P.1 

OAR Box 1147 

Prepped by Ollie Stewart 

Document Number: 

194) IV-E-68 

Docket Number: 

A-87-11 

Printed 4/22/2008 2:42:57 PM Sheet 194 of 242 
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

SEP 2 | IQfiP OFFICE OF 

AIR AND RADIATION 

MEMORANDUM 

SUBJECT: Meeting with Toyota Motor Corporation 

FROM: Donald E. Zinger, Assistant Director <-\J. £ . WwiA-^1 

Office of Mobile Sources " f 

TO: Docket A-87-11 

On September 12, 1988 representatives of Toyota Motor 

Corporation met with Don Clay, Acting Assistant Administrator, 

Office of Air and Radiation. They presented and discussed 

Toyota's views on EPA's proposal to require onboard, refueling 

emission controls. Attached to this memo is a copy of their 

presentation materials. 

Representing Toyota were Messrs K. Matsumoto, R. Ito, 

T. Iida and R. Penna, counsel. In addition to Mr. Clay, 

P. Anderson and D. Zinger of EPA were in attendance. 

Attachments 

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2. ONBOARD VAPOR RECOVERY 

2-1 Review of the Toyota's position 

We have been commenting on the vapor recovery control as often as we 

got a chance to comment. Today, it is the first ocasion to meet 

you, Mr. Clay. So, I would like to present you the summary of our 

position on this matter. 

First, We support the goal of the clean air act, and have been 

focusing our attention on the improvement of air quality as is one 

of our major objectives in designining our vehicles. However, 

concerning refueling emission control, we disagree with EPA's 

proposal to require onboard systems. 

If you consider refueling vapor recovery control is innevitable, we 

strongly recommend Stage II on service station, because it is 

suitable measure for the regional problem of ozone non-attainment, 

and quick effectiveness. 

In addtion to the US stage II implementation in California, 

Washington D.C, New Jersey and Missouri, stage II trial started in 

Europe. 

You may have already be informed, but I will show you some photos 

which demonstrate the trial of stage II service station in 

Goetheborg, Sweden. 

Stage II is favorably accepted by Swedish people because of nongasoline-odor. And we heard it is succeeded in commercial base with 

no problem. 

On the other hand, the onboard system involves a lot of problems 

such as packageability of large canister, increase of safety risk 

due to modification of fuel system, and the adverse effect on 

tailpipe emission caused by the higher rate of vapor purge. The 

system component cost is not so cheap as EPA's estimate. 

Finally, if the onboard control were adopted in spite of 

abovementioned disadvantages, the implementation schedule will be 

impractical because of its insufficient leadtime. 

We need minimum four years lead time with a moderate phase-in for 

three years over four model years and some exemption for certain 

special models, in order to establish technology, to plan and 

design for body construction, or to prepare testing facility and 

tooling. 

We have commented these items in detail at the public hearing, on 

written comments, and at SAE Government Industry meeting. I would 

like to focus today's discussion on two major concerns: EPA's 

simplified onboard system and topics at EPA workshop. 
P.4 

2-2. Comments on EPA's prototype onboard system 

Mr. Clay, I would like you to keep in mind that we have been 

making a faithful effort to comply with EPA's proposed 

regulation. However, this will be a very difficult task. While 

Toyota continues to oppose onboard controls, our intention for 

this meeting is to point out some technical defects with your 

system that should be improved. In fact, we have adopted certain 

of EPA's ideas, such as liquid seal, into our prototype. 

Through this discussion I hope you will understand the reason 

why our system can be neither simple nor cheap. 

We have already submitted a written comment on EPA's prototype 

of an onboard system, and today we would like to explain some 

problems from the viewpoint of the fuel system designer. 
P.5 

ONBOARD SYSTEM DEVELOPED 

B ENLARGE C SHORTEN BY EPA 

FROV /^ N VAPOR LINE 

D 2.5fl CANISTER 

BREATHER 

PIPE 

ONBOARD SYSTEM 

3/8"DIA 

8'LONG 

FUEL INLET 

CURRENT SYSTEM 

*x-J=/— 

EVAP. 1C 

CANISTER 

ONBOARD SYSTEM DEVELOPED BY EPA 

This' figure illustrates EPA's prototype. 

It is anticipated this system will cause overfilling cf fuel or will 

cause spillage through vapor control valve (float rol.lcver valve 

FROV). 
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OVERFILLING 

LARGE FROV 

EPA TYPE MODIFICATION 

EVAP. 

CANISTER 

ROLLOVER VALVE 

CHECK 

VALVE 

4 CURRENT SYSTEM 

OVJiRFlXLINti..' 

