Патент USA US2406373код для вставки
Aug. 27,1946. ‘ ’ H. E. HElGls ' - '2,406,373 TANK PURGING APPARATUS Filed sept. 19, 1942 ` _W -if- ~ 2 sheets-sheet ,2 ? l INVENTOR - ¿Md ATTORN Patented Aug. 27,' 1946 l 2,406,373 Y UNITED STATES ‘ „ ' , ’h ì l _` PATENT j-»ÓF?I-CE ï . '2,406,3ráj- ' . TANK PURGING Arraiwrus ’ß ç_.fneilrynrnèst Heig'is, Nutiey, N. „1.,.assignerto4 '__ffSzpecialties Development, Corporation, Bloom.-V ` field, N. .La corporation ofNew’JeI-sey " ` y Application september 19, 1,942, serial No. 459,022 y ` 21 claims. 1 The present-invention _relates to fuel .tank .purging and vapor diluting apparatus, and to a adapted ¿tebe 4.used in :connection with (Otago-[sci into `thef»purginglor. .vapor diluting vmedium delivi <ery conduit :is prevented. . » \ 1 ~ " \ - . VV'Etre-.fuel„tanks vof military aircraft usually are qAnother.object to provide »a iitting of the foregoing character which «is >automatic «in oper eration yand requiresrfa `minimum amount of vin _provided with onehor more )venting 'passages or spection andrepair..` such» apparatus. » - » I openings which _permit the‘rapid escape cf-fuel vapors vformed vin the tanks, wh'erebyexplosive ÍvaporY .mixtures Vare ¿minimized or eliminated, which .are likely -to explode the. event the ltanks are pierced `by ¿guniire orlthe like. These ventingpassages normailylare open, but may be closed by -a valve~inember„responsive vto :inert-ía or nthe nsurge of .theiuel `in 4the »tank when .plane is .eatapuited .into-night or is .brought to a‘sudden stop While landing, whereby theçspillage'oi fuel through venting passages is prevented. < « , Another object Visto provide -a fitting- of the foregoing. . character Whichfis readily7 assembled installed. 1 » v 'l l A» ‘ f f ` ~ ` `- A-¿further object consistsïin- the construction, arrangement and operation of parts, Wherebyzthe Y „foregoingtobjects are attained. v - ' . l Other and `further objects of the «invention will be obviousupon :an understanding .of the-illus VAtrative»embodiment 4about nto «be described., for »Will be .indicated .in `the appended claims, and var ious advantages not referred to herein will occur It .is customary ’to-further minimize or elim» to .oneskilled in the-.art uponempleyment of Athe inate the presence of explosive vapor 1mixtures invention .A preferred. ‘inpractice..-embodiment of theÍ~ , inventionhas . _‘ Vin the fuel tanks while» the plane is ina combat area by introducing an inert, »non-combustible Íbeen- chosen for A.purposes-fof lillustration and: de gas, such as carbon dioxide, which purges the scription andois »shown lin .the accompanying vapor space or dilutes the vapor ’suñiciently to drawings, forming a part of the specification, render them non-explosive. Where lsuch. a purg-Y v,vvhereini¿. n ~~: .» »f -» ‘ ing or vapor diluting medium is introduced into 25 . . Figure l is; _aidiagranimatiel view `-oiî an airplane tanks having an inertia, or surge operated fvalve, having ¿fuel tank purging or .vapor diluting appa~ it has been found that the pressure of the me ratua ¿illustrating .aner'nbodiment ¿of the inven dium operates the valve to cloee the-venting pas sages. The closing of the valve Acauses the rne »Figure .2 .is an -elevation-.al View of a giitting «.u-ïti-l . tion.: ì ~ ‘ dium to build up a pressure in the' tanks which li-zed in connectionwith-theapparatus shovvn'fin may eventually burst the tanks, and valso'prevents Figure the vapor mixtures from being Yremoved from the tanks. ' . An object of the present invention 'is to provide a, fuel tank purging and vapor diluting appara tus which overcomes the foregoing dilliculties. Another object is to provide an improved ap paratus, wherein an inert medium’ 'under pres sure is introduced into the vapor space of a fuel tank and the pressure of the medium is utilized for maintaining the vent passage valveA in open position. Another object is to provide an apparatus of Y .» 4l. ì f ' .