P.1 

OAR Box 1147 

Prepped by Ollie Stewart 

Document Number: 

163) IV-E-36 

Docket Number: 

A-87-11 

Printed 4/22/2008 2:42:56 PM Sheet 163 of 242 
P.2 

^

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

APR 2 0 '988 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

Briefings on Updated EPA Onboard Control Hardware 

John F. Anderson, S 

Standards Developme 

Docket A-87-11 

enior Project Manager \}P JL ([,*-_ 

nt and Support Branch ¥"^ /V**^"-*^— 

On April 12 and April 13, 1988 briefings were presented to 

several groups describing . the status of the simplified 

refueling control system which we have recently developed. The 

briefings included a short presentation (copy attached) and a 

description of the EPA hardware. The same briefing was given 

to these different groups: The Automobile Importers of 

America, NHTSA, and the Motor Vehicle Manufacturers' 

Association. Attendance lists for the latter two meetings are 

attached. No specific list was compiled for the AIA meeting. 

Attachments 
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P.4 

EPA/MIA Meeting 

April 13, 1988 

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EPA/MVMA Meeting 

April 13, 1988 

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P.6 

EPA Onboard Control Hardware 

Development Update 

EPA Office of Mobile Sources 

Emission Control Technology Division 
P.7 

Why Control Refueling Emissions? 

Provides a two percent VOC reduction 

Few remaining VOC control strategies can provide more 

reduction 

Reduction can be achieved cost effectively when compared 

to other available control alternatives 

Reduces exposure to toxic vapors during refueling — 

benzene is a known human carcinogen and gasoline vapors in 

general are a concern 

Our annual incident reduction estimates for controlling 

refueling emissions are 4 with just benzene, 14 if benzene 

and >C6 are included, and 42 if benzene and all gas vapors 

are included 
P.8 

Overview 

EPA published a study of the feasibility of onboard for 

comment on August 8, 1984, 

EPA formally proposed the adoption of onboard refueling 

controls in August 1987 

Some comments since the proposal have contended that 

onboard will add complexity; therefore it is inherently 

less safe 

EPA's anticipated designs were fairly simple (Figure 1) 

Manufacturers' proposed onboard designs appear to be much 

more complex (see Figures 2 and 3) 

EPA has undertaken the development of a simple onboard 

control system to address the "added complexity" issue 

i 

This briefing describes the development of the new hardware 
FIGURE 1 

Integrated Evaporative/Refueling System 

J - Tube Seal 

PRESSURE/VACUUM 

RELIEF CAP 

NOZZLE ACTUATED 

ROLLOVER/VENT VALVE 

5/8" DIA. 

8' LONG 

05" DIA. LIMITING 

ORIFICE 

PURGE VALVE 

TO PURGE 

INDUCTION 

POINT 

3 LITER 

CARBON 

CANISTER 

14 GALLON FUEL TANK 

V 

CO 
FIGURE 2 

VACUUM CONTROL SOLENOID 

REFUEUNQ VAPOR 

CARBON CANISTER 

3/16 IN. I.D. VAPOR UNE 

CONDENSATE CHECK VALVE AND 

UQWD 8HUTOFF VALVE 

NOZZLE-ACTUATED 

VENT VALVE 

FUEL TANK 

VACUUM PURGE VALVE 

o 

VAPOR/LIQUID SEPARATOR 

3/4 IN. IJ). VAPOR UNE 

V MKWIIM I MMtwM. mrtcm 

REFUEUNQ VAPOR RECOVERY SYSTEM 

CHEVROLET CAPRICE 

HUttLtW U1QCIHII . IMC tillhiow. MO 

»«• i o - ai\ tcAfi wove IS WE TC H |>»i i o» i. 
P.11 

FIGURE 3 

EVAPORATIVE/REFUELING 

VAPOR RECOVERY 

SYSTEM 

MANIFOLD PRESSURE 

VEHICLE SPEED 

COOLANT TEMPERATURE 

_ * 

. © 

RPM 

TIME 

DISTANCE 

THROTTLE POSITION 

2 PUS 

i =U: 

•t 3iF 

SYSTEM COMPONENTS 

CA? 

