P.1 

OAR Box 1147 

Prepped by Ollie Stewart 

Document Number: 

199)IV-E-73 

Docket Number: 

A-87-11 

Printed 4/22/2008 2:42:58 PM Sheet 199 of 242 
5 

^°J!A% 

P.2 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

OCT T 1988 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

Briefing on Ford's Onboard Hardware Program and 

Running Loss Control 

Glenn W. Passavant, Senior Project Manage 

Standards Development and Support Branch 

Public Dockets A-87-11 and A-85-21 

r J^J&^^A**"*d 

On September 26, 1988 Mr. Donald Buist, the Director of 

Ford's Automotive Emissions and Fuel Economy Office, and 

several other Ford staff members briefed EPA on the status of 

their evaluation of the simplified onboard control concept. 

Both a list of attendees and a copy of the briefing presented 

by Ford are attached. 

During the course of the meeting we discussed the concerns 

raised by Ford, and EPA pointed out .several key aspects of 

Ford's system which we felt they had not fully considered in 

their attempts to develop a system which performs 

satisfactorily. Ford and EPA agreed that several follow-up 

steps were necessary in order to identify the causes of the 

limitations of Ford's system and to address remaining 

problems. A follow-up letter will be sent to Ford summarizing 

EPA's perspective on their simplified system analysis and the 

follow-up steps agreed upon. 

Attachments 

z.<rfy-

•i^OC 
P.3 

List of Attendees 

EPA/Ford Meeting on 

Onboard Controls 

September 26, 1988 

EPA Ford 

Richard Wilson Donald Buist 

Charles Gray Kelly Brown 

John Anderson Harold Howey 

Glenn Passavant William King 

Dave Bartus Walter Kreucher 

Paul Laing Tim O'Brien 

Jean Schwendeman Tom Rolewicz 

Mike Schwarz 

Wally Wade 

6443W 
P.4 

FINDINGS 

FROM THE 

EVALUATION 

OF THE PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SEPTEMBER , 1988 
P.5 

FINDINGS 

FROM THE 

EVALUATION 

OF THE PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

PRESENTATION OUTLINE 

I- DESCRIPTION OF HARDWARE 

II. DESCRIPTION OF TEST PROGRAM 

III. EFFECTS OF A LARGER CARBON CANISTER 

IV- DEFICIENCIES OF THE "SIMPLIFIED" REFUELING CONTROL SYSTEM 

V. ADDRESSING THE DEFICIENCIES 

VI- RUNNING LOSS CONTRO; 

V I L CONCLUSIONS 
PR 

FINDINGS 

FROM THE 

EVALUATION 

OF THE PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION I 

HARDWARE DESCRIPTIONS 
P.7 

FORD PRODUCTION (OEM) EVAPORATIVE EMISSIONS SYSTEM 

1. FUEL TANK 

2- CARBON CANISTER (APPROXIMATELY 1 LITER) 

3- FUEL FILLER PIPE (SHOWN WITH EXTERNAL VENT LINE) 

4. ROLLOVER/VAPOR VENT VALVE (0-050" DIAMETER ORIFICE) 

5- VAPOR VENT LINE TO CANISTER (0-25" I-D-) 

6- LINE TO CANISTER PURGE CONTROL VALVE (IF FITTED) AND ENGINE 

INTAKE MANIFOLD 

© 

© 
P.8 

"SIMPLIFIED OBVR" REFUELING CONTROL SYSTEM 

(BASED ON THE PROTOTYPE HARDWARE PRESENTED 

BY EPA ON APRIL 13, 1988) 

1- FUEL TANK 

ENLARGED CARBON CANISTER (SIZE UNSPECIFIED) 

3- FUEL FILLER PIPE WITH VENT LINE REMOVED 

4- MODIFIED ROLLOVER/VENT VALVE WITH LARGE DIAMETER (0-350") 

ORIFICE TO ALLOW PASSAGE OF REFUELING VAPOR 

5- ENLARGED VAPOR VENT LINE 

6- PURGE LINE 

7- ANTI-SPITBACK CHECK VALVE 

© 
P.9 

FORD MODIFICATIONS TO "SIMPLIFIED" OBVR SYSTEM 

CONCERN: "SIMPLE" SYSTEM IN ITS ORIGINAL FORM PERFORMED VERY POORLY 

WITH REGARD TO REFUELING FLOW RATE AND FUEL SPITBACK- THE 

SYSTEM WOULD ACCEPT FILL RATES NO HIGHER THAN 6 GPMTHE FOLLOWING CHANGES WERE MADE TO IMPROVE THE SYSTEM'S PERFORMANCE: 

1. FILLER PIPE RAISED 5" ON F-250 (MOST CURRENT PRODUCTS DO NOT 

ALLOW THIS MODIFICATION INCLUDING PRODUCTION F-250) 

2- SECOND ROLLOVER/VENT VALVE ADDED 

VAPOR VENT LINE INCREASED TO 0-75" I-DEPA DID NOT SPECIFY THE CANISTER'S VOLUME 

FORD CHOSE 3 LITERS OF CARBON AS ADEQUATE FOR THIS SYSTEM (SEE 

3 ON DIAGRAM) 

© 

© 
P.10 

FINDINGS 

FROM THE 

EVALUATION 

OF THE PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION II 

DESCRIPTION OF TEST PROGRAM 
P.11 

TEST DESCRIPTIONS 

VEHICLES TESTED 

1. 1987 TAURUS LX SEDAN - 3-OL PORT INJECTION 

2- 1987 F-250 PICKUP - 5-OL PORT INJECTION 

SAME TEST SERIES FOR BOTH VEHICLES 

TEST PROGRAM 

1. FUEL TANK FILL QUALITY (OEM AND "SIMPLE" SYSTEMS) 

- TEST TO EVALUATE THE CUSTOMER'S ABILITY TO FUEL THE VEHICLE 

WITH NO POOR FILL BEHAVIOR 

- UNDESIRABLE BEHAVIOR INCLUDES FUEL SPITBACK (SPRAY OR 

LIQUID SURGE), PREMATURE NOZZLE SHUTOFF, OR INABILITY TO 

FILL TANK COMPLETELY 

- CONVENTIONAL AND VAPOR RECOVERY (CARB) FILLER NOZZLES 

- LOW AND HIGH VOLATILITY FUELS (9-0 AND 11-7 RVP) 

2- STATIC ROLLOVER (OEM AND "SIMPLE") 

- BASED ON FMVSS 301 TEST 

- NO CRASH 

- FUEL TANK OUT OF VEHICLE 

- VAPOR LINES REMOVED 

3. REFUELING EMISSIONS ("SIMPLE" SYSTEM ONLY) 

- TEST PROCEDURE PER JUNE 30, 1988 EPA WORKSHOP 

- LOW AND HIGH VOLATILITY FUELS (9-0 AND 11-7 RVP) 

