p.1 

OAR Box 1147 

Prepped by Ollie Stewart 

Document Number: 

215)IV-E-89 

Docket Number: 

A-87-11 

Printed 4/22/2008 2:42:58 PM Sheet 215 of 242 
P.2 

mT <*. 

USB 

Xr* ^ ^ 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

MAR I 3 ^ 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

THRU: 

Battelle Industry Presen 

Paul M. Laing, Chemical Engineer 

Standards Development and Support Branch ^ 

The Record 

Glenn W. Passavant, Senior Project Manage 

Standards Development and Support Branch 

r ^Ltdi^""-^ 

On March 7, 1989 an EPA contractor, Battelle, presented 

the results of their two recently completed draft studies, 

"Fuel System Comparative Risk Assessment", and "Service Station 

Refueling Risk Assessment" to representatives from the American 

Petroleum Institute, Motor Vehicles Manufacturers Association, 

Automobile Importers of America, and individual member 

companies. A complete list of attendees is attached. Also 

attached are a copy of the agenda and Battelle's briefing 

charts. 

Attachments 

cc: Docket A-87-11 

6903W 

J 
P.3 

Battelle Industry Presentation Agenda 

March 7, 1989; 1:00 p.m. 

I. Opening Remarks (EPA) 

II. Fuel System Comparative Risk Assessment (Battelle) 

III. Service Station Risk Assessment (Battelle) 

IV. Adjournment 

Battelle Team Members 

David J. Mitchell 

Jonathan F. Luedeke 

Joseph A. Hoess 

John T. Herridge 

Michael Murphy 

6891W 
P.4 

w "Fuel System Comparative Risk Assessment" 

Battelle Industry Presentation 

March 7, 1989; 1:00 p.m. 

Sign-In Sheet 

*•( * 

1. 

2 . 

3 . 

4 . 

5. 

6. 

7. 

8. 

9. 

10. 

1 1 . 

12. 

1 3 . 

14. 

1 5. 

16. 

17. 

18. 

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2 1 . 

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4 0 . 

4 1 . 

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4 3 . 

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4 5 . 

4 6 . 

4 7. 

4 8 . 

4 9 . 

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Sign-In 

Name 

P, l^uEb^ 

-

Sheet (Continued) 

Company/Orqanization 

(oYoTA 

~To^e>?4-

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Phone 

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3rs 3>c3U^-0(j 
* * P Battel le 

PRESENTATION 

on 

SERVICE STATION 

REFUELING RISK ASSESSMENT 

March 1989 

David J. Mitchell 

(614)424-4929 

Raymond E. Thompson 

(614)424-5171 

p 

CO 
Topics €* Battelle 

1) Objective 

2) Activities 

3) Battelle Findings 

4) Impact of EPA Reduction Factors 

on Battelle Findings 

r>i 
#fel 1) Objective i l Battelle 3 

Determine risks associated with current service 

station refueling events 

TJ 

CO 
£fe Areas of Interest % $ Battelle 

Refueling Event Consequences (number of incidents 

and cost) 

- Fires 

- Personal injuries 

- Deaths (number of incidents only) 