L_=R TUBS - "CP '• ENTSD 

L "*ANK VENT - INTERNAL PASS. Z± -

"ANK VENT - EXTERNAL TRUCK 

RENT.AL PRESSURE ZHzZ< :-.. i 

6 "wSl iANK 

7 REFUEUNG VAPOR CANISTER 

3 FILTER 

3 SURGE AlR INLET - REMOTE 

PASS. CAR - REAR SUSPENSION CROSS" 

TRUCK - UNOERHOOO 

'0 VAPCRL.N S - 5:3-: Z 

:: "ANK VENT/RCLLCVER VAL'.E 

•2 PURGE LiNE - 5/.6* 

'3 PURGE UNE - *.•&• 

'i SURGE SOLENOID - DUTY CYCLE CONTROLLED 

' . ELECTRONIC CONTROL UNIT 

16 EVAPORATIVE VAPOR CANISTER 

17 TO BI-LSVEl PURGE 

18 MANIFOLO VACUUM LINE 

19 VACUUM SOLENOIO - ON/OF? 

REFUELING FILLER TUBE FEATURES: 

- NOZZLE SEALING DEVICE 

- =E=USL:NG EVENT DEVICE 

- PRESSURE REUEF DSViCEiS) 

- NOZZLE SHUT-OFF (LIQUID) 

- VAPOR CONNECTION TO CANISTER 

- LiOUlO CARRYOVER PREVENTION 
P.12 

Development of Simplified System 

Bain goal was to resolve complexity issue 

Also desired to handle other specific hardware issues raised 

in the past 

Established the following design constraints 

Simplicity of design, consistent with necessary functions 

components based upon current production hardware 

Began with typical current fuel tank components (Figure 4) 

Design features (Figure 5) 

Fillneck seal - no modification to current system 

required 

Vapor control valve - modified stock rollover valve 

Moderately increase orifice size 

Vapor lines 

Eliminate current refueling vent line 

Shorten evap vent line 

Carbon canister 

Move to rear of vehicle 

Enlarge from IL to 2.5L 

Overall, system is simplification of current designs (Figure 6) 
FIGURE 4 

Typical Current Evaporative System 

PRESSURE / VACUUM 

RELIEF CAP 

EXTERNAL VENT LINE 

\ 

FLOAT/ROLLOVER 

VALVE 

V 

ANTI - SPITBACK 

VALVE 

3/8" DIA. 

8' LONG 

# 

PURGE VALVE 

1 LITER 

CARBON 

CANISTER 

TO PURGE 

INDUCTION 

POINT 

FUEL TANK 
REMOVE 

r 

FIGURE 5 

Onboard Modifications 

SHORTEN 

VAPOR LINE 

MODIFY 

ENLARGE 

CARBON 

CANISTER 

Tl 
FIGURE 6 

Onboard Plus Evaporative System 

PRESSURE/VACUUM 

RELIEF CAP 

NO 

EXTERNAL 

VENT LINE SHORTER 

VAPOR LINE 

v 

MODIFIE

v

D 

\ 

FLOAT/ROLLOVER 

VALVE 

-X 

ANTI - SPITBACK 

VALVE 

^ 

PURGE VALVE 

ENLARGED 

CARBON 

CANISTER 

TO PURGE 

INDUCTION 

POINT 

FUEL TANK 
P.16 

• J V " ' •»'-*- - — • T • , 

Review of Display Hardware 

First generation EPA system 

Examples of current fuel tank components 

New onboard system 
P.17 

System Performance 

System has consistently met proposed standard with 

substantial margin of safety 

Spitback appears to be fully controlled 

Test Data Results 

Test 

Number 

Emissions 

(q/qai) 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

.02 

.01 

.03 

.05 

,06 

.06 

.04 

.05 

,08 

.04 

.04 

.01 

,02 

Spitback 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

Canister 

Weight 

gain (g) 

77 

73 

77 

79 

73 

85 

87 

85 

86 

Comments* 

10 gpm 

10 gpm 

10 gpm 

5 gpm 

5 gpm 

5 gpm 

5 gpm 

5 gpm 

10 gpm 

10 gpm 

5 gpm 

4 gpm 

3 gpm 

* All tests were conducted using nominal 9,0 RVP Federal 

Test Fuel 
P.18 

Conclusions 

Onboard control can be implemented with simple 

modifications to current fuel tanks 

Onboard can reduce overall system complexity 

System will not degrade safety, likely to improve safety 
P.19 

198 8 Mazd a 626/MX- 6 WoTrKshop > Manvia l 

86U04B-O95 

Note 

Drain the fuel from the fuel tank before removing the tank. 

