US2564226A

US2564226A - Gas dispensing device

Info

Publication number: US2564226A
Application number: US395443A
Authority: US
Inventors: Harold L Norway
Original assignee: Bastian Blessing Co
Current assignee: Bastian Blessing Co
Priority date: 1941-05-27
Filing date: 1941-05-27
Publication date: 1951-08-14
Anticipated expiration: 1968-08-14

Description

Aug. 14, 1951 H. NORWAY GAS DIsPENsING DEVICE 3 Sheets-Sheet l Filed May 27, 1941 d nu INVENTOR.

HIS ATTORNEY Aug. 14, 1951 H. NORWAY GAS DIsPENsING DEVICE 3 Sheets-Sheet 2 Filed May 27, 1941 R. m m V n. W r 0. N L d l o r a mmH GQ HIS ATTORNEY Aug. 14, 1951 H, L. NORWAY GAS DISPENSING DEVICE 3 Sheets-Sheet 3 Filed May 27, 1941 INVENTOR.

H l S ATTOR NE Y .b En? mnww Fig.5

Patented ug. 14, i951 UNITED STATES `TENT OF FI CE GAS DISP-ENSING DEVICE Harold L. Norway, Evanston, Ill., assigner to The Bastian-Blessing Co., a corporation-of Illinois 21 Claims.

The ,present invention relates to liquefied petroleum gas equipment and more particularly to the method vand apparatus for handling liqueed petroleum gas and is oifspecial interest where fa storage tank is buried below the frost line of the ground to absorb heat of the ear-th.

1n many respects the embodiment employed .to represent the present invention, is similar to that lshown in my co-pending applications, Serial No. 375,079.1iled January 18, 1941, and Serial No. ,370,754 led December 17, 1940, reference to which is herebymade, and to the extent that a similarity of parts exists between the embodiments of the .several inventions, the disclosures of the above applications are incorporated herein ,for a better understanding of the present .invention. These applications have matured into Pat- .ents Nos. 2,361,866 of October 31, 1944 and 2,400,576 of May 21, 194:6.V

The petroleum product employed in the sys- .tem with ,which the present invention is ooncerned, is 4preferably a hydrocarbon fuel of the paraffin series such as butane or propane, or a .mixture -of both. Although the 4.embodiment illustrated herein Ymay .operate under favorable conditions aboveground to .dispense the fuel `in ,the form of gas, `,the tank in which the fuel is stored ,is preferably located underground where the assistance .of the heat of the .earth is utilized with a reduction in pressure to vaporize `the liquefied gas for use ina dwelling a substitute for natural gas.

One of the Ways of vaporizing the liqueed rgas is the so-.called batch system in 4which the `vaporizer is carried on in the storage ,tank 4and vapor lis withdrawn in the form of gas from the tank. Thepther wayof vaporizing -the liquefied gas is the socalled flash system in which the `liqueiied gas is withdrawn as a liquid lfrom the ,tank and passed ythrough a .pressure ,reducing ,regula-tor which causes the ,liquid to .flash into vapor.

Wherever vaporization takes place, vheat units are absorbed from surrounding parts, and, .in a ,batch system, this refrigerating action .is expended largely throughout .the tank, Whereas with the flash system, the heatv absorption is concentrated in a comparatively rsmall, space, namely ,around the .pressure reducing device and adja- .cent parts.

Although many features Aof the present inven tion will improve vaporization and operating con.- `ditions for batch systems, the primary concern pf .the present invention is with flash systems, l'having for one of its objects the adaptation of the flash process to take advantage of the benefits derived .with 'batch systems, in that the refrigerating ,action is expended throughout the tank.

With the storage tanks buried below `the frost line, the initial temperatures are sufficient to provide a substantial vapor pressure in the tank. This vapor pressure is constant at any given temperature andalthough it is relied uponsolely in most installations to orce liquefied gas or vapor from the storage tank, it cannot be relied upon or utilized for that purpose where the withdraw-al of ygas or the load upon the system is so great and continuous that the refrigerating action reduces the temperature of Vthe tank contents below that necessary to keep the system going.

However, even in installations Where this eX- treme .condition takes place, there is available'beyond the tank and around the service `1in-e sui- L,cient ground heat below the 'frost line to vmaintain a supply of gas 'if the 'liquefied gas could be carried .to it.

It is one of the purposes of the present invention to provide a safe and convenient means ior assuring or continuing the operation of a system which has been subjected to the above mentioned extreme conditions, and as a corollary thereto, another object of the invention is to provide a means whereby air may be employed to force liquid from a tank when the liquid in the tank has been chilled to a temperature at which the vapor pressure of the liquid is insuicient .to educt liquid from the tank and the 'heat available in the tank at that pressure is insufficient to accomplish vaporization of restricted quantities of liqueed gas.

