P.1 

OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

175) IV-C-142 

Docket Number: 

A-87-11 

Printed 11/13/2008 7:21:00 AM Sheet 175 of 232 
P.2 

? A \ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

DEC \ 4 1988 

Mr. James E. Pasek, Manager 

Automotive Emission Control 

Environmental Activities Staff 

General Motors Corporation 

General Motors Technical Center 

30400 Mound Road 

Warren, MI 48090-9015 

Dear Mr. Pasek: 

This is in reply to your letter of October 25, 1988 

concerning the GM evaluation of the EPA "simplified" refueling 

control concept. Your letter supplied some additional data on 

the evaluation of the GM hardware, and raised some questions 

which I would like to follow up on. 

Your letter restated the performance problems which GM has 

experienced with its version of the EPA system concept. These 

problems are the same items raised in your original briefing, 

which we have indicated are not characteristic of the EPA 

system. The supplemental information you provided has allowed 

us to better understand some of the difficulties you 

experienced, but not all. For example, it is easier to 

understand why you experienced higher emissions for partial 

fills from 95 to 100 percent of tank capacity when we know that 

you used six "click-offs" for each test. This, of course, is 

an unrealistic condition, but it explains v/hy you would get 

higher emissions. It is remarkable that your data indicates 

that a very high level of control is being realized even under 

such extreme conditions. 

Similarly, you used a "fill quality" test which employed 7 

automatic shutoffs before completion. Again, this is an 

unrealistic condition, and it is possible that you were simply 

overfilling the tank through the use of multiple repeated 

click-offs. We would also appreciate an explanation of an 

apparent inconsistency in your data. The partial fill tests 

indicated that no spitback events occurred in the three tests 

which proceeded to a full tank, while the fill quality test 

indicated some spitback on almost all tests. Please explain 

these different results. I should also point out that most of 
P.3 

the comparative fill quality data you provided for a stock fuel 

system were collected using only 3 automatic shutoffs, which 

you characterize as a "customer fills" procedure. We do not 

believe that results from these two different tests should be 

compared. Our own experience has shown the refueling control 

system to be as good or better than the stock system in normal 

fill operations. For example, our testing with different 

nozzle brands showed no effect on the refueling system, but 

some limited evidence of sensitivity on the stock system. 

Concerning the question of liquid loss from the tank 

during vehicle maneuvering, you indicated that the vent valve 

had received "functional checks" before being used. Since we 

are very concerned about liquid spillage, we would appreciate a 

more detailed description of the valve testing you conducted 

and your results. We would assume it included rollover tests 

and other liquid discrimination testing if, as you say, you 

verified proper function in areas related to liquid leakage 

from the tank. However, neither the type of tests or test 

results are identified in your letter. 

The final performance issue concerns running loss vapor 

generation rates. You state that if running losses are to be 

controlled, tank pressurization is probably essential. We are 

not convinced that this is the case. For example, the 

evaluation of an unpressurized fuel tank done by Ford indicated 

that there was less than a 10 percent difference in vapor 

generation rates once fuel RVP was controlled to 9 psi. Such 

differences should be of relatively small effect on well 

designed purge systems. Even a factor of two difference, such 

as you claim to have found under extreme conditions, does not 

appear to be excessive given the rarity of the conditions 

involved. We would think that you would find the safety issues 

involved in a move to high pressure fuel tanks to be at least 

as significant as those associated with the adoption of 

refueling controls. 

Your letter indicates that it is also to be taken as GM's 

response to our July 11, 1988 request for copies of 19 specific 

GM Uniform Test Specifications (GMUTS) related to testing of 

fuel and evaporative systems. We do not find your letter 

responsive to our request. As stated in our July 11 letter, we 

had been told by your staff that the copies requested had been 

assembled, but you had advised us that GM had decided to 

withhold the documents from EPA. The small amount of 

information in your present letter does not substitute for the 

GMUTS which we requested, and I would once again like to 

reiterate the request for these documents. 
P.4 

Lastly, you asked for copies of more recent data we have 

collected on our EPA hardware, indicating that you had not seen 

any data other than the original 13 tests released in April and 

May. Enclosed are copies of all currently available data for 

your review. Some of this data has been available in the 

docket for some time, some of it has only recently completed 

review. We are also enclosing a pressure trace for a typical 

fill event. 