1. Fuel pump connectors 

2. Fuel hoses 

3. Steering angle transfer shaft (4-wheel 

steering) 

(Refer to section 10) 

4. Cross member (4-wheel steering) 

5. Evaporative hoses 

6 Fuel filler hose 

7. Breather hose 

8. Fuel tank strap 

9. Fuel tank 

4R— 79 
-.,..,-

KEY TO DIAGRAM M-'h*4sAr 

1. Charcoal canister 

2. Air inlet to canister 

3. Purge line to plenum chamber 

4. Connector hoses with restrictors 

5. Restrictor in purge line 

6. Fuel expansion tank 

7. Fuel vapour pipe from manifold 

8. Breather hose with anti-surge valve 

9. Fuel tank filler neck 

10. Filler neck breather hose 

11. Manifold 

12. Fuel vapour pipes from fuel tank (3 off) 

13. Pressure relief valve and hose 

14. Fuel tank 

15. Float/rollover valve 

16. Crommet 
P.21 

03-3 4 EMISSION CONTROL GASOLINE ENGINE 

EVAPORATIVE EMISSION CONTROL SYSTEM (ECS) 

EVAPORATION CONTROL SYSTEM 

FUEL 

EVAPORATE GAS 

t9%7 JZsuzu 

AMBIENT AIR 

AIR CLEANER 

CHECK & RELIEF VALVE 

RELIEF VALVE 

FUEL TANK 

ROLL OVER & 

FLOAT VALVE 

The evaporation control system is designed • --id the fuel vapor emitted from the fuel tank and the carburetor into the 

carbon canister. This system consists of •• -; -oil over & float valves, relief valve, check and relief valve, charcoal 

canister, vent switching valve and tubes correcting these parts. 

The fuel vapor, stored in the canister and n-•.-;•: with ambient air, is led directly to the intake manifold for combustion 

when the engine is running. 

ROLL OVER & FLOAT VALVE AND RELIEF VALVE 

UPPER 

TO CHARCOAL CANISTER 

FLOAT 

SLITS 14 PLACES) 

The roll over & float valves are designed to prevent fuel leaks 

when the vehicle has turned over, and the relief valve is intended 

to relieve the tank internal pressure to avoid tank damage when 

the pressure has reached a certain level as the result of the roll 

over & float valves blocking the fuel escape. None of these 

components are relevant to evaporative emission control system. 
Tte fuel tank is mounted under the rear of the 

i. The fuel tank system contains fuel feed and 

ines and a fuel gauge sending unit. Fuel is 

from the fuel tank by an engine-driven 

•chantcal fuel pump. Fuel is drawn through the 

Mdativ-sry line, fuel filter, and fuel inlet line into the 

M pump. The fuel pump delivers fuel under 

pnNure through the fuel discharge line to the 

ortwetor inlet. Excess fuel is returned to the fuel 

tank through a return line through a separate line 

that extends from the pump to the top of the fuel 

tank. 

A vapor line is routed from the fuel tank to a vapor 

separator located in the left rear quarter panel. All 

lines run parallel underneath the vehicle on the left 

hand side. The filler neck is equipped with a 

restriction in the opening that allows only a 

nonleaded fuel nozzle to be inserted. 

FUEL 

TANK 

VAPOR 

SEPARATOR 

CHECK 

VALVE 

"V K/ ^ 

FUEL 

PUMP V6700-A 
P.23_ 

14-98 

FUELTANK 

REMOVAL AND INSTALLATION 

N1«OU 

COLT 

G39 

139 

Removal steps 

1. Fuel tank cap 

2. Drain plug 

3. Fuel gauge unit connect 

* * 4. Main hose 

*>« 5. Return hose 

• « 6. Vapor hose 

«•« 7. Leveling hose 

8. Filler hose 

9. Self-locking nut 

10. Tank band 

11. Fuel tank 

12. Fuel pipe and filter asse13. Gasket 

14. Fuel gauge unit 

15. Fuel check valve 

16. Overfill limiter (two-way ^ 

17. Filler neck 

Pre-removal Operation 

• Draining Fuel 

Post-installation Operation 

• Filling Fuel System with Fuel 

NOTE 

(i) Reverse the removal procedures to reinstall. 

(3) * * Refer to "Service Points of Installation". 