Although air pressure has been used heretofore to .handle gases of the class described, its use is impractical with 'batch vaporization `loecause it is rapidly depleted as the vapor is withdrawn from the tank. On the other hand, with liquid eduction 4or ash systems the air remains in the tank but certain difculties are incurred in handling it. The presence of air creates an .increasing back pressure when the tank .is Vbeing iilled, and unless applied properly to a storage tank, the ultimate pressures which will exist vin the tank are not immediately indicated.

An object of the invention is to provide an improved and safe system whereby air is utilized t0 augment eduction pressures.

A further object of the invention is to provide an improved means for applying the pressure to a container containing liquefied petroleum gas lin which the sum of the partial `pressures involved is indicated immediately and to remove such pressure when upon occasion such becomes desirable as when the tank is being filled.

Another object of the invention is to provide a simplied and improved eduction arrangement for systems of the type described which is inexpensive to manufacture and maintain.

Another object of the invention is to provide an improved and simplied means for utilizing the sensible heat of the liquid in the tank to flash liquefied gas into vapor with an accompanying reduction of pressure.

A further object of the invention is to submerge in an anti-freeze solution, those parts of the system which are subjected to the refrigerating action that takes place during the vaporization which accompanies a reduction in pressure.

A further object of the invention is to reduce to a minimum the volume and the distance the liquefied gas has to travel beyond the tank t reach heat conducting parts Which will assist in vaporizing any liquid in the eduction conduit.

A further object of the invention is to provide an improved means for preventing the iilling of the tank above a predetermined level and further to provide a construction wherein the predetermined level at which such a means is operative in relation to the temperature of the liquid in the tank.

Another object of the invention is to utilize the equipment conventionally employed to fill, service and empty the tank. A further purpose of the invention is to provide a combination of tank and fitting constructions characterized by safeguards against unsafe removal of gas and other contingencies experienced in unloading pressure containers.

Another object of the invention is to provide a construction wherein the Working parts of a vaporization regulator is disposed below the frost line, removed from contact with the earth and is disposed out of contact with any parts which are exposed to atmospheric temperatures. These being among the objects of the present invention, other and further objects will be apparent from the drawings, the description relating thereto and the appended claims.

Referring now to the drawings:

Fig. 1 is a fragmentary vertical section taken longitudinally through the tank, standpipe and eduction means illustrating a preferred embodiment of the invention.

Fig. 2 is a plan view, on an enlarged scale, of the tting mounted upon the standpipe shown in Fig. 1.

Fig. 3 is a side elevation of the construction shown in Fig. 2.

Fig. 4 is a section taken upon the lines 4-4 of Fig. 2.

Fig. 5 is a vertical section taken of the eduction means shown in Fig. l.

Fig. 6 is a fragmentary view taken upon lines 6-6 in Fig. 2.

Fig. '7 is an enlarged section of a fitting by which air may be introduced or removed through the device illustrated in Fig. 6.

Referring now to the drawings in further detail, a pressure tested, corrosion treated tank I0, as shown in Fig. l, is buried in the ground il below the frost line l2 thereof to absorb heat from the earth for the purpose of warming the liquid stored in the tank, the approximate maximum level of which is indicated by the broken line i3.

With this arrangement the heat of the proximate earth is utilized to establish vapor pressure in the tank which operates to force fuel from the tank through an eduction conduit indicated generally by the numeral I4.

The tank is provided with a riser pipe l5 which is welded at the lower end thereof to the tank l0 as at I6 where it is disposed over an opening l1 in the top of the tank.

At its top, the pipe I5 receives thereon `a concrete curb box having a cover Zi secured thereto by bolts 22, a bleeder opening 23 being provided to vent the box I8. The length of the pipe l5 is determined in relationship to the depth at which the tank i8 is expected to be buried. However, due to the box arrangement, a wide tolerance is provided for any particular tank and standpipe size because of the fact that the top of the pipe may be disposed at a point high or a point low in the box and thereby certain allowances be made for local conditions.

The upper end of the pipe I5 is threaded as at 24 to receive a companion flange member 25 for a body 26 bolted thereby by bolts 21 as sealed against pressure by a gasket 28 more particularly shown in tank 4. The body 26 comprises a forging capable of being made by two dies whose line of separation follows the outline contour of the body as seen in the sectional view in Fig. 4. The body 2S before machining comprises a, central portion 30, upwardly `extending bosses 3l and 32 thereon, and a preferably symmetrically contoured or hexagonal iiange 33 around the bottom. Recesses 34 are provided beneath the boss 32 to aord room to receive the nuts 35 with a clearance adequate enough for ready assembly and removal.

