P.1 

OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

13)IV-B-9 

Docket Number: 

A-87-11 

Printed 11/13/2008 7:20:51 AM Sheet 13 of 232 
^

£0S X 

T

i : UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

USE/ 

*'wt&>" 

ANN ARBOR. MICHIGA N 48105 

P.2 

OCT 2 4 !983 

OFFICE OF 

AIR AND RADIATION 

MEMORANDUM 

SUBJECT: EPA Testing of API Sponsored Vehicles Equipped With 

Onboard Refueling Emissions Control Systems 

FROM: David B. Bartus, Chemical Engineer /../>__> 

Standards Development and Support Branch 

TO: 

THRU: 

Docket A-87-11 

John Anderson, Senior Project Manager 

Standards Development and Support Branch 

/ 

<v^ rP^v^1— 

EPA has conducted tests on two vehicles on loan from Exxon 

Research and Engineering according to test procedures 

associated with the refueling SMPRM. These vehicles, a 1937 

Ford Taurus and a 1987 Buick LeSabre, had been modified by 

Exxon to include integrated onboard refueling emissions control 

systems. During the period 9/14/88 through 9/29/38, several 

telephone conversations were held with Dr. George Musser of 

Exxon Research and Engineering to obtain information on the 

specific modifications made to these vehicles, to obtain 

lnrormation the test procedures and rnet'->odoloav u; 

on, an-. 

on 

:o exchange test data obtained 

ov 

7^ v '.; Q r> roi 

obtained by Exxon are summarised in 

API," index number IV-E-6 4, and 

i -• s i- r-suii-a 

"Meeting wi; 

Chester J. France from H.F. Shannon 

dated 9/14/88 and 9/20/88, all in docket A-S7-11 

obtained by EPA are summarized in the attached ta 

a!!U \s . i 

nemorsncum 

letters to 

r of Exxon, 

"est results 

Both vehicles were tested, as received from Exxon, v/ith 

only minor modifications made to them. In each vehicle, the 

tank vapor line and. canister purge lines were extended 

approximately 12-15" to facilitate rapid canister disconnect 

and removal during testing and. to avoid, a tendency of the 

Exxon-supplied hoses to crimp when placing the canister into 

the vehicle. Hoses used for these extensions had diameters 

greater than or equal to the as-supplied hosss. 
P.3 

-2-

Test 885431, run on the Ford vehicle, was conducted after 

replacing the stock fuel tank vapor line (used as the canister 

purge line in the Exxon refueling emissions control system 

design) with a larger, 5/8" hose. This larger line extended 

from the downstream port of the purge control solenoid valve to 

within two feet of the fuel tank vent valve. A smaller hose 

was used over the remaining distance to pass through various 

frame member cutouts. This modification was made to determine 

if purge volume was limited by purge vapor line size. 

On both cars, type T thermocouples supplied with the 

vehicle were removed and replaced with type J devices of 

similar size and packaging. In addition, an extra thermocouple 

was added to each fuel tank through the sender disk to measure 

the 40 percent mid-volume fuel temperature. All diurnal tests 

on the Ford vehicle were run using this added thermocouple. 

Unfortunately, this added sensor proved defective on the Buick, 

resulting in abnormally high diurnal emissions during test 

885503. After discovering this problem, test 885503 was.' 

completed using an external skin temperature located at 

approximately the 40 percent mid-volume liquid level. The 

remaining tests on the Buick made use of an Exxon thermocouple 

fitting at the 10 percent liquid level. 

During refueling tests on the Ford at 10 gallons per 

minute, premature shutoffs were encountered which appeared to 

contribute significantly to refueling emissions. In addition, 

there was evidence that a liquid seal was not fully established 

near the start of some refueling operations. Spitback did not 

occur during the 5 GPM test on the Ford, and both problems were 

absent or of lesser severity during all Buick tests. Test data 

show the purge volume available from these vehicles is not 

sufficient to purge the refueling canister enough to pass the 

refueling test. A significant fraction of the needed purge is 

provided by the stock purge system, however, suggesting that 

only relatively minor purge system modifications are needed to 

obtain the required purge volume. 