(4) d : Non-reusable parts 

V 
P.24 

Evaporative Emission Controls 

r— Description (cont'd) 

service 

manual 

IGNITION 

SWITCH 

FUEL FILLER CAP 

« FUEL CUT-OFF 

VALVE 

CHARCOAL 

CANISTER 

11-74 
14-76 

FUEL TANK 

REMOVAL AND I 

Pre-removal Operation 

• Draining of the Fuel. 

Post-installation Operation 

• Supplying of the Fuel. 

25-30 Nm 

1&-22 ft.lbs. 

Removal steps 

1. Drain plug 

2. Fuel filler cap 

3. Fuel filler hose protector 

» 4 4. Vapor hose 

»-« 5. Check valve 

6. Overfill limiter (Two-way valve) 

7. Clamp assembly 

»<* 8. Fuel filler hose 

» « 9. Breather hose 

10. Packing 

11. Fuel filler neck 

•*>-« 12. Main hose 

» « 13. Return hose 

1S-<?0 Nm 

11-14 tt Ids 

4.Fuel gauge unit connector connection 

". Fuel tank assembly mounting nuts 

6 Fuel tank 

7 Pipe assembly 

i Separator tanks 

9 Fuel tank protector 

\OTE !

 • Reverse the removal procedures to reinstall* 

2) »-« : Refer to "Service Points of Installation" 

Outlet 

side 

irrr 

\ 

STB Revision 
FUEL TANK 

REMOVAL AND INSTALLATION 

20 

Standard body \ / 

MITSUBISH TRUCK 

14-73 

NMOA30-35 Nm 

22-2S ftlbs. 

0380045 

Pre-removal Operation 

• Drain of fuel 

Post-installation Operation 

• Filling fuel 

Long body and club cab 

23 

23 22 

Fuel tank removal steps 

1. Side skirt panel stay 

2. Fuel gauge unit connector 

3. Drain plug 

4. Main hose connection 

5. Return hose connection 

6. Vapor hose connection 

»*•* 7. Breather hose connection 

•>•• 8. Fuel filler hose connection 

9. Fuel tank mounting nut 

10. Fuel tank 

Fuel pipe assembly removal steps 

1. Side skirt panel stay 

4. Main hose connection 

5. Return hose connection 

i 7. Breather hose connection 

j ** 11. Pipe assembly 

j 12. In-take fuel filter 

i 

j 

| Fuel filler neck removal steps 

| ••« 7. Breather hose connection 

; -ft--* 8. Fuel filler hose connection 

; 13. Fuel filler cap 

j 14. Filler neck cover 

j 15. Reinforcement 

16. Filler neck 

17. Packing 

18. Retainer 

19. Grommet 

Fuel gauge unit removal steps 

1. Side skirt panel stay 

2. Fuel gauge unit connector 

9. Fuel tank mounting nut (standard 

body only) 

20. Fuel gauge unit 

0380046 

•#» 

Check valve and overfill limiter 

(2-way valve) removal steps 

6. Vapor hose connection 

»-« 21. Check valve 

22. Overfill limiter (Two-way valve) 

Separator tank removal steps (4WD only) 

9. Fuel tank mounting nut 

•«» 23. Separator tank 

NOTE 

(1) Reverse the removal procedures to reinstall. 

(2) * * : Refer to "Service Points of Removal". 

(3) ••>*: Refer to "Service Points of Installation". 

STB Revision 
N> 
r P.28 
P.29 
P.30 
P.31 

> 
P.32 

^ 
P.33 

u 

r 
P.34 

. 

v -

\i 
P.35 

Attendees 

API Vehicle Refueling Emissions Task Force 

April 15, 1988 

Mobil 

Chevron 

Amoco 

Texaco 

Mobil 

API 

Sun 

Exxon 

Exxon 

EPA (observer) 

Al 

D. 

P. 

Ha 

W. 

E. 

J. 

G. 

H. 

G. 