In machining the body 26 the boss 32 is machined to receive the filler means preferably having a double valve construction. The boss 32 is drilled out and threaded to a depth as indicated at `3S at which point a shoulder 31 is provided beyond which the boss is hollowed out and internally undercut as at 38 to a depth 40 beyond which a restricted bore 4l is provided to receive the stem 42 of the valve 43. The valve 43 is held in place by a lock ring 45 threaded against the shoulder 31 and having a valve seat 46 machined on the inner face thereof to cooperate with the Valve 43. A compression spring urges the Valve 43 to seat against the seat 46. The lower end of the spring is received in a recess 41 in the body 35 to permit a greater flexing of the spring.

The valve 43 is hollowed out as at 48 to receive in supported relationship an upper valve 55 which carries a resilient seat 5I thereon. A retainer member 53 having a lip 52 machined upon the bottom thereof to form a valve seat is threaded into the bore as sealed with respect to the body by means of a gasket. A stem 54 upon the valve 5D reciprocably supports the valve in the bore 48 and the valve is urged into contact with the seat 52 by a spring 55.

The retainer member 53 at its upper end is internally threaded as at 56 and externally threaded with a coarse thread as at 51 to receive a bore connection (not shown). A closing plug 58 is received in the threads 56 and the plug is provided with a depending peripheral flange 60, which, when the plug is in place, overlies the threads 51 to protect them. A gasket 6l is mounted on a groove 62 in the housing section to provide a seal.

The valve' areas are of diierent sizes but the valves operate preferably independently so that When a hose connection (not shown) is secured to the Shousing 'by ythe th-reads 5.7 .after ithe fcap which Aextends to apoint'iproximate the bottom s lof the-tank aslindicatedby the numeral 64.

`At :the lowerend of `the lpipeii is threaded .fa itting.containingitherein a flapnvalve {i-Which :closes in ithe .direction .of incoming .flow against theiseatifl when moved from its resting position lby arod .158 actuated lby a oat 11D. .Thefioatiis mounted upon an arm .1| pivoted :asat 12 iupon a collar v'lf3 that is vfastened to .the pipe .63. A runner .1l engages `-an adjustable .button "l5 upon :thefendof the arm 68 to move thecheckfout 4into .the .stream of 4incoming .liquid to be closed thereby when the float 'i0 reaches a predetermined level which is approximately that .indi- #catedfby theline |23.

'-Ineview of the f'fact lthat lthe vNational 'Boar-dof lf'l'ire 'Underwriters :designate :a .ll '.limit vin relaitionship to .thetemperature of :the liquid, :a means I'has -been .provided for @varying the :height at which the float uf'Hl accomplishes actuation :of the :valve IE5. -frnetal section 16 which feXes .the .float 70 up- =.wardly with respectfto the arm v7H vin relation `to :an-increase in .heat and to move the viioat 'i9 #downwardly with-respect to the arm 'H when the temperatureof .the 4liquid in :the tank is lower Ethan Ethat .at which the arm Il ,and section 16 :would beinalignedpositions.

The arm di Ais .preferably pivoted ata point belotvithe

maximum expectedll level

13,50 .that the'fbi---metal.section :16.is ysubmerged as 1th@ level ilfof .the'liqui-d intheitank is approached. :The :bt-metal section T5 thereby is in direct eontact :and fullyiinfluenced by the sensible temperature vcftheliquid inthe tank. Thereby, the jfloat "lil is automatically adjusted to the temperature of Theparticular means showniis a bi- .reading of:theflevelgaugefbeingindicatedfin the weight of .the -liquid present in `the tank, the :criterion which is the ultimate basis V,involved in the sale.V of liquefied 1 petroleum gas.

.fFor `purposes of mounting a liquid 1levelgauge in -the4body ,30, .a bore, indicated ,at 755, s:.pr0

vided .therethrough of proper ldimension to re- .,eeivega housing 385 of .a liquid levellgauge `and I,to accommodate the shaft 18| and `provide room gforwisual-examination of the interior of the tank when the gauge is removed, if upon occasion, such fmaybeldesired.