- Fire related property damage 

- Non-fire related property damage 

Hazards 

- Vapor emissions 

- Liquid spills from vehicles 

- Liquid spills from nozzles 

Geographical Area 

- Entire U.S. except State of California 

TJ 

CO 
2) Activities OBaffelle 

Identify the data and potential sources 

Obtain and review available data 

Perform the quantitative risk assessment 

• • 

o 
Organizations Contacted Cl Battelle 

American Petroleum Institute 

Automobile Dealers-Service Departments 

Center for Auto Safety 

Center for Firesafety Studies/Worcester Polytechnic Institute 

Dry Cleaners 

Failure Analysis Associates 

Federal Highway Administration 

Insurance Companies 

Insurance Institute for Highway Safety 

Major Oil Companies 

National Center for Statistics and Analysis-DOT/NHTSA 

National Fire Protection Association 

National Safety Council 

National Highway Traffic Safety Administration 

Ohio Environmental Protection Agency 

Service Station Dealers of America 

Society of Automotive Engineers 

State Fire Marshalls 

Transportation Research Board/National Academy of Sciences 

United States Consumer Product Safety Commission 

United States Environmental Protection Agency 

United States Fire Administration 
Primary Data Sources €* Battelle 

• NEISS Data - U.S. Consumer Product Safety Commission 

• NFIRS Data 

- U.S. Fire Administration 

- Center for Firesafety Studies, Worcester Polytechnic 

Institute 

- U.S. Environmental Protection Agency 

- Failure Analysis Associates Report 

- State of Ohio Fire Marshal's Office 

• Non-fire Property Damage Data - American Petroleum 

Institute 

ro 
3) Battelle Findings: **Ranpiip 

Incidents and Costs *#Banene 8 

Annual Number of Refueling Fires 162/$198,000 

Vapor related 4/$4,500 

- Spill related 158/$193,500 

Annual Number of Injuries 1395 

- Vapor related 39 

Spill related 1356 

Annual Number of Deaths 1 

Annual Number of Non-Fire Related Refueling 

Incidents (property data) ND 

Tl 

W 
4) Impact of EPA Reduction ^Battelle 

Factors on Battelle Findings 

Initial Findings 

- 162 refueling related fires annually 

4 due to atomized liquids/vapors 

- 158 due to spillage 

EPA Assumed Reduction Factors 

- 100% reduction in fires due to atomized liquids/vapors 

50% reduction in fires due to spillage 

Projected Findings 

51% of all refueling fires would be eliminated 

Tl 
€* Battelle 

PRESENTATION 

on 

FUEL SYSTEM 

COMPARATIVE RISK ASSESSMENT 

March 1989 

David J. Mitchell 

(614)424-4929 

Jonathan F. Luedeke 

(614)424-5145 

Tl 
Topics 

1) Background 

2) Objective/Scope 

3) Project Approach 

4) Overview of Cases Analyzed 

5) Analysis Approach 

6) Results 

7) Conclusions 

llBattelie

 2 

j 

* 
.m. 1) Background Cl Battelle 

Concern expressed by several parties over 

safety of onboard refueling emission control 

systems - increased risk of fire 

EPA conducted and released safety evaluation 

for public comment 

EPA published NPRM 

Battelle retained to perform independent and 

objective comparative risk assessment (FMECA) 

VA,\mrt-\-W 

Tl 
2) Objective/Scope .$%. O Battelle 

Objective 

• Scope 

Conduct comparative risk assessment of specific 

onboard refueling emission control approaches 

versus current approaches 

Limited to 10 fuel system configurations defined by 

EPA's Office of Mobile Sources (Ann Arbor, Michigan) 

Hazards are leakage of liquid fuel or vapor 

Three vehicle operating states addressed-- refueling, 

driving, parked 

Gasoline powered, passenger cars considered 

(also covers light trucks with similar fuel system 

approaches) 

Tl 

oo 
3) Project Approach O Battelle 

Work Assignment 

Configuration Definition 

and Confirmation 

FMECA 

I 

Draft Report 

J 

Safety Group Review EPA Review Industry Review Public Comment 

T 

Battelle Reanalysis 

Final Report 

T l 

CO 
< * % 4) Overview of Cases Analyzed M Battelle 

Existing Systems: 

Case 

1 

(Base Case) 

Descriptor 

Stock fuel injected (F.I.) 

Major Characteristics 

1986 GM A body with 

port fuel injection 

Stock carbureted 1986 GM A body with 

carburetor, bow-tie and 

no rollover valve 

Tl 

ho 
Overview of Cases Analyzed 

(Continued) 

* % O Battelle 

Modified Systems - No Onboard Controls: 

Case Descriptor 

2 Stock F.I. with steel 

fillpipe and ventpipe 

3 Stock F.I. with enlarged 

fillpipe 

5 Stock F.I. with 

submerged fillpipe 

6 Stock carbureted with 

rollover valve 

Major Characteristics 

Stock F.I. without flexible 

hose in fillpipe or ventpipe 

Stock F.I. with enlarged 

fillpipe diameter, no ventpipe 

Stock F.I. with extended and 

submerged fillpipe in fuel tank 

Stock carbureted with 

rollover valve, no bow-tie 

W/Arl-.l-m 

U 

ho 
Overview of 

(Continued) 

Cases Analyzed I I Battelle 

Modified Systems - With Onboard Controls: 

