P.1 

OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

15) IV-B-11 

Docket Number: 

A-87-11 

Printed 11/13/2008 7:20:51 AM Sheet 15 of 232 
9 mTm \ 

"»l««*« 

£-07-// 

P.2 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

NOV I 7 '988 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

THRU: 

Application of Simplified Refueling Controls to a 

Ford Taurus Fuel Tank 

John Polasek, Mechanical Engineer 

Standards Development and Support Branch ) 

Public Docket A-87-11 

John F. Anderson, Senior Project Manage 

Standards Development and Support Branch/ 

MffU 

Chester J. France, Chief 

Standards Development and Supp ort BraJfP W ^ 

I. Introduction: 

On September 26, 1988, Ford presented .a briefing to EPA on 

the results of its attempts at applying EPA's simplified 

refueling control concept to Ford vehicles. Ford identified a 

number of problems with the system which led Ford to conclude 

that simplified refueling controls are not readily adaptable to 

production vehicles. Key issues raised by Ford related to poor 

finability and inadequate liquid sealing at low flow rates. 

To deal with these problems Ford felt it was necessary to 

resort to a mechanical seal based system. 

Our initial evaluation of the Ford presentation was that 

the difficulties encountered by Ford should be relatively easy 

to avoid. To verify this evaluation, a short program was 

undertaken to evaluate the simple system design on a Ford 

Taurus fuel tank. This memo summarizes the program and its 

results. 
P.3 

-2-

II. Developing the Refueling/Evaporative System on the Ford 

Taurus 

The basic approach followed was the same as for the 

previously successful GM fuel tank. Beginning with the stock 

fuel tank, initial modifications were made to be able to 

collect refueling vapors. This configuration was then 

evaluated and additional changes were made as needed to obtain 

satisfactory performance. 

A. The Initial System 

Beginning with a Ford Taurus production fuel tank, two 

modifications were needed to collect refueling vapors. First, 

the existing external vent line was removed. Second, the 

current rollover valve was replaced with a multifunctional 

valve with a larger 0.350 inch diameter orifice connected to a 

canister. Two valves were available for this purpose. The 

"blue" valve which had been used in the GM system and a "white" 

valve which had been developed more recently by GT products. 

% These valves were largely equivalent, except that the white 

valve had a lower shutoff level and a secondary limiting 

orifice to relieve tank pressure during periods when the main 

float valve was closed. The white valve was also designed with 

adequate rollover shutoff capability. (Rollover testing of the 

white valve is documented in a separate memo.) The outlet of 

the vent valve was connected to a 2.5L carbon canister using 

approximately 3 feet of 5/8 inch diameter vapor line (Figure 1). 

Testing of this configuration indicated that refueling 

emissions were being successfully captured, but two problems 

existed. The first was spitback of fuel at the end of the 

fill. The second was that poor liquid seals formed at low flow 

rates. Taking these problems into consideration, modifications 

to the initial system were needed. 

B. Modifications to Initial System 

The fist problem to solve was spitback at high flowrates. 

This was easily solved by the addition of a spitback valve. 

Approximately 3 inches of fillpipe inside the tank were removed 

and a spitback valve was added. The valve was a production 

Chrysler valve, as had been used on the GM system. The check 

ball was modified by increasing the specific gravity to equal 

that of gasoline. The addition of the spitback valve to the 

system eliminated the spitback problem for further testing. 

With the system in this form, near zero emissions at 10 

gpm were observed, however, at low flow rates inadequate liquid 

seals were still indicated. To deal with this problem, we 

followed the same procedure used in developing the GM A-body 

refueling system. The procedure called for adding a small 

restriction in the fillpipe to maintain the seal at reduced 
P.4 

-3-

flow. Initially, the restrictor from the GM system was used in 

conjunction with the remaining length of fillpipe from inside 

the GM tank. Performance of this system was generally 

satisfactory. An adequate liquid seal was observed at 3 gpm 

and no premature shutoffs occurred at 10 gpm. However, at 

higher back pressures the 3 gpm liquid seal was lost. We 

therefore did some evaluations of other restrictors to improve 

the liquid seal at low flowrates. Tests were conducted with 

restrictor diameters ranging from 0.800 inches to 1.050 inches, 

also variations in restrictor inlet faces were tested. Tests 

were also conducted with restrictors with and without extension 

tubes. See Figure 2 for drawings of the basic restrictor 

designs used. 