McCluskey 

F. Gibson 

S. Bush 

/den Silver 

Koehl 

Crockett 

Freeman 

Musser 

Shannon 

Passavant 
ONBOARD CONTROL OF REFUELING EMISSIONS 

IMPROVED SAFE DESIGN 

PRODUCTS RESEARCH DIVISION 

EXXON RESEARCH & ENGINEERING COMPANY 

APRIL 15, 1988 
APPROACH - DESIGN WITH SAFETY AS OBJECTIVE 

• START WITH PRODUCTION EVAPORATIVE CONTROL SYSTEM 

DECREASE TANK VENT TO ONBOARD CANISTER HOSE SIZE WITH 

SATISFACTORY CONTROL OF REFUELING EMISSIONS 

• LOCATE CANISTER IN SAFEST POSITION INSIDE FRAME 

• NO SEAL APPROACH 

• CONFIRM REGUUTED EMISSIONS AND CANISTER PURGE 
VEHICLE 

1987 BUICK LESABRE 

PFI 

3.8L 

18 GALLON TANK 

SIDE FILL 

1/2" TANK VENT SEPARATE 

oo 
SAFETY ISSUES PARAMETER STUDY 

EXPERIMENTAL DESIGN 

- PRODUCTION 1987 BUICK LESABRE 

+ EVAPORATIVE CONTROL SYSTEM (ECS) INCLUDES: 

SEPARATE 1/2" FUEL TANK VENT 

0.057" ORIFICE BETWEEN TANK AND CANISTER 

0.078" ORIFICE BETWEEN CANISTER AND PORTED 

MANIFOLD PURGE 

- PARAMETERS VARIED 

+ VENT HOSE DIAMETER/LENGTH 

+ CANISTER SIZE/LOCATION 

+ CANISTER PURGE RATES 

- PARAMETERS NOT CHANGED 

+ ELECTRONIC CONTROL MODULE 

- NO SEAL APPROACH 
RESULTS 

Step No. Canister Vent Hose Size 

in. ID 

Other 

Average 

Fuel Rate 

gpm 

Refuelinq Emissions 

Grams/Gal % Control 

0 

1 GM IL 1/4" removed 0.057" orifice 

existing ECS lines 

canister in engine 

compartment 

9.5 4.86 

— on lowest nozzle setting 

shut off every 0.6 gal 

with burp 

GM IL 3/8" cut ECS exit hose 

from tank 

3.6 25% 

3 

4 

5 

6 

7 

GM IL 

ERE 3.5L 

GM IL 

ERE 3.5L 

ERE 3.5L 

1/2" 

1/2" 

5/8" 

5/8" 

1/2" Replaced production 

ECS 1/4" tank exit 

with 1/2" exit 

3 

4 

4 

7 

10 

0.87 

0.46 

1.53 

0.16 

0.11 

82% 

90% 

69% 

97% 

98% 
Step No. 

8 

9 

10 

11 

12 

13 

Canister 

ERE 3.5L 

ERE 3.5L 

ERE 3.5L 

ERE 3.5L 

ERE 3.5L 

ERE 3.5L 

Vent Hose Size 

in. ID 

3/8" 

1/2" 

3/8" 

3/8" 

5/16" 

1/4" 

RESULTS (CONTINUED) 

Other 

Moved canister 

to trunk 

Moved canister 

into tank 

Average 

Fuel Rate 

gpm 

9 

10 

9.5 

9.6 

9.5 

9.3 

Refuelinq Emissions 

Grams/Gal % Control 

burp 

0.19 96% 

0.06 99% 

i 

0.05 99% 

0.04 99% 

0.06 99% 
PRINCIPAL ELEMENTS OF 

ENHANCED ONBOARD SYSTEM 

Standard 

Fillpipe 

With Vent 

Rerouted to 

Canister 

Purged 

HC Vapors 

To Engine 

Opening 

From Tank 

and 

Rollover 

Valve Enlarged 

Charcoal 

Canister 

HC Vapors 

2676-02 

-p. 

PO 
Step No. Canister Vent Hose Size 

in. ID 

14 5L Tank 5/16" 

RESULTS (CONTINUED) 

Other 

removed vapor liquid 

separator 

added rollover valve 

Average 

Fuel Rate 

gpm 

9.5 

Refuelinq Emissions 

Grams/Gal 

0.07 

% Control 

99% 

15 

16 

17 

5L Tank 

5L Tank 

5L Tank 

5/16' 

5/16" 

5/16" 