Case 

8 

10 

Descriptor 

7 Onboard with steel 

fillneck valve 

Onboard with solenoid 

tank valve 

Onboard with mechanical 

tank valve 

Onboard with plastic 

fillneck valve 

Major Characteristics 

Stock F.I. with steel fillneck 

mounted rollover/refueling vent 

valve and liquid seal 

Stock F.I. with tank mounted 

solenoid rollover/refueling vent 

valve, rear canister, liquid seal 

and no ventpipe 

Stock F.I. with tank mounted 

rollover/refueling vent valve, 

rear canister, liquid seal 

and no ventpipe 

Stock F.I. with plastic fillneck 

mounted rollover/refueling vent 

valve, mechanical seal and 

overfill relief valve 

KAA*M-+«I-I7t 
Base Case Configuration 

Stock Fuel Injected I I Battelle 

Fuel Injection 

Rail Assembly 

Fuel Feed Line 

Fuel Return Line 

Lock Cam -<a> 

Cover Plate Assembly, 

(£&} Fuel Cap 

Filler Neck Head 

Fuel Pump 

Pulsator/Damper 

Fuel Level Gauge 

Sender Unit 

Fuel Filter/ 

Strainer 

^t**^y Fuel Feed Filter 

"0" Rings 

Fuel Pressure 

Regulator. 

"**=a a$ 

Limiting^fev 

Orifice ^ 

(0.055") & 

Rollover Valve 

Fuel Pump 

0" Ring Vapor 

Seal Vent Line 

Ventpipe Hose/ 

Tube Assembly 

Fillpipe Hose/ 

Tube Assembly 

mm <tX0XlZIX» 

Fuel Tank 

Purge Control 

Diaphragm Valve 

mnni D Elastomeric/Plastic Hose 

q jn Steel Tubing 

r=(fez long Hose or Tubing 

Vacuum 

Hose/Tube 

Assembly 

Throttle Body 

Purge Hose/Tube 

Assembly 

Purge Line 

Restrictor (0.050") 

Purge Solenoid Valve 

Canister, 1.5L, Open Bottom, Front Mount 
s^kKecfed '

 Hi9h"9h,s" Ouawe 

Identical to fuel system in 1986 Oldsmobile Cutlass Ciera: 

- Multiport fuel injection 

- Fuel tank cover plate mounted rollover/vent valve 

w/limiting orifice 

- Electric fuel pump in fuel tank 

- Fillpipe and ventpipe hose/tube assemblies 

- Purge control diaphragm valve 

- Purge solenoid valve 

- Purge line restrictor 

- Front mounted 1.5L open bottom canister 

10 

2 

-J 
Case 2 Configuration - Stock Fuel ^RattpiiP 

Injected w/Steel Fillpipe and Ventpipe ^ D c "

,c,, e 

11 

All Steel Fillpipe & Ventpipe 

Hose/Tube Assemblies 

(No Hose Sections) 
Case 2 Highlights - Stock Fuel ^Raftpiip

 u 

Injected w/Steel Fillpipe and Ventpipe WDCIIIOK; 

Same as Base Case - Stock Fuel Injected except: 

- Hose sections in fillpipe and ventpipe 

deleted 

Tl 

ho 

0) 
Case 3 Configuration - Stock Fuel 

Injected w/Enlarged Fillpipe 

I I Battelle 13 

No Ventpipe 

Hose/Tube 

Assembly 

Enlarged Fillpipe Hose/Tube 

Assembly 

ro 

^ i 
Case 3 Highlights - Stock Fuel ^^R^ttPiiP

 14 

Injected w/Enlarged Fillpipe %*Bdiieue 

Same as Base Case - Stock Fuel Injected except: 

- Fillpipe enlarged 

- Ventpipe deleted 

ro 
Case 4 Configuration -

Stock Carbureted 

&% O Battelle 15 

Fuel Pump & 

Pressure 

Reyuldtor 

fuel Return Restrictor 

* I nin 11 mi 

Orifice (0.0b!>") 

Antisyphoning 

How-Tie" Vent Tube 

fuel Return Line ^ m 

gartaumm* ^^-Fue l 

No Rollover Vdlve 

ai 

6 QnmusoP 

Tank Pressure 

Control Diaphragm 

Valve 

Canister 

Hose 

Assembly 

Purge 

Solenoid 

Valve 

Purge Line 

Restrictor 

Purge Hose/Tube 

Assembly 
Case 4 Highlights - ^R^ttaiio

 16 

Stock Carbureted wMiieiie 

• Same as Base Case - Stock fuel Injected except: 

Carburetor replaces fuel injection 

Antisyphoning bow-tie vent tube replaces rollover/ 

vent valve 

Tank pressure control diaphragm valve added 

Purge control diaphragm valve deleted 

Different purge line restrictor used 

Fuel bowl vent solenoid valve added 

Mechanical fuel pump replaces electric fuel pump 

Nonpressurized fuel feed line replaces pressurized 

line 

Fuel return line restrictor replaces fuel feed line 

pulsator/damper 

J° 
Case 5 Configuration - Stock Fuel 

Injected w/Submerged Fillpipe I I Battelle 17 

Fuel Tank 

(Lowered Fillpipe 

Extension) 

r 

Ico 
Case 5 Highlights - Stock Fuel #fcD»«taiio » 

Injected w/Submerged Fillpipe ^twnene 

• Same as Base Case - Stock fuel injected except: 

- Fillpipe extension in fuel tank submerged 
Case 6 Configuration - Stock 

Carbureted w/Rollover Valve I I Battelle 19 

Fuel Pump & 

Pressure Regulator 

Fuel Return Restrictor. 