In reviewing the results obtained from the restrictor 

variation, it was possible to get a liquid seal at low 

flowrates with several different restrictors. However, smaller 

restrictors tended to cause premature shutoff at high 

dispensing rates. Therefore, the largest restrictor which 

functioned at 3 gpm was selected because it was least likely to 

interfere with filling characteristics at high flowrates where 

most dispensing actually occurs. 

We also evaluated alternatives for the location of the 

rollover valve. The alternatives were used to reduce the fill 

height without having to modify the tank or the valve. 

Location C and B on Figure 3 gave adequate fill heights with 

the white valve, but location C was subject to splashing 

interference. 

The final modifications involved varying the system back 

pressure by changing the canister. We found that the system 

will operate if the back pressure inside the fuel tank at 10 

gpm is less than about 5 to 6 inches of water. Higher back 

pressure designs would sometimes cause loss of the liquid seal 

at low flowrates or premature shutoff at high flowrates. 

All of the test data collected on both the initial and 

modified system are given in Appendix 1. Overall, we 

determined the following: 

1. The addition of the spitback valve eliminated 

spitback for further testing. We had no difficulty 

in obtaining excellent fill quality at dispensing 

rates up to the 10 gpm maximum rate. 

2. Liquid seals at low flow were observed to be a 

function of restrictor diameter and shape. The 

smaller diameters resulted in better seals. It was 

also noticed that liquid seals were a function of 

back pressure. As back pressure increased the seal 

performance decreased. Considering the results on 

liquid seals, several restrictors gave excellent 

seals. 
P.5 

-4-

3. As mentioned above, back pressure effected seal 

performance. In addition, if the back pressure was 

too high premature shutoff occurred. This was 

observed with tank back pressures over the 5 to 6 

inches of water range. 

III. Final Configuration for Testing 

The final configuration selected for the refueling system 

was the same as that on the GM A-body tank (See Figure 4) . The 

changes to the stock system, in summary, are: 

A) Fillpipe 

1) Removed vent line 

2) Used 1.050 GM restrictor and tube 

3) Addition of a spitback valve with a ball 

weighed to neutral density in gasoline. 

B) Vapor Control Valve 

1) Replaced current rollover valve with the white 

GT valve (0.350 diameter orifice). 

C) Vapor Line - 5/8" I.D. 3' long 

D) Canister 

Any canister with a back pressure under 

approximately 2.5 inches of water at a 10 gpm 

dispensing rate can be used with this system. To 

optimize performance, we chose the 4 liter canister 

because it has the lowest back pressure. 

Once the final configuration was established, performance 

tests were done at both 10 and 3 gpm dispensing rates. In 

addition, since shifts in fuel tank alignment has occasionally 

produced differing fill heights, supplemental fill level tests 

were also conducted. Final test results are summarized in 

Table 1. 

IV. Conclusion 

The "simple system" concept has proven to be readily 

adoptable to the Ford Taurus. The Ford Taurus system, which 

uses the same modifications as the GM A-body system, displayed 

no spitbacks and no premature shutoffs. In addition, an 

adequate liquid seal was maintained throughout the 3-10 gpm 

range, such that near zero emissions were observed. In 

summary, we can conclude that the system developed is an 

effective system for controlling refueling emissions on the 

Ford Taurus. 
-5-

Table 1 

Results of Final Configuration Testing 

Ford Taurus Fuel Tank 

P.6 

Refueling Emissions Test 

Test No 

200 

201 

202 

203 

204 

205 

Flow 

(gpm) 

10 

10 

10 

3 

3 

3 

Nominal Pressure 

(in . H?0) 

2.3 

2.9 

3.0 

0.13 

0.12 

0.13 

Peak 

(in 

Pressure 

. H,0) 

8.5 

8.2 

8.5 

5.7 

5.9 

5.9 

Emissions 

(grams/qallon) 