Thank you for your responses to our earlier questions. We 

look forward to your cooperation in supplying the additional 

information needed. If you have any questions, please feel 

free to contact me. 

Sincerely, 

Chejster J. France, Chief 

Standards development and Support Branch 

Enclosures 

cc: Mr. Scott York, NHTSA 

Mr. Ralph Hitchcock, NHTSA 

Mr. Albert Warner, DOC 

Docket A-87-11 

6601W 
P.5 

Jjl '/3 -6' ^ 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OP _ 

AIR AND RADIATION 

AUG | 6 I988 

MEMORANDUM 

SUBJECT: 

FROM: 

TO: 

THRU: 

Passive Onboard Refueling Control System Testing -

Results Collected To Date 

A 

Peter Hutchins, Mechanical Engineer VjX^ 

Standards Development and Support Branch 

Charles L. Gray, Jr., Director 

Emission Control Technology Division 

John F. Anderson, Senior Project Manager 

Standards Development and S/pportj^Branch 

Chester J. France, Chief 

Standards Development an^Supj 

n>- /f^-in^c* 

In a memo dated June 14, 1988, SDSB requested that 

specified testing be performed by TEB using the "Passive 

Onboard Refueling Control System." The requested testing was 

subdivided into five phases. Phase 2, testing has been 

completed. One test remains to be performed in phase 1 and in 

phase 3. Phase 4 and 5 testing is being initiated and should 

be completed by August 19th. 

The results of the tests, together with brief descriptions 

of the test phases are provided in the following attachments. 

Attachments 

0386X 
P.6 

Attachment 1 

Phase 1. To determine the effects of fuel RVP on the control 

of refueling emissions' by the system using a test 

matrix of four refueling rates and three fuel RVPs. 

A four liter canister was employed to assure 

adequate storage capacity. The test results are 

shown below. 

Phase 1 Test Results 

Fueling 

Rate 

(gal/min) 

3 

4 

4 

5 

5 

5 

5 

5 

10 

10 

10 

10 

10 

Dispensed 

Volume 

(gal) 

13.9 

13.7 

14.2 

13.8 

13.3 

14.6 

14.2 

13.9 

12.7 

13.2 

13.1 

13.9 

13.9 

Measured 

RVP 

(psi) 

8.9 

9.0 

8.9 

8.9 

9.2 

10.5 

11.6 

11.3 

9.0 

. 9.2 

9.0 

10.5 

11.5 

Measured 

Refueling Emission's 

(gram/gal) 

0.02 

0.02 

0.01 

0.02 

0.01 

0.02 

0.02 

0.06 

0.02 

0.02 

0.02 

0.01 

0.00 
P.7 

Attachment 2 

Phase 2. To determine the effect of unplugging the 0.050 inch 

orifice in the sending unit. Vapors from the orifice 

routed to the canister. 

A four liter canister was employed in phase 2 

testing. The results of this testing are shown below. 

Phase 2 Test Results 

Fueling 

Rate 

(gal/min) 

5 

10 

Dispensed 

Volume 

(gal) 

13.6 

13.7 

Measured 

RVP 

(psi) 

9.3 

9.3 

Measured 

Refueling Emissions 

(gram/gal) 

0.01 

0.01 
P.8 

Attachment 3 

Phase 3. To determine the effect of tank positioning during 

refueling on system ' performance. Four tank 

positions, to simulate refueling on 10° angle, are 

investigated. The positions are as follows: 

Tank Position A: 

Tank Position B: 

Tank Position C: 

Tank Position D: 

"Vehicle" facing up grade 

"Vehicle" across grade, right 

side high 

"Vehicle" facing down grade 

"Vehicle" across grade, left 

side high (fuel filler on left 

side of "vehicle"). 

As in the previous test phases, a 4 liter canister 

was employed. The test results are shown below. 