This figure shows the full-fi Lied condition with a typical fuel tank 

and an overfilled situation with the same type of tank modified 

with EPA's prototype. To keep the same full-fill level, the float 

rollover valve of the EPA modified system was relocated. Such 

modification will result in reduction cf crashworthencss. 

We, however, want to discuss over-filling here. In the current 

system, the lower port of breather pipe will be choked when fuel is 

filled up and pressure in the air space rises. Then the fluid level 

in the filler inlet rises te let tho nozzle automatically shut-off. 

In EPA's system, the large float valve may easily release air in the 

air space, which means overfilling, before shutting off the nozzle. 
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OVERFILL PREVENTION 

HEAVY FLOAT 

SPRING 

BALL FLOAT 

H233 

EPA TYPE MODIFICATION 

EVAP. 

CANISTER 

VAPOR VENTVALVE 

TOYOTA'S PROTOTYPE 

OVERFILL PREVENTION 

This figure illustrates the construction of the float rollover valve 

which is similar to the EPA's system and the overfill-limiter (cutoff valve) which is applied to our prototype system. 

If we were to adopt the float rollover valve similar to the EPA's, 

the following failure modes are anticipated. 

i)due to its large diameter, inclination of the valve may loose 

sealing capability; 

ii)due to inaccuracy or deterioration of the spring, sealing 

capability may be reduced; 

iii)due to complexity of the valve, any other problems may be caused. 

Toyota's prototype system adopts a reliable ball-float for overfillprevention. And it is applied with normal dosed type vapor vent 

valve which opens only during refueling condition. Our prototype 

also contains a rollover valve as a part of the evaporative vapor 

line, however, it should be noted that the location of the rollover 

valve is different from that of the cut-off valve/vapor vent valve 

assembly. This will be discussed in the next figure. 
P.8 

STATIC SPILLAGE 

VAPOR VENT VALVE 

CLOSED 

CHECK VALVE 

TOYOTA'S PROTOTYPE 

PRESSURIZED 

EPA TYPE MODIFICATION 

STATIC SPILLAGE 

This figure shows static spillage in relation to the location of 

rollover valve. 

In the fuel tank, air space*- of 10 to 15 percent of nominal tank 

capacity i.s needed for the following purposes: 

i)to absorb increased volume of fuel associated with the heat of 

tank; 

ii)to assure anti-spillage performance; 

iii)to absorb loss of tank volume which may be caused by deformation 

at a crash. 

In accordance with the second purpose, our prototype set the 

rollover valve in the air space area where it is not under the fuel 

surface until some severe angle of vehicle inclination. 

On the contrary, EPA's system determines the full -filled level by 

the float rollover valve itself, therefore the valve will easily be 

under fuel when the vehicle is on a relatively gentle angle slope. 

Under the condition with diurnal heat-built, the EPA system will be 

pressurized and sealing performance with EPA's large valve cannot be 

expected. Liquid fuel will easyly pass through the vapor line to 

the canister because there is nothing to restrict the flow in the 

line, then it will flow out the canister or at least it damages the 

canister working capacity. 
P.9 

DYNAMIC SPILLAGE 

OPEN 

TO CANISTER 

EPA TYPE MODIFICATION 

DYNAMIC SPILLAGE 

This figure demonstrates dynamic spillage. 

Under fuel swinging condition in the tank due to rapid 

acceleration/deceleration, cornering or driving on a slope, fuel 

spillage to the vapor line and canister may be caused with EPA's 

system. This is because EPA's system adopts a normally open type 

valve which does not close unless the float is pushed up by the 

fuel. 
P.10 

REQUIREMENT FOR FUEL TANK 

1. FUEL FILLABILITY 

2. RELIABLE AUTO SHUT-OFF OF NOZZLE 

3. CONTROL EXCESSIVE VAPOR 

GENERATION 

4. PREVENT OVERPRESSURIZATION 

5. PREVENT STATIC AND DYNAMIC 

SPILLAGE 

6. PREVENT FUEL LEAKAGE AFTER 

CRASH TESTteg. FMVSS301) OR 

OTHER CRASH EVENTS 

REQUIREMENT FOR FUEL TANK 

This figure summarizes the requirements for fuel tank design. 

The fuel tank of the vehicle is not a simple container but, by 

considering real world conditions, it is designed to locate all the 

parts effectively in order to satisfy all the requirements 

mentioned here. 

The fuel tank of EPA's system seems to be designed for a very 

limited intention. Such a simple modification and/or reduction of 

parts will damage the required function of fuel tank. This is a 

very dangerous modification. 