0.04 

0.04 

0.03 

0.05 

0.05 

0.05 

Nominal Fill Test 

10 percent 

(gal) 

1.6 

1.6 

1.6 

10 GPM 

Dispensed 

(qal) 

16 

16 

16 

14 

05 

10 

Average 

Total 

(qal) 

17.74 

17 

17 

17 

65 

70 

70 

10 percent 

(qal) 

1.63 

1.60 

1.61 

3 GPM 

Dispensed 

(qal) 

17.18 

17.30 

17.20 

Average 

Total 

18 

18 

18 

18 

il) 

81 

90 

81 

84 

6556W 
P.7 

-6-

initial Tank Configuration 

Ford Production Fuel Tank (16 gal) 

Carbon Canister 2.5L 

Fuel Filler Pipe 

Rollover/Vapor Vent Valve with Large Diameter (0,350") 

Orifice to Mlow Passage of Refueling Vapor 

5/8 I,D. Vapor Vent Line 

Removed Existing External Vent Line 

3-icT 

Figure 1: Initial Configuration Tested 
FIG. 2: BASIC RESTRICTOR DESIGNS 

PLUG RESTRICTOR 

,s-./' 

s' 

v

v X 

v. 

RESTRICTOR TUBE 

i 

GMTUBE GM RESTRICTOR 

*NOTE: DRAWINGS ARE NOT TO SCALE 
FIG. 3 : ALTERNATIVE VALVE LOCATIONS 

r _ _ 

FILLER PIPE 

O B 

O C 

FUEL SENDER 

LOCATION 

B- REAR 

C- CENTER 

S - STOCK 

i 

00 

I 

1988 FORD TAURUS FUEL TANK 

CO 
P.10 

Final Configuration for Testing 

Ford Production Fuel Tank 

(16 gal-capacity) 

Fuel Filler Pipe 

Restrictor (1,050" dia restrictor as. used on GM tank) 

Rollover/Vapor Vent Valve vith Large Diameter (.350") 

Orifice to Allow Passage of Refueling Vapors 

5/8" I.D. Vapor Vent Line 

Mi-Spitback Check Valve 

2.5L or 4.0L Canister 

Figure 4: Final Configuration for Testing 
P.11 

-10 -

Appendix 1 
Test 

No. Configuration 

Gal 

GPM g/gal Disp. Pressure 

Valve Color 

and Location* Restrictor 

Spitback Canister & 

Valve Location** 

Ave. Peak 

(in H20) (in H20) 

Comments 

1 Blue stock (S) none 

2 White stock (S) none 

3 White stock (S) none 

80-1 Blue Center (C) none 

No 

No 

No 

Yes 

2.5L 

inside 

2.5L 

inside 

4.0L 

inside 

4.0L 

inside 

10 

10 

10 

20.8 

16.5 

16.4 

Stock tank 

1/2 cup spitback 

Stock tank 

1/4 cup spitback 

Stock tank 

1/4 cup spitback 

10 .02 19.7 5.5*** 8.7*** 

80-2 White Center (C) none 

81 Blue Center (C) 1.050 GM 

rest. & tube 

Yes 

Yes 

2.5L 

inside 

2.5L 

inside 

5 .12 15.6 

,02 18.2 

9*** 4.9*** 

,7*** 4.2*** 

Slight spitback 

Nozzle wasn't in 

all the way 

82 White Center (C) 1.050 GM 

rest. & tube 

Yes 2.5L 

inside 

,09 13.8 1*** 5.2*** 

83 White Center (C) 1.050 GM 

° rest. & tube 

Yes 2.5L 

outside 

.01 13.8 x.i*** 5.3*** 

84 White Center (C) 1.050 GM 

° rest. & tube 

Yes 4.0L 

outside 

10 7 8*** Kickoff 3X —-

Valve was being 

splashed on 

* See Figure 3 for key to location. 

** Inside means canister inside shed. Outside means outside shed. 

*** Uncalibrated data. Use for estimating only. 
Test 

Test 

No. 