9.6 

9.4 

9.5 

0.08 

0.17 

0.10 

98% 

97% 

98% 
REGULATED EMISSIONS 

Base car 

GM Canister 

1/2" hose 

ERE 3.5L Can 

5/8" hose 

ister 

ERE 3.5L Canister 

5/16" hose - close 

coupled - stock purge 

5L Tank/0.078" 

orifice 

moved purge location 

CO 

g/m 

2.029 

2.107 

1.517 

1.814 

1.630 

1.454 

1.765 

1.495 

HC 

g/m 

0.271 

0.291 

0.234 

0.252 

0.259 

0.271 

0.295 

0.247 

NOx 

g/m 

0.270 

0.284 

0.319 

0.273 

0.271 

0.283 

0.290 

0.225 

Diurnal 

g/T 

0.24 

0.42 

0.48 

0.10 

0.36 

0.94* 

0.20 

0.35 

Hot Soak 

9/T 

0.27 

0.22 

0.19 

0.16 

0.17 

0.21 

0.16 

0.34 

Total Evap 

g/T 

0.51 

0.64 

0.67 

0.26 

0.53 

1.15 

0.36 

0.69 

New proposed procedure 
PURGE 

GM DESIGN 

- PORTED VACUUM WITH 0.078" ORIFICE 

- SOLENOID VALVE DUTY CYCLE MODUUTED 

+ ABOVE 5 MPH 

+ COOLANT TEMP. >1780F 

+ 1 MINUTE U G AFTER ENGINE ON 

+ THROTTLE POSITION SENSOR VOLTAGE >0.75 

- PURGE RATES 

50 MPH 1.2 LPM 

40 MPH 0.5 LPM 

35 MPH 0 

U - 4 1.9 LPM 

- 11-16 GRAMS PURGED IN 1 1/2 U-4'S 
PURGE (CONTINUED) 

• MODIFIED DESIGN 

- SAME SOLENOID VALVE 

- MOVED PURGE FROM PORTED POSITION 

VACUUM 

- PURGE RATES 

ORIFICE SIZE 50 MPH 

0.078" 13.4 

0.059" 11.1 

0.052" 8.4 

0.046" 6.5 

TO PCV LINE MANIFOLD 

U-4 

4.2 

(3.5) 

2.6 

(2.0) 

Tl 

-p. 

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CANISTER PURGE 

FTP EMISSIONS TESTS 

(0.078" ORIFICE) 

SATURATION OF CHARCOAL 

220 GRAMS IN 3 REFUELINGS 

6 GRAMS HC IN SHED 

U S T REFUELING 92% CONTROL 

CHARCOAL WEIGHT HISTORY 

STEP 

START 

LA-4 PRE CONDITIONING 

1 HOUR SOAK 

OVERNIGHT SOAK - 15 HOURS 

DIURNAL TEST 

TAILPIPE EMISSIONS 

HOT SOAK TEST 

GAIN/LOSS 

GRAMS 

0 

-38 

0 

+7 

+16 

-19 

TOTAL 

GRAMS 

0 

-38 

-38 

-31 

-15 

-34 
CONCLUSIONS 

• 1/2" HOSE FROM THE TANK TO ONBOARD CANISTER IS SUFFICIENT IF 

THE ONBOARD CANISTER IS LOCATED IN THE ENGINE COMPARTMENT 

• 1/4" HOSE FROM THE TANK TO ONBOARD CANISTER IS SUFFICIENT IF 

THE ONBOARD CANISTER IS LOCATED IN THE TRUNK 

NOTE: THE PRODUCTION TANK VENT IS 1/2" 

FUTURE WORK 

BUICK LESABRE 

• DETERMINE REGUUTED EMISSIONS WITH CANISTER IN THE TANK 

• DETERMINE CANISTER PURGE CHARACTERISTICS 

FORD TAURUS 

t BASE LINE VEHICLE 

• MODIFY VEHICLE 

- CANISTER IN FRAME MEMBER 
VEHICLE 

1988 FORD TAURUS 

MPFI 

3.0L 

16 GALLON TANK 

SIDE FILL 

1/2" TANK VENT SEPARATE 
SERVICE STATION STORAGE TANK VENT EMISSIONS 

PRODUCTS RESEARCH DIVISION 

EXXON RESEARCH & ENGINEERING COMPANY 

APRIL 15, 1988 

Tl 

bi 
OBJECTIVE 

• 

APPROACH 

• 

• 

; 

DETERMINE EFFECT OF ONBOARD VEHICLES ON STORAGE TANK VENT 

EMISSIONS I N SERVICE STATIONS WITH STAGE I I 

DETERMINE STORAGE TANK VENT FLOWS BOTH I N AND OUT WITH 

PRESSURE DROP DRY GAS METERS 

CONTINUOUSLY MONITOR THE VENT FLOW FOR HC BY NDIR 

LOW 

•4 

1 

* 

X 

•j 

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bi 

. ro 
EQUIPMENT 

• 2 AMERICAN METER CO./SINGER CO. DRY GAS METERS MODEL AL-425 

(425 CTH AT 0.5 IN . H20) 

• SUN INFRA 2 MODEL 102 NDIR HC ANALYZER 

• 2 PING PONG BALL CHECK VALVES 

SERVICE STATIONS 

LINDEN RESEARCH SERVICE STATION 

- 1/4 IN . ORIFICE IN RAIN CAP ON 3 IN . VENT PIPE 

- PV VALVE 2 IN . (0.5 OZ VAC. 8 OZ PRESSURE) 

WASHINGTON, D.C. 