- . ~‘ v. .. . Figureß .isa bottom _plan View off'the ñtting.. >Figure 4 is ka sectional view taken along the yline 11-4 ori-Figure 2.. ’ - - . v Figure 5 is a partial sectional `View »taken sub`stantiallv along the yline 5_5 on »Figure 2. Referring to the drawings, and more particu larly -to Figure 1. there -is shown an airplane hav ing a kfuel tank lß in >its fuselage. Adjacent each end of the tank., a ñtting AIl is Vattached to the top wall of the tank.. The rñttìngs have an open ing adapted to vent the vapor `space of the tank to `the atmosphere .by Way of a conduitß, and the foregoing character which assures _proper 45 have means for >introducing an inert purging and vapor diluting medium, such `as gaseous >car-bon purging or vapor dilution While the plane is in dioxide under pressure. The fittings ~are each eight. provided with. valve member l2. suchas a Hap Another object is to provide a simple.. com» per, ‘for closingla ventopeninginthe ñttings in pact, inexpensive fitting comprising a. vent, an response >to inertia orV surges ofthe fuel. The inertia or rsur-ge operated valve -for closing the fitting at Fthe forward end of the tank is arranged vent, means for introducing an inert medium, so that the valve member or flapper IÍ2 closes the and means for _preventing the valve from closing vent .opening upon a forward surge of the fuel 'while the medium is Vbeing introduced. which may occur when the plane is «brought to an Y Another object is to provide a ñtting of the abrupt stop whilelanding; and the ñtting at `*the foregoing character, wherein leakage of the fuel 55 rearward end of the tank’is arranged sovthat its 2,406,373 3 erally described, the body 25 houses a piston oper- ~ flapper closes the Vent opening upon a rearward . surgevof the fuel which'may occur when the ated plunger 65 adapted to extend outwardlyV from the body and engage the extension 32 of _the plane is catapulted into iiight. The, fittings are flapper to prevent it from closing the venting flapper from closing the opening while the purg Ril passage. The conduit 2 I is suitably connected to the body 25 and supplies the purging or vapor ingor vapor diluting medium is introduced, as further provided with means for preventing the diluting medium under pressure which is adapted will'be described in detail hereinafter. f. to operate the plunger. Provision -islma'de in ther The source of the purging'or vapor diluting body for conducting the medium operating the medium adapted to be supplied to the tank may , >>plunger to an orifice 33A which meters the medium be a cylinder I4 containing carbon dioxide, which . into the tank. Preferably the Vorifice 33 is formed I4 is provided with Ya discharge control heard `I5 Y ’ , in a sleeve38, closed at one end and removably secured to the body by aV threaded connection. ' , of suitable design adapted to 'be operated in any ._ ' is suitably located in the fuselage. . The cylinder . Y v,In order to accomplish the foregoing, the body having desired amanner, handle I1forattached example, thereto by ai and pull mounted cable: I6 'Y 15 25 has an upper po‘rtion'35 which extends above the flange 22, and has a lower portion 35 adjacent theventing body 24 which is adapted to extend into> the tank. The lower body portion is pro vided with a chamber<31, which is enlarged at two pounds perV square. inch above the atmos-` ' _'pheric pressure to which the tank is subjected. 20 its upper end, and _which terminates in an open ing 40 vat its lower end. "Adjacent the opening, , Since the pressure V'of the carbon- dioxide in the an annular shelf 4I is provided in the> chamber Y cylinder I4_w may vary between 145' and ‘3000‘ , for supporting Ya flanged bushin`g`42 extending pounds per square inch, depending upon `atmos through the opening. A second annular; shelf` 44 pheric conditions, suitable pressure regulating Yand reducing meansy are provided. y Preferably, 25 is located at the lower end of the enlarged upper portion of the chamber 31 and la ring-shaped gas ` » these means comprise a pair of pressure regulat Y ket 45 is supported, which is retained on 4the shelf ors I9 and 20 connected in series in a conduit 2| by a cylindrical sleeve 45 ñtted into the enlarged leading from the'cylinder I4 to the fittingsv I'I. chamber portion. The sleeve 46 has