85 

86 

89-1 

89-2 

89-3 

A4 

A5 

200 

201 

202 

203 

204 

C 

Valve Color 

and Location* 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

nnfiduration 

Restrictor 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

1.050 GM 

rest. & tube 

Spitback 

Valve 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Canister & 

Location** 

4.0L 

outside 

2.5L 

outside 

2.5L 

outside 

4.0L 

outside 

4.0L 

outside 

4.0L 

4.0L 

4.0L Mod. 

inside 

4.0L Mod. 

inside 

4.0L Mod. 

inside 

4.0L Mod. 

inside 

4.0L Mod 

inside 

GPM 

10 

10 

3 

10 

3 

10 

3 

10 

10 

10 

3 

3 

g/gal 

.02 

.02 

.08 

.02 

.01 

.04 

.04 

.03 

.05 

.05 

Gal 

Gal 

Disp. 

(in H20) 

14.3 

14.5 

16.7 

14.3 

16.5 

17.1 

17.3 

16.5 

17.1 

17.1 

Pressure 

Ave. 

(in H20) 

6.0*** 

4.0*** 

.3 

4.2 

4.2 

2.9 

2.9 

3.0 

.13 

.12 

Peak 

8.5*** 

8.6*** 

6.6 

8.3 

8.3 

8.5 

8.2 

8.5 

5.7 

5.9 

Comments 

Valve moved to 

stop interference 

Liguid seal did 

not form 

i — , 

1 

No seal 

High fill amount 

due to tank 

misalignment 

High fill amount 

due to tank 

misalignment 
Test 

Test 

No. 

Configuration 

Valve Color 

and Location* Restrictor 

Gal 

Gal 

GPM g/gal Disp 

Spitback Canister & 

Valve Location** 

Pressure 

Ave. Peak 

(in H20) (in H20) 

Comments 

205 White Rear (B) 1.050 GM 

rest. & tube 

300 White Rear (B) 1.050 GM 

rest. & tube 

301 White Rear (B) 1.050 GM 

rest. & tube 

302 White Rear (B) 1.050 GM 

rest. & tube 

303 White Rear (B) 1-050 GM 

rest. & tube 

304 White Rear (B) 1.050 GM 

rest. & tube 

305 White Rear (B) 1.050 GM 

rest _ tube 

87 White Rear (B) 1.000 

modified 

rest, with 

GM tube 

90 White Rear (B) 1.000 

modified 

rest, with a 

lip. & GM tube 

yes 4.0L Mod. 3 .05 17.0 

inside 

.13 5.9 

91-3 Blue Rear (B) 1.000 

modified rest, 

with lip. and 

GM tube 

yes 4.0L Mod. 10 

Yes 4.0L Mod. 10 

Yes 4.0L Mod. 10 

) 

Yes 4.0L Mod. 3 

Yes 4-0L Mod. 3 

Yes 4.0L Mod. 3 

yes 2.5L 3 

Yes 2.5L 

outside 

Yes 2.5L 

outside 

16.1 

16.1 

16.1 

17.2 

17.3 

17.2 

.07 13.6 6.5 

No emissions 

taken 

No emissions 

taken 

No emissions 

taken 

No emissions 

taken 

No emissions 

taken 

No emissions 

taken 

No seal 

4.0 gals in tank 

at start. 

No seal formed 

using blue valve. 

I 
Test 

Test 

No._ 

91-4 

93 

91-2 

101 

112 

113 

97-1 

97-2 

102 

103 

92 

B2 

C 

Valve Color 

and Location* 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

White Rear (B) 

i-infi miration 

' si 

Restrictor 

1.000 

modified rest. 

with lip. and 

GM tube 

1.000 

rest, tube 

1.000 

modified rest, 

with a lipNo tube. 

.99 rest, tube 

with a lip 

.99 rest, tube 

45° 

.99 rest, tube 

45° 

.950 plug 

no tube 

.950 plug 

no tube 

.95 plug 

no tube 

.95 plug 

no tube 

.95 plug with 

GM tube 

.95 rest, 

no tube 

»itback 

Valve 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Canister & 

Location** 

2.5L 

outside 

2.5L 

outside 

2.5L 

outside 

4.0L 

outside 

4.0L 

outside 

4.0L 

outside 

2.5L 

outside 

2.5L 

outside 

4.0L 

outside 

4.0L 

outside 

2.5L 

outside 

2.5L 

GPM 

3 

3 

3 

3 

3 

10 

3 

10 

3 

10 

3 

10 

g/gal 

.07 

.08 

.07 

.01 

.06 

.015 

.06 

.04 

.05 

.01 

Gal 

Gal 

Disp. 