Fuel Return Line _ ^.fc* Fuel 

Feed 

Filter 

Purge 

Solenoid 

Valve 

Purge Line 

Restrictor 

Purge Hose/Tube 

Assembly 

co 

co 
Case 6 Highlights - Stock ^RattPifp

 20 

Carbureted w/Rollover Valve wwiiiaic 

Same as Case 4 - Stock Carbureted except: 

Rollover valve replaces antisyphoning bow-tie 

vent tube 

co 
Case 7 Configuration - Onboard 

w/Steel Fillneck Valve I I Battelle 21 

Steel Refueling Vent 

and Rollover Valve 

IIIIIH M nin»»- — Enlarged ^ 

\Vapor Vent Lines 

A anmn255> Antispitback 

Valve 

Canister, 4.5L 
Case 7 Highlights - Onboard ^RattoH^

 22 

w/Steel Fillneck Valve wBaneiie 

Same as Base Case - Stock Fuel Injected except: 

- Liquid seal used 

- Steel refueling vent and rollover valve added 

- Enlarged vapor vent lines used 

- T-fitting added 

- Antispitback valve added 

- Enlarged front mounted 4.5L open bottom 

canister replaces 1.5L open bottom canister 

T l 

CO 
Case 8 Configuration - Onboard 

w/Solenoid Tank Valve 

* & O Battelle 23 

Microswitch 

<^L*.*<: : *mt> 

No Rollover Valve 

or Limiting Orifice 

tened and 

rged Vapor 

Purge Control 

Diaphragm 

Valve 

(Engine 

Compartment) 

Canister Purge Line 

/ 

Canister, 4.5L, Rear Mount 

13 
Case 8 Highlights - Onboard 

w/Solenoid Tank Valve II Battelle 24 

Same as Base Case - Stock Fuel Injected except: 

- Liquid seal used 

- Solenoid activated tank mounted refueling vent, 

rollover and overfill valve with limiting 

orifice replaces rollover/vent valve on cover plate 

- Nozzle activated microswitch added 

- Enlarged rear mounted 4.5L canister with dust 

cap replaces 1.5L front mounted open bottom 

canister 

- Long canister purge line used 

- Enlarged vapor vent line used 

- Purge control diaphragm valve remains in 

engine compartment 

- Antispitback valve added 

- Ventpipe deleted 

co 

oo 
Case 9 Configuration - Onboard 

w/Mechanical Tank Valve II Battelle 25 

<s» .«-< ^ *^& > 

Limiting Orifice 

Overfill & Rollover 

Valve 

Refueling Vent, 

Overfill & Rollove 

Valve 

No Ventpipe 

Hose/Tube Assenibl 

\ 

No Rollover Valve or 

Limiting Ori fice 

Shortened & Enlarged. 

Vapor Vent Line 

Purge Control 

Diaphragm 

Valve 

(Engine 

Compartment) 

A QmrrrflfiP (XtrTnt 

Canister Purge Line 

Canister, 4.5L, Rear Mount 

co 

CO 
Case 9 Highlights -Onboard ||Battelle

 26 

w/Mechanical Tank Valve 

Same as Base Case - Stock Fuel Injected except: 

- Liquid seal used 

- Tank mounted rollover, refueling vent and 

overfill valve with limiting orifice replaces 

rollover/vent valve with limiting orifice on 

cover plate 

- Enlarged rear mounted 4.5L canister with dust cap 

replaces 1.5L front mounted open bottom canister 

- Long canister purge line used 

- Enlarged vapor vent line used 

- Purge control diaphragm valve remains in engine 

compartment 

- Antispitback valve added 

- Ventpipe deleted 

TJ 
Case 10 Configuration - Onboard 

w/Plastic Fillneck Valve I I Battelle 27 

Overfil l 

Relief 

Valve 

Mechanical Seal 

Plastic Filler Neck Head 

Refueling Vent & 

Rollover Valve 

<& 

@f> (Added Hose 

Section ) 

Fillpipe Hose/ 

Tube Assembly 

(Added Hose Section ) 

