pressure regulator and pressure relief valve).
The cycle life for the components of the sampling assembly should be defined and stated so that planned
maintenance activities can pre-empt a failure.
High pressure hydrogen dispensing system components should be marked with the pressure class only if
components are designed and verified to meet or exceed the pressure, temperature, material compatibility,
and service life requirements.
High pressure components shall be mounted in strict compliance with the supplier's instructions, following
a well-defined assembly procedure. The sampling system should be clearly labelled with all information as
stated in 6.5.
Sampling systems shall be protected against over pressurization. This may use over pressure protection
incorporated into the dispensing system where appropriate, see 7.1.2, or necessitate further overpressure
protection within the sampling system where components are not rated to the dispensing system maximum
allowable working pressure (MAWP), see 7.1.3.
Vent valves and over pressure protection shall be capable of being connected to either the dedicated fixed
vent line, or temporary vent stack described in 6.1.
In addition to the pressure rating, the HQSA or HPSA should meet the following requirements:
— an ambient temperature range of –40 °C to +50 °C, unless local conditions permit or require other
temperature limits, for the gas container. It is important to consider temperature and pressure change
in the definition of the pressure regulation. This is to ensure that the gas container pressure will not be
over-pressurised during transport of the gas container;
— material compatibility of materials normally in contact with hydrogen;
— a specified cycle life before maintenance or replacement.
— components rated for the maximum hydrogen flow delivered; it is important to ensure that the maximum
flow can be achieved by the components according to the fuelling protocol. If components are used that
are below the flow ratings of the HRS fuelling protocol, then the maximum flow of the dispensing system
shall be lowered accordingly to the component with the lowest flow rating.
The fuelling receptacle shall comply with ISO 17268 and/or SAE J2600. Where included in the sampling
apparatus, the fuelling nozzle shall comply with ISO 17268 and/or SAE J2600.
NOTE Fuelling protocols include pauses in the fuelling, which need to be considered in the design/operation of
the sampling apparatus. A pause is typically included at the start of fuelling in order to perform a leak test. In certain
protocols, further pauses for leak checks are also defined part way through the fuelling.

7.1.2 Maximum allowable working pressure for parts of a sampling system directly connected to
the dispenser nozzle
Where no pressure regulation is incorporated into the sampling system, or upstream of any pressure regulation,
all components shall be rated to the maximum allowable working pressure of the dispensing system.
The MAWP of dispensing systems may vary from station to station. For example, a dispensing system
compliant with ISO 19880-1 will be protected against over-pressurization according to the dispensing
system MAWP as defined in Table 2, relative to the dispenser hydrogen service level (HSL), the pressure
class (as defined in ISO 17268). See ISO 19880-1 for explanation of dispensing system pressure levels.
Table 2 — Dispensing system pressure levels and recommended component minimum pressure ratings
Maximum operating Dispensing system MAWP
Hydrogen service level Pressure
pressure Minimum component pressure rating for
(HSL) class
(MOP) dispensing system components
Equal to NWP of vehicle 1,25 × HSL 1,375 × HSL
being fuelled Highest pressure during Highest permissible setpoint for dispensing
normal fuelling system pressure protection
25 MPa H25 31,25 MPa 34,375 MPa
35 MPa H35 43,75 MPa 48,125 MPa
50 MPa H50 62,5 MPa 68,75 MPa
70 MPa H70 87,5 MPa 96,25 MPa
These are maximum values of MOP and MAWP, and recommended minimum component pressure ratings based on achieving the
MOP needed to fuel the CHSS of the hydrogen vehicle over the full range of operating conditions.
In addition to the pressure rating, the hydrogen sampling apparatus should meet the following requirements:
— an ambient temperature range of -40 °C to +50 °C, unless local conditions permit or require other
temperature limits.
7.1.3 Maximum allowable working pressure for parts of a sampling system downstream of
pressure regulation
Gas sampling may require using a sample container or other component that is rated lower than the
dispensing system MAWP. The sampling components rated lower than the MAWP should be positioned after
pressure regulation and be protected by an additional pressure relief device(s) (PRD) set appropriately
for the MAWP for this part of the sampling system. Pressure regulating devices should not be self-venting
without capture to vent.
PRD's shall be compliant with ISO 4126-1 or ISO 4126-2 as appropriate.
The pressure relief valve and any other purging system should be compliant in term of pressure and flow
with the venting assembly (i.e. flow and pressure specification of the HRS vent if accessible or mobile vent
stack). The sampling assembly should not create over-pressurization to the dispensing system. Any pressure
safety valve (PSV) or venting components should be connected to a safe vent to avoid any significant
hydrogen vented on HRS forecourt.
7.2 Gas sample containers to be used with HQSA
Hydrogen gas sample containers should have the appropriate certification, marking, and suitable packaging
for transportation with hydrogen. The use of the containers should be within the operating temperature
and pressure range given by the manufacturer.
In order to obtain a representative sample, containers with wall treatment, such as passivation, to minimize
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