P. 1



# OAR Box 1830 Prepped byOllie Stewart



### Document

Number: 

# 174 ) IV-C-14 1 Docket Number: 

# A-87-1 1

Printed 11/13/20087:21:00AM Sheet 174of 232P. 2



## *«>* „ HZ-c-/y / £

_ _T i UNITE D STATE S ENVIRONMENTA LPROTECTIO N AGENC Y AN N ARBOR . MICHIGA N 4810 5

OFFIC E O F AI R AN D RADIATIO N 

### DE C

### I4 

### 193 3

Mr . Kell yBrown , Executiv e Enginee r Noise , Emissions , Fue l Econom yPlannin g For d Moto r Compan y Th e America n Roa d Dearborn , M I 4812 1 Dea r Mr . Brown : Than k yo u fo r you r Novembe r 7 , 198 8 lette r concernin g th e performanc e o f th e refuelin g contro l hardwar e whic hw e hav e teste d o n a For d Tauru s fue l tank . A s yo u know , w e believ e tha t th e performanc e o f thi s hardwar e demonstrate s th e successfu l applicatio n o f ou r simplifie d refuelin g contro l concep t t o th e Tauru s tank . Hopefull yI ca n addres s som e o f th e question s whic hstil l exis t i n you r mind . Yo u firs t indicate d som e concer n tha t th e performanc e o f ou r syste mma yb e overl ysensitiv e t o th e precis e dimensionin g o f th e fillpip e orifice . Thi s i s no t th e case . A s w e indicate d i n ou r briefing , w e obtaine d successfu l configuration s tha t worke d a t bot h3 and 1 0 gallon s pe r minut e dispensin g rate s employin g orific e size s froma s smal l a s 0.8 5 inc hdiamete r al l th e wa yu p t o th e larges t siz e tested , whic h wa s 1.0 5 inches . Sinc e durin g thi s proces s w e wer e doin g a goo d dea l o f explorator ytesting , i t i s no t a t al l surprisin g tha t w e als o teste d a numbe r o f configuration s whic hdi d no t perfor m

successfully . Th e fac t tha t suc hthing s a s th e shap e o f entr yand exi t surface s fo r flo wdiscontinutie s affect s turbulenc e level s and flo wresistanc e doe s no t i n anywa y indicat e sensitivit yt o "mino r changes. " A s I a msur e yo u ar e aware , i n a productio n syste mon e woul d no t us e specia l insert s t o obtai n reduce d diameters , bu t woul d incorporat e th e appropriat e reduce d pip e diamete r directl yint o th e fillpip e design . I wa s somewha t surprise d a t you r statement s abou t th e emission s performanc e o f thi s syste mstil l bein g i n doub t becaus e som e o f th e measurement s wer e take n wit hth e caniste r outsid e th e SHED . Yo u ar e a s awar e a s w e ar e that , shor t o f th e breakthroug hpoint , caniste r emission s ar e essentiall y zero . W e hav e see n n o detectabl e differenc e i n emission s whe n th e caniste r i s insid e th e SHE D compare d t o whe n i t i s outsid eP. 3



### -2

- th e SHED . I n an

yevent , a s yo u als o know , fina l test s o nou r selecte d configuratio n wer e al l don e wit hth e entir e system insid e th e SHED . O f thi s serie s o f si xconsecutiv e tests , al l result s wer e a t or belo w0.0 5 gram s pe r gallon , meetin g our propose d standard wit ha margi n o f safetyo f 5 0 percen t o r more . Thes e test s wer e al l don e according t o th e requirement s o f our draf t procedure s including 1 0 percen t initia l fill , etc . Anothe r significan t issu e i nyour lette r concern s adequat e rollove r performanc e fo r th e vapo r contro l valve . Ther e i s n o doub t tha t th e valv e whic hFor d teste d had no t bee ndesigne d o r adequatel yteste d fo r ful l rollove r protection . Whethe r yo u wis ht o attribut e the problem s yo u experience d t o a "defectiv e seal " (ou