- LOW AND HIGH FILL RATES (2-0 GPM, AND 10-0 GPM OR MAXIMUM 

ACHIEVABLE) 

- CONVENTIONAL FILLER NOZZLE 

4- EXHAUST/EVAPORATIVE/RUNNING LOSS EMISSIONS (OEM AND "SIMPLE") 

- BASED ON FTP TEST PROCEDURE, WITH SATURATED CANISTER 

- CVS TEST RUN IN SHED TO CAPTURE RUNNING LOSSES 

- TWO FUEL VOLATILITIES (9-0 AND 11-7 RVP) 

- TWO AMBIENT TEMPERATURES (8 W AND 95<>F) 

- HEAT LAMPS ON FUEL TANK DURING CVS FOR SOME TESTS 

- EPA "DOUBLE DIURNAL" EVAP TESTS (FROM JUNE 30 WORKSHOP) 
P.12 

FINDINGS 

FROM THE 

EVALUATION 

OF THE MODIFIED PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION III 

EFFECTS OF A LARGER CARBON CANISTER 
FINDING: EVAPORATIVE EMISSION TEST RESULTS CONFIRM THAT THE LARGER 

CARBON CANISTER ASSOCIATED WITH THE "SIMPLIFIED" SYSTEM CAN 

REDUCE EVAPORATIVE EMISSIONS UNDER SOME CONDITIONS OF 

HIGHER VOLATILITY TEST FUEL AND MODERATE AMBIENT 

TEMPERATURE 

NOTE: THE EMISSIONS BENEFITS ATTRIBUTABLE TO THE "SIMPLIFIED" 

REFUELING CONTROL SYSTEM WOULD BE ACHIEVED WITHOUT THE ADDED 

COMPLEXITY OF REFUELING CONTROLEVAPORATIVE EMISSIONS COMPARISON 

TAURUS 

tea aunj lBwmnug (an. n 

EVAPORATIVE EMISSIONS COMPARISON 

F-250 
P.14 

FINDINGS : EVAPORATIVE EMISSION TEST RESULTS CONFIRM THAT THE 

LARGER CARBON CANISTER ASSOCIATED WITH THE 

"SIMPLIFIED" SYSTEM CAN REDUCE EVAPORATIVE EMISSIONS 

DURING A DOUBLE HIGH-TEMPERATURE DIURNAL HEAT BUILDNOTE: THE EMISSIONS BENEFITS ATTRIBUTABLE TO THE "SIMPLIFIED" 

REFUELING CONTROL SYSTEM WOULD BE ACHIEVED WITHOUT THE ADDED 

COMPLEXITY OF REFUELING CONTROLSEVAPORATIVE EMISSIONS COMPARISON 

DOUBLE DIURNAL 

TAURUS 

EVAPORATIVE EMISSIONS COMPARISON 

DOUBLE DURNAL 

F-250 

SM«J)«NP 

Z~7» UflSt O-MfTER 
P.15 

FINDINGS 

FROM THE 

EVALUATION 

OF THE MODIFIED PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION IV 

DEFICIENCIES OF THE "SIMPLIFIED" REFUELING CONTROL SYSTEM 
POTENTIAL FAILURE MODE EFFECTS ANALYSIS (FMEA) 

SUMMARY OF MAJOR CONCERNS 

MODIFIED, LARGE DIAMETER ORIFICE ROLLOVER VALVE 

- VALVE MAY ALLOW VAPOR CONDENSATE OR RAW FUEL INTO VENT 

LINES UNDER SOME CONDITIONS 

- REFUELING IS IMPOSSIBLE IF VALVE STICKS CLOSED 

- FUEL SPITBACK COULD OCCUR IF VALVE CLOSES PREMATURELY 

DURING REFUELING 

- VALVE DOES NOT SEAL PROPERLY IN ROLLOVER- LARGE ORIFICE 

WILL ALLOW MAJOR FUEL LEAKAGE IF THIS OCCURS 

- VALVE DOES NOT ALLOW TANK TO VENT WHEN FULL 

2- LIQUID SEAL FILLER PIPE 

- HIGH VAPOR GENERATION IN INITIAL STAGES OF FILL DUE TO FLOW 

DYNAMICS OF THE LIQUID SEAL MAY LEAD TO FUEL SPITBACK FROM 

VENTLESS PIPE 

LARGE-DIAMETER VAPOR LINE 

- REFUELING IS IMPOSSIBLE IF LINE IS BLOCKED, KINKED, OR 

CRUSHED SHUT 

- HIGH VAPOR EMISSIONS WILL OCCUR IF LINE IS CUT OR REMOVED 

FIRE HAZARD EXISTS IF VAPORS COLLECT NEAR IGNITION SOURCE 

4- LARGE CARBON CANISTER COULD TRAP MORE LIQUID FUEL 

- BECAUSE OF THE HIGHER VAPOR FLOW RATES WITH THE "SIMPLE" 

SYSTEM, THE CANISTER IS LIKELY TO BE EXPOSED TO LARGER 

AMOUNTS OF LIQUID 

NOTE: SOME OF THESE FAILURE MODES WERE OBSERVED IN TESTING- THESE 

ARE TREATED IN GREATER DETAIL ON LATER PAGES-
COMPONENT 

Liquid Seal 

Modified (0.350" dia.) 

Rollover Valve 

POTENTIAL EPA "SIMPLE" ONBOARD 

HIGH POTENTIAL FAILURE MODE 

Excessive fuel vapor 

generation due to hot fuel 

in tank and/or warm, high 

volatility dispensed fuel 

(or other possible 

temperature combinations.) 

Lack of sufficient pressure 

differential to actuate 

automatic nozzle shutoff 

feature - due to pressure 

buildup from liquid seal. 

Valve does not close at end 

of refueling. 

Valve Sticks Closed 

- defect/misassembly 

- improper design 

• 

Premature closure and 

sealing shut of valve 

during refueling due to 

aerodynamic lift. 

- excessive vapor 

generation 

- defective/improper 

design of valve 

VAPOR RECOVERY FAILURE MODES 

POTENTIAL EFFECTS 

High pressure surge 

during refueling 

causes spitback. 

Fuel spillage. 

Fuel goes into vent 

lines and canisters. 

Fuel overflows from 

canisters to beneath 

vehicle. 

Liquid fuel remains in 

vent lines and 

canisters (crash 

risk). 

Prevents refueling, or 

reduces fill rate. 

Spitback. 

Uncertain nozzle 

shutoff. 

Excessive vapor 

emissions if slow fill 

is used to avoid 

spitback, (i.e., no 

liquid seal formed) 

Delay in refueling as 

pressure bleeds down. 

Premature shutoff 

followed by spitback, 

possibly multiple if 

customer attempts to 

resume refueling too 

quickly. 

' 

POTENTIAL FIX 

a 
2 -

COMPONENT 

Modified (0.350" dia.) 

Rollover Valve 

(Continued) 

HIGH POTENTIAL FAILURE MODE 

Excessive vapor generation 

due to hot Ambient/High RVP 

Fuel. 

