Tiêu chuẩn iso ts 19880 1 2016

This document is a pl ca le t o fuel ing for lght d ty hydrog en land vehicles, but it can also be used as guidanc for fuel ing buses, trams, mot or ycles an fork-lf truck a plcations, w

Gaseous hydrog en — Fuel ing

Part 1:

Carb ra t d’h dro ène g zeu — Stations-service —

Partie 1: Exigenc s g n rale s

Refer ence n mb r

ISO/TS 1 8 0-1:2 16(E)

Fir t edition

2 16-07-0

COPYRIGHT PROTECTED DOCUMENT

© ISO 2016, P blshed in Sw itz rlan

A ll rig hts r eserved Unles otherw ise spe ified, nopar of this p blc tion ma y be r epr od c d or utilz d otherw ise in an form

or b an me ns, ele tr onic or me hanic l, inclu in p oto opying , or postin on the internet or an intranet , w ithout prior

written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

F reword vii

1 Sc ope 1

2 Nor mati ve r eferenc es 2

3 Terms an definitions 3

4 A bbreviated terms 10

5 General safety rec ommendations 11

5.1 Hydr og en fuel ng s ation safety recommen ations 1

5.2 R isk as es ment 1

5.2.1 Methodolog y for semi-q antitative an q antitative risk as es ment or as es ing hydr og en ins alation safety 1

5.3 Mitigation measur es to impr ove sys em safety 2

5.4 Mitigations which r educ the p tential for the formation of a flamma le or ex plosive mix tur e 2

5.4.1 General 2

5.4.2 Hydr og en dete tion sys ems 2

5.4.3 Safety an emer g ency sh t-of sys ems 2

5.4.4 Mitigation for the formation of a flamma le or ex losive mixtur e in enclosur es 2 5.4.5 General r eq ir ement hydrog en venting for mitigation for the formation of a flamma le or ex plosive mix tur e 2

5.5 Mitigations which r educ the p tential for ig nition 2

5.5.1 General 2

5.5.2 A r eas subje t to r estriction of activity 2

5.6 Mitigation of theescalation an / r imp ct of a fir e or ex plosion orig inating fr om the fuel ng instalation 24

5.6.1 General 24

5.6.2 Flame dete tion sys ems 2

5.6.3 E closur es containing hydr og en sys ems 2

5.6.4 Emer g ency r elease of gas fr om hydr og en s orag e tan s u de fir e conditions 2

5.7 Mitigation of theefe t of an ex te nal fir e/event on the fuel ng station ins alation 2

5.7.1 General 2

5.7.2 La yout 2

5.7.3 Fire b r ie recommen ations 2

5.7.4 Mitigating agains vehicular imp ct 2

5.7.5 Firefighting sys ems 2

5.7.6 Emer g ency principles an o erations 2

5.8 Safety dis anc s 2

5.8.1 General 2

5.8.2 T ypes of safety distanc s 2

5.8.3 Examples of safety distanc s 3

5.8.4 Safety dis anc sr elating to hydrog en vent stack outlets 3

5.9 Pr ote tion measur es for non-hydr og en hazar ds 3

5.9.1 General 3

5.9.2 Pr ote tion measur es for asphyxiation hazar d in an enclosur e .3

5.9.3 Pr ote tion measur es for emer g ency eg r es from enclosed sp c s 3

5.9.4 Pr ote tion measur es from envir onmental conditions 3

5.9.5 Pr ote tion measur es for hose whip 3

5.9.6 Pr ote tion measur es for noise 3

6 Proc es c ontrol and safety systems 33 6.1 General 3

6.2 Emer g ency sh tdown fu ctionalty 34

6.3 Man aly actuated emer g ency s o devic s 3

6.4 Remote sys em control 3

7 Hy r og en su pl y safety and operatio 36

7.1 On site g eneration 3

7.1.1 Hydrog en g ener ators using wate ele tr olysisproc s 3

7.1.2 Hydrog en g ener ators using fuel pr oc s ing te h olog ies 3

7.2 Hydrog en delve y 3

7.2.1 Gaseous hydr og en sup ly b tube tr aie s an multiple element gas containe s (ME C) 3

7.2.2 Liq id hydr og en sup ly 3

7.3 Pipelne 3

8 Hy r og en dispensing 39 8.1 Dispensing desc iption 3

8.1.1 Dispense comp nent 40

8.1.2 Dispense sensors location 40

8.1.3 A mbient temperature rang e of fuel ng 40

8.2 Hydrog en F EV fuel ng 41

8.2.1 Refer enc fuel ng lmit of F EV vehicles 41

8.2.2 Fuel ng pr oc s contr ol 41

8.2.3 Manual contr ol of dispensing .4

8.2.4 Pr es ur e integ rity che k (leak che k) 4

8.2.5 Mete ing 4

8.2.6 Max imum flow rate and pr es ure dr op 4

8.2.7 Flow contr ol an isolation 4

8.3 Dispense safety devic s 4

8.3.1 General considerations 4

8.3.2 Dispensing emer g ency sh tdown 45

8.3.3 Ove -pr es ure pr ote tion 45

8.3.4 Dispense temper atur e contr ol fault 46

8.3.5 Limitation of hydr og en r eleased in case of fuel ng lne br eak 46

8.3.6 Pr oc s contr ol faiure 46

8.3.7 Sh tdow n in case ofbr eakawa y activ tion 46

8.3.8 P ysical distur banc of the dispense 46

8.3.9 Hazar dousar ea arou d the dispense 47

8.4 Hydrog en q alty 47

8.5 Hydrog en q alty contr ol 47

8.5.1 General 47

8.5.2 Dispense fuel fite s 48

9 Equipment and c omponents 48

9.1 General 48

9.1.1 General eq ipment r ecommen ations 48

9.1.2 Mater ial hydr og en comp tibi ty 48

9.1.3 Hydrog en an mate ial compatibi ty at c y g enic temperatur es .49

9.1.4 Othe mate ial r ecommen ations 49

9.2 Piping car ying gaseous hydr og en

49 9.2.1 General 49

9.2.2 Piping , fitting s, v lves, reg ulator for c y g enic se vic 49

9.3 Hydrog en s or ag e r ecommen ations 5

9.3.1 Gaseous hydr og en s orag e ves els 5

9.3.2 Hydrog en s orag e siting r ecommendations 5

9.4 Hydrog en compres ors 5

9.4.1 General 5

9.4.2 Vibration an mo ement 5

9.4.3 C ntrol an monitoring 5

9.5 Cry g enic pumps 5

9.5.1 General 5

9.5.2 High pr es ur e v p riz r 54

9.6 Pr es ure r elef devic s for gaseous hydr og en sys ems 54

9.7 Valves for gaseous hydrog en 5

9.8 Ins rument for gaseous hydrog en 5

9.9 Fite s for gaseous hydr og en 5

9.1 Dispense s 5

9.1 1 L cation an pr ote tion of dispense s 5

9.1 2 Fuel ng p d 5

9.1 3 Dispense sys em desig n 5

9.1 4 Dispense fuel ng as embly 5

9.1 Hose as embly 6

9.1 1 Rated o er ating con itions 6

9.1 2 Hose as embly desig n 6

9.1 3 Hose as embly type tes ing and pr od ction testing 6

9.1 4 Venting hose as embly 6

9.1 Fuel ng con e tor (noz le) g eneral desig n an as embly 6

9.1 1 General desig n an as embly 6

9.1 2 Depres urization of noz les 6

9.1 Hose br eakawa y devic g eneral desig n and as embly 6

9.1 1 Rated o er ating con itions 6

9.1 2 Breaka wa y d rabi ty 6

9.14 Gaseoushydr og en vent ys ems 6

9.14.1 General 6

9.14.2 Piping desig n 6

9.14.3 Flame arres ors 6

9.14.4 Vent outlet 6

9.14.5 Max imum flow r ate calculation 6

9.14.6 Piping diamete an exit velocity 6

9.14.7 Max imum pr es ure dr op 6

9.1 Pneumatics 6

9.1 Hydr og en purifie 6

10 Electrical safety 64

1 1 General 64

1 1.1 Ove view of ele trical hazar ds .64

1 1.2 C mp nent 6

1 1.3 Site intercon e tions to an / r betwe n eq ipment as embles 6

1 1.4 Ele trical g r ou ding 6

1 1.5 Lightning pr ote tion 6

1 2 Hazar dous ar eas (potentialy ex plosive atmospher es) 6

1 2.1 General 6

1 2.2 Pr ote tion r eq ir ements for ele trical eq ipment within hazar dous (clas ified) areas 6

1 2.3 Othe eq ipment in hazar dous (clas ified) ar eas 6

1 2.4 A r eas adjac nt o hazar dous areas 6

1 2.5 Pr ote tion from ig nition d e to ac umulation of s atic char g e 6

1 3 Ele tr omag netic comp tibi ty an inte fer enc (EMC) 6

1 3.1 General 6

1 3.2 In ustrial (EMC)envir onment 6

1 3.3 Residential, commer cial, an lg ht-in us rial (EMC)environment 6

11 Mar king s 69

1 1 General 6

1 2 Warning sig ns 6

1 3 Fu ctional identification 7

1 4 Mar king of eq ipment (data plate) 7

1 5 Referenc desig nations 7

1 6 Emer g ency contact information 7

12 Technical documentation 72

1 1 General 7

1 2 Information to be pr ovided 7

1 4 Ins alation document 7

1 4.1 General 7

1 4.2 Ins alation documentation for hazar dous (clas ified)areas 74

1 4.3 Venting 74

1 4.4 S ismic documentation 74

1 4.5 Han lng an lfing documentation 7

1 5 Ove view diag rams and fu ction diag rams 7

1 6 Cir cuit diag r ams 7

1 7 Flow (P& ID) diag rams 7

1 8 Fuel ng s ation o er ating man al 7

1 9 Hydrog en fuel ng s ation dispense o eration ins ructions 7

1 1 Maintenanc manual 7

1 1 S rvic man al 7

1 1 Part ls 7

1 1 Te h ical fie .7

13 Statio inspectio and tests 77

1 1 General 7

1 2 Minimum hydr og en fuel ng station ac eptanc inspe tion 7

1 2.1 General 7

1 2.2 Minimum hydr og en fuel ng s ation ac eptanc tes ing 7

1 2.3 Pr es ur e tes 7

1 2.4 Leak tes 7

1 2.5 Ele trical tes ing 8

1 2.6 C mmu ications tes 8

1 2.7 Safety an pe formanc fu ctional tes ing of the hydr og en fuelng station 8

1 3 Minimum pe iodic hydr og en fuel ng s ation inspe tion an tes 8

A nne x A (informative) S fety distanc es definitio and basic pr inciples 87

A nne x B (informative) Pr oposal for h ydrog en fueling verification of the SA E J26 1 fueling pr otoc ol 93

A nne x C (informative) Example matric es for g uidanc e for hydr og en qualty c ontrol 104

A nne x D (informative) Pres ur e level definitio s for the c ompr es ed hydrog en storag e system an fueling station dispenser 112

A nne x E (informative) Examples of vehicula impact pr otectio me sures 113

Biblog raph y 115

ISO (he Int ernational Org nization for Stan ardization) is a worldwide fede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Standards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a l shed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www.iso.org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identif ied d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www.iso.org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