an'aperture The ñrst regulator I9 may be adjusted to reduce the-'pressureat its outlet to atleast 200 pounds,v 30 41 adapted to conduct the-purging or vapor dilut per squareV inch, while lthe second regulator 20 y ing medium to a passage~49 leading to the orifice 33 for delivering the medium to the tank. In VVmay be adiusted to reduce the pressure Vat 'its on the instrument panel. V ' During purging or vapor dilution, .it is desired ` that the pressure in the fuel tank does not exceed . order'to maintain the slèeveïaperture 41 in align- . outlet tor about ,115`V poundsper square inch. As ment with the passage 49, a set screw 50 Vmay be » will be described hereinafter, the ñttingsiII are threaded through the wall of the body to ñt >into provided with a metering orifice adapted to re-l` duce the pressure to labout two pounds per square inch. ' Y . a notch 5| or recess formed in the sleeve, ' A The the upper end of 'the' chamber, av ring shaped gasket 52 is seated on a shelf 54 and on the upper end of the sleeve v4e, and a iiange 55 _of a . By providing a primary and secondary'regu lator for regulating the pressure in two stages, more accurate regulation is attained. Suiiicient‘ 40 disc-shaped member 5_5 is' in turn seated on the ‘gasket 52. A gasket 51 is seatedv on the ñange 55 » vcarbon dioxide is supplied at all times without and is engaged by the lower end of a chambered bushing member 59 threadedly secured in the up per portion 35 ofthe body 25. The upper end of . InFigures >2. 3, 4 and 5, the Lfitting II'Y is illus# ï ,'trated in detail. The fitting comprises a'ñange 45 the bushing member has a threaded connection for Asecuring the conduit 2 I. f When the bushing _mem `22adaptedto be securedto the wall ofthetank, ber 59 _is threaded into position, pressure is ex» ‘and a venting body 24 kand body 25 housing the danger >ofV bursting the tank due to excessive pressures . ì erted on the gaskets 45, 52 and, 51 to form seals _flapper operating means carried by the ñange between .thelparts which 'the gaskets are inter (Figure 2). The ventingbodyis _substantially tubular and has a venting passage or openingv 2B 50 posed. Y l ,l _ ` The disc-'shaped member 55 has a central aper extending therethrough (FigureA). The upper> ture 6D into which isV insertedgat its'upper end, a cylindrical strainer 6I housed in the 4chamber of the bushing member. This strainer prevents portionpf the Vventing body extends above the flange 22 and is in the form of a „threaded sleeve 21 adaptedfoi` connectingÍ the venting conduit 9 thereto. 'I'helower portion of the venting> body 55 foreign matter such as dust or’corroded'metal particles from reaching the orifice 33 and caus is adapted to extend into the tank andthe lower ing it to become partly or completely clogged. 'end thereof is provided with ran, annular lip 29, _inclined slightly with respect to the horizontal, against which the ñapper or valve memberV I2 is adapted to abut to close the venting passage 26. , As shown in »Figures 2 and 4, the _flapper I'2 is , pivotally supported by a rod or pin 30 carried byV At the lower end of the aperture 59, a downwardly facing annular valve seat 52' is provided against which a valve member, about to be described, is Vadapted to abut; VThe meansfor preventing the flapper i2' from _ closing the venting passage, comprise ‘the plunger v`bearings 3l formed at the lower end of the vent 55 located in thechamber 31 of the body 25, one ing body 24. The iiapperr I 2 vmay comprise a sub-` stantially fiat member having a surface adapted 65 end of which is adapted to extend downwardly and >outwardly‘through the opening 4€) and en to abut the lip 29 to close the ventingpassage, gage the extension 32 of the .flapperg and apis-V ' and having an arm or extension 32 positioned'be‘ ton 6.6 attached to the other end ofthe plunger and slidably positioned in the sleeve 45. The piston is provided with an upwardly facing valve disc 51 adapted to abut the valve seat Bland neath lthe bodyzräland adapted to beengaged by `the.,_i‘lap'pe'r operatingmeans about to bede lscribed.