Ainoundthe upperypart of the bore A18a recess .812;isfprovided to receive the gasket 83 whichis :disposed thelow the anee 84 Aupon v4the gauge Yfhilusing` 85. The gasket=83 is compressedto ;pro vide a seal, by means of four bolts 86 (Fig."2) th-readed into .the metal of -the body 130. The .gauge gpleferably a grotary facting magnetic .operates a rotably I.opposed lead nut 9,2 up and down along a helically threaded shaft 93 .sup

ported 'in a .bracket `9.4 by means of collars 95 .upon the vpipe .63. 'The lead -nut rotates l,the ih elical shaft progressively as Vit ,moves vlongitudinally, and the Yhelical shaftin-.turn operates` the float shaft 8|. In vthis way movement of the float 'l0 about the pivot point 12 is translated to :a rotary movement of the hand 88 inthe .gauge body fin relationship ,to :the labsolute volume of liquid present `in the y,tank :as vrelated ljto zits .absolute weight.

:In assembly, the iioat 'lil and associated vparts are inserted through :the'bore g1-8 Aii.constr.ucted as .-anassembly, and after Imountngisame withlrespect v-to .the .pipe 5.63, the entire Iassembly. canebe insertedinto.and removed from thetank through :theriser7 pipe v"I 5 In kthis waya new and improved .means'is .provided for preventing :the overlling of fthe tank that :also obviates the .necessity of providing .a fixed level indicator so that Warmer liquids may be :filled toa `higher vlevel safely, .thereby yfacilitating llingoperations andthe :nlling of the tank .toits fullest `level ofsafetyirrespective of thetemperature of the liquid introduced .into theftank.

A pressure safety relief Valve isinstalledin the .boss 3| by drilling the bossoutto the depthin- .-dicated Aat I Oil 'beyond :which .a r.reduced :bore il 0I is provided around .themouth of .which .the -valve .seat .lip *.I @g2 `is machinedto beengagedbyasafety -yalve ,U33 heldin placeby acompression spring I Mbacked up v.by an adjustable spider |105. .'I.he bore wl is -placed iin openy communication -with the interior of the tank vby.means of abore L|06 Ysoarranged thatit can be made .from the bottom of the body past the lip indicated at .Hlla'large bore `IDB beingprovided in the bottom of .the-body ytoremove as much. of the excess stock as possi-ble from the bottom of the body V3|)` -In order t0 facilitate the .llingof the tank a bleed relief is provided to 'remove any Yair v`and -foreign vapor vpresent in the top of the tank. This relief comprises an opening through the body/33.0- and in open communication with the tank as shown in phantom by the lines III in LFig. `3, -Whereingan adapter nipple ||2A (Fig. 3) having :mounted therein afDill valve .I I3 such as shownin Eig. l6 serves as a check valve that canbe opened by imeans of a hose-connector H4 such as that shown in Fig. `'l where the body portion' H5 is adapted to engage atop I |16 of the Dill valve stem I |'I whenever the plugll I8 is removed by loosening `the lock nut kle2lA. A:.similar lockfnut l2;|Aupon thehose connection, when tightened in place,

vforces-,the body-'portion lagainst the stern head gislinsufilcent-tovaporize thediquigiy theairi pres- 7 sure will force the liquid along the service line to a point where heat is available. This means is shown in Fig. 6 in which the threading upon the adapter nipple I|2 is different from the threading on the nipple I |2a and a small diameter tube |23 is secured to the bottom thereof to ex- .tend to a point adjacent the bottom of the tank as indicated by the numeral |24 in Fig. 1. The threading may differ in pitch or direction of helix, preferably the latter, in which case one of the threads upon the adapter nipple I |2 is a right hand thread and that upon the adapter nipple |I2A is a left hand thread. This prevents the use of air pressure equipment upon the wrong adapter nipple.

The adapter I2|A is connected to a source of air under pressure and the air entering the tank is forced to bubble up through the liquefied petroleum gas in a manner by which diffusion is immediate and the added partial pressures are immediately indicated upon the gauge.

If air were to be introduced into the tank as an undiffused body, the partial pressure thereof wound not be additive to the vapor pressure in the tank. If such occurred the serviceman would continue to force large volumes of air into the tank without additive pressures being registered until long aiter the serviceman had completed his call.

The air pressure added is preferably 2O to 25 pounds per square inch, which when applied with an approximately outage will be effective to educt liquid when outage is above 80%.

The opposite threading of the two adapters also prevents the serviceman connecting the vent and bleed to the wrong opening and running the chance of removing liquid from the bottom of the tank instead of vapor and air from the top of the tank. Although an improved and safe means is provided for the handling of air pressure to assist vapor pressure in the tank, and although air pressure is preferred, other gases such as nitrogen may be employed upon occasion without departing from the teachings of the present invention provided such gases are those which are not absorbed to any material extent by the liquefied petroleum gas such as carbon dioxide would be.