F or an ex lanation on the meaning of ISO spe if ic t erms an ex r s ions r lat ed t o conformity

as es ment, as wel as information a out ISO’ s adhe enc t o the World Trade Org nization (WTO)

principles in the Te hnical Bar ie s t o Trade (TBT) se the fol owing URL: F or word – Sup lementary

information

The committ ee r sp nsible for thisdocument is ISO/TC1 7, Hydro en techn lo ies

ISO/TS 1 8 0-1 has be n pr p r d with the ultimat e g oal of develo ing an Int ernational Stan ard an

it r plac s ISO/TS 2 1 0:2 0 , on the same subje t, w hich was with rawn in 2 1

A l s of al p rt in theISO 1 8 0 se ies can be fou d on the ISO websit e

Gaseous hydrog en — Fuel ing stations —

Part 1:

This document r commen s the minimum design charact eris ics for safety an , w he e a pro riat e,

for pe formanc of publ c an non-publc fuel ing s ations that dispense g seoushydrog en t o lght d ty

lan vehicles (e.g Fuel Cel Ele tric Vehicles)

NOTE T ese recommen ations are in ad ition t o ap lica le national re ulations an codes, which can

prohibit certain aspects of this document

This document is a pl ca le t o fuel ing for lght d ty hydrog en land vehicles, but it can also be used as

guidanc for fuel ing buses, trams, mot or ycles an fork-lf truck a plcations, with hydrog en st orag e

ca acities out ide of cur ent publshed fuel ng prot ocol s an ards, such as SAE J2 0

R esidential a plcations t o fuel lan vehicles and non-publ c demons ration fuel ng s ations ar not

inclu ed in this Te hnical Spe if ication

This Te hnical Spe if ication pro ides guidanc on the folowing element of a fuel ng s ation ( e

Figur 1 an Figur 2):

— hydrog en prod ction/delve y sy st em

— del ve y of hydrog en b pipel ne, trucked in g seous an / r lq id hydrog en, or metal hydride

st orag e traie s;

— on-sit e hydrog en g ene at ors using wat er ele troly sis proc s or hydrog en g ene at ors using fuel

proc s ing t echnolo ies;

— lq id hydrog en st orag e;

— hydrog en purif ication sy st ems, as a plca le;

— compr s ion

— g seous hydrog en compr s ion;

— pumps and v p riz rs;

— g seous hydrog en bufe st orag e;

— pr -co l ng devic ;

— g seous hydrog en dispense s

Figure 1 — Example of typical elements ina hydrog n fueling statio , including the

hydrog n supply

Figure 2 — Imag e of an example hy rog en fuel ing statio

2 Normati ve referenc es

The folowing document , in w hole or in p rt, ar normatively r fe enc d in this document an ar

in ispensa le for it a pl cation F or dat ed r fe enc s, only the edition cit ed a pl es F or u dat ed

r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment )a pl es

The e ar no normative r fe enc s in this document

3 Terms and definitions

F or the purposes of this document, the folowing t ermsand definitions a ply

ISO an IEC maintain t erminolo ical data ases for use in s an ardization at the folowing ad r s es:

— IECEle tro edia: a aia le at ht p:/ www.ele tro edia.org

— ISO Onlne brow sing plat orm:a ai a le at ht p:/ www.iso.org o p

org nization, offic or in ivid al r sp nsible for a pro ing a faci ty along with an eq ipment, an

ins al ation or a proc d r

3.3

ble d venting

ex iration or inspiration of air or g s from, or t o, one side of a dia hra m of any ac es ory, comp nent,

or eq ipment such as a v lve, pr s ur r gulat or or swit ch

3.4

bre kaway device

devic ins aled on a dispensing hose that separates w hen a given pul for e is a pled an closes the flow

of hydrog en to pr vent g s leakag e an prot ect the dispense from damage from vehicles driving aw ay

3.5

bufe storag e tanks

pr s uriz d tan s, w hich can be locat ed betwe n a hydrog en g ene at or an a compr s or for an even

flow of g s t o the compr s or or betwe n the compr s or an dispense for ac umulation of pr s uriz d

g s sup ly for vehicle fuel ng

3.6

co trol sy stem

syst em w hich r spon s t o input signals from the proc s an / r from an o e at or an g ene at es output

signals causing the proc s t o o e at e in thedesir d man e

Note 1 t o entry: A separate safety instrumented syst em ( SIS), ty icaly with a gre ter relia ility than the more

b sic proces control sy stem (B CS), may b req ired, ac ording to the man facturer’ s risk as es ment, to

respon solely to safety c itical alarms F rther information is provided in IE 6 15 8an 6 15 1

p rt of the pr s urised-g s fuel ing s ation via w hich the pr s urised g s is dispensed t o vehicles

Note 1t o entry: As an e ample, the dispenser may inclu e a dispenser ca inet, g s flow meter, a fueling hose an

fueling noz le at achments

3 9

dispenser cabinet

prot ective housing that encloses proc s piping an ma also enclose measur ment, control an

anci lary dispense eq ipment

dispensing sy stem

sy st em comprising al eq ipment ne es ary t o car y out he vehicle fuel ng o e ation, downs r am of

the hydrog en supply sy st em

3.11

enclosure

prot ective housing that ma enclose, or p rtial y enclose, eq ipment in orde t o prot ect it from the

environment, pro ide noise att en ation, or pro ide safety t o the ar as sur ou ding the eq ipment

design featur that ensur s that safeo e ating con itions ar maintained in the event of a malfu ction

of control devic s or an int er uption of a sup ly sour e

fueling as embly

p rt of the dispense pro iding the int erfac betwe n the hydrog en fuel ing s ation an the vehicle

- an as embly consis ing of a br akawa devic , a hose(), a noz le an conne t ors between these

comp nent

3.18

fueling hose

flexible con uit used for dispensing g seous hydrog en t o vehicles through a fuel ing noz le

3.1 9

fueling pad

ar a adjac nt t o the hydrog en dispense s, w he e cust ome sp rk their vehicles for fuel ing

3.20

fueling statio

faci ity for the dispensing of compr s ed hydrog en vehicle fuel, oft en r fe r d t o as a hydrog en fuel ng

s ation (HRS) or hydrog en f il ng s ation, inclu ing the supply of hydrog en, an hydrog en compr s ion,

st orag e an dispensing sy st ems

3.21

standalo e

in epen ent faci ty for the dispensing of compr s ed hydrog en only

Not e 1t o entry: T is is a ty e of f el n s ation (3.2 )

integrated

faci ity for the dispensing of compr s ed hydrog en int egrat ed int o an exis ing, or new buid,

conventional fuel ing s ation

Note 1t o entry: T is is a ty e of f el n s atio (3.2 )

3.23

fueling statio o erator

pe son or org nisation r sp nsible for the safe o e ation, maintenanc an housek eeping of the

fuel ng s ation

3.24

guard

p rt of a machine spe ialy used t o pro ide prot ection b means of a phy sical b r ie

Note 1 to entry: Depen ing on its construction, a guard may b caled casing, cover, s re n, do r, enclosed

guard, etc

3.25

harm

phy sical injury or damag et o the health of peo le, or damag e t o pro e ty or the environment

[ SOURCE:ISO/IEC Guide 5 :2 14, 3.1]

3.26

harmo ised standard

Euro ean s an ard develo ed b a r co nised E ro ean Stan ards Org nisation (CEN, CENELEC, or

ETSI), in lne with a E ro ean Dir ctive

Note 1 t o entry: harmonized stan ards are c e t ed folowing a req est from the E rope n Commis ion t o one

of these org nisations Man facturer , other economic operator , or conformity as es ment b dies can use

harmonised stan ards t o demonstrate that prod cts, services, or proces es comply with relevant EU le islation

3.27

hazard

p t ential sour e of harm

[ SOURCE:ISO/IEC Guide 5 : 2 14, 3.2]

3.28

hose as embly

inclu es the hose, a pro riat e en conne t ors (coupl ngs or f it ings), ben r s rict ors ( if ne es ary),

an a pro riat e markings

3.29

ho sing

se tion of a sy st em that encloses, an is int en ed t o prot ect, o e ating p rt , control me hanisms, or

othe comp nent that ne d not be ac es ible d ring normal o e ation

3.30

hy rog en purifier

eq ipment t o r mo e un esir d cons ituent from the hydrog en

Note 1t o entry: Hydro en p rif ier may comprise p rif ication ves els, dryer , f ilt er an separator

3.31

incident

any u planned event that r sult ed in injury or i l health of peo le, or damag e or los t o pro e ty, plant,

mat erials or the environment or a los of busines o portu ity

Note 1t o entry: T e use of the term incident is inten ed to inclu e the term ac ident

maximum alowable working pres ure

ma imum pr s ur that a comp nent ma ex e ienc in se vic , inclu ing upset con itions,

in epen ent of t empe atur , befor initiating mitig tion o tions, ty icaly the b sis for the set p int of

the pr s ur r lef devic prot ecting the ves el or piping sy st em

Not e 1 t o entry: T e ma imum al owa le working pres ure may also b def ined as the design pres ure, the

ma imum alowa le operating pres ure, the ma imum permis ible working pres ure, or the ma imum al owa le

pres ure for the rating of pres ure ves els an eq ipment man factured in ac ordance with national pres ure

highes pr s ur that is ex e t ed for a component or sy st em d ring normal o e ation

Not e 1t o entry: T is is the pres ure from which hydrog en at a temperature of 8 °C would set le at the NWP at a

t emperature of 1 °C

Not e 2t o entry: F rther guidance on pres ure terminolo y is inclu ed in An e D

3.34

mechanical y actuating safety equipment

me hanicaly actuating eq ipment that pr vent the fuel ing s ation o e ation out ide spe if ied

ac epta le ma imum or minimum o e ating pr s ur s or that pr vent a g s leakag e in theevent of an

incident

3.35

mitig tio

combination of the measur s incorp rat ed at the design s ag e, an those measur s r q ir d t o be

implement ed b the s ation o e at or, dispense o e at or, or othe s inv lved with the o e ation an

maint enanc of the fuel ng s ation

3.36

multiple-element g s container

MEGC

multimodal as embly of cy lin e s, tubes or bun les of cy linde s w hich ar int er onne t ed b a manifold

an as embled within a framework, inclu ing se vic eq ipment an s ructural eq ipment ne es ary

for the transport of g ses

Not e 1t o entry: T is def inition is taken from the UN Model R egulations ADR uses a diferent def inition

[ SOURCE:ISO 1 2 6:2 1 , 2.2.1]

3.37

nominal wor king pres ure

NWP

pr s ur for w hich the dispense is int en ed t o be o e at ed for a given g st empe atur of 1 °C

Not e 1t o entry: T is def ines a ful vehicle tan g s density, of either 3 MPa or 70 MPa at 1 °C

Not e 2t o entry: F rther guidance on pres ure terminolo y is inclu ed in An e D

3.38

no -p blc fuel ing statio

fuel ng s ation (3.2 )that does not sel or dispense g seoushydrog en t o the g ene al publc

EXAMPLE priv t e or mu icip l vehicle fle t o e ation

noz le

devic con e t ed t o a fuel dispensing sy st em, w hich pe mit the q ick con e t an discon e t of fuel

supply t o the vehicle or st orag e sy st em

[ SOURCE:ISO 1 2 8:2 1 , 3.8]