- STAGE I I 

- 2 IN . VENT PIPE WITHOUT RAIN CAP 

3Ul 

,co 
P.54 

Ping Pong 

FLOW SCHEMATIC 
RESULTS TO DATE 

t STAGE I SERVICE STATION IN NJ IN DECEMBER WAS IN A VAPOR 

SHRINKAGE CONDITION 

• ONBOARD VEHICLES TENDED TO MAKE STAGE II SERVICE STATION MORE 

LIKE STAGE I SERVICE STATION 

PV VALVE REDUCED AIR INGESTATION DURING FUEL DELIVERY 

• ONLY 38 GMS OF HC EMITTED IN STAGE II STATION WITH 5000 GALLONS 

PUMPED 

NO HC EMITTED IN STAGE I STATION WHEN MEASURED 2ND TIME 
P.56 

Z 

< 

Zm 

Z ^ 

3 

STORAGE TANK VENT AIR INTAKE 

AT LINDEN ie WASH. D.C. 

i 

20 

-I 1 1-

50 40 

LINDEN 

HOURS MONITORED 

WASH. D.C. D.C. w ONB 
-rwyRATE OF AIR IN VS GASOLINE SOLD 

WASH. D.C. 

a: 

o 

0 

x 

Id 

a. 

<f 

IA 

Z 

o 

-I i o 

4O0 

300 -

200 -

100 -

-10 0 

400 

GALLONS FUEL PER HOUR 

Q WASH. D.C. DATA REGRESSION 
RATE OF AIR IN VS GASOLINE SOLD 

3 

o 

r 

a: 

UJ 

a 

it 

1/1 

z 

0 

300 -

200 -

100 -

a 

m . 

I I 

LINDEN 

/ ^ °cP 

I I 

a a 

i 

a 

i i 

100 200 300 400 

GALLONS FUEL PER HOUR 

D UNDEN DATA REGRESSION 
P.59 

RATE OF AIR IN VS GASOLINE SOLD 

IT 

D 

O 

r 

tt 

ut 

a. 

X. 

z 

o 

-I 

300 -

200 -

100 -

0 -

100 -

WASH. D.C. WITH ONBOARD VEHICLES 

D^- " 

1 1 " 1 ~ " ' -T ' 1 

a 

i 

a 

i -

100 

WASH. D.C. DATA 

200 

GALLONS FUEL PER HOUR 

300 

REGRESSION 

400 
STORAGE TANK VENT AIR INTAKE 

RESEARCH SERVICE STATION 2ND TIME 

z 

2 

< 

i/i 

z 

o 

i 

900 - e 

800 -

700 -

600 -

500 -

400 -

300 -

200 -

100 

WITH ORIFICE 

HOURS MONITORED 

+ WITH PV VALVE 
P.61 

400 

300 

RATE OF AIR IN VS GASOLINE SOLD 

RESEARCH STATION WITH ORIFICE 

or 

D 

O 

r 

E 

UJ 

0. 

200 -

IA 

Z 

0 

100 -

D n 

-10 0 1 1 1 1 1 1 r 

100 200 300 

GALLONS FUEL PER HOUR 

D WITH ORIFICE DATA REGRESSION 

400 
P.62 

£ 

D 

o 

Z 

CC 

Id 

CL 

IT 

? 

</) 

Z 

o 

-I 

RATE OF AIR' IN VS GASOLINE SOLD 

RESEARCH STATION WITH PV VALVE 

400 

300 -

200 -

100 -

-10 0 

400 

GALLONS FUEL PER HOUR 

D WITH PV VALVE REGRESSION 
FUTURE WORK 

RE-MEASURE TANK VENT EMISSIONS FOR BOTH STAGE I AND STAGE II SERVICE 

STATIONS UNDER: 

- WARM AMBIENT CONDITIONS 

- WITH AND WITHOUT PV VALVE 

- NON 24 HOUR STATION