A further and improved feature of the invention resides in the manner is which liquid is withdrawn from the tank for purposes of vaporization. In the embodiment illustrated, such comprises a conduit threadedly carried by a collar I3I which is mounted upon the flange |32 welded to the tank I@ as at |33 over an opening |34 in the tank, which opening is large enough to receive the tube |35 therethrough after the tank has been assembled. The collar I3I is secured to the flange |32 by means of a coupling nut |35 which, when tightened, establishes a seal between the body |3I and the flange |32 by compressing a gasket |36 disposed therebetween. At the lower end of the conduit |30 a fitting |31 is internally threaded thereto as at |38, which tting can be admitted into the tank through the opening |34, and has a downwardlyl presenting valve seat |40 therein surrounding a bore |4 I,

A cap 42 closes the bottom end 0f the fitting and has therethrough, inlet openings |43 by which liqueed gas in the tank can fiow into the valve compartment |44 which is provided in the lower portion of the iitting |31. A valve |45 is disposed in the valve compartment and carries a valve disc |45 which cooperates with the valve seat |40. `The lower end of the valve member is `provided. with a stud |41 which cooperates with the guide bore |48 provided in the cap so that the valve |45 may reciprocate to carry the valve disc into and out of contact with the seat |40. The valve body |45 has a hexagonal outer contour as indicated by the broken lines |5| so that liquid entering the valve compartment from the opening |43 can ow past the valve |45 and through the bore |4| when the valve is open.

In order to operate the valve, two springs are employed which oppose each other, the lower one of which |52, is supported in a groove |53 in the ca-p between the valve |45 and the cap |42 to urge the valve towards the valve seat. The other spring |54 is disposed above the valve as received in a groove |55 in the tting |31. The upper spring |54 is preferably the stronger of the the two springs and under the action of the two springs, the valve consequently would be urged normally to open position, the two springs operating to stabilize the action of the valve in a beneficial manner by preventing any pounding or chatter- The valve is controlled by means of a shaft |56v threaded through the valve disc |46 into the valve body |45 as indicated at |51. A shoulder |53 is `provided upon the shaft to hold the valve disc against the valve member |45 and thereby to prevent the disc from sticking or adhering tothe valve seat |40. The shaft |56 extends up to and beyond the upper end of the conduit |39 where it is threaded as at |60 to receive a plurality of elements thereon which will now be described, in connection with the regulator body ISI threaded to the collar I3I as at |62.

The valve body is provided with an upwardly presenting shoulder |63 supporting a diaphragm |64 which is held in place by a regulator bonnet |65 threaded tightly into place thereagainst in the regulator body as at |66. The control of the valve |45 is such that it can be used as a regulator valve for regulating the pressure existing inside the conduit |3 or as a manual shutoff valve operable from above ground by means of a shaft |51 having a hand wheel |58 thereon disposed in the curb box I8.

The valve shaft |51 has a four prong construction |84 on the bottom thereof which engages corresponding recesses |85 upon the cap whereby the cap may be manually manipulated by means of the hand wheel |68 in the curb box I8.

In this construction, it is preferred that the threading |16 upon the sleeve |15 and the thread- 9 ing, by which the cap, |14. is` mounted in the. bonnet, beinpppositedirectionsone a left hand, and; one a right handthread, so that tightening.

. The. construction thus shown. and` described preferably constitutesanrststag pressure reduction upon the educted gas and is preferably set at. approximately 3# output pressure. The regulator body is laterally threaded as at |86 to. receive theservice line, |81' whichruns to the second; stage, pressure regulator |88. withor without. avaporizer between. the two regulator housings, whil'shvaporizenV not shown,` may be anunderground vaporizer of aboveground vaporizer preferabh. using a convectively circulated liquid in theform of an, anti-freeze.` The. second stage regulator. |88 reduces the gas pressure to a service pressure of 11""V water column. which gas isthen.

delivered to an. appliance (notshown). througlia pipe IEII.. Y

A casing. |92. is providediover the regulator body |81 as, shown.. in liig.v 1 with an, opening |93 throughthe topthereof through which the forked end"` [8.4; of the hand. valve will be introduced with. sufcient clearance to take care of normally expected' manufacturing tolerances developing in relationship to theposition of the casing |92. and the regulator body |561. Although the casing |92 may be secured to the riser pipe |5 for the purpose oistructural rigidity, it is preferred.; that any connection provided therebetween be as little heat conductive as possible so that cold'. air chilling` the head 26 and the top of, the riser pipe |'5 will not, bev materially eiTective` upon the casing |92.V In. theV particular. embodiment shown', an insulating amount'of dirt is shown between the riserpipe and the. casing |92 whereby the temperature in the; casing |92' willbe' substantially the temperature` of the ground below the frost line I2.