3.40

outdoor

location out ide of any buiding or s ructur , or locations u de a ro f, weathe shelt er or cano y

pro ided this ar a is not enclosed on mor than two sides

pro ision of a safe environment for pe forming maint enanc , r p ir or r plac ment o e ations on

proc s faci ties

Note 1 to entry: Positive isolation can b provided t o eq ipment or piping items for maintenance p rposes using

various ar ang ments depen ing on folowing factor , as piping rating, eq ipment in sh tdown or eq ipment

u der service

Note 2 t o entry: An as embly commonly refer ed t o as Double Block an Ble d is oft en used for this p rpose F or

such sy st ems, two block valves are req ired for ad itional isolation b tween the operational proces side an

the device req iring maint enance A ble d is used t o drain/vent the fluids trap ed b tween the two block valves

Note 3t o entry: A blin or a spade is an alt ernative way to provide positive isolation

devic designed t o r lease pr s ur in orde t o pr vent a rise in pr s ur a o e a spe if ied v lue d et o

eme g ency or a normal con itions

Note 1 t o entry: PRDs can b activated by pres ure or another parameter, such as temperature, an may b either

re-closing devices (such as valves) or non-re-closing devices (such as ru ture disks an fusible plugs) Common

designations for these specif ic ty es of PRDs are as folows:

— Pres ure S fety Valve (PSV)— pres ure activated valve that opens at specif ied set point t o prot ect a sy st em

from bur t an re-closes when the pres ure fal s b low the set point

— Temperature-activated Pres ure R elief Device (T RD) — a PRD that opens at a specif ied t emperature to

protect a system from bur t an remains open

3.4

pro abi ity

an ex r s ion of the chanc (l kel ho d) that a conside ed event wi l take plac t o pro e ty, sy st em,

busines or t o the environment

3.46

publ c fueling statio

fuel ng s ation (3.2 ) that sel s g seous hydrog en t o the g ene al publc

combination of the pro a i ity of oc ur enc of harm an the seve ity of that harm;encomp s ing b th

the u c rtainty a out an seve ity of the harm

[ SOURCE: ISO/IEC Guide 5 : 2 14, 3.9 – ad ed part from “encomp s ing” t o “ eve ity of the harm” an

Not e 1 t o entry r mo ed]

3.49

risk as es ment

the det ermination of q antitative or q altative v lue of risk r lat ed t o a spe ific situation an a

r co nised thr at (also caled hazard)

Not e 1 t o entry: Based on national req irements,a review of a risk analy sis or a safety concept by third party is

sometimes req ired

3.50

risk (ac eptance)c iteria

t erms of r fe enc b w hich the significanc of risk is as es ed

[ SOURCE:ISO/IEC Guide 73:2 0 , 3.3.1.3]

use of spe ific t ech ical means t o prot ect pe sons from the hazards w hich can ot r asona ly be

r mo ed or sufficiently lmit ed b design

3.53

safety

fr edom from u ac epta le risk

[ SOURCE:ISO/IEC Guide 5 :2 14, 3.14 ]

dis anc t o ac epta le risk level or minimum risk-informed dis anc between a hazard sour e an

a targ et (h man, eq ipment or environment), w hich wi mitig t e the efe t of a l kely for se a le

incident an pr vent a minor incident escalating int o a larg er incident

Not e 1 to entry: S fety distances are split into R estriction distances, Cle rance distances, Instalation layout

distances, Protection distances an Ext ernal risk zone S e 5.8.2for further details

Not e 2 t o entry: T e term “ afety distance” may also b refer ed t o as “ afe distance,” “separation distance,” or

“ etb ck distance.”

safety functio

fu ction t o be implement ed b a control sy st em or safety-ins rument ed sy st em, w hich is int en ed t o

achieve or maintain a safe s at e for the proc s with r spe t t o a spe ific hazardous situation

Note 1 t o entry: Other tech olo ies or risk red ction me sures have a safety fu ction not achieved through a

control system, however validation of these me sures is eq al y important

3.57

safety-nstrumented sy stem

ins rument ed sy st em used t o implement one or mor safety ins rument ed functions

Note 1 to entry: A safety instrument system is composed of an combination of sensor , lo ic solver an f inal

elements

3.58

safety-related sy stem

designat ed sy st em that b th implement the r q ir d safety fu ctions ne es ary t o achieve or maintain

a safe s at e for the EUC an is int en ed t o achieve, on it own or with othe E/E/P safety-r lat ed

sy st ems, othe t echnolo y safety-r lat ed sy st ems or ext ernal risk r d ction faci ities, the ne es ary

safety int egrity for the r q ir d safety functions

Note 1 t o entry: T e term refer to those sy stems, designat ed as safety-relat ed syst ems, that are inten ed to

achieve, to ether with the e ternal risk red ction facilities (IE 6 15 8-5:2 1 , 3.4.3), the neces ary risk

red ction in order t o me t the req ired t olera le risk (IE 6 15 8-5:2 1 , 3.1.6 an An e A)

Note 2 t o entry: The safety-related systems are designed to prevent the EUC from g ing int o a dang rous state

by taking ap ropriate action on receipt of comman s T e failure of a safety-related sy stem would b inclu ed

in the events le ding t o the determined hazard or hazards Although there may b other syst ems having safety

fu ctions, it is the safety-related systems that have b en designated t o achieve, in their own right, the req ired

t olera le risk S fety relat ed systems can bro dly b divided int o safety-related control sy stems an

safety-relat ed protection systems, an have two modes of operation (IE 6 15 8-5:2 1 , 3.5.1 )

Note 3 t o entry: S fety-relat ed systems are potential y an int egral part of the EUC control sy stem or int erface

with the EUC by sensor an / r actuator T at is, the req ired safety inte rity level is achieved by implementing

the safety fu ctions in the EUC control sy stem (an pos ibly by ad itional separat e an in epen ent sy st ems as

wel ) or the safety fu ctions may b implemented by separate an in epen ent sy stems dedicated to safety

Note 4 t o entry: A safety-related syst em is designed:

a) to prevent a hazardous event (i.e if the safety-related systems perform their safety fu ctions then no

hazardous event arises);

b) to mitig te the efects of the hazardous event, there y red cing the risk by red cing the conseq ences;

c) to achieve a combination of a)an b)

3.59

state of charg e

SOC

ratio of compr s ed hydrog en st orag e sy st em (CHS ) hydrog en density t o the density at ma imum

o e ating pr s ur rat ed at the s an ard t empe atur 1 °C

Note 1 to entry: SOC is e pres ed as a per enta e an is comp ted b sed on the g s density ac ording to

formula b low

Note 2 to entry: T e ac uracy of the NIST formula has b en q antif ied to b to within 0,0 % from 2 5 K to

10 0 K with pres ures to 1 0 MPa at he p blishing of this document

SOC

P T

x(%)

( , )

=

°ρ

1 0

Note 3t o entry: T e hydro en densities at he two major nominal working pres ures are:

Not e 4 to entry: The ρ(P, T) fu ction for hydro en is availa le from the National Institut e of Stan ards an

Tech olo y (NIST)at ht p:/ www.b ulder.nist.g v/div8 8 Hydrog en/PDF s/Lemmon.2 0 pV1 3.N06.A05.p f

3.60

statio pres ure

pr s ur of the hydrog en g s sup led t o the vehicle b the s ation, measur d near the hose br akawa

3.61

targ et pres ure

s ation pr s ur that he hydrog en fuel ng prot ocol targ et for the end of fuel ing

AHJ A uthority Ha ing Jurisdiction

AiCHE Ame ican Ins itut e of Chemical E gine rs (AICh )

ALARP As L w As R easona ly Practica le

API Ame ican Petroleum Ins itut e

CEN Fr nch: C mit é E ro é n de Normal sation (E ro ean C mmitt ee for Stan ardization)

CENELEC Fr nch: Comit é E ro é n de Normal sation Éle trot ech iq e (E ro ean Committ ee for Elec

-trot ech ical Stan ardization)

CFD C mputational Fluid Dynamics

CHS C mpr s ed Hydrog en St orag e Sy st em

ESR eDA E ro ean Safety, R ela i ty an Data As ociation

ETSI E ro ean Tele ommu icationsStan ards Ins itut e

L L L wer Flamma i ity Limit

MAWP Ma imum Alowa le Working Pr s ur

ME C Multiple Element Gas Containe s

MOP Ma imum Ope ating Pr s ur

NWP Nominal Working Pr s ur

OREDA Ofshor an onshor REla i ity DA ta

QRA Quantitative Risk As es ment

PRD Pr s ur R elef Devic

PSD Pr s ur Safety Devic

SOC Stat e of Charg e

TPRD Tempe atur -activ t ed Pr s ur R elef Devic

5 General safety rec ommendations

5.1 Hy rog en fuel ing station safety rec ommendations

The hydrog en fuel ing s ation ins alation should be sit ed t o minimiz risk t o use s, o e ating pe sonnel,

pro e ties, an the environment The folowing element of a hydrog en fuel ing s ation should be

conside ed pot ential hazard sour es:

— on-sit e hydrog en prod ction u it ;

— hydrog en delve y sy st em, inclu ing r mot e fil p int as a plca le;

— compr s ors;

— st orag e;

— piping;

— dispensing u it

Mor spe if ical y, the hydrog en fuel ng s ation should inclu e measur s t o r d c harm from the

folowing hazards:

— f ir s, defla rations, det onations an blas wa es;

— asphy iation hazard (d e t o r lease of g seous hydrog en or ine t g ses in confined sp c s);

— c y g enic burns (lq id hydrog en sup ly);

— imp ct from pr s ur / debris;

— any ad itional hazards as ociat ed with the sy st em, inclu ing:

— ele trocution hazards;

— working at height (e.g ro f mou t ed eq ipment);

— injury from mo ing eq ipment / hose w hip

The folowing thr e s ag es of safety as uranc should be conside ed:

— pr vention of ac ident through a combination of the folowing:

— a plcation of s at e of the art t ech olo y;

— folowing t echnical s an ards an simple han lng proc d r s t o use s an o e at ors;

— designing the user-machine-int erfac s in a s raight orward man e ;

— emphasizing training of pe son el, mana ing compet enc of pe son el;

— implement Manag ement of Chang e proc s es;

— es a lshing pr ventative maint enanc

— mitig tion s rat egies b combination of the folowing:

— a plcation of s at e of the art t ech olo y;

— b r ie s an la e s of prot ection;

— safety measur s;

— safety dis anc s

— s ructur d an efe tive eme g ency r sp nse (conting ency plan ing)

In g ene al, the folowing mitig tion s rat egies should be conside ed:

— minimization of the p t ential for the formation of a flamma le or ex losive mixtur ;

— minimization of the p t ential for ignition (from b th piot ed an sp ntaneous ignition sour es);

— mitig tion of the efe t of a fir or ex losion originating from the fuel ng s ation ins al ation;

— mitig tion of the imp ct t o the fuel ing s ation ins alation from an ext ernal fir ;

