OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

8) IV-B-4 

Docket Number: 

A-87-11 

Printed 11/13/2008 7:20:51 AM Sheet 8 of 232 

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March 6, 1979 

Status of Ia Hufi taftfUng Loss 

Martin Reinenan, SBft 

Robert E. Maxwell, Chief, SDSB 

Two API teat vehicles, the Exxon 1978 California Pinto and tha Mobil 

1978 California Sunblrd, have been —mine * la hone* tor refWlin* 

control effectiveness. Refueling lose taiW haw ^Oso beaar conducts*? 

with an in-houso fuel tank modified for sutaergoff fill. HPA conducted 

several tests t*»ailfy that operation} of tha Aft vefcfclasv As reported 

by Exxon and Mobil, theae vehicles are capable of controlling refueling 

loss to better than 95 perecnr while still MosTing feat-It?* «kftfwr*L» " 

emission standards^ Since «Ke EPA test tkwaStaf suypuig" "eW'aerHer^! ' -» 

findings by Exxsv and Mobil, they will not; be> reported further, lather, 

this memo presents and discusses test data on the subjects of test 

pfiniluie eanrlTlvity, refualiag lose ceofrol feeoifcllltr v*tb^* production evaporative canister, and aiihnsvgiid fill fsosfMl'lgyv '; 

Procedure Sensitivity 

Tha measured refueling/exhaust emission interaction la known to be a 

funotiav of iwii l variables, one of th* mom* important bwlag? the test 

procedure^ A cosjparlsoti of eha tesi* procedure* used" by4 E«»1» and Mobil 

to Measure raruaixnglosses to useful for Observing interaction effects. 

The basic difference between the Exxon- and Mobil test procedures Is the 

location of the refueling operation ia" th* sequence- of events which is' 

currently required fox exhaust and evaporative- eelsslon aeasurenent. 

Exxon locates the refueling test lmsediately before the FTP, while Mobil 

locates the refueling test on the day before the FTP. The Mobil test 

procedure follows the refueling operation with a preconditioning LA-4 

and thus, tho Mobil test sequence does not peradt an asaeaswenfr of cold 

stave- anissions laaediately following tha refueling operation. Thia 

latter condition represents a sore severe (although impractical for a 

real world simulation) test condition. 

Experimenti 

The Mobil Sunbird was tested) using the following sequence: of 

events: 

SDSB: M. Reineman, wgw, 2565 Plymouth Rd., Ext. 227, 3-9-79 
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ENVIRONMENTAL PROTECTION 

SEP - 2 1988 

GfciSirs"*"-.. DOCKET 
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-"* Saturate canlstsr with gasoline vapor. Precondition 

vehicle with a series of LA-4a and one-hour hot soaks. 

Day 2 - Diurnal heat build (fuel tank drained and filled to 

40 percent without loading the refueling canister). FTP 

with emission measurements. Condition vehicle with LA-4s 

and one-hour hot soaks. 

Day 3 - Same aa Day 2. 

Day 4': - Same, as Day 2. 

Day 5 - Diurnal SHED test (fuel tank drained and filled to 

40 percent without loading canister). Refuel tank (10 

percent to 100 percent capacity refueling). FTP with 

emissions meaaurements. Hot soak SHED teat. 

Day * - Diurnal hast build- (fuel tank drained aaaV.iilUd to 

40 percent without loading- canlstsr)* JTP;.wifch emissions 

measurement. Bot soak SBFJfc tear. 

Other equipment uaed for measuring refualiag lossss included the large 

SHED with explosion-proof aixlng fans and a aodified fuel cart capable 

of delivering 8S*F fuel at a 9.3 gpm flow rata. A nitrila seal (supplied by AftCO as part of tha ATI project) mounted la the fillpipe 

prevented vapor from escaping at the noxsle/fillpipe latarfi 

This test sequence is similar to the test; procedure uaed by Mobil to 

assese the effect of refueling controla on exhaust emissions. The EPA 

procedure measures exhaust emissions on Days 2, 3, end 4 and measures 

the refueling and exhaust emissions on Day 5. Results reported on Day 

6 represent data obtained when the refueling loes test and the exhaust 

emission test sre not conducted on the same day (Mobil test method). 

Results: 

Table 1 summarises test results obtained during the week starting 

January 22nd. 

Day 2 

Jan. 23 

Table. 1 

Refueling/Emissions Interaction 

Day 3 Day 4 Day 5 Day 6 

Jan. 24 Jan. 25 Jan. 26 Jan. 27 

Mobil Baseline 

n - 10 
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.r-*'.3T- __5c r' 

HC ^M3 : 0^50 

CO 8.4 9.2 

NO* .._• 1.03 0.98 

MFC 22.4 21.0 

Evaporative Emissions (g) 

Diurnal 

Hot Soak 

0.4* 

8.6 

0.94 

21.5 

0.63 

12.0 

0.91 

22.3 

0.32 

2.17 

0.47 

8.6 

0.96 

21.0 

0.46 

3.69 

0.39 

6.4 

0.98 

0.87 

U 12 

The results from two refueling loee tests at aa iaetheraal condition of 

85*F show that refueling emissions are controlled in exceee of 98 percent. Controlled refueling emissions consistently averaged less than 

0.2 g/gal. 

Dlseusslomi 

These results show a substantial refueling/exhaust cmlsslsa Interaction 

problem on Day 3, while results on Day 6 ase similar to the data reported by Mobil. Assuming the vehicle's purge control system and the 

aleeeeVloop feedback control system arc working properly (assumptions 

which are presently begin verified):, these reaults are Indicative of the 

range of exhaust emissions which can be expected when using the same 

vehicle but different teat procedures. 