Ventpipe Hose/ 

£, Tube Assembly 

Canister, 4.0L 

P 
Case 10 Highlights - Onboard ftRaitpilp

 28 

w/Plastic Fillneck Valve WDOIICIIC 

Same as Base Case - Stock Fuel Injected except: 

Plastic fillneck mounted refueling vent and 

rollover valve added 

Mechanical seal added 

Overfill relief valve added on fillneck 

Additional fillpipe and ventpipe hose sections 

added 

Enlarged vapor vent lines used 

- T-fitting added 

Enlarged front mounted 4.0L open bottom canister 

replaces 1.5L front mounted open bottom canister 

ro 
4%i Component Grouping/Hierarchy f I Battelle 29 

• Components grouped into 4 subsystems based on function and 

location 

Fuel reservoir 

Vapor vent line and canister 

Canister vacuum/purge 

Fuel supply 

• Allowed assessing probability of failure modes at higher level 

• Provided consistency in analyses and comparisons 

CO 
Component Grouping Example O Battelle 30 

Subsys tem/Component 

Fuel Reservoir Subsystem 

- Refueling Nozzle-Filler Neck Interface 

- Fuel Cit[> 

- Fuel Tank Filler Neck Head 

Steel Head 

Plastic Head 

Leaded Gas Restrictor 

Mechanical Vapor Seal 

Overfill Relief Valve 

- Fillpipe Hose/Tube Assembly 

Tube 

Hose 

Brazed/Welded Tube Joint 

Hose Connector, Screw Clamp 

- Ventpipe Hose/Tube Assembly 

Tube 

Hose , 

Brazed/Welded Tube Joint 

Hose Connector, Screw Clamp 

No. of 

Items 

in 

Base Case 

1 

1 

1 

1 

NA 

1 

NA 

NA 

1 

2 

1 

2 

2 

1 

2 

1 

2 

2 

Case 

2 

1 

NA 

NA 

1 

NA 

NA 

Number of Items in Cases 2-10* 

Case 

3 

NA zzzz 

>>>> 

Case 

4 

Case 

5 

Case 

6 

Case 

7 

Case 

8 

NA xxxx >>>> 

Case 

9 

NA 

NA 

NA 

NA 

NA 

Case 

10 

NA 

1 

1 

1 

2 

1 

4 

2 

1 

4 

'No entry implies same as base case. 
5) Analysis Approach | | Battelle 31 

• Established FMECA process and format 

• Defined FMECA categories and developed ranking methodology 

and criteria (e.g. hazard, hazard probability, leakage rate, 

proximity to ignition source, severity, risk) 

• Determined failure modes and possible causes for each 

component 

• Determined effects and hazards for operating states and failure 

mode 

• Performed ranking (scoring) process 

• Tabulated risks 

• Compared by case and operating state 

cn 
FMECA Process .m. O Battelle 32 

Efted 

(toss of seal Integrity) J 

f 

FaiKira Mod* 

(broken) ] 

f 

Possfcfe Causa 

(improper installation) 3 

t 

Componant 

(hosa clamp) J 

Hazard 

(leakage ol fual 

or vapor) ) 

Severity 

(leakage rata, proximity 

to ignition source) J Hazard Probability 

(likelihood that failure 

mode occurs and results 

in hazard) 

) 
P.47 

0) * = cu CQ 

IMF 05 

£ 

o LL 

< O LU 

.at 

fl. 1 *" 8

 a 

1 v 

r~-

mO 

t / 1 

K 

O k-

& 

-a£ 4> 

0) <c 

-J (X j a 

mC. N o ^" 

r^j *~ 

= o. 

At-. 

u Effe 0) 

mm. 

CL «Q o *-

l/l ossibl e Causes a. ^tA . 0) Failur e Mo 

1 

I 

| 

I i l i 

i 

i i i i 

I 

i 

i 

i 

I 

i i 

i 

i 

[ 

i 

i 

i 

i 

! 

i 

i 
Failure Modes/Possible Causes .*%. pBaffelle 34 

Failure modes consistently assigned based on component type 

Possible causes identified for each failure mode 

Failure of mounting hardware included as possible causes 

Causes originate in all phases of vehicle life (design, 

manufacturing and use) 

00 
Operating States and 

Characteristics 

%.M. I Battelle

 35 

L 

State 

Refueling (R) 

Driving (D) 

Parked (P) 