— r d ction of the phy sical efe t of the ex losion s r ngth p t ential of ex losive atmosphe e

g ene at ed b pot ential leaks or r leases

5.2 Risk as es ment

Risk as es ment ma be used as a flexible complanc o tion Use of risk as es ment alow s s ation

owne s an designe s t o flexibly define s ation-spe if ic mitig tions that achieve an eq al or bett er level

of safety t o those of pr sc iptive r commen ations

Risk as es ment is the o e al proc s of risk identif ication, risk analy sis, risk ev luation an risk

mitig tion Risks can be as es ed at an org nizational level, at a departmental level, for proje t ,

in ivid al activities or spe if ic risks A risk as es ment should be pe formed for the hydrog en fuel ng

s ation in ac ordanc with one of the folowing s an ards: ISO 3 00 , ISO/IEC3 0 0, an / r ISO 1 1 0

Methods used in as es ing risks can be q altative, semi-q antitative or q antitative The degr e of

detai r q ir d wi l depen up n the p rticular a plcation, the a aia i ity of r la le data an the

de ision-making ne ds of the org nization Some methods an the degr e of detai of the analy sis ma

be pr sc ibed b legislation

It is r commen ed that the risk as es ment car ied out for the hydrog en fuel ing s ation should be

q antitative or semi-q antitative R ecommen ations for the method, degr e of detai, an sour e of

information used in the as es ment w hen car ied out spe if ical y for a hydrog en fuel ng s ation ar

inclu ed in 5.3an 5.4

Q ualtative as es ment def ines conseq enc , pro a i ty an level of risk b ma nitu e levels such as

“high ” , “ medium ” an “low” , ma combine conseq enc and pro a i ity, an ev luat es the r sultant

level of risk a ains q altative c it eria

S mi-q antitative methods use detai ed models an data for eithe conseq enc or pro a i ty, an

q altative tr atment for the othe One ex mple is a “conseq enc only” analy sis w hich uses detaied

conseq enc model ng an as umes the pro a i ity of a sc nario is 1,0

Q uantitative analy sis uses detai ed models an data t o es imat e for conseq enc s an their

pro a i ties, an prod c s v lues of the level of risk using b th pro a i ty an conseq enc Level of

risk is ex r s ed in spe ific u it defined w hen develo ing the cont ext

5.2.1 Method log y for semi quantitati ve and quantitati ve r isk as es ment for as es ing

hydrog en instalation safety

5.2.1.1 General

It ma be p s ible t o use Quantitative Risk As es ment (QRA) an / r semi-q antitative (e.g

conseq enc -only) analy sis inst ead of pr sc iptive r q ir ment t o alow the hydrog en fuel ing s ation

t o use alt ernative methods w hich ar of an eq iv lent, or highe , level of safety t o the pr sc iptive

r q ir ment Using QRA ma alow (for ins anc using mitig tion measur s) for short er safety

dis anc s an / r simpl fied s ation la out

If QRA is used, this clause pro ides r commendations for pe forming that analy sis This analy sis

focuseson at hazards inv lved with the r leasean ignition of hydrog en mixtur s an r lat ed phy sical

efe t This does not co e non-hydrog en hazardsas ociat ed with the fuel ng s ation, se 5.1

Develo ing an a pro ch t o prot ect a ains harm should conside thefolowing fact ors:

— natur of the hazards (e.g the mal, pr s ur , t oxicity, et c );

— phy sical pro e ties of hydrog en un e the design an o e ating con itions;

— eq ipment design an o e ating con itions;

— ins alation design an location, inclu ing prot ection measur s;

— targ et (e.g pe son, pro e ty, eq ipment) w hich ar being prot ect ed from efe t of p t ential

hazards

A semi-q antitative risk as es ment pro ides an int ermediary level betwe n the t extual ev luations of

q altative risk as es ment an the n me ical ev luation of q antitative risk as es ment, b ev luating

risks with a scor S mi-q antitative risk as es ment pro ides a s ructur d wa t o rank risks

ac ording t o their pro a i ty, seve ity or b th (c iticalty), an for ranking risk r d ction actions for

their efe tivenes This is achieved through a pr def ined scoring syst em that alow s one t o ma a

pe c ived risk int o a cat eg ory, w he e the e is a lo ical an ex lcit hie ar hy betwe n cat eg ories S

mi-q antitative risk as es ment is g ene al y used w he e one is att empting t o o timiz the alocation of

a ai a le r sour es t o minimiz the imp ct of a group of risks

It helps achieve this in two way s:

— f irs the risks can be plac d ont o a sort of ma so that the mos important risks can be sep rat ed

from the les imp rtant ;

— se on , b comparing the t otal scor for one or a se ies of risks befor an aft er any pro osed risk

r d ction measur s, so one can g et a fe l for how r latively efe tive the mitig tion s rat egies ar

an w hethe they me it their cos s

F or pe forming a semi-q antitative risk as es ment, a ful mathematical model is not alway s ne ded

It could sometimes ofe the adv ntag e of being a le t o ev luat e a larg er n mbe of dife ent kin of

risk is ues in a lmit ed time Nonetheles , al forms of risk as es ment r q ir the gr at es pos ible

cole tion an ev luation of data a aia le on the risk is ue

5.2.1.2 Summar y of metho olog y

Risk as es ment pro ides a framework t o es a lsh a common u de s anding of the sy st em safety level

b sed on ro us scienc and engine ring models The proc s ena les transp r nt, evidenc -b sed

safety de isions The QRA a pro ch uses a combination of pro a i s ic an det erminis ic models t o

ev luat e pot ential conseq enc s on the targ et identif ied in the pr vious clause Risk is charact eriz d

b a set of hazard ex osur sc narios, the causes as ociat ed with each sc nario, the u desira le

conseq enc s as ociat ed with the sc nario, an u c rtainty a out these element ( his u c rtainty is

g ene aly ex r s ed b pro a i ty) In conseq enc -only model ing, the pro a i ty t erm is ignor d,

One major aim of risk as es ment is t o pro ide a desc iption of the hazard sc narios, their causes an

conseq enc s an u c rtainties ( aken in p rt or in w hole), for use in de ision making (e.g comp rison

a ains a def ined risk ac eptanc c it eria)

The proc s for risk-informing mitig tions inclu es the folowing st eps, as displa ed in Figur 3:

— targ et det ermination– Define the targ et being prot ect ed, an as ne es ary, the hazard sour es

Ta le3 pro ides many ex mples of targ et ;

— analy sis sco ing – S le t a pro riat e risk ty e for each targ et and es a lsh t ole a i ty c it eria

(e.g ac epta le /unac epta le risk level) for each targ et ;

— sy st em desc iption – Document the sy st em and ins alation being analy sed, inclu ing mitig tions t o

be c edit ed in the analy sisan w hich event they mitig t e ( e 5.1);

— cause analysis – Identify an model the hazard sc narios an q antify the pro a i ty of each

sc nario in the model for each sour e an targ et ;

— conseq enc analy sis – Identify the phy sical efe t for each sc nario, an q antify the imp ct of

those efe t on the targ et ;

— risk as es ment – Int egrat e the cause an conseq enc models int o an as es ment of the t otal

risk ; Pe form sensitivity s u ies an changing model ng as umptions t o identify a pro riat e

combination of mitig tion element t o maintain risk level within the t ole a i ity r gion;

— risk-informed mitig tions - Inc ease or r d c mitig tions t o achieve risk level within t ole a i ty

r gion ( inclu ing conside ation of u c rtainty)

Figure 3 — Example of a risk-nformed approach to safety distances

5.2.1.3 Tar g et deter minatio and anal ysis sc oping

Each charact erisation of safety dis anc in Ta le 1, afe t oneor mor clas es of targ et Ta le 3 pro ides

many ex mples of targ et for each ty e of safety dis anc Ty es of safety dis anc should be def ined

ac ording t o national r q ir ment / guidanc , with a pro riat e targ et an hazards sour es def ined

for each ty e of safety dis anc

5.2.1.4 Hazards

The primary hazards r lat ed t o the use of hydrog en ar the r lease an subseq ent ignition of hydrog en

The two main hazards ar the mal efe t (e.g con uction or radiation from hydrog en flames or p s

flame g ses) an blas efe t (o e pr s ur an impulse) from defla rations and det onations Both of

these hazardsshould be modeled for al sour es an al targ et

5.2.1.5 Risk and har m c iteria and tolerabiity lmit selectio

Risk an harm c it eria ar es a lshed through close int eractions with s akeholde s, w hich ma inclu e

detaied survey s of exis ing risk benchmarks A bes practic is t o ensur that risk from hydrog en

fuel ng should be eq al t o or les than the risk p sed b simi ar activities, w hich could inclu e g solne

fuel ng, oc up tional ac ident , g ene al ac ident rat es within the po ulation, et c

F or pe son el risk, inclu ing workers an / r membe s of the g ene al publc, four widely used fatalty

risk c it eria ar :

— FAR (Fatal A ccident Rat e) – the n mbe of fatalties pe 1 0 mi ion ex osed hours;

— AIR (Ave ag e In ivid al Risk) or In ivid al risk pe ann m - the in ivid al risk a e ag ed o e the

po ulation w hich is ex osed t o risk from the faci ity;

— PL (Pot ential L s of Life)– the a e ag e n mbe of fatalties (pe sy st em-year);

— F-N curves r pr senting the ex e t ed fr q ency at w hich N or mor peo le wi l be ex osed t o a

fatal hazard (cumulative dis ribution fu ction) Such curves ma be used t o ex r s societal risk

c it eria

Othe c it eria ma be used, such as:

— a e ag e n mbe of hydrog en r leases pe sy st em-year;

— a e ag e n mbe of jet f ir s pe sy st em-year;

— a e ag e n mbe of defla rations /det onations pe sy st em-year

Conseq enc -b sed harm or damag e c it eria ma be used, such as:

— heat flux level;

— the mal dose;

— flame t empe atur ;

— flame length;

— peak o e pr s ur ;

— g s conc ntration;

— fluid t empe atur

A cc ptanc c it eria should be spe ified These ma be spe if ied in t erms of single v lues, ac eptanc

b u ds or dis ributions, useof ALARP (As L w AsR easona ly Practica le), o tion comp rison, et c

Due t o the complexity an u c rtainties inv lved in pr dicting pe formanc in engine r d sy st ems,

the e wi l alway s be a level of subje tivity at ached t o any risk as es ment r sult This unc rtainty

should beconside ed w hen sele ting risk an harm c it eria an t ole a i ity lmit

5.2.1.6 System des r iption

The analysis should contain documentation of the ins alation an o e ational environment

(as-buit and as-o e ated) Documentation should contain suff icient detai t o alow r pl cation b an

in ependent ex e t

The documentation should def ine an identify the sy st em, an component , their fu ctions, an their

r lationships an int erfac s Block dia rams, P&IDs, an othe f igur s should be inclu ed t o faci itat e

un e s an ing of the boun aries of the sy st em, comp nent of the sy st em, an functions of each

comp nent in each o e ational environment Ins al ation charact eris icsshould be desc ibed, inclu ing

ex e t ed use con itions an la out dia rams Ex e t ed o e ating p ramet ers /s at es of hydrog en in

the sy st em should be document ed

The sco e of work should ca tur an def ine the work activities an int en ed a plcations If multiple

o e ational environment ar contained in one analy sis, the work activities should be def ined for each

o e ational environment

5.2.1.7 Cause anal ysis

The g oal of cause analy sis is t o pro ide insight int o the causes of hazardous ex osur s an the l kel ho d

of those causes This inv lves c eating models that desc ibe the sc narios that oc ur aft er a r lease of

hydrog en, and q antifying these models using pro a i ty information

5.2.1.8 Ex posure sc enar ios

A t a minimum, ex osur sc narios should contain the folowing element :

— r lease of hydrog en R elease siz s that ar t o be model ed should be defined b sed on national

r q ir ment or guidanc ;

— oc ur enc of ignition A t a minimum, ignition should be sub-divided int o immediat e an dela ed

ignition;

— jet f ir s, defla rations/det onations

R oot causes of r leases should be identified q altatively Use of ro t cause information in q antification

is o tional R oot causes should inclu e:

— leaks from in ivid al comp nent , inclu ing sep ration of a component or u int en ed o e ation;

— sh tdown faiur s;

— ac ident , inclu ing col isions an drive-ofs;

— h man e rors

S enario an ro t cause models ma also inclu e:

— leak det ection sy st ems;

— sy st em isolation;

— mor detaied bifur ations of “ignition”

F or QRA, ex osur sc nario fault ex r s ions ma be document ed gra hicaly, e.g in Event Tr es or

Event S q enc s Dia rams, or fault ex r s ions can be man al y spe ified R oot causes ma be given as

a ls , or document ed gra hicaly, e.g in F a ult Tr es, or through fault ex r s ions

5.2.1.9 Data for sc enar io quantificatio

Data used should be of sufficient q al ty t o supp rt de ision making Sour es of data should be

Analy st should use publ shed, hydrog en-spe ific data if it is a aia le.