POTENTIAL EFFECTS 

Excessive vapor 

generation due to 

non-pressurized tank 

could lead to 

condensed fuel in 

canisters and/or vapor 

lines. 

Spurting/spitback if 

rollover valve 

aerodynamically lifts 

and shuts the valve 

due to high vapor 

flow. 

POTENTIAL FIX 

Impact due to multiple 

vehicle crash could unseat 

the rollover seal (due to 

larger seating area) 

Fuel sloshing in tank due 

to operation on rough roads 

and/or inclined surfaces 

and/or G-force from impact. 

Large Diameter Vapor Line Kinked/Crushed Shut 

Open/Cut/Removed 

Fuel spillage 

Fuel spillage into 

vapor line and/or 

canister as a result 

of the larger valve 

opening. 

Prevents refueling, or 

reduces fill rate. 

Spitback. 

Uncertain nozzle 

shutoff. 

Excessive vapor 

emissions if slow fill 

is used to avoid 

spitback, (i.e., no 

liquid seal formed) 

Possible leakage path 

in rollover (assumes 

liquid fuel in vapor 

lines or canister 

and/or rollover valve 

failure). 
3 -

COMPONENT 

Large Diameter Vapor Line 

(Continued) 

HIGH POTENTIAL FAILURE MODE 

Open/Cut/Removed 

(Continued) 

Carbon Canisters Breakage (Crash or 

Non-Crash) 

POTENTIAL EFFECTS 

Excessive vapor 

emissions in all 

driving and parking 

modes (possible fire 

hazard if vapors 

collect near ignition 

source). 

Vapor leakage (also 

liquid, if other 

failures allow it to 

enter or condense in 

canister and/or 

lines.) 

POTENTIAL FIX 

Difficult to locate 

larger canisters in 

crash-protected area 

(greater cpncern than 

location of smaller 

evap canister due to 

greater potential for 

condensed fuel). 

TFR.6A 

CO 
P.20 

CONCERN: EXCESSIVE EXHAUST EMISSIONS WITH HIGH-VOLATILITY FUEL (11-7 

RVP FUEL TESTED) DUE TO PURGE LIMITATIONS 

- 11.7 RVP FUEL VOLATILITY IS PRESENT IN ASTM CLASS "C" 

CITIES DURING THE OZONE SEASON 

- HIGH VOLATILITY FUEL CAUSED BOTH SYSTEMS TO PRODUCE MUCH 

HIGHER HC AND CO EMISSIONS THAN STANDARDS A,LLOW, ESPECIALLY 

AT HIGH AMBIENT TEMPERATURES- BOTH SYSTEMS PERFORMED 

ACCEPTABLY ON 9-0 RVP FUEL (SEE TABLE BELOW)-

- BOTH VEHICLES HAD HIGH PURGE RATES BUT THE GREATER QUANTITY 

OF HC VAPOR GENERATED WITH THE "SIMPLE" SYSTEM WERE HIGHER 

THAN THE ENGINE COULD EFFECTIVELY CONSUME-

- SYSTEM PERFORMANCE IS DEGRADED ON HIGH VOLATILITY FUEL, MAY 

BE FOLLOWED BY VEHICLE DRIVEABILITY PROBLEMS-

- EMISSIONS INCREASES AND DRIVEABILITY PROBLEMS MAY BE 

FURTHER AGGRAVATED BY DIFFERENT OPERATING PATTERNS AND/OR 

MORE SEVERE WEATHERTEST RESULTS FROM "SIMPLE" SYSTEM 

TAURUS F-SERIES 

RVP HC CO HC CO 

11-7 UP TO 2X STD UP TO 7X STD MEETS STD UP TO 2X STD 

9-0 MEETS STD MEETS STD MEETS STD MEETS STD 

TEST RESULTS FROM OEM SYSTEM 

RVP 

11-7 

9-0 

TAURl 

HC 

UP TO L3 X STD 

MEETS STD 

JS 

CO 

JP TO 4X STD 

MEETS STD 

FHC 

MEETS STD 

MEETS STD 

-SERIES 

CO 

MEETS STD 

MEETS STD 

NOTE: TEST RESULTS BASED ON JUNE 30, 1988 TEST PROCEDURE 
FUEL VAPOR GENERATION 

MODEL PREDICTIONS 

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EPR 11.5 RVP 

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RSSUMES 95 F DRY RND RVERRGE 

FUEL TANK TEMPERRTURE PROFILE 

DETERMINED FROM THE EPR 

CflR LRREDO TEST PROGRRM 

HEAT BUILD I UDDS AFTER 2nd UDDS 

TEST CYCLE TIME 

TJ 
EXHAUST HC COMPARISON 

TAURUS 

1.0 „ 

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EVAPORATIVE EMISSIONS COMPARISON 

TAURUS 

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BP« 11.7 RVP 

BO-84 fkg. Hi 

HEflT BUILD TB-PSWTIJRE <d« . F) la oouadai a* hoi u>k i 

EXHAUST CO COMPARISON 

TAURUS 

60-84 daQ. Mi 75-86 -*B- hb 

HBtt BUILD TBfB-WTUE (d^ . F> 

EXHAUST NOx COMPARISON 

TAURUS 

80-84 d^ . Hi 75-«6 Oat). M> 

tCHT BUILD TEH>BWTl*6 (T*O- F) 

TJ 

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EXHAUST HC COMPARISON 

F-250 

OBI H.T RVP 

60-84 d-«. I * 76-86 <ho. Mi 

t-S-T BU1U) TEWBWTUPE (cteQ. F) 

EVAPORATIVE EMISSIONS COMPARISON 

F-250 

BO-84 •*« . Ht 76-86 d-«. Mi 

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Mal* Sua* aa gru» » « laal 

EXHAUST CO COMPARISON 

F-250 

BO-84 d^ . Hi 76-86 ifaB. •* 

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EXHAUST NOx COMPARISON 

F-250 

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BO-84 d-q. Kb 76-86 ifcg. hb 

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P.24 

REFUELING EMISSIONS FROM "SIMPLIFIED" OBVR SYSTEM 

- AT LOW FILL FLOW RATES, LIQUID SEAL FORMATION IS 

INCONSISTENT, AND ALLOWS HIGH HC EMISSIONS-

- AT MODERATE FLOW RATES (4-7 GPM), SYSTEM APPEARS TO CONTAIN 

REFUELING VAPOR AS DESIGNED-

- HIGHER FLOW RATES THAN SYSTEM CAN ACCEPT LEAD TO LARGE 

NUMBERS OF PREMATURE SHUTOFFS AND HIGH HC VAPOR EMISSIONS 

FROM THE FILL PIPE 

- SPITBACK AT SHUTOFF NOTED DURING 25% OF F-250 TESTS 

- SYSTEM ALLOWS OVERFILLING, ESPECIALLY AT LOW FILL FLOW 

RATES- THIS CAN BE A CONCERN WITH SOME VEHICLESCONCERNS: 