Having thus described the invention, they assein-bage of the4 several associated parts is had as'follows:

After the riserpipe |-5 and ange |32 are welded to the tank around their respective openings |5= and' lf3, the companion flange 25' is tightened' in place at the top of the riser` pipe as sealed by litharge; suitable directionsbeing given toleave the companion ilange in any one of six positions in whichl the bolts are so arranged that when the body 26 having thefill pipe and float thereonV is lowered in position, theV shaft 'H of the float willI be in longitudinal alignment with the tank IU, the opening H/ being so located longitudinallyA ofthe tank thatadequate room for the action of the float 'l0 is provided at one end of'thetank'. Once the bod`y-26V is in position, the conduit |30 may be lowered and the union nut |35 tightened in place with the casing |92 securedf in position by ilanges |94 at the bottom l thereof securedV to. the. tank. The` tank and .assembly partsv are then ready for shipment and after burial in the ground,v the concreter box is. lowered, in place` with. the hand wheel and shaft |61 disposed so that the earth can be filled. in around the installation` as shown in Fig.v 1.

The vent valve H3 is then opened as has been. described and the ller connection 32. is secured;

to a tank truck after which liquefied gas is introduced into the tank through the valves D and 43. Once liquefied gas reaches the. interior of. the tank vapor pressurebecomes effective there and' the liquefied gas vapor being heavier than air,. the air is compressed and forced upwardly out the vent with little, if any, diffusion. After the. level ofthe liquid. has risen. high enough for' the bi-metal T6. to be submerged, the float when the predetermined level I3 is reached, movesthe nap valve (i3 out into. the stream of' the incoming liquid which causes it to close. action of the pump at the service truck is then by-passed back into the tank andV overlling; of

the tank |0 is positively prevented. Thereafter,

they vent valve ||3 is closed and the plug H82' returned in position and the air plugY |22 is removed. A suitable connection leading from the source of' air under pressure is attached to the adapter. nipple ||2 and air is forced' down the tube |23 and out of the` mouth thereof below the level of the liquid Where the. air bubbles up through thek liquid and becomes immediately difffused with liqueed gas vapor', theA sum of the partial pressures of which areV immediately indi'- cated upon the pressure gauge |I-9. It is preferred to apply enough air to bring the tankpressure to approximately lbs. per square inch higher thanthe vapor pressure so that therezwill be suli'cientv pressure in the tank above vapor pressure atall times toforce liquid from the tankv regardless ofthe depth of'the liquid therein or the increasing' space thev air has tovk occupy before the tankis emptied. Thus, under the most' extreme conditions of load upon the system, the air will be'effective to force liquid from the tank upthe conduit and into the service line |81 wheretheearth heator a vapori'zer providing aI source of heat will cause vaporization to takeplace tomaintain a constantA now of" gas to the appliance.

After the tank has been placed in operation with a supply ofliqueed gastherein, liquidE will ow through the opening |43 in a stream past the normallyl openedv valve |45 into the passage |l||` and conduit.` |30: where a reduction in pressure takes place by gas' being used in an ap-y pliance.- Under this reductionv of' pressure, the'` liquid will progressively vaporize, drawing heat" from the fitting |31 which is supplied' with heat bythe body liquid in theV tank until the pressure in the conduit! isV returned to 3# at which timethis pressure eiective over the area of the diaphragm |64 will cl'ose the valve |45 until suchv time as the pressure in the conduit |30 drops` the conduit llllli'saccomplished outside ofthe Further' tank as where heavy withdrawal conditions exist.

Having thus described an embodiment of the invention, it will be apparent to those skilled in the art that various modifications and changes and arrangement of parts may be made therein without departing from the spirit of the invention, the scope of which is commensurate with the appending claims.

What is claimed is:

1. An apparatus for supplying fuel of substantially uniform composition and at a low pressure from a mixture of liquid hydrocarbons, said apparatus comprising an underground tank buried below the frost line, conduit means extending from said tank to a place where the fuel is consumed, said conduit including a section having its inlet adjacent the bottom of said tank and arranged to be normally covered by the body of liquid fuel in the tank, a second section connected with the iirst and terminating near the place of fuel consumption, and control means including a pressure reducing valve at said inlet, and a pressure regulator in said second section.