Non-publ shed, hydrog en-spe if ic data, such as pro rietary comp ny-spe if ic data, ma be used If such

data ar used, the data should be document ed an should be made a ai a le t o the AHJ or designat ed

r viewe if r q est ed The designat ed r viewe should give extra sc utiny on input that lowe

pro a i ties below commonly used data sour es

In leu of hydrog en-spe if ic data, commonly ac ept ed, publ shed data sour es (OREDA, ESR eDA, AiCHE

or API5 1) from simi ar in us ries an a plcations should be used

5.2.1.10 Co sequenc e anal ysis

This inv lves det ermining the phy sical efe t of the sc narios, as wel as the targ et r sp nse t o those

phy sical efe t

5.2.1.11 Physical efects of the ac cidents

The phy sical efe t of hydrog en f ir s w hich should be modeled for a targ et ar 1) the mal efe t an

2) pr s ur efe t The primary phy sical efe t r lev nt t o ignit ed hydrog en r leases ar f ir efe t

(for ex mple; impinging flames, high t empe atur , heat lux) an ex losion efe t such as pr s ur an

impulse wa es

NOTE De ris efects (e.g from over -pres urization of hydro en ves el)are not req ired to b modeled

Model ing of these r q ir d phy sical efe t r q ir s model ng seve al phy sical proc s es: r lease, jet

flames, an defla rations an det onations

The phy sical models used should be v ldat ed for use in on hydrog en within the p ramet er rang es

ex e t ed in the fuel ng ins al ation or spe if ic eq ipment

5.2.1.12 Hy rog en rele se character istic

The firs st ep in charact erizing conseq enc s is t o charact eriz the r lease of hydrog en an the ext ent

of the flamma le envelo e The modynamic paramet ers of r leases from high-pr s ur hydrog en

sy st ems can be es imat ed using notional noz le models The sele t ed model should be v ldat ed for use

in high-pr s ur hydrog en sy st ems within the p ramet er rang esex e t ed in the fuel ng ins alation or

spe ific eq ipment The sele t ed model should be spe if ied in the analy sis documentation

5.2.1.13 Ig nitio so rc es

The sour e of ignition for an ins al ation or the proc s it elf should be ex mined A non-compr hensive

l s of ex mples is as folow s:

— l ghtning

— s atic ele tricity ( inclu ing clothing)

— me hanical sp rks (for ex mple; mo ing p rt , t ools not uita le for ex losive atmosphe es)

— naked flames

— hot urfac s (for ex mple; o e heating b adia atic compr s ion)

— ele trical component an ins alations (for ex mple;ele tric sp rks)

— ex osed lve ca les

5.2.1.14 Jet flame behaviour

R eleases from high-pr s ur hydrog en sy st ems that ar ignit ed immediat ely prod c momentum

flame ne es ary t o me t the g oals of the analy sis The sele t ed charact eris ic() should be spe ified

in the analy sis documentation Charact eris ics r lev nt t o the g oals of the analy sis ma inclu e flame

length, flame width, or heat flux The position at w hich these charact eris ics ar calculat ed should be

spe if ied in the analy sis

5.2.1.15 Deflag ratio and deto atio behavio r

R eleases from hydrog en sy st ems w hich ar not immediat ely ignit ed ma ac umulat e an r sult in a

flash fir , blas or v p ur clou ex losion (VCE) w hen ignit ed with the mal an pr s ur efe t

The mal an overpr s ur efe t c eat ed from hydrog en defla ration or det onation can v ry

signif icantly b sed on the sc nario

The leas signif icant is a flash fir w hen the clou is ignit ed in it extr mity (r gions below 1 % of

hydrog en) Flash f ir s r sult in the mal efe t with ve y smal o e pr s ur

When the clou is imp rtant an ignition near the c ntral st oichiometric r gion, the o e pr s ur

efe t (and as ociat ed impulse) prod c d could be mor imp rtant

The turbulenc in the hydrog en r lease, an / r the pr senc of o je t can pot ential y r sult in an

inc ease of theoverpr s ur g ene at ed

Blas efe t ma be modeled using v ldat ed sof war code b sed on Computational Fluids Dynamics

(C D ), empirical or P enomenolo ical methods

5.2.1.16 Har m mo els

A harm or damag e model or c it eria isused t o translat e the phy sical efe t int o the harm t o a pe son, a

comp nent, or s ructur This should be donethrough use of eithe a model or c it eria, inclu ing single

c it eria, det erminis ic models, pro a i ity models, pro it fu ctions The sele t ed c it eria or model ma

come from r fe enc t o es a l sh scientif ic information or national s an ard The sele t ed model or

c it eria should bespe if ied in the analy sis documentation

5.2.1.17 Risk calculatio

Some forms of risk as es ment calculat e risk for multiple in ivid al sc narios an some use one

calculation of risk for multiplesc narios

When the t otal risk for the sy st em is r q ir d, this should be calculat ed b combining the r sult of the

sc nario (ca use) analy sis an the conseq enc analy sis int o the t otal

is the fr q ency of sc nario n, and c is the

conseq enc for sc nario n

Risk ma be calculat ed sep rat ely for each ty e of conseq enc (e.g harm, los )

In al cases, a combination of risk analy sisan conseq enc only analy sisma be used F or ex mple, an

AHJ ma ask for a conseq enc only analy sis for ad itional spe if ic sc nario an an AHJ ma ask for a

t otal risk analysis t o inclu e ad itional sc nario

5.2.1.18 Risk- nfor med mitigatio s

The es imat ed risk level should be comp r d t o the risk ac eptanc c it eria

If the es imat ed risk level is a o e the ac eptanc c it eria, the analy st should implement ad itional

If the es imat ed risk level is below the ac eptanc c it eria, the mitig tions or safety dis anc ma be

r d c d

Analy st should conside /discus ion a pro riat e methods t o ac ou t for u c rtainty w hen comparing

t o risk c it eria This should be ad r s ed through use of conse v tive risk c it eria, or sensitivity

analysis or methods t o pro a at e unc rtainties

5.3 Mitigation measur es to impr ove system safety

The risk as es ment should demons rat e that the mitig tion measur s ar a pro riat e t o achieve the

desir d r d ction of the pro a i ty an / r conseq enc s of each sc nario Mitig tions w hich impro e

o e al safety of the sy st em (as demons rat ed b use of the q antitative risk as es ment proc s defined

a o e)ma be used t o:

— r d c pr sc iptive safety dis anc s through the risk-informed safety dis anc proc s ;

— r la exis ing pr sc iptive mitig tion measur sb car ying out a semi-q antitative or q antitative

risk as es ment

As long as t otal sy st em risk r mains below the sele t ed t ole a i ity thr shold (Risk ac eptanc c it eria)

S ve al mitig tion featur s afe t the pro a i ity an / r imp ct of multiple aspe t of the analy sis

(e.g use of enclosur s can r d c the pro a i ity of ignition, but it could p t entialy inc ease the

conseq enc of defla rations) – w hen c edit is taken for a mitig tion, the entir analysis should be r

-ru t o ensur that t otal risk is suff iciently low

5.4 Mitigations which r educ e the potential for the formation of a flammable or

e x plosi ve mix tur e

5.4.1 General

Hydrog en fuel ing s ations should be designed an o e at ed such that, w he e an int entional or

unint entional r lease of flamma le g s oc urs d ring normal o e ation, the formation of a flamma le

or ex losive atmosphe e is pr vent ed, minimised, det ect ed or controled Furthe detaied information

is a aia le from the IEC6 0 9 se ies of s an ards

Whe e pos ible, it ma be pr fe a le t o locat e hydrog en proc s eq ipment in the o en air, with natural

ventiation t o dis ip t e any leaked hydrog en Alt ernatively the hydrog en eq ipment ma be locat ed in

an enclosur t o pe mit det ection of leaks and ins ig t e for ed venti ation t o pr vent ac umulation

The folowing mitig tions ma r d c the fr q ency or pro a i ity of a r lease

— eq ipment designs w hich minimiz the n mbe of con e tions, ar leak-fr e b design or use

inhe ently safe eq ipment design;

— pe manent ine t atmosphe e;

— in-proc s leak det ection such as the a i ity for isolat ed sy st ems t o hold pr s ur ;

— r gular inspe tionsan maint enanc

The folowing mitig tions ma r d c the fr q ency of sc narios r lat ed t o g s ac umulation (dela ed

ignition sc narios)

— hydrog en det ect ors t o pro ide det ection an aut omatic sh t down/isolation if flamma le mixtur s

pr sent, p rticularly in enclosed spac s;

— ventiation (e.g p s ive or active venti ation)

Whe e the sour e of r lease is situated out ide an ar a or in an adjoining ar a, the penetration ofa

significant q antity of flamma le g s or v ap ur into the ar a can be pr vented b suita le means such as:

— phy sical b r ie s;

— maintaining a suff icient o e pr s ur in the ar a r lative t o the adjac nt hazardous ar as, so

pr venting the ingr s of the ex losive g s atmosphe e;

— purging thear a with suff icient flow of fr sh air, so ensuring that the air esca es from al o enings

w he e the flamma le g s or v p ur ma ent er

5.4.2 Hy rog en detectio systems

Hydrog en det ection a paratus used in hydrog en sensing an monit oring sy st ems should comply with,

an me t the ac uracy r q ir ment of ISO 26 142

Hydrog en det ection a p ratusan / r hydrog en det ection sy st ems should ha ea suita le rang e for the

conc ntration set-point used t o initiat e a r sp nse through the control or safety sy st em

When used, hydrog en det ection a p ratus should be ins aled w he e it has the highes l kel ho d of

det ecting the for se a le leaks, such as:

— ups r am of the venti ation sy st em;

— w he e the r leased hydrog en is mos lkely t o ac umulat e

The a pro riat e r sp nse should be det ermined b the man factur r’s risk as es ment

This ma inclu e dife ent activ tion lmit , for ex mple:

— a lowe activ tion lmit, set at a ma imum v lue of 2 % of the lower flamma i ity l mit LF ), w hich

ins ig t es furthe mitig tion measur s an ale t the fuel ing s ation o e at or, an othe use s An

alarm set p int lowe than 2 % L L ma be a pro riat e depen ing on the s ation risk as es ment,

for ex mple, for enclosed ar as with a high level of cong es ion;

— a highe activ tion l mit, set at a ma imum v lue of 5 % of L L, w hich ins ig t es an eme g ency

sh tdown an ale t the fuel ing s ation o e at or, an othe use s An alarm set p int lower than

5 % L L ma be a pro riat e depen ing on the s ation risk as es ment, for ex mple, for enclosed

ar as with a high level of cong es ion

Furthe mitig tion measur s that ma be a pro riat e t o be taken up n det ection of a flamma le

atmosphe e a o e the lowe activ tion l mit inclu e, but ar not l mit ed t o:

— sh t of of the hydrog en sup ly t o the eq ipment within the enclosur from an isolation p int out ide

of the containe ;

— depr s urisation of the hydrog en eq ipment within the enclosur t o a safe location;

— de-ene gization ofele trical eq ipment not int en ed for use in flamma le atmosphe es;

— inc eased ventiation

The d ration of the au ible an visual signals ins ig t ed b the hydrog en det ection sy st em should be

det ermined b the man factur r’ s risk as es ment Whe e safe t o do so, it is r commen ed that the

visual signals should r main unti the alarm con ition has be n cor e t ed an the fuel ing s ation control

or safety sy st em has be n man aly r set The au ible signals ma be aut omaticaly extinguished w hen

the conc ntration of hydrog en fal s below a def ined set-p int, aft er a spe if ied pe iod of time or w hen

the control sy st em is man aly r set

5.4.3 S fety and emer g ency sh t-of systems

In orde t o minimise the ma nitu e of an unint entional r lease, or t o minimise the d ration of the

flamma le or ex losive atmosphe e, eme g ency isolation v lves that can safely sh t-of the hydrog en

sup ly from the hydrog en st orag e t o othe ar as of the hydrog en fuel ng s ation should be ins aled

The fai-safe p sition of aut omatic v lves in lq id hydrog en lnes in the event of p we or pneumatic

pr s ur los should be def ined b risk as es ment an implement ed ac ordingly

5.4.4 Mitigation for the formatio of a flammable or ex plosi ve mix tur e in enclosur es

The formation of hazardous ex losive atmosphe es r sulting from anticip t ed hydrog en leaks or

r leasesin enclosur s should be minimised w hen practical

NOTE 1 When this is not practical, se 1 2 for guidance on clas ifying hazardous are s an controling

ignition sour es within the hazardous are

A non-compr hensive l s of ex mplepr vention methods is as folow s:

— pas ive venti ation;

— active venti ation;

— flamma leg s det ection sy st em or ultrasonic g s det ection;

— int egrity t es ing (rat e of pr s ur los measur ment) of isolat ed piping se tions;

— othe means of leak det ection

Whe e p s ive or active ventiation is r led upon for pr venting ignita le mixtur s, the ventiation

rat e should maintain a v lume fraction below 2 % of the lower flamma i ity lmit (L L) of hydrog en

or any othe flamma le g ses ( e 5.4.2) Whe e contin ous or primary grades of r lease, as def ined in

IEC 6 0 9-1 -1, ar anticip t ed, a lowe v lume fraction ma bea pro riat e

Smal diution v lumes w he e the s ructural int egrity of the enclosur would not be afe t ed in case of

ignition, b sed on the ma imum anticipat ed flamma le g s leak rat e int o the enclosur as det ermined

b the man factur r, ma be ex empt ed from this r q ir ment The man factur r should demons rat e

that he eq ipment is f it for the purp se

This rat e of ventiation ne d not be pe manently pr sent if it is initiat ed b a flamma le g s det ection

sy st em up n measur ment of the lowe activ tion l mit complying t o the r commen ations of 5.4.2

Howeve , the rat e ofventi ation ne es ary t o pr vent the formation of an ex losive atmosphe e d e t o

normal an ex e t ed r leases (e.g natural leaks from f it ings, or hydrog en pe meation through

non-metal c mat erials), should be maintained w heneve the proc s contains hydrog en u de pr s ur ,

w hethe the sy st em is in o e ation or not

Wheneve active ventiation is used, the minimum r q ir d ventiation rat e of the ventiation sy st em

should be spe ified The pr s ur dro ac os the venti ation syst em an thema imum outlet pr s ur

of the ventiation sy st em should be taken int o ac ount as important design c it eria

Enclosur s containing non-clas if ied ele trical eq ipment, not suita le for o e ation in a hazardous

ar a, that r ly on active ventiation for prot ection a ains the formation of a flamma le atmosphe e

should bepurg ed with suff icient air chang esprior t o the ene gization of such eq ipment

Faiur of active venti ation or det ection of flamma le g s in an enclosur at the ma imum v lume

fraction of 2 % of the L L of hydrog en or any othe flamma le g ses pr sent should cause the sh t-of

of the sup ly of hydrog en an othe flamma le g ses t o the enclosur an the de-ene gization of

non-clas if ied ele trical eq ipment

Computational fluid dynamicsanaly sis, using calculation t ools v ldat ed for hydrog en, phy sical t es ing

using a trac r g s, or simiar methods given in IEC 6 0 9-1 -1, ma be used t o design the means of

active an / r p s ive ventiation an the means of hydrog en det ection for pro iding the r q ir d

prot ection

NOTE 2 Su den an catastrop ic failure of ves els or piping systems ne d not b considered a le k s enario in

this analysis when protection a ainst such failures has alre d b en contemplated in the tan an piping design

Ar a clas ification det ermined ac ording t o 1 2 an the prot ection r commen ations for eq ipment in

clas ified ar as ma be adjust ed taking int o ac ou t the means of ventiation an the means of flamma le

g s det ection that ar pr sent In al cases, ele trical a p ratus o e ating in diution v lume that can

exis near pot ential sour es of r lease (leaks p int )should be prot ect ed in ac ordanc with 1 2.2

Enclosur s should be designed so as t o avoid high p int w he e hydrog en can ac umulat e u det ect ed

5.4.5 General r equirement h ydrog en venting for mitigatio for the for mation of a flammable

or ex plosi ve mix ture

Flows from vent an safety r lef eq ipment should be piped outdo rs t o a safe location t o a oid

formation of a flamma le or ex losive mixtur in hydrog en eq ipment enclosur s or othe locations

w he e the conseq enc s of ignition of the vent ed hydrog en would pose a hazard

The p sition of hydrog en vent s acks should be taken int o ac ou t in the la out of the ins alation an

should be such that he vent ma be used for o e ation, maint enanc and eme g ency r sp nse without

c eating hazardous con itions Conside ation should be given t o the t empe atur of the hydrog en that

is vent ed, an the efe t that his can ha e on the density of the vent ed g s

The vent outlet location should be ar ang ed t o discharg e t o o en air, an so as not t o g ene at e a hazard

for pe sons or neighb uring s ructur s, awa from pe sonnel ar as, ele trical lnes an othe ignition

sour es, air intakes an buiding o enings The vent s ack should not discharg e w he e ac umulation of

hydrog en can oc ur, such as below theea es of buidings

Hydrog en dispe sion an radiat ed heat calculations should be car ied out t o es a lsh the location an

height of vent s ack exit Furthe detai is pro ided in 5.8.4

The outlet of the vent s acks should not be eq ip ed with devic s that defle t the dir ction of the vent ed

— design b cons ruction of comp nent or eq ipment ;

— ele trical measur s; (e.g groun ing an b n ing)

— eq ipment enclosur s;

— proc d r s (e.g anti-s atic clothes or non-sp rking t ools, lmit ed ac es )

5.5.2 A reas subject to r estr iction of acti vity

Eq ipment or ar as of the hydrog en fuel ing s ation in w hich flamma le mat erials ar han led or

st or d should be designed, o e at ed an maintained so that any r leases of flamma le mat erial, an

conseq ently the ext ent of pot entialy ex losive atmosphe es, ar kept t o a minimum with r g rd t o

fr q ency, d ration an q antity, w hethe in normal o e ation or othe wise

In a situation in w hich the e ma be an ex losive g s atmosphe e, the folowing st eps should be taken:

— minimise the lkelho d of an ex losive g s atmosphe e oc ur ing aroun the sour e of ignition;

— minimise the lkelho d of p t ential sour es of ignition being pr sent

This ma be achieved through the control of ignition sour es in the pot ential y ex losive atmosphe es

b the r s riction of activities within def ined dis anc s, r fe r d t o as “ res riction dis anc s” , an

b the implementation of a hazardous ar a, as clas ified ac ording t o IEC 6 0 9-1 -1, in w hich fix ed

ele trical eq ipment should be a pro riat ely clas ified, se 1 2.2

Ar as w he e r s rictions on ignition sour es should be implement ed ar a plca le from point of

p t ential r leases of hydrog en an / r othe flamma le fluids, or from the exhaus of p s ive or active

ventiation of enclosur s arou d eq ipment containing flamma le fluids In some cases the dis anc s

from the pot ential r lease sour e w he e activities should be r s rict ed (r s riction dis anc s) ar

eq iv lent t o the hazardous ar a as defined ac ording t o IEC 6 0 9-1 -1, in othe cases the r s riction

dis anc s ma be det ermined b othe methodolo ies

Only authoriz d pe sons should be alowed t o ent er such ar as They should be awar of the hazards

p t ential y encou t er d an the r lev nt eme g ency proc d r s

R es riction of activity does not a ply t o the dispense ar a, for w hich spe ific risk as es ment ma

alow ac es t o dispense s without any r s rictions

Al p rta le eq ipment w hich ma g ene at e an ignition sour e w hen brought int o the r s rict ed

ac es ar a ( i.e p rta le lamps, flashlght , commu ication devic s) should comply with the safety

r commen ations for use in hazardous ar as

Maint enanc o e ations r q iring the g ene ation of an ignition sour e within the r s riction dis anc s

w hi e the ins alation is in o e ation or pr s uriz d with hydrog en should only be pe formed in case

of se vic ne es ity w he e hydrog en pr senc in the atmosphe e is not l kely un e normal con itions

During such o e ations, the atmosphe e in the work ar a should be contin ously analy sed using a

p rta le analy se Welding an grin ing should be done with the utmos car Hydrog en pipes an

eq ipment should be prot ect ed from welding an grin ing sp rks b suita le prot ection devic s such

as welding fir blan et Such maint enanc o e ations should be co e ed b a risk as es ment, with

spe ific att ention t o ex losion an f ir risks, in w hich al the measur s ne es ary for ensuring safety

ar pr -def ined

Furthe information on ele trical grou ding an b n ing to pr vent ignition sour es is pro ided in 1 1.4

5.6 Mitigation of the es alation and/ r impact of a fir e or ex plosion orig inating fr om

the fuel ing instal ation

— ac es control measur s (e.g fenc s, wals, eq ipment enclosur s);

— safety dis anc s such as minimum dis anc betwe n st orag es ( e 5.8.1);

— ex losion r lef prot ection [se for ex mple; API5 1 Guide for pr s ur -r leving an depr s urising

sy st ems ]