` The flapper I2 may be provided with a Vcounterbalancing larm 34 Aadapted to facilitate' with a downwardly facing annular seater sealing Y ridge 68 adapted to engage the gasket 45. , ` The plunger is adapted to be normally main ‘actuation of _the flapper in response to inertia .or surgeof the fuel. Y h Y LIn Figure 5, the body 25 housing the flapper ‘operating means is Villustrated in detail., G611 75 tained in the position'shown in >Figure 5 by a 2,406,373 -‘cylindrical helical spring 69 .telescoped about the plunger. The .spring is under compression 'and has one end engaging the underside of the piston and has itsother end seated on the flanged bush ing 42, whereby the piston ’is urged upwardly to Icause the ‘valvedisc 61 to close 'the >opening 60. ‘The piston -and 'the aperture 4.1 inthe sleeve are -so »related that 'the piston >may be moved down » 6 boats, armed motor vehicles .and “tanks” ymay be protected with apparatus substantially .inaccord .ance with the .invention From the foregoing description it will ‘be seen that the present invention .provides :improved .fuel vapor diluting and purging apparatus. "The appara-tusis readily operated, and once put into wardly beyond the aperture 41, whereby .the me operation, functions automatically. 'The danger of bursting the tanks is eliminated. The fitting dium 'under Lpressure .acting on the piston passes ‘through the aperture 41 .and is conducted to the .orifice 133. When ‘the piston is driven .down wardly, the .ridge 68 vengages the gasket ~4'5 to pre vent leakage of the medium through .the opening l0. serves .as a'ñapper valve, `a ñapper valve operat ing means, a check valve, and fa -purging medium ¿introducing means. lThe parts thereof are rugged .in construction and Acan readily withstand any 'rough usage :to which they may be subjected. various changes may be `made .in the form, .inthe operation of the apparatus, the plunger .65 normally is in its .retracted position, as shown in Figure 5, and the iiapper is spaced .slightly away from the lip 29 .of the fventin'g passage 26, construction andarrangement of the parts herein, without departing from the spiritzand scope of the invention and without vsacrificing any of its ad vantageait is to be understood `that all matter as shown in Figures 2 and 4. ’In the event the :20 herein is to be interpreted as illustrative and not plane is catapult-ed into night, a surge of fuel to in any limiting sense. ` ward .the .fitting .fl I will »cause the flapper to close VIt is also to be understood that the following the venting passage. During normal flight the claims are intended to Icover all the vgener-ic and flapperzremains spaced away 'from .the passage to .specific vfeatures of the invention herein Ide .allow fuel vapors to -pass to the atmosphere by 25 scribed, 'and all statements of the scope of the way of the conduit 9. invention which, <as a, matter of language, .might While the plungei-.is retracted, dueto the spring 69 urging the piston upwardly, the valve Idisc V61 closes the `opening .6.0, whereby >the plunger and its :associated parts fact las a check lvalve 'for Apre venting ;fuel from .getting into .the purging me dium »conduit 2|. . When the pilot venters :a combat area or .antic be said to fall therebetween. ` ~ ‘ I claim: 1. `In .an apparatus of the class described, Ithe 30 combination of ‘a fuel Átank .having a venting pas sage, valve means for closing said >passage in re sponse to inertia or in response to the >surge »of fuel in said tank -towards .said passage'. a source ipates `.being attacked, ‘he operates the vapor of inert mediumunder pressure, .means .for intro~ diluting `or purging apparatus by pulling the 35 'ducing the medium into said tank, and :means handle ‘l1 .attached tothe .pull :cord ~Hi which .in associated `with .said last :means ~and operablel vby turn :operates .to control head |:5 to :effect dis themedium for preventing .said valve meansffrom charge of the carbon dioxide or other medium closing said passage. ’ " ' in the cylinder 14. The pressure of the vine y 2. .Inl an apparatus yof vthe class described, the . vis ¿reduced ¿by 'the two ,regulators 19 .and 29 .40 .combinationlof