There are other items such as difficulty in vapor line routing, high 

vapor flow resistance with fuel fillability, insufficient canister 

capacity (some manufacturer may be happy if EPA accept such small 

canister for 16 gallon fuel tank), adverse effect on tailpipe 

emissions, and reduction of crashwortheness, which will make the 

establishment of an onboard system difficult.. This system, however, 

should not come into existence because of its basic problem as a 

fuel tank and the overall fuel system. 
ONBOARD VAPOR RECOVERY SYSTEM 

p.11 

PURGE CONTROL VALVE REFUEUNG CAMSTER 6-8L 

VAPOR VENT VAIVE 

W/VAPOR UQUID SEPARATER 

WATER SEPARATER 

UQUID SEAL 

EVAP. CAMSTER 1-1.8L VALVE OVERFILL LIMITER 

TOYOTA'S PROTOTYPE 

UQUID SEAL 

w/FLAPPER 

REFUEUNG 

CANISTER 

VAPOR VENT VALVE 

w/OVERFILL UMITER 

5/8" VAPOR 

UNE //PURGE UNE 

/ EVAP. LINE 

TO ENGINE 
P.12 

2-3. Concerning discussion after June 30 workshop 

We can imagine the existence of running loss, but the actual state 

of it is still under study. We reviewed EPA's available data 

regarding this condition, however, it is not clear enough for us to 

make judgements. 

Nevertheless, we believe the best way to reduce any running loss is 

to control the volatility of the fuel during summer time. This 

action should be taken as quickly as possible. 

Anyway, we will continue to study how much vapor are generated, 

under what conditions, and how to reduce it. 

We heard a strange opinion that if running loss control will be 

enforced the canister size shall become large enough to control 

refueling vapor recovery. We believe this is caused by 

misunderstanding of the nature of the refueling canister and the 

difference between evaporative control including running loss and 

refueling vapor recovery. 

In evaporative canister, fairly high flow resistance will be 

permitted because it captures pressurized vapor from fuel tank. 

And so, it is possible to add supplementary canister in series with 

original one to enlarge the working capacity when packageability is 

in problem. However, before EPA considers requiring additional 

componrents, we believe more thorough study of the running loss 

issue is necessary. 

On the contrary, refueling canister shall be limitted to be very low 

flow resistance to keep fuel fillability. To devide the canister 

into series connection cannot be accepted due to its higher flow 

resistance, and to devide it into pararrel connection cannot be 

accepted due to its unbalance on loading vapor and purging 

performance. 

We shall consider the difficulty of onboard vapor recovery 

countermeasures on not only size and installation of the canister 

but the function of whole fuel tank system and whole emission 

control system. 
ONBOARD SYSTEM DEVELOPED 

B ENLARGE C SHORTEN BY EPA 

FROV S~\ VAPOR LINE 

mt\ SPITBACK VALVE 

ONBOARD SYSTEM 

D 2.50. CANISTER 

BREATHER 

PIPE FROV 

3/8"DIA 

8'LONG 

txj=^-— 

FUEL INLET 

EVAP. 1fi 

CANISTER 

CURRENT SYSTEM 

Ico 
OVERFILLING 

LARGE FROV 

EPA TYPE MODIFICATION 

EVAP. 

CANISTER 

ROLLOVER VALVE 

CHECK 

VALVE 

CURRENT SYSTEM 
OVERFILL PREVENTION 

HEAVY FLOAT 

SPRING 

BALL FLOAT 

VAPOR VENTVALVE 

EVAP. 

CANISTER 

EPA TYPE MODIFICATION TOYOTA'S PROTOTYPE 
STATIC SPILLAGE 

VAPOR VENT VALVE 

CLOSED 

CHECK VALVE 

TOYOTA'S PROTOTYPE 

PRESSURIZED 

EPA TYPE MODIFICATION 
DYNAMIC SPILLAGE 

OPEN 

TO CANISTER 

EPA TYPE MODIFICATION 
REQUIREMENT FOR FUEL TANK 

1. FUEL FILLABILITY 

2. RELIABLE AUTO SHUT-OFF OF NOZZLE 

3. CONTROL EXCESSIVE VAPOR 

GENERATION 

4. PREVENT OVERPRESSURIZATION 

5. PREVENT STATIC AND DYNAMIC 

SPILLAGE 

6. PREVENT FUEL LEAKAGE AFTER 

CRASH TESTCeg FMVSS301) OR 

OTHER CRASH EVENTS 

Tl 

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