1. RANGE OF ACCEPTABLE FLOW RATES IS TOO NARROW, AND PROBABLY 

CANNOT BE SIGNIFICANTLY EXPANDED2- IF THE SYSTEM CONTROLS REFUELING EMISSIONS AT THE LOWER END OF 

EPA'S REQUIRED RANGE OF FLOW RATES, IT WILL NOT OPERATE 

PROPERLY AT REALISTIC GAS STATION RATES3- ATTEMPTS TO USE THE SYSTEM AT REALISTIC RATES CREATES 

AGGRAVATION AND POTENTIAL HAZARDS FOR THE CUSTOMER, AS WELL AS 

REDUCES THE SYSTEM'S EMISSION CONTROL EFFECTIVENESS IN-USE-
REFUELING EMISSIONS 

TAURUS WITH THE SMPLE SYSTEM 

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RJM MTE (flat lens pmr »lruto> 

10 

REFUELING EMISSIONS 

F-SERIES WITH THE SIMPLE SYSTEM 

2 0 10 

RJM MffE C^l tana far almtel 
P.26 

FINDINGS 

FROM THE 

EVALUATION 

OF THE MODIFIED PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION V 

ADDRESSING THE DEFICIENCIES 
POSSIBLE 

LIQUID SEAL SYSTEM 

1) OEM ROLLOVER/VENT VALVE 

2) FILLPIPE DESIGNED FOR LIQUID SEAL, WITH ANTI-SPITBACK VALVE 

3) OEM EVAP CANISTER PLUS ENLARGED REFUELING CANISTER (OTHER SYSTEMS 

UNDER EVALUATION) 

4) ENHANCED ELECTRONIC PURGE CONTROL 

5) FILL PIPE MODULE 

- NORMALLY CLOSED VENT VALVE 

- VENT ACTUATOR 

- SHUTOFF ACTUATOR 

- LIQUID-VAPOR SEPARATOR 
P.28 

POSSIBLE 

MECHANICAL SEAL SYSTEM 

(TANK MOUNTED VENT VALVE) 

1) OEM ROLLOVER/VENT VALVE 

2) ELECTRICALLY-OPENED REFUELING VENT VALVE 

3) OEM EVAP CANISTER PLUS ENLARGED REFUELING CANISTER (OTHER 

SYSTEMS UNDER EVALUATION) 

4) ENHANCED ELECTRONIC PURGE CONTROL 

5) MECHANICAL NOZZLE SEAL WITH OVERPRESSURE SPILL VALVE 

6) LIQUID/VAPOR SEPARATOR 
P.29 

POSSIBLE 

MECHANICAL SEAL SYSTEM 

(FILL PIPE MODULE) 

1) OEM ROLLOVER/VENT VALVE 

2) CONVENTIONAL FILLER PIPE WITH ANTI-SPITBACK VALVE 

3) OEM EVAP CANISTER PLUS ENLARGED REFUELING CANISTER (OTHER SYSTEMS 

UNDER EVALUATION) 

4) ENHANCED ELECTRONIC PURGE CONTROL 

5) FILL PIPE MODULE 

NORMALLY CLOSED VENT VALVE 

VENT ACTUATOR 

SHUTOFF ACTUATOR 

LIQUID-VAPOR SEPARATOR 

MECHANICAL SEAL 

OVERPRESSURE SPILL VALVE 
MECHANICAL DESIGN 

TO CANISTERS 

EMERGENCY RELIEF 

VALVE i 

VAPOR/LIQUIO 

DISCRIMINATOR 

OAS NOZZLE 

NOZZLE SEAL 

TRAPDOOR 

W/SEAL 

VIEW IN DIRECTION OF 

ARROW Z 

CARRYOVER 

EVAP. SYSTEM 

ftK 

VIEW IN DIRECTION 

OF ARROW Y 

VENT TUBE 

3M' - 8/8* LO. 

VAPOR/LIQUIO 

DISCRIMINATOR 

MODULAR CARBON 

CANISTER 

VAPOR TUBE 
P.31 

FINDINGS 

FROM THE 

EVALUATION 

OF THE MODIFIED PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION VI 

RUNNING LOSS CONTROL 
P.32 

CONCERN: OVERCOMING THE DEFICIENCIES FOUND WITH THE "SIMPLE" SYSTEM 

WILL NOI RESULT IN EFFECTIVE RUNNING LOSS CONTROL-

- PRELIMINARY EPA RUNNING LOSS TEST DATA SHOWS LARGE RUNNING 

LOSSES UNDER CERTAIN CONDITIONS-

- PRELIMINARY EPA ANALYSIS OF OZONE DAY AMBIENT TEMPERATURES 

SHOWS AN AVERAGE HIGH TEMPERATURE OF 95°F IN ASTM CLASS "C" 

CITIES 

- EPA DATA FROM 16 VEHICLES OPERATED ON VARIOUS DRIVING 

CYCLES SHOWS AN AVERAGE FUEL TANK TEMPERATURE RISE OVER 

AMBIENT OF 250F- THIS RESULTS IN 120OF FUEL TEMPERATURE ON 

OZONE DAYS-

- THE APPROXIMATE BOILING POINT OF ASTM CLASS "C" FUEL (11-5 

PSI RVP) AT ATMOSPHERIC PRESSURE IS 1130F-

- EVALUATING THE EPA RUNNING LOSS DATA SHOWS NO HIGH RUNNING 

LOSS VEHICLES BELOW THE APPROXIMATE BOILING POINT OF THE 

TEST FUEL-

- THE SIGNIFICANCE OF THE LOW RUNNING LOSS VEHICLES ABOVE THE 

APPROXIMATE BOILING POINT OF THE TEST FUEL IS UNKNOWN AND 

DEPENDENT ON THE 

- IMPACTS OF TEST PROCEDURAL CHANGES BETWEEN TESTS 

- AMOUNT OF TIME SPENT ABOVE THE BOILING POINT 

- TEST VARIABILITY 

- IMPACTS ON EXHAUST EMISSION CONTROL (UNMEASURED UNDER 

THE EPA PROGRAM) 

- SHIFTS IN THE BOILING POINT OF FUEL IN THE TANK DUE TO 

FUEL TANK PRESSURE 
ANALYSIS OF PRELIMINARY EPA RUNNING LOSS DATA 

11.7 RVP TEST FUEL 

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ANALYSIS OF PRELIMINARY EPA RUNNING LOSS DATA 

9.0 RVP TEST FUEL 

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FUEL TEMPERATURE 
P.36 

CONCERN: COMPUTER MODELING SHOWS THE "SIMPLE" SYSTEM GENERATES OVER 

40% MORE VAPOR AND GENERATES THIS VAPOR AT A FASTER RATE 

THAN PRODUCTION EVAPORATIVE EMISSION CONTROL SYSTEMS 

SYSTEM FUEL RVP (PSI) VAPOR GENERATED (G) I OF FUEL BURN 

OEM 

"SIMPLE" 