(in H20) 

17.1 

16.8 

16.7 

15.5 

17.2 

16.4 

16.9 

14.8 

17.1 

15.3 

Pressure 

Ave. 

(in H20) 

.3 

.35 

.4 

4.2 

.28 

3.0 

.30 

4.7 

.3 

4.0 

Peak 

3.9 

6.2 

5.9 

7.9 

5.5 

6.7 

6.7 

6.5 

4.9 

7.5 

. 

Comments 

No seal 

No seal 

i 

i 

Premature shutoff 

at 3 gal & 13.2 gal 

Repeated once 
Test 

Test 

No. Configuration 

Gal 

Gal 

GPM g/gal Disp. Pressure 

Valve Color 

and Location* Restrictor 

Spitback Canister & 

Valve Location** 

Ave. Peak 

(in H20) (in H20) 

Comments 

B3 White Rear (B) 

CI White Rear (B) 

95-2 White Rear (B) 

96 White Rear (B) 

.95 rest, 

no tube 

.95 rest, 

no tube 

.930 

rest, tube 

.930 

rest. tube 

Yes 2.5L 

Yes 2.5L 

Yes 

Yes 

104 White Rear (B) .93 rest, tube Yes 

105 White Rear (B) .93 rest, tube Yes 

Al White Rear (B) 

A2 White Rear (B) 

110 White Rear (B) 

111 White Rear (B) 

.925 restrictor Yes 

.925 rest. Yes 

.900 modified Yes 

rest, no tube 

.900 modified Yes 

rest, no tube 

106 White Rear (B) .900 rest, tube Yes 

108 White Rear (B) .850 modified 

rest, no tube 

Yes 

4.0L 

outside 

4.0L 

outside 

4.0L 

outside 

4.0L 

outside 

,06 16.3 5.1 

10 .01 18.5 3.9 7.5 

10 .01 15.5 3.7 6.7 

3 .06 16.9 .33 5.6 

10 .01 14.8 3.2 4.5 

10 .05 15.8 2.7 8.4 

11 1/2 RVP, Temp 

of 10% - 95° F 

2.5L 

outside 

2.5L 

outside 

4.0L 

outside 

4.0L 

outside 

4.0L 

4.0L 

10 

3 

10 

3 

3 

10 

.02 

.07 

.007 

.07 

.05 

.04 

14.6 

17.1 

14.9 

16.3 

18.1 

17 

3.2 

.3 

4.5 

.3 

.3 

4.0 

6.8 

6.8 

5.7 

7.0 

5.8 

7.7 1 Premature shutoff 

Nozzle was not in 

all the way 

i 

Ul 

I 

Prematura shutoff 

at 13.2 gal 

Repeated test and 

kicked off at 3.0 

gal 
Test 

Test 

No. 

Configuration 

Gal 

Gal 

GPM g/gal Disp Pressure 

Valve Color 

and Location* Restrictor 

Spitback Canister & 

Valve Location** 

109 Wh i„R-r(B > -BSO-l-if*- TM * u ° ^ 

rest, no tube 

98 rest, no tube 

107 White Rear (B) .800 

rest, no tube 

94 White Rear (B) .800 

rest, tube 

95-1 White Rear (B) .800 

rest, tube 

outside 

-1 *it . Pear (B, .800 modified Yes 2 5L 

outside 

9 8 -2 Wfcite Hear ,B, -S^-dified * " ^sid e 

modified Yes 4.0L 

outside 

Yes 2.5L 

outside 

Yes 2.5L 

outside 

10 

10 

Ave. Peak 

(in H20) (in H20) 

3 .05 17.1 

3 .059 17.2 -29 5.3 

10 .02. 15.1 3.0 7.0 

3 .06 19.8 .28 5.0 

4.0 

,30 6.1 

Comments 

Kickoff at .6 and 

1.6 gal 

Kickoff 3X 

i 

6484W