Car 

Movement 

No 

Yes 

No 

Engine 

Off 

On 

Off 

Severe 

Traffic 

Accidents 

No 

Yes 

Yes 

Rollover 

No 

Yes 

No 

Fuel 

Cap 

Off 

On 

On 
Effects Q Battelle 36 

Effects cited for each failure mode of each component 

for each operating state 

Effects are worst case 

Effects cited are present during specific state 

cn 

o 
Hazards * * O Battelle 37 

Category Description 

V 

L 

N 

Leakage of fuel vapor only 

Leakage of liquid fuel 

(subsequently forms fuel 

vapor) 

Essentially no leakage 

XI 

cn 
Hazard Probability I I Battelle

 38 

• Definition - Likelihood that failure mode exists in operating 

state with particular effects and hazards 

• Based on: 

Fuel system design differences 

Expected relative occurrences of failure modes 

Vulnerability and orientation of components 

Professional and personal experience 

• Augmented wherever possible by data found in literature 

cn 

ro 
Hazard Probability Scale •3>-i- O Battelle 39 

Description Rank 

Relative Probability 

For Individual Vehicle 

Frequent 

Probable 

Occasional 

Remote 

Improbable 

A Likely to occur frequently 

in life of vehicle 

B Will occur several times 

in life of vehicle 

C Likely to occur sometime 

in life of vehicle 

D Unlikely but possible to 

occur in life of vehicle 

E So unlikely, it can be 

assumed occurrence may 

not be experienced in 

life of vehicle 

cn 

co 
Leakage Rate Scale 4% Cl Battelle 40 

Ranking Leakage Rate Criteria 

I 

II 

III 

IV 

>110 g/5 min 

11-110 g/5 min 

1.1-11 g/5 min 

<1.1 g/5 min 

>NHTSA limit1 

>1/10 NHTSA limit 

<1/10 NHTSA limit 

Zero or nearly so 

* Based on NHTSA specification of 5 oz/5 min 

for FMVSS 301 crash testing 

Ol 
Potential Ignition Sources 4OTatteiie * 41 

Sparks/Arcs 

- Electrical components/wiring and friction 

Hot Surfaces 

- Hot engine 

- Exhaust components 

- Metal heated by electrical shorts 

- Hot particles produced by friction 

Flames 

Intake or exhaust backfires 

cn 

cn 
Proximity To Ignition 

Source Scale C4% I Battelle 42 

Rank* 

I 

II 

III 

Criteria 

On or immediately adjacent to engine 

» 

Other locations in engine compartment 

Everywhere else on vehicle 

*Based on likelihood that ignition source exists in close 

proximity to leak 

cn 

0) 
Severity O4*. Battelle 43 

Proximity to Ignition Source 

On Near 

Leakage Rate 

(g/5 min) 

>110 

11-110 

<11 

Zero 

Description Rank 

High 1 

Medium 2 

Low 3 

Negligible (no hazard) 4 

* Massive liquid fuel leaks considered Rank 1 

Far 

1 

1 

2 

4 

1 

2 

2 

4 

2* 

2 

3 

4 

• A,'»*-l-**' ?0 
Risk I I Battelle 44 

• Definition - Likelihood of fire due to a liquid fuel 

or vapor leak 

• Function of probability and severity 

• Examples: 

Hazard Probability Severity Risk 

C 2 2C 

D 1 1D 

• Highest risk is 1A, lowest is 3E 

cn 

oo 
6) Results I I Battelle 45 

FMECA tables 

Risk matrices 

Risk level comparisons 

Summary 

cn 

co 
FMECA Table Example .i?*. O Battelle 46 

Component: Ventpipe Hose/Tube Assembly 

Failure Modes/Possible Causes 

Small hole, crack or seal failure 

- Manufacturing error (brazing, welding) 

- Clamp omitted, wrong type, not fully 

tightened, loosens, or fails 

- Wrong hose material and/or size 

- Hose aging/cracking 

- Hose abrasion from adjacent part 

- Struck by object (e.g., stone, accident) 

- Excessive internal pressure 

- Tube corrosion or joint failure 

- Support bracket or fitting failure 

Ruptured/cut/severed/disconnected 

- Not connected or misrouted during 

manufacture or repair 

(e.g., stone, accident) 

- Excessive internal pressure 

- Support bracket or fitting failure 

Obstructed 

- Kinked during manufacture or repair 

- Blocked by foreign material 

- Swelling (wrong material) 

- Kinked or pinched during vehicle accident 

- Collapsed from excessive vaccum 

Op 

State 

R 

D 

P 

R 

D 

P 

R 

D 

1' 