9-0 

10-5 

11.7 

9-0 

10-5 

11-7 

104 

179 

261 

113 

230 

386 

9 

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MAXIMUM VAPOR GENERATION RATE AS A PERCENTAGE OF AVERAGE FUEL 

CONSUMPTION RATE DURING CYCLE, ASSUMING 23 MPG AVERAGEPOTENTIAL SOLUTIONS TO CONCERNS: 

1- FULL COMPUTER CONTROL OF VAPOR PURGE AND 

2- ENHANCED EXHAUST EMISSION CONTROL AND 

3- MORE COMPLEX NORMALLY-CLOSED REFUELING VENT SYSTEM AND 

4- LARGER CARBON CANISTER CAPACITY AND/OR 

5- FUEL CHILLERS OR 

6- FUEL VOLATILITY CONTROL 
FUEL VAPOR GENERATION 

MODEL PREDICTIONS 

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cr 

CD 

EPfl 11.5 RVP 

5 RVP 

RSSUMES 95 F DRY RND RVERRBE 

FUEL TRNK TEMPERATURE PROFILE 

DETERMINED FROM THE EPR 

CAR LAREDO TEST PROGRAM 

HEAT BUILD 1 UDDS AFTER 2nd UDDS 

TEST CYCLE TIME 

TD 

CO 

^1 
P.38 

FINDINGS 

FROM THE 

EVALUATION 

OF THE MODIFIED PROTOTYPE 

"SIMPLIFIED" REFUELING CONTROL SYSTEM 

SECTION VII 

CONCLUSIONS 
P.39 

PROBABLE HARDWARE TO 

CONTROL REFUELING VAPOR 

FROM LIGHT-DUTY VEHICLES 

ENHANCED PURGE CONTROL 

- LIKEL Y TO BE SAME AS ENHANCE D EVAP SYSTE M 

FILLER PIPE VENT CONTROL MODULE 

NOZZLE SEAL MECHANISM 

LIQUID/VAPOR SEPARATOR 

ENHANCED ROLLOVER VALVE 

LARGER CARBON CANISTER 

- 3-4 LITER S FOR 9-0 PSI FUEL 

LARGER DIAMETER VAPOR TUBES TO CANISTER 

OVER-PRESSURE RELIEF MECHANISM 

ASSUMPTIONS: EPA WILL ADOPT 9-0 PSI RVP FUEL IN CLASS "C" REGIONS-
P.40 

PROBABLE HARDWARE TO CONTROL 

"EXCESS" EVAPORATIVE EMISSIONS PLUS 

RUNNING LOSSES 

FROM LIGHT-DUTY VEHICLES 

ENHANCED PURGE CONTROL SYSTEM 

- HIGHER FLOW VALVES 

- FULL ELECTRONIC CONTROL 

ADDITIONAL HEAT SHIELDING 

INCREASED FUEL SYSTEM COOLING MECHANISM 

- DUCTING TO PROVIDE HIGHER AIR FLOWS 

MEASURES TO REDUCE FUEL SYSTEM HEAT FLUX 

- VARIABLE VOLTAGE PUMPS 

LARGER CARBON CANISTER 

- 1-2 LITERS 

ASSUMPTIONS: (1) EPA WILL NOT INTERPRET THE PROPOSED PROHIBITION 

AGAINST VAPOR VENTING LITERALLY-

(2) EPA WILL ADOPT 9-0 PSI RVP FUEL IN CLASS "C" 

AREAS-
P.41 

CONCLUSIONS 

THE "SIMPLE" SYSTEM HAS THE SAME, IF NOT GREATER, SAFETY 

CONCERNS AS OTHER PREVIOUSLY REVIEWED PROTOTYPE REFUELING 

CONTROL SYSTEMS-

"SIMPLIFIED" REFUELING CONTROL SYSTEMS ARE NOT READILY 

ADAPTABLE TO PRODUCTION VEHICLESLIQUID/VAPOR SEPARATORS ARE REQUIRED IN REFUELING CONTROL 

SYSTEMSNORMALLY OPEN FUEL TANK VENT SYSTEMS CAUSE A LOSS OF EXHAUST 

AND/OR EVAPORATIVE EMISSIONS CONTROLTHE ONLY BENEFITS IDENTIFIED FOR THE "SIMPLE" REFUELING SYSTEM 

CAN BE ATTRIBUTED TO THE LARGER CARBON CANISTER- THESE SAME 

BENEFITS CAN BE ACHIEVED AT A LOWER COST WITHOUT THE ADDED 

COMPLEXITY OF REFUELING CONTROLTHE "SIMPLIFIED" REFUELING CONTROL SYSTEM WILL NOT BE CAPABLE 

OF CONTROLLING RUNNING LOSSES UNDER "OZONE DAY" CONDITIONSVOLATILITY CONTROL PLUS ADDITIONAL RUNNING LOSS CONTROL AND 

ENHANCED EVAPORATIVE EMISSION CONTROL IS THE MOST 

COST-EFFECTIVE CONTROL STRATEGY AND PRESENTS NO SAFETY 

CONCERNS- THE ADDITIONAL COST AND SAFETY CONCERNS OF REFUELING 

CONTROLS SUBSTANTIALLY OUTWEIGH THE MINIMAL ADDITIONAL 

EMISSIONS CONTROLTFR91688 
TESTS REMAINING 

1- ADDITIONAL HIGH AMBIENT TEMPERATURE TESTS OF "SIMPLE" SYSTEM 

2- ADDITIONAL REFUELING TESTS WITH OTHER PROTOTYPE OBVR SYSTEMS 

3- LABORATORY HIGH-TEMPERATURE VAPOR GENERATION TEST OF "SIMPLE" 

