US2361865A

US2361865A - Liquefied petroleum gas system

Info

Publication number: US2361865A
Application number: US375078A
Authority: US
Inventors: Harold L Norway
Original assignee: BASTIAN BIESSING CO
Current assignee: BASTIAN BIESSING CO
Priority date: 1941-01-18
Filing date: 1941-01-18
Publication date: 1944-10-31
Anticipated expiration: 1961-10-31

Description

Oct. 31, 1944. H NORWAY 2,361,865

LIQUEFIED PETROLEUM GAS SYSTEM Filed Jan. 18, 1941 s Sheets-Sheet 1 Harold L. Norway ENTOR ISI m nwu H m M FIG. 7

Harold L. Norway INVENTOR- M mm m 75 go as c2 c4 6 :32 l tv I IN \R S .l I. m l as m ml 3 5 Mme Oct. 31, 1944.

Patented Oct. 31, 1944 UNITED STATES PATENT OFFICE LIQUEI'IID PI'I'IOLIUH GAS SYSTEM llarolllsltcrwamlvanstomlll assignorto'llie Bastianllessingfla, 01116 8 11L, a corporationcflllinois Application January 18. 1.41, Serial No. 375,078

ZSClaims.

- ation and filled with liquefied petroleum gas, it

becomes necessary uponroccasion to unload or empty the tank for repair, removal or replacement, and also to drain of! heavy ends or replace a winter gas with a summer gas for seasonal operating conditions. 7

with conventional systems it is difficult. if not impossible, to unload the tank rapidly and with safety. Excess now check valves interfere with rapid withdrawal in wet gas systems and dry gas systems require complicated mechanisms for t P 9 It is one of the objects of the present invention to provide an improved system and method for filling and unloading tanks under pressure, and further to provide a system in which an unlicensed withdrawal is hampered to such an extent as to discourage the practice.

A further object of the invention is to provide equipment readily convertible to fill or unload a pressure container at will and to accomplish this preferably through one port where elements must be operated in a predetermined relationship for the unloading of the container.

Another purpose of the invention is to utilize equipment conventionally employed to fill the tank,toalsoemptythetankasusingthe same fie hose with a reversible pump-upon a service Another object is to provide a combination of tank and fitting construction characterised by safegu rds against unsafe removal of Ias and other contingencies experienced in unloading pressure containers.

The present invention also provides an improved means for maintaining house service independently of liquid unloading.

Another object of the invention is to provide an improved system in which stratified heavy endsinthetankarestirredupinthefillingoperation, and withdrawn first from the tank in the unloading operation. In this connection, one of the objects of the invention is also to provide a withdrawal system which permits the light endsinthetanktomaintainagauge pressure which assists a suction pump in unloading operations.

Afurtheroblectistoprovideasystemand Cl. I -1) which are easy to fabricate and assemble, and which are rugged in use and simple to operate.

These being among the objects of the invention. other and further objects will become apparent from the drawings. the description relating thereto and the appended claims.

In the drawings;

Fig. 1 is a side elevation of one form of the apparatus mounted in association with the storage tank;

Fig.2isaplanviewonanenlargedscaleof a part of the apparatus shown in Fig. 1;

Fig. 3 is a vertical section taken at line 3-4 .of P18. 2;

Fig. 4 is a vertical section of the apparatus of Fig. 2 taken at line 4-4 of that figure;

Fig. 5 is a longitudinal section through a modified form of the invention in which it is embodied in a single connection, the parts being shown in the closed or inactive position;

Fig.6isavlewsimilartoFig.5showingthe device of that figure associated with means for withdrawing fluid from the tank; and

Fig. 7 is a section similar to 'Fig. 5 illustrating another and more compact embodiment of the invention.

By way of illustrating representative conditions relating to the storage and the handling of liquefied petroleum gas, the invention is illustrated in an embodiment where the storage tank is buried in the earth. This refers the invention to another condition which requires unloading. namely, that if the tank were to be raised and exposed to the warmth of sun-light, it would have to be emtpied or liquefied petroleum gas such as propane or butane, stored therein.

The system illustrated, preferably has the tank I located below the frost line 2 or below the level to which the ground will freeze under the weather 40 conditions prevailing where the tank is installed.

A manhole casing 3 may be secured to the tank or mounted adjacent to it to provide a space for the filling, emptying and dispensing connections and parts. The casing I will normally be provided with a cover 4 which may be removably secured in any desired manner, and, ordinarily, some means is provided in the cover or the easing to permit circulation of air into and out of the casing and to allow for relief valve venting such as a vent la. The invention is not limited combination of elements of the class described to any particular tank or tank assembly of course, but may be used with above or below ground installations.