2. In a liquefied gas dispensing system of the class described, a pressure storage tank buried underground in heat exchanging relation with the surrounding earth, an eduction conduit leading from the bottom of the tank and through the tank, a pressure reducing valve at the inlet of said conduit, a gas service pipe connected to the outlet of said conduit and a pressure regulator connected to the service pipe.

3. For use in a liqueiied petroleum gas dispensing system having a storage tank and a riser pipe connected thereto, a unitary fitting including means for supporting the fitting upon the riser pipe in sealed communication with the interior of the tank, a machined boss upon the fitting having a filling valve therein and a conduit in communication with said boss, said conduit extending to a point adjacent to the bottom of the tank, a liquid level responsive device carried by the fitting in association with the filling means, means for withdrawing liquid from the tank through said conduit, and means controlled by said liquid level responsive device to prevent overiilling the tank including a valve opening in the direction of outward flow of gas through said conduit.

4. A process of handling liquefied butane and butane mixtures as a gas comprising storing a body of liquefied fuel of the class described under a pressure greater than the vapor pressure of the liqueed fuel at ground temperature, simultaneously reducing the pressure upon a restricted portion thereof within the confines of the body to a predetermined pressure substantially less than the vapor pressure thereof at ground temperatures and subjecting said portions to heat exchange relationship with the remaining contents of the tank and discharging the vapors thus formed.

5. A fuel supply apparatus comprising a tank adapted to contain a liquefied gas under pressure, means for establishing a pressure in the tank above the vapor pressure of the liquefied gas, means to restrict and vaporize a portion of liquid in the tank including a tube extending from a point adjacent the bottom of said tank to a point outside said tank and an expansion valve for expanding said liquid in said tube said expansion valve being disposed in that portion of said tube which is within said tank.

6. In a liquefied petroleum gas dispensing system having a storage tank, an opening in a wall thereof, a unitary fitting, means for securing the iitting detachably in the opening, a liquid level responsive device carried by said fitting, said fitting having a machined boss thereon communicating with the tank, a filling valve assembly in said boss, and means including a conduit extending into the tank and a flow blocking element to obstruct the flow of gas into the tank when said device is moved to a predetermined liquid level in the tank, said device and said last mentioned means being insertable into said tank through said pipe.

'7. In a liquefied petroleum gas dispensing sys.- tem having a storage tank and a riser pipe secured thereto, a unitary fitting, means for securing the fitting detachably to the riser pipe, said iitting comprising a machined opening communicating with the tank, a filling valve assembly in said opening, and means including a conduit connected to the filling valve assembly and extending to a point proximate to the bottom of the tank to prevent overfilling of the tank.

8. In a liquefied petroleum gas dispensing system having a storage tank and a riser pipe secured thereto, a unitary tting, means for securing the fitting detachably to the riser pipe, said fitting comprising a machined opening communicating with the tank, a lilling valve assembly in the opening and means associated with the ller valve and carried as an assembly insertible through the riser pipe for preventing further flow of liquid into the tank when the level therein reaches a predetermined height.

9. In a liquefied petroleum gas dispensing system having a storage tank and a riser pipe secured thereto, a unitary iittting, means for securing the fitting to the pipe, said fitting comprising a forged body having a machined opening therein in communication with the tank iriterior, a filler valve assembly in the opening comprising two spaced valves closing with the outward iiow of gas from the tank and a conduit extending to the bottom of the tank, a liquid level responsive device carried by said iitting and means associated with said conduit and controlled by said device for preventing overfilling of the tank above a predetermined level.

10. A system of the class described comprising an underground storage tank for storing a liquefied gas including butane, means for introduc-` ing air under pressure thereto below the levelv of liquid therein, means for educting gas therefrom including a conduit leading from a point proximate the bottom of the tank, meansI for reducing the pressure in said conduit to a pressure between the vapor pressure of the stored gas and a service pressure, and service conduit means including a pressure regulator connected to said conduit.

l1. A system of the class described comprising a storage tank having an opening therein, a unitary fitting closing said opening, a fuel filler valve in said fitting and a filler conduit extending therefrom to a point adjacent the bottom of the tank for introducing liquid fuel into said tank, a check valve in said fitting and a second conduit extending to a point adjacent the bottom of the tank for introducing air into said tank, and eduction means for withdrawing fuel from the tank including a vaporizer for absorbing heat from the contents of the tank and vaporizing the fuel withdrawn.

12. In a system of the class described, the combination of a storage tank and a pressure regulator, said pressure regulator including an 13 elongated valve chamber extending into said tank to a point adjacent the bottom thereof.