a fuel tank having a venting pas .andfiiows ‘through the .conduit .2| to the .fittings sage, yalvemeansfor closing said passage in re# il.; 'The medium enters the bushing member 5B, ` rsponse to inertia or in Vrcsponselto the surger of <isiiltrere'd or .strained by the strainer 'Bl 'and fuel in said tank towards said passage, ayzsource :enters the opening 159) lea-ding to the chamber of ,inert :medium underpressure, means for'releas 131. The medium is 'effective to unseat the -valve ing 'the medium from its source, .means for ~introdisc `v6l zand ‘to vdrive the .piston downwardly ¿past ducing the medium linto said tank, and :means the aperture '41„ whereby rthe >medium flows :to -the associated with said .last means .and operable- 'by vorifice and :is ‘introduced into the tank. The the medium for `preventing 4said valve means :from medium is 'effective to dilute or Ídisplace the fuel closing said passage. " ~ vapors which may be formed in the space above y. 43. 'In lan apparatus -of the class described, th the fuel. l , >combinanon :of a fuel tank having a venting The ilapper Ll2 ’is prevented from closing. the passage., valve means :for closing said passage venting ‘passage 26 by therplunger, which, Yas in response to inertia ‘or in response to the surge shown in broken lines in Fig-ure 5„-zis now ex Io'f'fuel.1in-said tank towards >said passage., a source tended from the body 25 and engages the ex- , lof inert medium under pressure, means `-for `intro tension 32 of the dapper and maintains the nap ducing lthe medium into said tank -including pres >per away from the venting opening, thereby per sureregulating means, `and'mea'ns >associa-ted with mitting free .passage of the fuel vapors to the said introducing means and operable by `the me conduit v9. dium for Ipreventing 'said valve means .from clos When >it is desired to restore the system to its 760 ’fing said passage. K normal condition, the source (of the purging me 4. In an apparatus of the Aclass described, the dium is disconnected and `t-he »conduit 2| is :combination of .a fuel tank having a venting pas' vented to 4the atmosphere. rllhis permits the sage, valve means in said :tank adjacent said pas» .spring 69 to yreseat the valve disc 'of the piston .sage for closing said passage î'n Aresponse to ‘in and retract the plunger. Thereafter, if the pilot 65 ferïtia Ior .in response to the surge of fuelnln said lands a't ahigh speed and stops abruptly, a surge tank 'towards said passage, a container ,of inert of .fuel is again adapted to cause the flapper to medium under pressure, means for‘releas’ing the close the venting passage. . medium ¿from said container, means ¿for introduc While the present invention has been described in »connection with an aircraft fuel tank purging or vapor diluting .system by Way of example, it will be understood that the principles involved »sta-ge pressure regulator, and means operable >by can be applied to systems for >other craft or ve hicles 'where itis vdesired to 'purge or :dilute ¿fuel sage. vapors. ing the íinedilnn 'into said ta'nk including a. two -the medium .introduced into said `-tank for pre venting said valve means ‘from closing said pas ;5. A .fitting la venting forpassage .fuel tanks therein, comprising ~inertia respon a For example,V the fuel tanks :of .speed 75 having ~ @406,373v z8 7 >sive‘valve means for closing said passage, said »body having asecon'd-passage for introducing a medium under pressure into a Vfuel tank, and means adapted to be operated by the pressure medium ñowing through said second passage for Avpositioning said valve` means to maintain said passage open. . . ' ' . . and a plunger carried by said 'piston adapted to engage >said valve means and prevent said valve means from closing said venting passage. . 