Effect 

Loss of ventpipe 

integrity 

Vapor/fuel splash out 

and fluid loss with 

rollover 

Loss of ventpipe 

integrity 

Loss, of ventpipe 

integrity 

Vapor/fuel splash out 

and fluid loss with 

rollover 

Loss of ventpipe 

integrity 

Fuel spitback 

Tank vented via 

fillpipe 

* 

Haz 

V,L 

V,L 

V 

V,L 

V,L 

V 

L 

N 

N 

Haz 

Prob 

D 

0 

0 

D 

D 

D 

D 

-

-

Leak 

Rate 

II 

II 

III 

I 

I 

III 

III 

IV 

IV 

Prox 

III 

III 

III 

III 

III 

III 

III 

-

-

Sev 

2 

2 

3 

2 

1 

3 

3 

4 

4 

Risk 

2D 

2D 

30 

20 

10 

30 

3D 

-

-

TJ 

00 
Risk Matrix Example 

m. O Battelle 47 

Risks tallied by counting FMECA entries 

for each case and operating state: 

A 

B 

Hazard C 

Probability 

D 

E 

Totals 

Severity 

1 2 3 

0 

0 

0 

16 

7 

23 

3 

2 

2 

33 

79 

119 

0 

0 

1 

9 

25 

35 

Grand 

Total 

177 

M/I.--M-1 \ 
Risk Level Index O•fife Battelle 48 

Matrix entries grouped by combining similar risks: 

Hazard 

Probability 

A 

B 

C 

D 

E 

RiSr 

1 

I 

III 

Severity 

2 3 

ll 

II 

III 

III 

IV 

4 

v 

c Level Relative Risk 

i 

II 

in 

IV 

V 

High 

Medium 

Low 

Very Low 

None 

*A/l»y.|.4«-1 -4A 

O) 

ro 
Risk Level Comparison Chart 

All States p Battelle 49 

160 

Risk Level and Case 

LU 

0) 

• M B 

DC 

0) 

E 

3 

150 -

140 -

1 JO 

120 

1 10 -

100 -

90 -

ao -

70 -

60 

50 -

40 -

30 -

20 -

10 -

0 ZHZECp 

/\?$x/ \ 

/\^$x/\^Jx l /s^sx/\^x 

/f^M/ 

A4AI /\^x/\^x A<K 

/\£$x/\£$x 

/\£$x/\*sx 

/\^$x/\*$x 

/\/;s:x/\^$x 

/\£$x/\£$x 

/\«x/\^$x 

/\2$x/\£$x 

/\Z$r<r'\Z§X 

/\2NX/\^S:X /\£$x/x*$x 

/\^$x/\^ x /\2Sx/x^ x 

f7P3 / X / x 

/ X 

2-S 

Level I Level II Level III Level IV 

Note: Cases 1-10 shown left to right 
Risk Level Comparison 

All States O•&% Battelle 50 

Finding 

Risk entries increase as 

risk level decreases 

Cases 8, 9 and 10 lowest 

in risk level I 

Cases 7, 8 and 9 lowest 

in risk level II 

Cases 8 and 9 lowest in 

risk level III 

Cases 4, 6, 8 and 9 highest 

in risk level IV 

Driving Factor 

Most risks not of severe 

nature (risk shift) 

Refueling emission control 

and rear mounted canister 

(cases 8 and 9) 

Antispitback valve 

Rear mounted canister 

Cases 8 and 9 lower in more 

critical risk levels; more 

complex canister vacuum and 

purge configurations in cases 

4 and 6 
Risk Level Comparison Chart -

Refueling State OBafleiie

 51 

Risk Level and Case 

60 

50 

40 

30 -

20 

10 -

CO 

C 

UJ 

GC 

« * -

O 

i _ 

<D 

n 

E 

3 

PT^^Y1^^1 nwffi^ 2K 

-<i N n 7 X >7 

sr^SX/N^ ^ 

\^X/\£$ X 

s^X/\^ X 

iti: 

/ 

^^3 /f^^x/\^x /\^$x/\^sx 

/\^sx/\^$x /\/;sx/\$$x /\£$x/\^$x /\$$x/\^$x /\^$x/\^$x /\£$x/\^$x /\^$x/\^$x /\«x/\^sx /\^x/\$$x /\£s:x/\£s>< /\^x/\^x 

dS 

Level I Level II Level III Level IV 

Note: Cases 1-10 shown left to right 
Risk Level Comparison 

Refueling State I I Battelle 52 

Finding 

Cases 8,9 and 10 lowest in 

risk level I 

Cases 7, 8 and 9 lowest in 

risk level II 

Cases 3 and 9 lowest in risk 

levellll 

Case 10 highest in risk level • 

III 

Cases 4, 6,8 and 9 highest in 

risk level IV 

Driving Factor 

Refueling emission control and rear 

mounted canister (cases 8 and 9) 