Phase 3 Test Results 

Tank 

Position 

A 

A 

A 

B 

C 

C 

D 

D 

Fueling 

Rate 

(gal/min) 

5 

5 

5 

5 

5 

10 

5 

10 

Dispensed 

Volume 

(gal) 

9.1 

7.8 

8.0 

11.3 

17.5 

17.2 

15.4 

14.5 

Measured 

RVP 

(psi) 

8.9 

9.0 

9.0 

- 9.0 

9.0 

9.0 

9.0 

9.0 

Measured 

Refueling Emissions 

(gram/gal) 

0.01 

0.05 

0.02 

0.02 

0.00 

0.00 

0.01 

0.01 

0386X 
P.9 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

DEC f 3 1988 

MEMORANDUM 

SUBJECT: Results From Phases 4 and 5 of Test Plan for Passive 

Onboard Refueling Control System 

FROM: 

To: 

F. Peter Hutchinsy Mechanical Engineer 

Standards Development and Support Branch 

Charles L. Gray, Jr., Director 

Emission Control Technology Division 

This memo is a follow up on the memo dated August 16, 

1988. It summarizes the results of Phase 4 and Phase 5 testing 

performed by E&D in response to a June 14, 1988 memo from SDSB. 

Phase 4 

The objective of this test phase was to evaluate the fuel 

tank fill characteristics of a stock tank and of the EPA 

passive- onboard refueling tank under dissimilar dispensed 

fuel/tank temperatures. The desired dispensed fuel temperature 

and 10 percent tank fuel temperature were 70°F and 100°F 

respectively. Fuel with an RVP of 11 1/2 psi was required to 

be used. The specified fuel dispensing rate was 10 gpm. An 

OPW H A nozzle was used in phase 4 testing. Fueling was 

requested to be performed from 10 percent tank volume to at 

least 95 percent tank volume. 

For the stock tank test, a stock tank, fuel filler pipe 

assembly and tank sending unit were used (GM components). The 

stock sending unit incorporated the vapor pickup and orifice. 

A stock 1.5 liter canister was used. For test purposes the 

stock canister was connected to the fuel tank by approximately 

11 feet of 5/16" diameter tubing. 
P.10 

-2-

In the case of the passive onboard system, the EPA 

modified tank, filler pipe assembly and "blue" vent valve were 

used. A 4 liter canister was connected to the vent valve by 

approximately 2 1/2 feet of 5/8" diameter tubing. The canister 

to purge control valve line was simulated by approximately 11 

feet of 5/16" diameter tubing connected to the 5/8" tubing by a 

T at the canister. The "engine" end of the 5/16" tubing was 

plugged to simulate a closed purge control valve as would exist 

during fueling. 

Phase 4 test results are shown in Table 1. Both tanks 

fueled successfully during these two tests. 

Phase 5 

Phase 5 of the testing requested to be performed by E & D 

focused on the fueling performance of three commercial fuel 

nozzles. Information collected from nozzle manufacturers by 

EPA over approximately the last year indicates that the nozzles 

selected for testing represent between 80 to 85 percent of the 

new nozzle market. The nozzles to be evaluated were an OPW 

11A, an Emco-Wheaton A2000 and a Husky 1+X . The performance 

of the OPW H A nozzle was investigated with both the EPA simple 

onboard system and a stock GM system from which the EPA system 

had been derived. Premature shut-offs, final shut-off and spit 

back were to be evaluated at flow rates of 5 gpm and 10 gpm 

using the EPA passive onboard system. Refueling emission 

measurements were not to be performed. 

All fueling operations were initiated with 1.5 gallons 

(approximately 10 percent) of fuel in the tank. The reported 

results are summarized in Table 2. For all three nozzles, 

fueling into the simple onboard system were performed without 

either premature shut-offs, spitback, or spillage of fuel. 

Three of the four tests performed on the stock system incurred 

either a premature shut-off or a spill. 