13. ln a system of the class described, the combination of a liquid eduction conduit, extending to a point adjacent the bottom of the tank,^means for maintaining a pressure in said conduit below the pressure in the tank under normal conditions, and means for providing a pressure in said .tank above the normal vapor pressure of the contents thereof.

14. A system of the class described comprising a storage tank having an opening therein, a unitary tting closing said opening, a fuel ller valve in said fitting and a iiller conduit extending therefrom to a point adjacent the bottom of the tank, a second conduit extending from said iitting to a point adjacent the bottom of the tank for introducing air into said tank, said second conduit having a check valve therein7 eduction means arranged to absorb heat from the tank including a vaporizer disposed in said tank and a pressure reducing device for reducing the pressure in said eduction means ahead of said vaporizer, and heat insulating material separating said eduction means from the atmosphere.

15. In a system of the class described, the combination of a storage tank and a pressure reducer, said pressure reducer including an elongated valve chamber extending into said tank to a point adjacent the bottom thereof, a diaphragm exposed to the pressure existing in the valve chamber, a valve carried by the chamber, and means interconnecting the diaphragm and vvalve for controlling the operation of the valve by the diaphragm.

16. A system of the class described comprising an underground storage tank for storing a liqueiied gas including butane therein in both its liquid and vapor phases, means for introducing air under pressure into the tank below the level of the liquid therein and in direct contact with the liquid, means for educting gas from the tank including a conduit leading from a point proximate the bottom of the tank, means for reducing the pressure in said conduit, and service conduit means leading from said pressure reducing means including an element for delivering the gas to a consuming device at service pressure.

17. In a liqueed petroleum gas dispensing system having a storage tank, a fitting adapted to be secured in sea-led relation to the tank and having a boss thereon, means for lling the tank through the boss including a self closing back ilow check Valve in the fitting, a liquid level responsive device supported on the fitting and extending therefrom, and means including a conduit for interconnecting the check valve and the interior of the tank in normally open communication and a normally open inflow check valve c controlled by said device for limiting the amount of liquid which may flow into the tank through said conduit.

18. A method of handling a liquied gas cornprising storing a body of gas underground in both its liquid and vapor phases in heat exchange relationship with the earth, progressively separating gas in its liquid phase from the remaining body within the connes of said body to provide a stream of gas segregated from the body but in heat exchange relationship with the liquid remaining in the body, reducing the pressure on the separated gas to a substantially constant pressure as it is progressively separated, and simultaneously with said reduction of pressure supplying to the separated gas its latent heat of Vaporization from the sensible heat of the remaining liquid to flash the separated gas into vapor, and after vaporization conducting said vapor to a place of use at a service pressure.

19. A method of handling a liquiied gas comprising storing a body of gas in both its liquid and vapor phases, progressively separating gas in its liquid phase from the remaining body Within the connes of said body, reducing the pressure on the separated gas toa substantially constant pressure simultaneously with said separation of the gas, and simultaneously with said separa-tion and pressure reduction supplying latent heat of vaporization from the sensible heat of the liquid remaining insaid body to the sep-arated gas as it is being separated to ash the separated gas into vapor, and after vaporization conducting said vaporized gas to a place of useV at a service pressure.

2Q. A process of dispensing vaporizable liquied gas as a vapor from a body of liquiied gas stored under pressure in both its liquid and vapor phases comprising separating gas in its liquid phase from the remaining body of gas, simultaneously with separating the gas reducing the pressure thereon in heat exchange relationship with the remaining liquid present in said body, and through said heat exchange relationship supplying from the sensible heat present in said remaining liquid to said separated gas the latent heat of vaporization required to flash the separated gas into vapor, and thereafter further reducing the pressure on said vapor to a service pressure.

21. A process of discharging a vaporizable liquied gas as a vapor from a body of liquied gas stored in both its liquid and vapor phases comprising progressively educting liquid from said body to separate it therefrom at'a point near the bottom of said body, reducing the pressure on said educted liquid to a predetermined substantially constant pressure as it is being separated, warming the educted liquid with the` sensible heat present in the remaining liquid in said body to supply the latent heat of vaporization required to vaporize the educted liquid, and further reducing the pressure on the resulting vapor to a service pressure, said progressive eduction and said first reduction of pressure and said Warming of the educted liquid taking place simultaneously and at substantially the same place.

HAROLD L. NORWAY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,935,925 Wannack Nov. 21, 1933 1,960,108 Hermsdorf 1 May 22, 1934 2,072,713 Folmsbee et al Mar. 2, 1937 2,121,675 White June 21, 1938 2,339,134 Baker et al Jan. 11, 1944