All tests on the Ford were carried out with the canister 

installed in its normal position according to the Exxon system 

design. At various points during the test procedure, the 

canister was briefly removed from the vehicle and weighed, as 

indicated in the canister weight section of the attached 

table. During canister removal, the vapor inlet and purge 

outlet ports on the canister were sealed, as were the tank 

vapor and canister purge hoses. Because of the awkward 

location of the canister on the Buick, removal of it to obtain 

weights during vehicle testing was not attempted when the 

canister was installed in its design position as in test 

885503. During tests 885504 and 890103, the canister was 

placed inside the trunk to allow canister weights to be taken. 

In this configuration, the canister was placed upright, that 

is, in the same orientation as when it was installed in its 
P.4 

-3-

design position, and near the trunk floor cutout that normally 

provided access to the canister vapor and purge line 

connections. 

Each vehicle was driven for approximately 40 minutes over 

a non-specific route covering at least 22-24 miles between each 

test sequence to provide some canister purge before the next 

load to breakthrough procedure. These drives did not reveal 

any driveability problems, and canister weight changes obtained 

during them can be found from the canister weight data shown on 

the following page. 

Exhaust test results indicate that emissions by EPA are 

somewhat higher for the modified Ford vehicle compared to test 

data from Exxon. For the Buick, some exhaust emissions were 

found to be nearly twice the level reported by Exxon. When 

compared to base vehicle data (stock evaporative emissions 

control systems) reported by Exxon, EPA data on vehicles with 

refueling system are only minimally higher, suggesting that 

little or no interaction exists between exhaust emissions and 

purge of refueling canisters. 

Attachment 

6430W 
P.5 

-4-

Vehicle: 

Test Number: 

Exhaust(g/mi): 

HC: 

CO: 

NOx 

Evap(g/test): 

Diurnal: 

Hotsoak: 

Total: 

Refueling: 

Emiss(g/gal) 

Disp(gal): 

Rate(gal/min) 

Shutoffs: 

Premature: 

Auto/Man.: 

Taurus 

885428 

0.177 

1.60 

0.59 

0.46 

0.28 

0.74 

0.13 

13.6 

: 10.0 

1 

m 

Taurus 

886529 

0.186 

1.69 

0.58 

0.69 

0.34 

1.03 

0.46 

13.9 

10.0 

2 

a 

Taurus 

885431 

0.175 

1.60 

0.64 

1.22 

0.27 

1.49 

0.32 

16.0 

5.0 

0 

a 

LeSabre 

885503 

0.362 

2.00 

0.36 

26.4 

0.45 

26.82 

0.03 

14.3 

10.0 

0 

a 

LeSabre 

885504 

0.257 

1.80 

0.37 

0.83 

.43 

1.26 

0.19 

14 .9 

5.0 

0 

a 

LeSabre 

890103 

0.333 

2.33 

0.36 

1.47 

0.60 

2.07 

0.33 

15.1 

10. 0 

0 

a 

Canister Wts (g): 

Start 

After 

After 

After 

After 

After 

After 

After 

LTB: 

LA-4: 

HB: 

FTP: 

HS: 

LA-4: 

ref. : 

4588 

4759 

4729 

4750 

4712 

4713 

4695 

4771 

9 

1 

9 

2 

2 

7 

0 

8 

4704 

4786 

4744 

4769 

4740 

4741 

4723 

4803 

0 

4 

4 

3 

7 

6 

0 

3 

4732 

4740 

4721 

4741 

4698 

4699 

4683 

4751 

8 

4 

4 

2 

0 

6 

.6 

2 

4762.0 

* 

4951.8 

4918 

5050 

5011 

5027 

4997 

4998 

4986 

5140 

8 

3 

4 

6 

6 

4 

6 

9 

5100 

5175 

5135 

5151 

5116 

5117 

5103 

5170 

0 

2 

8 

4 

6 

7 

.7 

1 

End-of-test purge 

drive (miles)**: 28.4 29.3 26.3 31.0 

* * 

Canister weights not obtained during this test. 

Prior to the start of the second and third test sequences 

on each vehicle, an on-road drive was conducted to provide 

canister purge before the load-to-breakthrough step of the 

next test. Data shown above are the total miles travelled 

during these drives. The route travelled was not 

explicitly specified, but was similar for all drives, 

consisting of mostly rural and highway travel.