r term ) or a "prototyp e designdefect " (the valv e supplier' s term) , i s o f n o particula r concer n t o EPA . Th e redesigne d valv e produce d b yth e vendo r fo r our us e di d pas s rollove r tests , an d w e hav e offere d t o showyo u vide o tape s o f th e test . Yo u ar e incorrec t i n your understanding tha t othe r test s run ove r th e same weekend wer e unsuccessful . A s w e hav e previousl yshare d wit hyou , w e had earlie r ha d some problem s wit hth e valv e function , bot hfo r refueling shutof f an d fo r rollover . Thes e problem s wer e du e t o the fac t tha t prototyp e parts , being hand machine d rathe r than molded , ca nonl yb e mad e o f plastic s whic har e no t totall ystabl e whe nexpose d t o gasolin e fo r extende d periods . W e wer e no t awar e tha t suc h prototype s ar e intended fo r limite d testing onl yan d foun d tha t th e valv e experience d gradua l swelling an d subsequen t sticking whic hprevente d i t fro mclosing properly . Upo n bein g ai r dried , th e valv e regaine d ful l function . W e understand suchdifficultie s t o b e quit e norma l whe n dealing wit hprototyp e materials . Fo r mor e extende d use , th e valv e woul d hav e t o b e mad e fro mproductio ntyp e molds , whic h ar e to o expensiv e whe n onl yon e or two valve s ar e needed , o r machine d frommeta l parts . Howeve r i t i s deal t with , thi s i s a material s availabilit yproblemtotall yunrelate d t o th e abilit y o f a productio n versio n o f thi s valv e t o functio n properl yove r th e ful l lif e o f a vehicle . Th e availabilit yo f suitabl e productio n material s i s clearl ydemonstrate d b yth e many plasti c valve s alread yi nwidespread use . Yo u als o raise d a poin t abou t the occurrenc e o f situation s wher e a

n assume d suitabl e productio n versio n o f a rollove r valv e wa s eithe r defectiv e o r damage d i n a sever e crash . Thi s concer n i s somewha t surprising , sinc e th e refueling vapo r ven t line o n existing Ford vehicles , whic hour systemreplaces , ha s n o protectio n whatsoeve r agains t fue l leakage . Thus , an y valve , eve n i f onl ypartiall yfunctional , woul d greatl yreduc e an yris k associate d wit hfue l escaping fromthi s larg e tank opening . I f ther e wer e n o valv e a t all , th e ris k woul d b e n o greate r tha n o n your curren t productio nvehicles . I naddition , your curren t refueling ven t lin e i s locate d i na relativel y vulnerabl e cras hzone aroun d th e fillnec k opening an d i s muc h mor e liabl e t o b e damage d i na cras htha nwoul d our system , whic huse s a shorte r lin e wel l protecte d unde r th e vehicle . Finally , standard industr ypractic e toda

yi s fo r al l productio n

### -3

-

rollove r valve s t o b e individuall yteste d befor e delivery . Thi s make s i t extremel yunlikel ytha t a defectiv e valv e woul d eve r b e installe d o n a vehicle . Overall , i t i s quit e eviden t tha t a vapo r ven t system sucha s w e hav e designe d improve s th e safetyo f curren t fue l tan k systems . You r concer nsuggest s tha t th e standard agains t whic hyo u ar e measuring our hardwar e i s one whic heve n curren t productio ncar s do no t meet . Overall , w e d o no t agre e wit hyou r conclusio ntha t furthe r work i s neede d t o demonstrat e a satisfactorysystem . W e d o agre e tha t furthe r wor k i s neede d o nyour versio no f our system t o identif yth e difficiencie s whic hhav e cause d yo u t o experienc e suc hpoo r results . W e hav e demonstrate d tha t "substantia l redesign " o f components , a s yo u pu t it , i s no t needed . Clearly , "substantia l redesign " wa s no t eve n possibl e i n th e roughl ytwo wee k perio d whic hwa s require d fo r u s t o adap t our system

t o the Tauru s tank . Thi s i s no t t o sa ytha t an eve n better , mor e carefull yoptimized , se t o f component s coul d no t b e developed . Tha t simpl ywa s no t th e inten t o f our program . Our goa l wa s t o demonstrat e th e basi c applicabilit y o f ou r simplifie d designt o your products , an d tha t ha s clearl y bee n done . Lastl yyo u raise d th e questio n o f th e effec t o f our system on running losse s du e t o the lack o f a pressurize d tank wit h ou r approach . Yo u ar e correc t i nobserving tha t th e running los s dat a w e hav e collecte d indicat e a widesprea d lac k o f contro l o f running losse s base d oncurren t vehicl e designs . Tha t i s no t surprising give n th e lack o f attentio n t o running los s contro l i n vehicl e developmen t an d certification . Wha t i s significant , however , i s the abilit yo f some o f th e teste d vehicle s t o contro l th e releas e o f running los s vapors , eve n wit hunpressurize d tanks . W e do no t believ e tha t hightank pressure s ar e neede d t o successfull ydea l wit hrunning los s contro l during th e ozon e season . Th e modeling result s yo u hav e give n t o u s indicate d a relativel ysmal l impac t o f tank pressurizatio n fo r 9. 0 ps i RVP fuel . W e think tha t th e potentia l for safet yrisk s associate d wit hhighpressur e tank systems i s a significan t drawbac k o f sucha n approach . Onc e again , than

k yo u fo r you r letter . W e look forwar d t o continue d discussion s wit hyo u an d your staf f o n thes e areas . Hopefull yw e can soo n resolve th e ope nissue s t o our mutua l satisfaction . Sincerel yyours ,
Charle s L . Gray , Directo r Emissio nContro l Technolog yDivisio n 6632 W