Attachments: Tables 1 and 2 

6431W 
Table 1 

Phase 4. Dissimilar Temperatures 

Configuration 

Fuel RVP Tank 

(psi) Temp.(°F) 

Dispensed 

Fuel Temp(°F) 

Volume 

Dispensed(gal) Comments 

Stock 11.5 

Passive System 11.5 

100.4 

102.0 

71.4 

70.0 

16.2 

13.9 

No premature 

shut-off, 

spitback, or spill 

No premature 

shut-off, 

spitback, or spill 
Table 2 

Phase 5. Nozzle Characteristics 

Nozzle/ Fueling Rate RVP 

Date Tank (gpm) (psi) 

Volume Temperatures 

Dispensed (gal) Tank; Fuel(°F) Comments 

8-18-88 OPW-llA/Mod. 5.0 

8-18-88 OPW-llA/Mod. 5.0 

8-18-88 OPW-llA/Mod. 10.0 

8-23-88 OPW-llA/Mod. 10.0 

8-24-88 OPW-llA/Mod. 10.0 

8-30-88 OPW-llA/Stock 5.0 

8-30-88 OPW-llA/Stock 5.0 

8-31-88 OPW-llA/Stock 10.0 

8-31-88 OPW-llA/Stock 10.0 

9.0 

8.8 

8.8 

8.9 

8.9 

9.0 

9.0 

9.0 

9.0 

14.9 

14.5 

13.8 

13.8 

14.5 

15.8 

15.3 

15.3 

15.2 

81.5; 81.1 No premature shut-off. No spill. 

80.5; 80.2 No premature shut-off. No spill. 

80.0; 79.9 No premature shut-off. No spill. 

80.2; 82.2 No premature shut-off. No spill. 

80.2; 81.7 No premature shut-off. No spill. 

80.5; 79.3 Premature shut-off @5.4 gal. No spill 

81.0; 81.0 No premature shut-off. No spill. 

81.5; 82.0 Premature shut-off @ 0.1 gal. (nozzle 

position). No spill. 

81.5; 79.7 No premature shut-off. 1/2 cup spill. 

8-25-88 Emco-Wheaton 

A2000/Mod. 

8-25-88 Emco-Wheaton 

A2000/Mod. 

8-26-88 Emco-Wheaton 

A2000/Mod. 

8-26-88 Emco-Wheaton 

A2000/Mod. 

5.0 

5.0 

10.0 

10.0 

9.1 

8.9 

8.9 

8.9 

15.6 

14.6 

14.6 

14.3 

80.5; 80.1 

81.5; 79.9 

81.0; 80.4 

81.9; 81.2 

No premature shut-off. No spill. 

No premature shut-off. No spill, 

No premature shut-off. No spill. 

No premature shut-off. No spill, 

9-7-88 

9-7-88 

9-7-88 

Husky 

Mod. 

Husky 

Mod. 

Husky 

Mod. 

1+X/ 

1+X/ 

1+X/ 

5.0 

5.0 

10.0 

9.0 

9.0 

9.0 

14.1 

15.0 

14.7 

81.3; 81.9 No premature shut-off. No spill. 

81.0; 80.4 No premature shut-off. No spill, 

81.0; 81.3 No premature shut-off. No spill, 
P.13 

^

t 0 STA> 

\ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

USE,-

ANN ARBOR. MICHIGAN 48105 

OFFICE OF 

AIR AND RADIATION 

DEC I 3 -p q 

MEMORANDUM 

SUBJECT: Refueling Emission - Partial Fueling 

yi 

FROM: Peter Hutchins 

Standards Development and Support Branch 

TO: The Record 

The results of nine partial fuelings and one full fueling 

are shown in Table 1. These tests were performed by EPA to 

evaluate refueling emissions during partial fuelings of the EPA 

passive refueling emission control system. 

The EPA passive refueling emission control system used in 

this data collection consisted of a modified GM fuel tank and 

fuel filler, a "blue" vent valve, and a 4 liter canister 

connected to the vent valve be approximately 3 feet of 5/8" ID 

tubing. The RVP of the fuel used in this project was 

approximately 9 psi (measured values are shown in Table 1). 