5.6.2 Flame detectio systems

Whe e identified b the hydrog en fuel ng s ation risk as es ment, means of det ection ofhydrog en f ir s

should be pro ided t o avoid escalation d e t o flame imping ement on neighb uring eq ipment

Infra-r d, ultra-violet emis ion or the mal sensors ma be used for hydrog en f ir det ection

Means should also be pro ided t o det ect f ir s (e.g smoke det ect ors) in eq ipment hat ha e p rticular

fir hazards (e.g high cur ent ele trical eq ipment) if such f ir s can dir ctly afe t hydrog en st orag e

sy st ems

5.6.3 E closures c ontaining h ydrog en systems

Enclosur s containing hydrog en sy st ems should be cons ruct ed of non-combus ible mat erials

W indow s an do rs should be in ext erior wals an should be locat ed so as t o be r adiy ac es ible in

case of eme g ency

R eq ir ment for the f ir r sis ivity of the flo r, wal s, c i ing an any o enings (do rs, win ow s)

should be defined b risk as es ment

If the flo r, wals an c i ng ar inclu ed t o prot ect the hydrog en sy st em from sour es of f ir , or t o

r d c safety dis anc s from the hydrog en sy st em t o ext ernal o je t d e t o a f ir inside the enclosur ,

these should ha e a fir -r sis anc rating a pro riat e for the sc nario an , w he e a plca le, pro ide

time for fir brig de int ervention

R eq ir ment for o er-pr s ur r lef should be def ined b risk as es ment

Whe e r q ir d, ex losion venting should be pro ided in ext erior wal s or the ro f only Vent should

consis of any one or any combination of the folowing:

— l ghtly fast ened hat ch co e s;

— l ghtly fast ened, outward-o ening, swinging do rs an / r suita le pr s ur r lef win ow s in

ext erior wal s;

— l ghtly fast ened wal s or ro f ;

— wals of l ght mat erial;

— contin ously o en vent in the ext erior wals or ro f of the enclosur

Whe e a plca le, snow lo ds should be conside ed

The conseq enc s of ex losion r l ef e.g o er-pr s ur out ide the o ening, proje ties, movement of

do rs or hat ches should be conside ed b risk as es ment

R eq ir ment for the o er-pr s ur r sis anc of the flo r, wals, c i ing an any o enings (do rs,

win ows), w he e not int en ed for ex losion r lef, should be defined b risk as es ment

If the flo r, wals an c i ng ar inclu ed t o r d c safety dis anc s from the hydrog en syst em t o

ext ernal o je t d e t o an ex losion inside the enclosur , these should ha ean o er-pr s ur ca a i ty

a pro riat e for the sc nario

5.6.4 Emer g ency rele se of gas from h ydrog en storag e tanks u de fire c on itio s

If hydrog en st orag e tan s ma be ex osed t o f ir con itions (from inside or out ide the st orag e ar a

or comp rtment) that could lead t o ruptur , the maly activ t ed (non-r closing) an / r man aly

activ t ed v lves should be pro ided t o safely vent al the cont ent of the hydrog en st orag e Whe e such a

v lve ne ds man al activ tion, thisshould be p s ible from a safe location In this case, the vent sy st em

should bedesigned ac ordingly, se 9.14.5

NOTE National re ulations can prohibit he use of man aly activated valves

5.7 Mitigation of the efect of an ex ternal fire/ vents on the fuel ing station instal ation

5.7.1 General

Measur s should be taken t o minimiz the efe t of event that ha e p t ential t o take plac in the

vicinity of the fuel ng s ation These measur s ma inclu e the folowing:

— safety dis anc s;

— l ghtning prot ection;

— f ir b r ie s;

— vehicle imp ct prot ection;

— prot ection a ains spi lag e of flamma le fluids from othe sour es;

— ac es control measur s;

— prot ection a ains ext ernal event

5.7.2 Layout

The la out of a hydrog en fuel ng s ation should minimise the lkel ho d of damag e from activities

car ied out on the fuel ng s ation, or ext ernal t o the fuel ng s ation pro e ty

This ma inclu e hazards from fir s of st or d fuel or othe combus ibles, inclu ing buidings, on or in the

vicinity t o the fuel ing s ation, damag e from imp ct of mo ing eq ipment / vehicles or environmental

hazardssuch as fal ing tr es

Hydrog en ins alations should be kept r e of debris an othe flamma le wast e

No flamma le l q ids should be a le t o ac umulat e u de the hydrog en st orag e tanks

5.7.3 Fir e bar r ier r ec ommendatio s

A fir bar ie ma be used as a mitig tion o tion t o r d c safety dis anc s A non-compr hensive l s

of ex mple safety dis anc s for w hich a f ir bar ie could be used is as fol ow s:

— buiding of combus ible mat erial;

— flamma lelq idsa o e grou d;

— st ock of combus ible mat erial;

— flamma leg s st orag e a o e grou d;

— jet flames folowing ignition of hydrog en r leases from the fuel ng s ation;

— o e pr s ur folowing dela ed ignition of hydrog en r leases from the fuel ing s ation;

— po l f ir s folowing ignition of hydraulc oi r leases

If a f ir b r ie is used as a mitig tion o tion, it should be made of suita le non-combus ible mat erials

an ha e a minimum f ir r sis anc rating of 3 min, as measur d ac ording t o ISO 834-1 C nside ation

should be taken for the o e pr s ur efe t g ene at ed arou d the b r ie b an u ignit ed or ignit ed

r lease Wal s int en ed as mitig tion a ains fir s / o er-pr s ur should ha e r q ir ment def ined

b risk as es ment

Any wal s int en ed t o function as a fir b r ie should not inclu e means of o e pr s ur r lef

When used in conju ction with an out do r st orag e sy st em, the fir b r ie should not g ene at e

ad itional risks for o e ating pe sonnel in case of for se a le incident , also se 5.7.6

5.7.4 Mitigating against vehicula impact

Hydrog en st orag e an dispense s should not be locat ed in a dir ct l ne of traffic, e.g entranc / exit t o

s ation Furthe detai s for the prot ection of dispense s from traff ic ar inclu ed in 9.1 1

The s ation design should minimise the ne d for vehicle manoeuvr s as far as is r asona ly practical,

in orde t o r d c the risk of an unsafe situation arising through, for ex mple, the ne d for vehicle

r ve sing Vehicle mo ement on the s ation should be clearly identified b means of signs an markings

The fuel ing s ation o e at or should con uct an impact as es ment that takes int o ac ou t the vehicle

mo ement within the fuel ing s ation

Vehicular imp ct prot ection should be a pro riat e for theanticipat ed ty e an spe d of vehicles in the

vicinity of the hydrog en eq ipment

NOTE F rther guidance on e amples of how t o achieve this is inclu ed as An e E

5.7.5 Fir efighting systems

The location an q antity of fir fighting eq ipment should be det ermined depen ing on the siz of the

hydrog en fuel ing s ation and in consultation with the local f ir authorities

Wat er should be made a aia le in adeq at e v lume an pr s ur for f ir prot ection ( fir fighting an

co l ng of f ir afe t ed eq ipment)as det ermined in consultation with the local fir authorities

F or fir -fighting purp ses, suita le fir -extinguishing a pl anc s should be plac d in r adines in the

vicinity of hazardous ar as Detai s ar t o be co-ordinat ed with the local f ir authorities

Hydrog en fir s should neve be extinguished w his alowing a r lease t o pe sis Whe e the sour e

of hydrog en cannot be isolat ed from the p int of the leak, hydrog en f ir s should be alowed t o burn

unti the hydrog en fuel is complet ely consumed Extinguishing a hydrog en f ir befor the hydrog en fuel

is complet ely consumed could lead t o an ex losion in the event of a r -ignition of the hydrog en The

fir fighting eq ipment should only be used t o pr vent the spr ad of a hydrog en fir , e.g for co lng

sur ou ding eq ipment or for co lng down the hydrog en st orag e t o a oid burs ing of the ves els Wat er

from the fir fighting sy st em should not be dir ct ed at or introd c d int o a hydrog en sy st em vent s ack

5.7.6 Emer g ency pr inciples and operatio s

Suita le ro dway s or othe means of ac es for eme g ency eq ipment, such as fir dep rtment

a paratusshould be pro ided

The ins al ation should be designed so that authorised pe sonnel ha eeasy ac es at al times an ha e

adeq at e means of esca e in the case of eme g ency A cc s should be pr vent ed t o al u a uthorised

pe sons Eme g ency exit should be kept clear at al times

Whe e fencing is pro ided t o pr vent ac es of u authorised pe sons, an a p s ag e wa is ne es ary t o

alow un inde ed ac es t o an esca e from the enclosur , the minimum clearanc betwe n the fenc

an hydrog en eq ipment hould be 0,8 m Timbe or othe r adiy combus ible mat erials should not be

used for fencing

Al g t es should comply with the local fir an buiding codes The g t es should be wide enough t o

pro ide for easy ac es an exit of authoriz d pe son el Gat es should not alow entry without a key

or simi ar locking me hanism d ring normal o e ation Gat es should ha e ac es outwards an if

eq ip ed with a lat ch, should be eq ip ed on the inside with fas r lease hardwar that can be o e at ed

without a key

Conside ation should be given t o the pro ision of an ad itional eme g ency exit w he e the siz of fenc d

ar a or eq ipment location ne es itat esthis In cases w he e a uthoriz d pe son el can be tra ped inside

comp u ds, the e should be at leas two sep rat e outward o ening exit , r mot e from each othe , that

ar s rat egicaly plac d in r lation t o the hazard conside ed

Ful eme g ency proc d r s should be es a lshed for each p rticular fuel ing s ation in consultation

with local f ir a uthorities Pe iodic dri lsshould becar ied out

Whe e a risk r mains that c itical hydrog en eq ipment can be dang erously ex osed t o fir con itions,

w hich ma originat e from non-hydrog en r lat ed eq ipment, despit e al the means that can r asona ly

be taken at design level, the folowing safety sy st ems should be conside ed:

— wat er sprinkle s for co lng of eq ipment ex osed t o fir , se 5.7.5;

— means for the eme g ency venting of hydrog en st orag e tan s ac ording t o 5.6.4

5.8 S fety distanc es

5.8.1 General

The safety dis anc is the dis anc t o an ac epta le risk level or the minimum risk-informed separation

betwe n a hazard sour e an an o je t (h man, eq ipment, or environment) that wi mitig t e the

efe t of a lkely for se a le incident and pr vent a minor incident from escalating int o a larg er incident

This inclu es efe t from hazard sour es bey n the b un aries of the fuel ng s ation

In v rious r gulations an in us rial practic s, the t erm ‘safety dis anc ’ oft en inclu es many ty es of

dis anc s, such as:prot ection dis anc s, clearanc dis anc s, ins al ation la -out dis anc s, dis anc s t o

ext ernal risk sour es, an dis anc s within w hich r s rictions a ply (r s riction dis anc s)

NOTE 1 T ese safety distances are not inten ed to provide complete protection a ainst catastrop ic events