AND OEM SYSTEMS 
EVALUATION OF THE "SIMPLE" REFUELIMG COMTBOt SYSTEM 

EXHAUST / EVAPOKATIVE / RIMMING LOSS EM1SSI0MS DATA SHEET 

VEHICLE TEST 

Taurus 12 

7 

10 

13 

8 

9 

6 

11 

3 

1 

5 

tt 

2 

# SYSTEM 

EPA 

OEM 

OEM 

EPA 

OEM 

OEM 

EPA 

OEM 

EPA 

EPA 

EPA 

EPA 

EPA 

HC 

0.19 

O.20 

0.23 

0.22 

0.22 

0.22 

0.19 

0.21 

0.15 

0.21 

0.23 

0.21 

0.27 

CO 

1.8 

2.6 

3.3 

3.0 

3.4 

3.8 

3.4 

double 

double 

3.8 

double 

double 

2.3 

3.0 

2.7 

3.4 

4.4 

CC-j 

445 

428 

438 

448 

448 

438 

445 

NOx 

.58 

.43 

.41 

.71 

.54 

.50 

.49 

diurnal #1 

diurnal #2 

444 .51 

diurnal #1 

diurnal #2 

457 

439 

441 

435 

446 

.60 

.48 

.62 

.58 

.62 

FE 

19.8 

20.5 

20.0 

19.6 

19.5 

20.0 

19.7 

19.7 

19.2 

20.0 

19.9 

20.1 

19.5 

DI 

0.77 

0.59 

0.65 

0.32 

0.32 

0.59 

1.27 

0.64 

0.89 

0.42 

1.20 

15.11 

1.68 

1.44 

0.56 

0.45 

0.80 

HS 

0.62 

0.76 

5.08 

0.70 

0.80 

0.81 

0.95 

0.60 

0.83 

1.34 

3.83 

0.94 

1.33 

R/L 

1.36 

1.57 

1.32 

1.38 

2.71 

2.22 

1.84 

1.53 

1.54 

1.86 

2.86 

2.13 

2.65 

POP 

0 

RVP 

9.0 

9.0 

0.06 9.0 

0.08 9.0 

0 

0 

0.05 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

HB 

60/84 

60/84 

60/84 

75/95 

75/95 

75/95 

60/84 

71/96 

71/96 

60/84 

71/96 

71/96 

60/84 

60/84 

60/84 

75/95 

75/95 

TEMPERATURE 

FTP 

84 

84 

84 

95 

100 

95 

84 

84 

84 

84 

84 

95 

95 

TANK 

98 

97 

98 

107 

103 

106 

98 

98 

97 

99 

106 

107 

.n 

A/S 

137 

140 

142 

162 

151 

135 

127 

104 

140 

200 

TANK 

PRESSURE "Hg COMMENTS 

-0.2 

0.4 

0.75 

-0.2 

0.75 

0.8 

-0.25 

0.6 

-0.25 

-0.25 

-0.25 

-0.25 

H/S Evap void • 2 

FTP Temp too high 

Fixed Evap leak in hose 

Evap void - 2 

Evap void - 2 

Evap void - 2 

Evap void - 2 

Evap void - 2 

Codes: 1 - Equipment Void 

2 - Vehicle Void 

3 - Procedure Void 

Notes: The HB (heat build) temperature is low/high; FTP, fuel tank and A/S (air space before the fuel tank) temperatures are maximum values. 

All tests are started uith a saturated canister (i.e. non-standard FTP) 

September 22, 1988 

-p. 

co 
EVALUATION OF THE "SIMPLE- REFUELING CONTROL SYSTEM PAGE 2 

VEHICLE TEST 

Taurus 19 

21 

14 

16 

22 

" 20 

17 

15 

# SYSTEM 

EPA 

EPA 

OEM 

OEM 

EPA 

EPA < 

OEM 

OEM 

HC CO 

0.33 6.4 

0.28 5.0 

0.30 4.7 

0.29 4.5 

fm.n 19.7^ 

T 0.87 26.3 

0.55 12.5 

0.50 11.5 

COj 

436 

432 

481 

432 

y 413 

)410 

426 

423 

NOn 

.88 

.82 

.59 

.59 

.84 

.87 

.70 

.58 

EXHAUST / EVAPORATIVE / 

FE DI 

19.9 1.07 

20.1 0.64 

18.1 4.27 

20.2 16.04 

19.9 0.63 

19.5 0.44 

19.8 30.10 

20.0 25.71 

HS R/L 

0.53 0.79 

0.61 0.60 

1.25 0.65 

2.8 0.86 

0.78 0.92 

0.80 1.25 

105.3 32.80 

106.5 47.73 

RUNNING LOSS BUSSIONS DATA SHEET 

POP 

0.04 

0.04 

0.03 

0.03 

0.05 

0.05 

0.0 

RVP 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

HB 

60/84 

60/84 

60/84 

60/84 

75/95 

75/95 

75/95 

75/95 

TEMPERATURE (F) 

FTP 

84 

84 

84 

84 

95 

95 

95 

95 

TANK 

96 

99 

100 

100 

114 

116 

116 

120 

A/s 

N/A 

143 

167 

142 

147 

142 

155 

140 

TANK 

PRESSURE 

0.0 

-0.25 

0.6 

1.3 

-0.25 

0.0 

3.4 

2.3 

"Hg COMMENTS 

R/L appears low 

Exh Void • 3 

R/L IN THIRD BAG (113°F) 

R/L began at 114°F 

23 EPA 0.20 2.6 433 .86 20.3 0.64 0.54 

double diurnal #1 0.35 

double diurnal #2 0.46 

0.87 0.06 11.7 60/84 84 94 N/A -0.25 

18 OEM 0.29 5.2 427 .74 20.4 8.10 0.73 

double diurnal #1 38.48 

double diurnal #2 52.04 

1.05 N/A 11.7 60/84 84 100 160 1.0 

Codes: 1 - Equipment Void 

2 - Vehicle Void 

3 - Procedure Void 

Notes: The HB (heat build) temperature is low/high; FTP, fuel tank and A/S (air space before the fuel tank) temperatures are maximum values. 

All tests are started with a saturated canister (i.e. non-standard FTP) 

September 22, 1988 

-p. 
VEHICLE TEST 

F-250 3 

1 

5 

8 

9 

6 

7 

14 

10 

2 

4 

11 

12 

13 

17 

18 

15 

16 

# SYSTEM 

EPA 

EPA 

EPA 

OEM 

OEM 

OEM 

OEM 

OEM 

OtA 

EPA 

EPA 

OEM 

OEM 

OEM 

EPA 

EPA 

OEM 

OEM 

HC 

.45 

.57 

.83 

.69 

.44 

.66 

1.01 

.58 

.60 

.49 

.48 

.82 

.78 

.46 

.55 

.97 

.51 

Codes: 1 * Equipment Void 

Notes: The HB (heat bu 

co 

4.3 

5.5 

13.1 

8.4 

3.4 

4.1 

16.4 

6.6 

5.4 

6.0 

3.4 

22.8 

6.8 

6.3 

4.3 

31.5 

5.2 

2 -

co2 

651 

675 

627 

625 

651 

631 

625 

660 

653 

706 

689 

684 

690 

double 

double 

657 

double 

double 

660 

double 

double 

673 

double 

double 

Vehicl 

NOx 

.81 

.83 

.70 

.75 

.71 

.83 

.69 

.77 

.91 

.79 

1.13 

.66 

.82 

.74 

EVALUATION OF THE "SIMPLE" 

EXHAUST / EVAPORATIVE / 

FE 

13.5 

13.0 

13.4 

13.8 

14.0 

13.4 

13.4 

13.9 

DI 

0.48 

3.6 

0.49 

0.36 

0.37 

11.2 

0.45 

0.46 

HS 

0.90 

1.6 

0.82 

0.45 

0.51 

2.90 

3.56 

0.64 

ABORTED - NO DATA 

13.2 

13.3 

12.4 

12.2 

12.7 

12.7 

diurnal #1 

diurnal #2 

.79 13.3 

diurnal #1 

diurnal #2 

.70 12.4 

diurnal #1 

diurnal #2 

.77 13.0 

diurnal #1 

diurnal #2 

e Void 3 

Id) temperature is low/high; 