As shown in the first four figures, a stand-.

pipe or dome I is welded to the tank at 6 to form an integral extension of the tank and at the top thereof, the pipe is preferably threaded to receive a unitary housing member 1. The interior of the standpipe communicates with the interior of the tank and the housing member I may be of almost any desired shape, preferably being provided with a hollow chamber M in communication with the tank through the standpipe as shown provided with a round section it that is interiorly threaded as at 9 with a tapered thread to engage the threading E on the upper end of the standpipe 5.111 gas tight relationship. Other appropriate means of securement may he. employed.

A hollow branch l2 communicates with the chamber H and is provided with an opening l3 about which is formed a valve seat M. A safety or pressure relief valve :5 is movably mounted adjacent the seat and is provided with a relatively compressible seating portion l6, removably held in position in the valve body in a flanged, threaded retaining member H.

The safety valve itself is provided with an upwardly extending portion 98 in which is formed a hollow I9. The valve may be generally rounded in cross section or otherwise shaped. As here shown, ducts or passages 20 are formed in its interior to permit passage of fluid past the valve when it is unseated. A spring retaining member 2| is threadingly engaged with the threads 22 formed in the branch l2. This spring retainer is provided with one or more perforations 23, and a spring 24 is seated with one end against the spring retainer, its other end being against the valve l5 and within the cavity or depression iii.

The hollow branch l2 communicates with the main chamber ll through a passage 25. A second passage 26 communicates withthe chamber H and with the interior of a second hollow branch or arm 27. As shown, this branch is or use for certain installations, as when it is desirable to have greater pressure relief capacity, in which case the upper wall of thebranch 21 will be cut away to provide for the installation of a second or additional pressure relief valve which will be generally like that shown in detail, in Fig. 3 and described above.

It is preferred to fill and empty the tank through the housing member I and through a single opening. This is accomplished by forming a hollow boss 28 preferably integral with the housing and providing it with a threaded opening 39 between the interior 29 of the boss and the chamber H to receive a pipe 3i which extends to a point close to the bottom of the tank, as shown in Fig. 1, and a liquid connection opening outside of the housing.

The liquid outlet and inlet connection as shown in Fig. 3 is formed in a portion 32 which is preferably integral with the main housing 8. A depression 33 is formed in the member 32, and an annular depression 3d is formed about it. A stem 35 of a valve member 36 is slidably positioned in the depression 33. 38a is a projection formed on the upper surface of the valve 36. A spring 3'1 is positioned about the stem 35; one end rests within the annular depression 3 3 and the other bears upon the valve 36 and tends to hold it, when free to do so, upon the seat portion 38 of the annular member 39. This member is removably seated in the threaded portion 40 of the housing section 32. It is provided with one or more perforations 4| through which fluid may pas in or out. It is also provided with a cylindrical, outwardly directed section 62 within which a stem 43 of a second valve member 44 is positioned.

A spring 45 is positioned about the cylindrical portion 42 and about the valve stem 43. It bears at one endv upon portions of the member lid and at the other upon the bottom or the valve 34, and

tends to hold it closed, when free to do so. A

seating portion oi compressible material 43 preferably removably mounted on the upper or.

outer face of the valve 36 and held in place by a washer 4! and a screw 68. A'connection and seating member 49 is removably engaged in the threaded portion 0! the housing section 32. It is provided on its inner or lower end witha seat portion 50 against which the member dd of the valve 44 is seated when the valve is closed. Ad-

jacent its upper end, the member 49 is interiorly threaded as at B8 to receive a closure plug 52. The member 49 is also exteriorly threaded as at 53 to receive a filling hose or adapter connection. The closure plug is provided with an overhanging, downwardly disposed peripheral flange It which overlies and covers, to some degree at least,

the threads 53 when'the plug is in the closed position. A gasket 55 may be positioned within a groove or undercut portion 56 formed in the open, upper end of the member 49, and a shoulder 5'! of the closure plug seats against, and to some degree compresses this gasket when the plug is in the closed position.

Formed generally within the branch or arm 2i is a passage 60 which communicates at its inner end with the interior of the houesing 1, and particularly with the chamber ll through an enlarged branch passage 15 having a threaded open ing 61 at the lower end thereof and a valve seat at the top. Adjacent its outer end, the passage 60 is provided with a yalve seat 62 within.

which it may be engaged by a tool for rotation to move it into or out of seating position. A cover or cap 10 is received upon the threaded portion ll, and may have laterally extending wing portions 12 by means of which it may be rotated, and itmay have an angular cavity '58 used to rotate the stem ill. An outlet passage it branches downwardly from the passage 60 beyond the seat 52 and is threaded as at 82 to receive the nipple portion of a swivel connection and nut 83 by which a pressure regulator 87 is secured in place. The pressure regulator 8i may be of any desired type or capacity. From the regulator 83, a pipe 88 leads through a connection 89 to a second pipe 90 which leads-to the point of use of the fluid which passes through the system. SM is a pressure-vent tube which, if desired, may be attached to the regulator 31!.