All fueling operations were performed with the fueling cart 

dispensing flow rate set at 10 gpm and with the tank and 

dispensed fuel temperatures within NPRM limits (measured 

temperatures are given in Table 1). Prior to each refueling 

emission measurement, the canister was purged for approximately 

1 1/2 hours at a flow rate of 1 cfm. Three refueling emission 

measurements were performed for each of three partial fueling 

ranges. The partial fueling ranges were; a) from approximately 

10% fuel tank volume to approximately 1/2 fuel tank volume, b) 

from approximately 1/2 fuel tank volume to full and c) from 

approximately 90% fuel tank volume to full. 

The averages of the partial refueling emission 

measurements are as fellows: 

a) 10% to 1/2 tank volume ; 0.07 gram/gal. 

b) 1/2 tank volume to full; 0.01 gram/gal. 

c) 90% tank volume to full; 0.12 gram/gal. 
P.14 

-2-

The highest average refueling emissions rate (gram/gallon) 

occurred during the 90 percent tank volume to full tank 

fuelings; While this refueling emission rate was higher than 

the proposed standard (0.10 g/gal) for full fuelings, the 

actual mass of hydrocarbon emitted was low and represented 95 

percent or greater control of refueling emissions. It is also 

worth noting, that fuelings in this range; i.e., from an almost 

full tank to a full tank, occur infrequently. Two of these 

test had multiple shutoff, simulating customer topping off. 

Inspection of the SHED hydrocarbon concentration strip charts 

and other data sheets showed that these shut-offs do not appear 

to have been major contributors to the refueling emissions 

measured in the SHED. Most of the emissions appear to have 

been associated with the first shutoff in each case. 

Attachment: Table 1 
Date 

9-9-88 

9-13-88 

9-14-88 

9-9-88 

9-13-88 

9-15-88 

9-12-88 

9-14-88 

9-15-88 

9-13-88 

Measured 

RVP 

(psi) 

9.05 

9.00 

8.95 

8.95 

9.00 

9.00 

8.95 

8.95 

9.05 

8.95 

Fuel Volume 

Initially in 

tank (gal) 

1.51 

1.50 

1.50 

7.51 

7.52 

7.5 

14.2 

14.2 

14.2 

1.50 

Table 

Refueling Emissions 

Fuel Volume 

Dispensed 

(gal) 

6.0 

6.01 

6.02 

8.83 

8.85 

8.9 

2.45 

2.38 

2.22 

14.51 

Nozzle 

Shut 

Off 

manual 

manual 

l,auto. 

+manual 

l,auto. 

2,auto. 

l,auto. 

3,auto. 

4,auto. 

l,auto. 

l,auto. 

Tank 

Temp. 

(»F) 

79.7 

79.0 

79.7 

79.2 

79.3 

80.1 

80.0 

80.4 

79.9 

81.0 

1 

- Partial 

Dispensed 

Fuel temp 

(°F) 

81.1 

81.7 

81.3 

81.9 

81.0 

81.0 

81.7 

81.1 

81.3 

81.3 

Fueling 

Canister 

Initial 

<9> 

4152.1 

4168.2 

4159.7 

4153.0 

4163.7 

4159.8 

4177.1 

4162.6 

4157.3 

4166.9 

Weights 

Final 

( g ) 

4187.8 

4210.0 

4199.6 

4207.8 

4222.2 

4217.2 

4192.4 

4178.6 

4171.5 

4266.0 

HC Collected 

by canister 

(g) 

35.7 

41.8 

39.3 

54.8 

58.5 

57.4 

15.3 

16.0 

14.2 

99.1 

(g/gal) 

5.95 

6.97 

6.65 

6.23 

6.65 

6.45 

6.12 

6.67 

6.45 

6.83 

Refue ling 

Emissions 

(g) i 

0.31 

0.22 

0.71 

0.15 

0.00 

0.11 

0.44 

0.27 

0.13 

0.28 

g/gal) 

0.05 

0.04 

0.12 

0.02 

0.00 

0.01 

0.18 

0.11 

0.06 

0.02 

6544W 
P.16_ 

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