All tests are started with 

0.73 

0.49 

0.41 

0.66 

0.46 

0.36 

0.98 

1.08 

0.67 

0.87 

0.83 

0.71 

ABORTED 

ABORTED 

0.60 

0.61 

0.82 

0.46 

3.38 

16.09 

0.61 

1.68 

18.57 

0.50 

0.75 

0.55 

R/L 

2.34 

3.8 

2.63 

1.70 

1.74 

3.23 

2.33 

2.02 

3.1 

3.11 

2.35 

3.12 

1.92 

• Procedure Void 

REFUELING CONTROL SYSTEM 

RUNNING LOSS B-USSIONS DATA SHEET 

POP 

0.0 

0.05 

0.04 

0.0 

RVP 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

HB 

60/84 

60/84 

60/84 

60/84 

60/84 

60/84 

60/84 

60/84 

75/95 

75/95 

75/95 

75/95 

75/95 

60/84 

60/84 

71/96 

71/96 

60/84 

71/96 

71/96 

60/84 

71/96 

71/96 

TEMPERATURE 

FTP 

84 

84 

84 

84 

84 

84 

84 

84 

95 

95 

95 

95 

84 

84 

84 

84 

FTP, fuel tank and A/S (air space before the 

a saturated canister (i. e. non standard FTP) 

TANK 

99 

100 

100 

98 

99 

100 

101 

106 

106 

108 

N/A 

102 

102 

101 

100 

(FJ 

A/S 

122 

124 

123 

106 

126 

132 

128 

119 

123 

128 

125 

122 

120 

TANK 

PRESSURE "Hg 

-.25 

-.25 

-.36 

0.0 

0.0 

-.20 

0.0 

0.0 

-.25 

-.25 

0.2 

0.25 

0.0 

-1.0 

0.0 

-.25 

COMMENTS 

Evap void - 3 

Exh. void • 1 

Exh. void - 1 

Evap void • 2 

Exh. void - 1 

PREP 9 RVP TEST U/11.5 

Exh. void - 1 

VOID-RUN U/O EXTRA CANISTER 

DOUBLE 01URINAL EVAP TEST 

TANK VACUUM HIGHER AND MORE 

FREQUENT THAN PREVIOUS 

TESTS - 4 CANISTERS 

Exh. void - 1 

REPEAT OF #15 CAN ISTERBREAKTHROUGH INDICATED 310-

MIN. INTO d.d.#2 

fuel tank) temperatures are maximum values. 
EVALUATION OF THE "SIMPLE" REFUELING CONTROL SYSTBI PAGE 2 

VEHICLE TEST 

F-250 25 

27 

22 

19 

26 

28 

20 

24 

21 

29 

# SYSTEM 

EPA 

EPA 

OEM 

OEM 

EPA , 

EPA \ 

OEM 

OEM 

EPA 

HC 

0.73 

0.66 

0.65 

1.0 

/0.72 

^1.34 

0.59 

0.68 

0.78 

CO 

14.0 

15.4 

7.1 

35.6 

15.2S 

20.4, 

6.2 

9.4 

7.8 

COj 

651 

710 

650 

659 

664 

1 633 

663 

643 

663 

double 

double 

NO„ 

.68 

.54 

.77 

.53 

.72 

.71 

.78 

.69 

.70 

EXHAUST / EVAPORATIVE / RUNNING LOSS EMISSIONS DATA SHEET 

FE 

13.1 

12.0 

13.4 

12.4 

12.6 

13.3 

13.1 

13.4 

13.1 

diurnal #1 

diurnal #2 

DI 

0.55 

0.54 

7.22 

5.52 

0.57 

0.43 

25.28 

30.9 

2.53 

0.47 

1.07 

HS 

0.42 

0.66 

0.20 

0.69 

0.61 

0.57 

4.37 

27.7 

0.51 

R/L POP 

1.65 

2.17 0.0 

2.53 0.0 

2.03 

2.73 

1.88 

2.84 

4.37 0.1 

1.88 

RVP 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

11.7 

HB 

60/84 

60/84 

60/84 

60/84 

75/95 

75/95 

75/95 

75/95 

60/84 

TEMPERATURE (F) 

FTP 

84 

84 

84 

84 

95 

95 

95 

95 

84 

TANK 

98 

101 

99 

102 

108 

113 

107 

110 

98 

A/S 

112 

133 

115 

125 

120 

132 

130 

115 

TANK 

PRESSURE "Hg 

-0.5 

-0.25 

+0.2 

•0.4 

•0.25 

-0.2 

•1.2 

+1.7 

-0.25 

COMMENTS 

Exh. void • 2 

WITH HEAT LAMPS 

UITH HEAT LAMPS - NO HISS 

Exh. void - 3 

23 OEM CVS DOWN - NO CHEMISTRY 2.60 0.59 

double diurnal #1 25.62 

double diurnal #2 51.19 

11.7 60/84 84 97 127 +0.5 BREAKTHROUGH a 59 MIN 

71/96 " a 24 MIN 

71/96 CVS RECALIBRATED BEFORE #24 

Codes: 1 - Equipment Void 

2 - Vehicle Void 

3 - Procedure Void 

Notes: The HB (heat build) temperature is low/high; FTP, fuel tank and A/S (air space before the fuel tank) temperatures are maximum values. 

All tests are started with a saturated canister (i.e. non-standard FTP) 