Antispitback valve inhibits liquid 

fuel spitback 

Rear mounted canister and antispitback valve in case 9; lack of 

ventpipe in case 3 

More connections in fillpipe/ 

ventpipe, and fillerneck head 

complexity 

Cases 8 and 9 lower in more critical risk levels; more complex 

canister vacuum and purge 

configurations in cases 4 and 6 
Risk Level Comparison Chart 

Driving State 

4O% Battelle 53 

CO 

CD 

c 

LU 

CO 

• 1MB 

GC 

CD 

JQ 

E 

3 

60 

50 -

40 -

30 -

20 -

Risk Level and Case 

/\«x/\^x /\vsx/\xSx 

1 

Level I 

/\: 

iA 

/K 

-1YY CAx 

Bx/\^x 

/ \ 

A<K 

^b PS \ 

s^X/N^ X 

v^X/N^ X 

>sx/\^sx 

<SX 

I 

KM& 

/\£$x/\£$x /\x$x/x£s:x /\^x/\$$x /\x$x/x^s:x /\2$x/\^$x /\x$x/\^$x /\£$x/\^$x /\^$x/\^$x 

/sv.sx/sv.sx 

/\\V.%X/\A%X 

Z$x/\t$x 

RIS3 £x ''A 

^t: 

Level II Level III Level IV 

Note: Cases 1-10 shown left to right 
Risk Level Comparison 

Driving State 

4O% Battelle 54 

Finding 

No risks in risk level 

I 

Cases 3, 4, 6, 7 and 9 

lowest in risk level II 

Cases 8 and 9 lowest in risk 

levellll 

Cases 4, 6, 8 and 9 highest 

in risk level IV 

Driving Factor 

Fuel cap in place and canister 

purging 

Lack of ventpipe in cases 3 and 9; 

low pressure fuel lines in cases 4 

and 6; antispitback valve in cases 

7 and 9 

Rear mounted canister 

Cases 8 and 9 lower in more critical risk levels; more complex 

canister vacuum and purge configurations in cases 4 and 6 
Risk Level Comparison Chart -

Parked State 

&*a %9 Battelle « 

Risk Level and Case 

CO 

CD 

c 

LU 

CO 

CD 

n 

E 

3 

z 

60 

50 

40 

30 

20 -

10 -

• • T^T y , i r^ PN^XpU^X ] 

/\-x$x/\^x /\^x/\^x 

/\^x/\^x 

/\^x/\^x 

/\XSX/\XSX 

/\xsx/\xsx 

/sxsx/sxsx /\xsx/\xsx /\xsx/\xsx 

/\XSX/\XSX 

/\XSX/\XSX 

/\XSX/\XSX 

/\XSX/\XSX 

/\XSX/\XSX 

/\xsx/\xsx 

/\XSX/\XSX 

Level I Level II Level III Level IV 

Note: Cases 1-10 shown left to right 
Risk Level Comparison 

Parked State I I Battelle

 56 

Finding 

Cases 8 and 9 absent of 

risks in risk level I 

Cases 4 and 6 highest in 

risk level II 

Cases 8 and 9 lowest in 

risk level III 

Cases 4, 6, 8 and 9 highest 

in risk level IV 

High number of risks in 

risk level IV 

Driving Factor 

Rear mounted canister 

Fuel bowl vent solenoid valve 

Rear mounted canister and 

relocation of vapor vent line 

Cases 8 and 9 lower in more critical risk levels; more complex 

canister vacuum and purge configurations in cases 4 and 6 

Parked state is low in critical 

risks 

XI 

^1 

o 
Summary of Results I I Battelle 57 

Higher 

Base Case • • a • 

Lower 

2,3,4,5,6,0 " 2,3,4,5,6,1110 

m im 

m 

IZ.10 

•-2,4,5,6 •••• 

3 

ii 

4H 

6 

0 

•—2,3,5jl0— 

Risk 

Level I 

Risk 

Level II 

Risk 

Level III 

Risk 

Level IV 

Q = Onboard systems 

r>i 
^Dott^ll ^ 58 7) Conclusions ^Battelle 

1) Most risks for all cases and states have "remote" or 

"improbable" likelihood of occurrence 

2) Most risks for all cases and states have medium 

severity or less 

3) In general, level of risk is not greatly different 

among cases 

4) Of 10 cases analyzed, onboard systems have 

relatively less overall risk than stock systems 

ro