Protection a ainst such events is fu damentaly provided by other req irements or through an emerg ncy

response plan

F or s an ard eq ipment an event , safety dis anc s ma be pr sc ibed b national r gulations,

se ex mples pr sent ed in Annex A, Ta le A.1 an / r ma be det ermined through q antitative risk

as es ment of a g ene ic design F or any given fuel ing s ation, one ma also con uct a q antitative risk

as es ment, w hich can be used t o u de s and the risks an the efe t of s ation-spe if ic mitig tions;

the r sult of the analy sis ma r sult in a r calculation of the safety dis anc t o r sult in s ation-spe ific

safety dis anc s Ifthe safety dis anc is t oo larg e, ad itional mitig tion or pr vention measur s should

be conside ed and the safety dis anc s ma be r -calculat ed using a q antitative analy sis

NOTE 2 The b nef it of con ucting q antitative analy sis is that it g nerat es safety distances that are specif ic to

the fuel ing station/site that is analy sed

The q antitative analysis is used t o demons rat e that the fuel ing s ation does not pose unac epta le

risk t o spe ific targ et , taking int o ac ou t the design an mitig tion featur s of the actual ins alation

A cc pta le q antitative t ech iq es inclu e Quantitative Risk As es ment (QRA) an conseq enc

model ng ( i.e a QRA without q antif ication of the pro a i ty of sc narios) The analysis uses a

combination of information an data r g rding the fuel ing s ation design and o e ation, v ldat ed

phy sical models, an pro a i is ic models that me t the c it eria discus ed in the r mainde of this

clause Useof a common, ISO s an ard t oolkit is s rongly sugg est ed

NOTE 3 An e ample of a safety distance to lkit is given in An e A

This Te h ical Spe ification r commen s making a dis inction betwe n safety dis anc s designed t o

prot ect a ains dife ent hazards, an usesthe folowing t erms:

— R es riction dis anc s

— Clearanc dis anc s

— Ins al ation layout dis anc s

— Prot ection dis anc s

— Ext ernal risk zone

5.8.2 T ypes of safety distanc es

5.8.2.1 Restr ictio distanc es

The r s riction dis anc is the minimum dis anc from hydrog en eq ipment or ar a arou d w he e

c rtain activities ar r s rict ed or subje t t o spe ial pr ca utions (e.g no o en ignition sour es, l ke

flames, hot works, ele trical sparking, use of sp rking t ools, smoking, et c )

NOTE T is is ad res ed in 5.5.2 The remaining ty es of safety distances mitig te forese n an u forese n

events other than those arising from activities restricted d ring normal operations

5.8.2.2 Cle ranc e distanc es

The clearanc dis anc is the minimum dis anc betwe n the fuel ng s ation eq ipment an the

vulne a le targ et within the fuel ing s ation sit e b un ary He e, the hydrog en ins alation is r g rded

t o be the sour e, w hie the sur ou ding peo le / bje t ar conside ed t o be the targ et

Ex mples of targ et that ma be ex osed inclu e pe son el ofthe fuel ing s ation, use s of the fuel ng

s ation, an othe faci ities within the fuel ng s ation lke g solne st orag e, g solne dispensing an

del ve y faci ities Ad itional ex mples ar lst ed in Ta le 3

5.8.2.3 Instalatio layout distanc es

The ins alation la -out dis anc is the minimum dis anc betwe n the v rious eq ipment of the

hydrog en ins alation r q ir d t o pr vent escalation t o othe eq ipment in case of an incident

Ins alation la out dis anc s ma be dife ent combinations of hydrog en eq ipment

Ex mple of sour e-targ et pairs ar dispense an bulk st orag e; lq id or g seous hydrog en st orag e an

hydrog en venting Ad itional targ et ar lst ed in Ta le 3

5.8.2.4 Pr otectio distanc es

The prot ection dis anc is t o pr vent damag e t o the hydrog en ins alation eq ipment from ext ernal

hazards(e.g f ir s) not ac ou t ed for in the ins alation layout dis anc s

NOTE In this case, the t erm e t ernal refer t o b th of-sit e events an also on-site events u related t o the

hydrog en eq ipment

The prot ection dis anc pr vent of-sit e and non-hydrog en-r lat ed event from escalating t o the

hydrog en eq ipment Prot ection dis anc s ma be dife ent for spe if ic element of the fuel ing s ation

eq ipment

Ext ernal sour es of hazard oft en inv lve fir s an col sions Sour es inclu e pr senc of combus ibles

(e.g g sol ne st orag e ar a), on sit e vehicles using non-hydrog en part of the fuel ng s ation, an

vehicles on nearb ro ds; ad itional ex mple sour es ar pro ided in Ta le 2 Ex mple targ et ar any

eq ipment of the hydrog en fuel ng s ation, inclu ing eq ipment l st ed in Ta le 3

5.8.2.5 Ex ternal risk zo e

The ext ernal risk zone is the dis anc (or ar a) out ide fuel ng s ation w hich is t o be prot ect ed from

hazardscaused b the fuel ing s ation He e, the fuel ing s ation is the hazard sour e, w hi e peo le an

cons ructions ofsit e ar r g rded t o be the targ et (s)

Ex mple of-sit e targ et inclu e membe s of the publc r siding or working near the fuel ing s ation;

ad itional targ et ar l st ed in Ta le 3

5.8.3 Examples of safety distanc es

Table 1 — Summary of ty es of safety distances

C aract erization

ofsafety dis anc

R es riction

dis-tanc s

Minimize risk in are s adjacent

to hydro en eq ipment

F el ing station eq ipment

An open are adjacent o

hydro en eq ipment

Clearanc dis anc

Prot ect per ons an o jects

within the fueling station from

hazards as ociated with the

fuel ing station

E uipment an o jects

within fuel ing station

Per ons an other facilities

within the fueling station

Ins al ation la

-out dis anc

Prevent es alation of events

within fuel ing instal ation

F el ing station eq ipment F el ing station eq ipment

Prot ection

dis-tanc

Protect he fuel ing station

from dama e d e to an e

ter-nal hazards

Of-site facilities an

on-site things (ex cept or the

fueling station eq ipment)

F el ing station eq ipment

E t ernal risk zone

Mitig te of-site risks from

hazards as ociated with the

F el ing station

F el ing station eq ipment

Sur ou ding pe ple

property outside of the

fuel ing station

Table 2 — Example sour es for e ch ty e of safety distances

Cle rance distance

AND

Instal ation lay-out distance

AND

External risk zone

E uipment of the fuel ing station

• Dispenser;

• Compres or;

• Liq id hydro en st ora e;

• Gase us hydro en st ora e

Protection distance Of-site or on-site:

• Presence of other comb stible lq ids or g ses (e.g g solne stora e,

L G stora e, pipelines containing flamma le g ses of liq ids);

• B ildings of combustible materials

On-site:

• Vehicles using non-hydro en parts of the fuel ing stations

Of-site:

• Vehicles on ne rby ro ds;

• Specif ic ty es of in ustrial buildings

NOT The information in this ta le is provided to facilitate identif ication of hazard sour es that could b

in-clu ed in the model It is not req ired t o esta lish safety distances for an of the sour es in the ta le.It is also

pos ible t o esta lish safety distances for sour es not list ed in this ta le

Table 3 — Example targ ets for e ch ty e of safety distance.

• Worker in the fuel ing station (1

Other facilities within the fueling station:

• B ilding such as convenience stores, carwash;

• Gasoline stora e;

• Gasoline dispensing facilities;

• F el delivery are s;

• B ilding openings, air intakes

Instal ation lay-out distance

• Liq id hydrog en st orag e;

• Gase us hydro en stora e;

• Vent stack e its

External risk zone Per ons:

• P blic buildings such as s ho ls, hospitals;

• High voltag e lines

NOT The information in this ta le is provided t o simplify targ t selection It is not req ired to esta lish safety

distances for an of the targ ts in the ta le It is also pos ible to esta lish safety distances for targ ts not list ed

in the ta le

5.8.4 S fety distanc es relating to hydrog en vent stack outlets

The vent outlet location (heigh dis anc t o ex osur s) should be such that the lmit for the mal

radiation an o er-pr s ur efe t of ignit ed vent ed g s ar not ex ce ded u de any for se a le

venting situation conside ing u favoura le win con itions The safety dis anc s for vent ed g s from

lq id hydrog en sy st ems should takeint o conside ation the density of the g s

The the mal radiation an o e pr s ur efe t of ignit ed vent ed g s ( immediat e or dela ed ignition)

should beconside ed for the anticipat ed vent ed g s

Hydrog en conc ntration at win ow s, o enings, air intakes an at locations w he e pe sons or pe son el

ma be pr sent should not ex ce d 4 % in air (1 0 % LF ), u les a lowe conc ntration of hydrog en in

air is r q ir d b national r gulations or b risk as es ment

5.9 Protection me sures for non-hydrog en hazards

5.9.1 General

In ad ition t o the hazards r lat ed t o hydrog en sup ly, st orag e an dispensing on the fuel ng s ation

sit e, othe non-hydrog en hazards should be ad r s ed The risk as es ment should identify measur s

taken t o prot ect a ains the spe if ic hazardsl st ed below, w he e a plca le:

— working at height ( e 9.3.2.3);

— asphy iation ( e 5 9.2);

— eme g ency egr s rout es out of enclosur s or v ult ( e 5 9.3);

— ele trocution ( e 1 1);

— mo ing machine y ( e IEC60 04-1);

— anti-w hip measur s for hoses ( e 5.9.5);

— noise ( e 5 9.6)

5.9.2 Protectio me sur es for asphyx iation hazar d in an enclosure

When an eq ipment comp rtment is int ended t o be ent er d and contains or is con e t ed t o a sour e of

hydrog en or ine t g ses that compartment should be ev luat ed for the p t ential of an o yg en deficient

atmosphe e d ring normal or of-normal con itions

When the p t ential exis s for an o y g en deficient atmosphe e, proc d r s should be put in plac t o

pr vent this oc ur ing w his pe son el ar pr sent in or ent ering int o the comp rtment, or det ection

an notif ication a pl anc sshould bepro ided t o warn pe son el of an o yg en-def icient atmosphe e

Whe e fix ed det ections an notif ication a pl anc s ar used, notification a planc s should prod c a

dis inctiveau ible an visual alarm an be locat ed out ide the entranc t o al locations that w he e the

o y g en-deficient con ition could exis

Hydrog en piping an eq ipment hould be isolat ed, depr s uriz d an made safe prior t o r plac ment

of comp nent Vent g s an purg e g s should be exha ust ed out ide of the hydrog en comp rtment

befor an aft er r plac ment or se vic work r q iring depr s urization

5.9.3 Protectio me sur es for emer g ency eg res from enclosed spac es

Ext erior ac es do rs should be se ur d a ains una uthoriz d entry Whe e ac es do rs do not ne d

t o be se ur d t o prot ect worke s a ains hazards, for ex mple, lve ele trics, se IEC 6 2 4-1, do rs do

not ne d t o be se ur d if a se ur d pe imet er fenc or wal is pro ided t o pr vent u authoriz d entry

L cks or lat ches on eme g ency do rs should not r q ir the use of a key, a t ool for the o e ation from

the egr s side

Enclosed spac s e.g eq ipment containe s or v ult ( e 9.3.2.2), should be pro ided with a pe son el

ac es wa with a minimum width of 0,8 m an ensur a pe manent esca e rout e The tra el dis anc

from p int of maint enanc inside an enclosed sp c t o an eme g ency egr s point should not ex ce d

6 m, othe wise multiple means of egr s should be pro ided

NOTE Egres recommen ations are not ap lica le when al operation an maintenance-relat ed work is

performed from the e terior of the enclosure