September 22, 1988 

-p. 
VEHICLE 

Taurus 

F-250 

TEST # 

3 

6 

2 

7 

* 4 

* 5 r-l 00 9 

10 

11 

8 

10 

7 

9 

12 

14 

11 

13 

TOTAL 

GALS DISP 

18.6 

18.5 

. 19.6 

17.5 

17.0 

17.1 

16.6 

18.4 

18.4 

17.8 

17.0 

17.0 

17.1 

18.0 

17.4 

17.1 

17.2 

18.1 

17.7 

TOTAL 

GRAMS 

1.68 

4.12 

1.20 

0.12 

8.04 

4.22 

3.53 

7.06 

1.92 

0.47 

3.45 

8.5 

35.24 

5.16 

19.81 

37.47 

91.48 

23.45 

31.06 

REFUELING 

GMS/GAL 

0.09 

0.22 

0.06 

0.01 

0.47 

0.25 

0.21 

0.38 

0.10 

0.03 

0.20 

0.50 

2.06 

0.29 

1.14 

2.19 

5.32 

1.30 

1.75 

EMISSIONS DATA SHEET 

RVP 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

11.7 

11.7 

11.7 

11.7 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

DISPENSING 

RATE 

2.0 

2.0 

6.0 

6.7 

10.0 

10.0 

10.0 

6.7 

2.0 

6.7 

2.0 

2.0 

2.0 

10.0 

10.0 

2.0 

2.0 

10.0 

10.0 

# OF 

SHUTOFFS 

0 

0 

3 

0 

56 

37 

42 

0 

0 

0 

0 

3 r-l 0 

2 

0 r-l 0 

0 

TEMPERATURES 

FUEL 

84 

83 

82 

82 

83 

82 

82 

83 

82 

81 

83 

83 

82 

81 

82 

83 

84 

82 

81 

VEHICLE 

80 

81 

79 

79 

80 

79 

79 

81 

82 

82 

81 

81 

80 

81 

81 

81 

83 

81 

80 

COMMENTS 

LO RESTRICTOR 

HI " /SHORT SOAK 

VOID 

BREAKTHROUGH 

H Cs at S/O 

no apparent seal 

3rd can replaced 

fuel spitback 

with open slots 

with open slots 

with open slots 

with open slots 

1 

3 

4 

5 

2 

6 

15.7 

18.6 

17.9 

19.8 

17.2 

1.80 

34.60 

7.59 

0.17 

12.22 

0.11 

1.86 

0.42 

0.01 

0.71 

11.7 

11.7 

11.7 

11.7 

11.7 

2.0 

2.0 

2.0 

9.0 

10.0 

0 

0 

0 

1 

81 

82 

81 

81 

82 

83 

82 

82 

VOID; ZERO CHECK 

abort zero check 

some spitback 

* UNOFFICIAL PURGE HOWEVER, CANISTER MASS TO WITHIN ONE GRAM OF PREVIOUS OFFICIAL TEST, 

TEMPS WITHIN ACCEPTANCE RANGE 

September 22, 1988 
CONCERN: FUEL LEAKAGE FROM MODIFIED ROLLOVER VALVE 

- TESTS SHOW "SIMPLE" SYSTEM ROLLOVER/VENT VALVE LEAKS LARGE 

VOLUME OF FUEL DURING STATIC ROLLOVER TEST 

POTENTIAL SOLUTIONS TO CONCERN: 

1. COMPLETE REDESIGN OF ROLLOVER VALVE 

- NEED TO BALANCE THE REQUIREMENT FOR REFUELING CONTROL 

(E.G., HIGH VAPOR FLOW DURING FILL SUGGESTS LARGE FORCE 

NEEDED TO HOLD VALVE FLOAT OPEN) WITH THE REQUIREMENT FOR 

ROLLOVER PROTECTION 

2- SMALLER ROLLOVER VALVE ORIFICE (HOWEVER, ALSO FURTHER LIMITS 

MAXIMUM FILL RATE) AND/OR 

3- INSTALL LIQUID/VAPOR SEPARATOR (ONLY A PARTIAL SOLUTION) 

AND/OR 

4- INSTALL MECHANICAL SYSTEM TO CLOSE ROLLOVER VALVE WHEN NOT 

REFUELING (MUST USE ALTERNATIVE WAY TO VENT VAPORS DURING 

OPERATION) 

TEST RESULTS FROM SIMPLE SYSTEM 

1ST 5 MINUTES OF TEST: 

- 28 OZ- FLUID SPILLED 

- FMVSS 301 LIMIT = 5 OZOVER SAME PERIOD 
P.49 

CONCERN: NO VENTING OF VAPORS ON FULL FUEL TANK 

- OEM SYSTEM RETAINS USE OF 0-05" ORIFICE IN ROLLOVER/VENT 

VALVE WHEN TANK IS FULL 

- "SIMPLE" SYSTEM ROLLOVER VALVE IS FULLY CLOSED WHEN TANK IS 

FULL 

- THIS MAY RESULT IN EXCESSIVE PRESSURE BUILDUP IN FUEL TANK 

POTENTIAL SOLUTIONS TO CONCERNS: 

1- INSTALL VENT MECHANISM IN VAPOR DOME AND/OR 

2- REDESIGN ROLLOVER/VENT VALVE TO VENT ON FULL TANK AND/OR 

3- REDESIGN SYSTEM TO USE ALTERNATIVE MEANS OF FULL-TANK SHUTOFF 
P.50 

CONCERN: VAPOR CONDENSATE IN VENT LINE 

- HIGH REFUELING VAPOR FLOW RATES CAUSED BY GREATER 

ENTRAINMENT OF VAPOR CAN LEAD TO LIQUID CONDENSATION IN 

VAPOR LINE TO THE CANISTER 

- TESTS SHOW THAT MODIFIED VENT VALVE CAN ALLOW LIQUID TO 

ENTER VENT LINE- THIS COULD ALSO HAPPEN UNDER DRIVING 

CONDITIONS WHERE THE FUEL IS AGITATED WITH THE TANK NEARLY 

FULLPOTENTIAL SOLUTIONS TO CONCERNS: 

1. INSTALL LIQUID/VAPOR SEPARATOR 

2- REDESIGN ROLLOVER/VENT VALVE TO PREVENT LIQUID FROM ENTERING 

VENT LINE 
P.51 

CONCERN: SUBSTANDARD FUEL TANK FILL QUALITY WITH "SIMPLE" SYSTEM 

- F-250 FILL RATES ACHIEVED WITH FILLER PIPE RAISED - NOT 

FEASIBLE ON ALL VEHICLES INCLUDING PRODUCTION F-250 

- FILL RATE IS AFFECTED BY CHOICE OF FILLER NOZZLE 

- "SIMPLE" SYSTEM WILL NOT PASS C-A-R-B- FILL RATE 

REQUIREMENT 

- LARGE NUMBERS OF PREMATURE SHUTOFFS OCCUR AT HIGH FLOW 

RATES 

POTENTIAL SOLUTIONS TO CONCERNS: 

1. MECHANICAL SEAL REFUELING CONTROL SYSTEM AND/OR 

2- LARGER DIAMETER ORIFICE IN ROLLOVER/VENT VALVE (TO REDUCE BACK 

PRESSURE) AND/OR 

3- STANDARDIZED FILL NOZZLES COMBINED WITH REDESIGNED FILLER 

PIPES AND/OR 

4- INCREASE MINIMUM PROPOSED FLOW RATE AT WHICH REFUELING VAPOR 

CONTROL MUST BE ACHIEVED (CURRENTLY 3-10 GPM) SO THAT FILL 

QUALITY MAY BE OPTIMIZED FOR REALISTIC GAS STATION RATES-
"SIMPLE" SYSTEM FILL QUALITY RESULTS: 

CONVENTIONAL NOZZLE: 

F-250 " - 10 GPM 

TAURUS - 7 GPM 

VAPOR RECOVERY (CARB) NOZZLE 

F-250 9 GPM 

TAURUS = 6-5 GPM 

NOTE: - ARB MINIMUM FLOW RATE = 10 GPM 

- CORPORATE OBJECTIVE FOR 

CUSTOMER SATISFACTION = 12 GPM MINIMUM