Ths results reportsd on Day 5 aro representative of results which might 

be expected when the refueling test Is conducted immediately before the 

FTP. 

2. Tests with Small Caniater 

A single refueling test was conducted using the Sunbird with a production evaporative emission control canister replacing the single large 

refueling/evaporative caniater. 

Experimentt •- • 

The production canister was purged with a vacuum pump for three hours at 

an air flow rate of approximately 20 liters/tain. The caniater was then 

installed in the vehicle and loaded with evaporative emissions from a 

diurnal heat build and a hot soak* With the fuel tank vents connected 
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to a production caniater (one to the fuel tank port and one to the 

carbureter ^ert) , the-vehicle waa refueled isotharaally at 83* from a 

condition ef 10 percent fuel tank capacity to 100- percent capacity» 

Results* 

Fuel Added SEEP EC Increased Caniater HC Increase X Controlled 

17.1 gallons 23. (Sg 45g 66 

Discussion: 

An earlier fuel fill teat with a 1978 production vehicle (no refueling 

control hardware) demonstrated that tank pressure buildup waa too high 

to permit refueling with a modified Stage II nozsle. Automatic shutoff 

occurred after approximately two gallons of fuel were added to the fuel 

tank. The particular nozzle was designed to shut off at about 25 Inches 

of water pressure. To prevent excessive pressure buildup In this test, 

the 5/8" ID vapor line in the Sunbird was teed Into the diurnal and hot 

soak ports oa the production canlstsr. 

The results of this test serve as an eatlmate of the refueling control 

effectiveness which may be obtained when a small caniater (1500 cc) 

replacea tha large canister (4350 ec). A conversation with Stu Martens 

reveeled that during a series of refueling loee experiments, GM once 

accidentally refueled e vehicle with a production caniater in the SHED 

and found that about 1/3 of the hydrocarbon mass waa retained in the 

systea. Stu didn't know the test conditions which produced this result, 

but he assumed the SAE J1045 procedure for measuring refueling emissions 

was probably used. If so, the teet conditlone were: fuel tank liquid 

temperature — 95*; dispensed fuel temperature — 82*; fuel quantity in 

the tank at atart of test — 25 percent of tank volume; and fill rate — 

8 gpm. These conditions produced uncontrolled emission factors of about 

5 g/gal. of dispensed fuel, which compared with API uncontrolled emission factors that averaged about 4.5 g/gal. This implies that the mass 

of hydrocarbon vapor to be adsorbed by the control systea was about the 

same for the GM and EPA tests. Additional work would be required to 

resolve the difference In control efficiencies measured by GM and EPA. 

3. Submerged Fill Teat 

A 8ingle refueling loss test was conducted with a modified fuel tank in 

the large SHED to assess the effectiveness of the submerged fill technique for obtaining a seal at the fillplpe/nozzle Interface. 

Experiment: 

A 27-gallon Ford fuel tank was modified for submerged fill by the 

fabricating an extended fillpipe, adding a fuel vent line from the tank 

to the Mobil carbon caniater, and installing a plexiglass observation 
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window In tms) fuel tank. The fuel tank fillpipe wee extended to about 

one Inch e#uttsf bottom et the tank, and exceeded out of the fuel tank 

approximately IS inches, or about 10 inches above the top of the tank, 

fuel vapors were vented to the Mobil canlstsr through a 1/2" JD^plpe 

teed into two 3/6** 00 lines. 2.7 gallons of fuel were added to coves 

the tip of the fillpipe* Fuel tank temperature at the start of the 

refueling was 76* and the dispensed fuel temperature waa 85*. 19.7 

gallons of fuel were added at a fill rate of 9.3 gallons/min. before 

automatic shutoff occurred* 

Results: 

The following values were measured: 

SHED HC Increase - O.Slg 

Canister HC Increase - 67*g 

The maximum recorded fill pressure was approximately 1.6 inches of 

water. 

Discussion: 

Although the loss to the SHED is small and compares very will with 

looses from teets using the ARCO nltrile seal or the Exxon trl-clover 

fittings as methods of preventing vapor escape, theee results do not 

permit a calculation of control effectiveness due to the large quanitity 

of vapor which condensed In the llnee to the canister. It would be 

neceasary to heat the vapor linea to permit an accurate determination of 

the total vapors vented to the canister. 

A second submerged fill test to determine fill capacity resulted In a 

larger quantity (22.9 gallons) of fuel being added before automatic 

shutoff occurred. 

Mobil observed some condensation In the vapor vent line during their 

refueling tests. To prevent excessive condensation, Mobil routed the 

vapor vent line eloeer to the exhaust pipe. It appeara that additional 

work ia necessary to resolve the problem of vapor condensation. 

In summary, ln-house refueling loss tests have demonstrated the following: 

1. The API vehicles perform as claimed by Exxon and Mobil. 

Significant amounts of condensed vapor were observed in the 

lines between the fuel tank and caniater. 
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2. Tee effectiveness of the Mobil onboard control system is e 

fmmteiam of the teat procedure uaed to assess the exhaust 

emissions Interaction. 

/ 

3. A algnlfleant level of refueling loss control is achievable 

using s refueling loss control system with a standard evaporative emiaaiona caniater. 

4. Submerged fill ia an effective method of obtaining a vapor 

aeal at the fillplpe/nozzle Interface.