13. A fitting for fuel tanks vcomprising-body means having a venting passage therein, inertia yoperated valve means for closing said passage, said body means having a chamber provided with ¿ pressure medium inlet and a pressure medium 6.' A ñtting for fuel tanks comprising a body outlet and a passage leadinghfrom said outlet and havingY a -venting passage therein, a pivotally mounted inertia responsive valve `member for 10 terminating in a metering orifice, a piston in said closing said passage, and means adapted to be operated by a pressure medium for positioning ^ >said valve memberto maintain said passage open. 7. Aiitting for fuel tanks comprising a body having a venting passage therein, an inertia re sponsive pivotally mounted valve member for` closing said passage, and a plunger adapted to bev operated by la pressure medium vfor position ing said'valvemember- to maintain said passage open. ` 8. A fitting for fuel tankscomprising a body havingf‘a venting passage therein, a pivotally -mounted". inertia responsive valve member adja `eentsaid'passag'e for closing said passage, Vsaid chamber having a valve member for closing said inletto shut off communication between said inlet and said outlet, resilient means for normally 'urg ing said piston towards said inlet, anda plunger :15 carried by said piston adapted to extend out of said body and engage said valve means and pre vent said valve means from closing said venting passage. ' ' ‘ ` . s l - 14. In a system of the class described,~the com 20 bination of a fuel tank having a venting> passage, a pivotally mounted valve member for closing said passage inres'ponse to inertia `or in response .to the surge of fuel in said tank towards saidy pas sage, a source of inert'medium under pressure, valve? member having an extension thereon and 25 means for introducing tne medium into said tank, and means associated with said last means ladapt ‘a‘counterbalancing arm, means including a pas sage for conducting Sa medium under pressure ed to be operated by the medium for preventing through the fitting, a piston adapted to be oper said valve member from closing said passage. i --ated -by the medium, and a plunger on said piston ' ' 15. In a system of the class described, the com adapted to'engage said extension' and position 30 bination of a fuel tank having aventing passage, . a pivotally vmounted valve member. for closing said valve member to maintain said venting pas sageopen;` ' « . - . ' i ‘ . 9. ‘A fitting for'fuel tanks comprising a body Y said passage in responsev to inertia or in response to the surge of fuel in said tank towards said Y passage, a, `source 0f inert medium under pressure, means having aventing passage therein, valve ~means for closing .said passage, said body means 35 means for introducing the medium into said tank, and a plunger associated with said `last means having .a chamber provided with a pressure me adapted to be operatedïbythe `medium for pre: .diurninlet and a pressure medium outlet, a, piston f Y in'said'chamber having a valve member for clos Y -ing saidlinlet- to shut oiî communication between »said inlet and said outlet, and a plunger 'carried by said pistonV adapted to engage said valve means ’ .and prevent said valve means from closing said ' vventing'passage. ' ' ' venting said valve! member from -closing, said passage' . - i .1. .Y . *_ ` ; 16. In a system'of the class described vthe com ’ bination of a fuel tank having >a venting passage therein, a- pivotally mounted inertia responsivey valve member adjacent> said passage for closing Y 10. i?ivñttingcforv fuel tanks comprising body means-having a venting passage therein, valve means for closing >said passage, said body means said passage in response to' inertiagor in response to the surge of fuel in said tank towards said passage, said valve member having an' extension having a chamber provided with a pressure me thereon and a counterbalancing arm, a source of inert medium under pressure,.means for intro dium` inletA and a pressure medium outlet and ducing the medium into said tank, 'a ‘piston- asso a passage leading from said outlet and terminat ing in a metering orifice, a piston in said cham 50 ciated with said last means adapted to be op erated by the medium, and a plunger 'on` said ber'having a valve member for closing vsaid inlet piston adapted to engage said extension and posi- ' Y f 'to shut off communication between said inlet and tion said valve member to maintain said venting said;outlet, resilient means for normally urging ' said vpiston towards said inlet, and a plunger car .ried by said piston adapted to extend out of said vbody means and engage said va-lve means and pre i vent -said valve means from closing said venting passage. ' Y . passage open; » Y ' - , ` ' ' . ^ V17. The combination of a‘fuel tank and a ñt ting attached to said tank comprising a body hav ing a venting passage therein, valve lmeans. for yclosing said passage in response to inertia or in response to the surge of fuel in said tank towards having a venting passage therein, a flapper valve 60 said' passage, said body having a chamberfpro vided with a ‘pressure medium inlet and a' pres _member- adjacent f said passage for closing said Y sure medium outlet for introducing the pressure passage,V said valve member having an extension medium into said tank, a piston in said chamber thereonand a counterbalancing arm, a piston having a valve member for closing said inlet to „adapted to be operated by a pressure medium, and shut off communication between said inlet and aplunger on said piston adapted to engage said said outlet, 'and a plunger carried by said piston extension on said valve member and position said adapted to'engage said valve means and prevent valve member to maintain said'passage open. said valve means from closing said venting pas V12.Y -A fitting for fuel tanks comprising body means having a` venting passage therein, inertia 18. The combination of a fuel 'tank and a ñt responsive'valve means-for closing said passage, ting attached to said tank comprising a body hav said body- means having a chamber provided with ing a venting passage therein,- valve means for pressure medium inletand a pressure medium Y Y V11.»A fitting for fuel tanks comprising 'a body sage. outlet, aV piston in said chamber having a Ívalve member for closing'said inlet- to shut-.off com munication between said inlet andsaid outlet', . , " ‘ = ' _ closing said passage inresponse to inertia or in , response to the surge of fuel insaid tank to wards said passage, said body'having- a chamber 2,406,373 provided with a pressure medium inlet and a pressure medium outlet and a, passage leading from said outlet and terminating in a, metering oriñce, a piston in said chamber having a valve member for closing said inlet to shut oñ com sage, valve means for closing said passage, a source of inert medium under pressure, means for introducing the medium into said tank including a 'metering oriñce, and means associated with said last means and operable by the medium to main munication between said inlet and said outlet, tain said valve means from closing said passage resilient means for normally urging said piston towards said inlet, and a plunger carried by said piston adapted to extend out of said body and engage said valve means and prevent said valve While the medium is being introduced into said tank. 21. In a system for purging fuel supply means, the combination of liquid fuel storage means nor mally conditioned for venting vapors of the fuel means from closing said venting passage. 19. In an apparatus of the class described, the combination of a -fuel tank having a venting pas sage, valve means for closing said passage, a source of inert medium under pressure, means contained in said means, fuel operated means ef fective for sealing said storage means to retain the fuel in said storage means, external fluid pressure operated means associated with said fuel for introducing the medium into said tank, and operated means for rendering they latter ineffec tive for sealing said storage means, and means connecting said external means With the interior erable by the medium to maintain said valve of the tank to permit purging of said storage means from closing said passage while the me dium is being introduced into said tank. 20 means by the medium for operating said :duid pressure operated means. 20‘. In an apparatus of the class described, the means 'associated with said last means and op ' combination of a fuel tank having a venting pas HENRY ERNE‘ST I-IEIGIS.