Within the enlargement 15 is positioned an excess flow check valve member Tl, which as shown is provided with drilled passages 78 therethrough to permit a predetermined amount of vapor or liquid to flow therethrough with a spring 19 holding the valve open against the flow of fluid within the limits determined. A retainer 9i holds the valve and spring in position. When the flow is excessive the valve closes against the seat 80'. it is a small by-pass opening through the excess flow check valve member ll which permits equalization of pressure so that the excess flow check valve can open, once it has closed.

aseness 3 with this arrangement it is possible to service the valve l3 and packing ll whenever necessary and rapid withdrawal of liquid is prevented in large'quantities if a person seeking to unload the tank removed the valve GI or the regulator 01 to make connection with an unloading hose at either of these points. The top or upper surface of the housing 1 is provided with an opening "to receive a slip tube gauge 5! or the like therein to gauge the level of liquid in the tank.

The valves 30 and preferably have the same port area, allowance being made for the stud "a on the top of the valve 3| which is contacted by I eifective separately for both valves.

The particular arrangement shown is of an advantage upon filling operations where the pressure of the incoming fluid may not be very great in some instances both valves being preferably identical where the port areas are the same. However, when it is desirable to unload the tank, mechanical means can be used which is conveniently strong enough to overcome the additive pressure of both springs with little dimculty.

A modification of this valve arrangement and operation is shown in Figs. 5 and 6 which comprises a hollow housing 92, preferably threaded exteriorly as at 93 to be received into a corresponding threaded opening in a container. The housing is provided with an internal spider 94 which has one or more perforations 95 formed in it. On its lower or inner face, the spider has a valve seat 96 against which a valve 91 may be seated. The valve is provided with a stem 98 mounted for sliding movement in a central portion 99 of a spider IIIII which is provided with one or more perforations Ill. This spider is formed in a separate or additional section III! which is threadedly en aged with the main housing section 82. It may be interiorly thredded as at I to receive a pipe connection it desired.v

A spring I is positioned to bear at one end against the valve 91 and at the other end against the spider 89 or the portion I of that spider. U'ponits upper face, the valve 91 has a raised projection I which is adapted to contact the valve stem I" of the valve IlL. This stem is mounted to slide in the spider 9|. A spring Ills bears at one end against the spider ll and at the opposite end against the valve II". This valve may carry on its seating face a compressible member Ill'la which is removably held in place by a washer I" and a screw IIII. A connecting and seating member III is in threaded engagement with the housing 92, and it has formed on-its inner face a valve seat III against which the valve portion Illa may be seated.

At its upper end the member III is interiorly threaded as at I I3. It is also exteriorly threaded a at Ill. A closing plug I I5 may be removably seated in the threads Hi. This plug is provided with a downwardly depending peripheral flange II6 which, when the plug is in the closing position, overlies some, at least, of the threads Ill. A gasket II'I may be mounted in a groove III! within the housing section III; and a shoulder 9 on the closing plug IIB bears against and to some degree compresses this gasket when the plug is seated.

Asshown in Fig. 8, the seating plug III has been removed and in its stead positive displace-' ment means have been provided for withdrawing liquid from the tank or container to which the connector assembly is secured. As shown. a connector if. has been inserted in the place of the closing plug III. This connector is exteriorly shouldered as at III, and a connecting collar I22, having a flange I23, surrounds the member I" and engages the threads Ill and, thus, the member I22 is held in position upon the threads Ill of the member III. The gasket III is compressed by the shoulder Ill of the member I20. Positioned within the member Ill is a valve operating part I". As shown the part I25 is hollow. At its lower end it is provided with a'contacting point I26 and it has one or more passages or openings I21 formed in its lower end. It is preferably shouldered as at III at its upper end. Secured to the upper end of the member I" is an internally threaded tubular member II! which is also externally threaded tubular member II! which is also externally threaded as at IlIl to receive a hose coupling. A gasket Ill is received in a groove I32 formed in the member I28. A hose connection I33 may be inserted within and connected to the member In and held in place therein by a coupling nut Ill which is interiorly threaded as at I35 and provided with an inwardly directed flange III which engages a shoulder Ill.

By this means the hose connection is held in place and the valve operating member III is depressed to open the valve as shown in Fig. 6. A hose, which is not here shown, may be secured to the upper or free end of the hose connector I" in any desired manner.

Referring to Fig. '7 another modification is shown which is very compact in form, one valve being receivable within the confines of the other. In this particular embodiment, the housing I is threaded into the top of a fitting I" which fitting has a valve seat Iii proximate to and larger than the valve seat II2 upon the lower end of the housing III. A spider IE2 is threaded into the bottom of the fitting I" to support the stem I53 of the lower valve lil for reciprocation in an opening I through a central boss Ill upon the spider. The spring lilo urges the lower valve upwardly into contact with the seat III. The lower valve Ill is hollowed out to receive the upper valve I51 therein which carries a resilient seat IIlla into contact with the seat H2. The upper valve is small enough to clear the seat ISI for removal and repair whenever the housing III is removed for that purpose.

The stem I58 of the upper valve III is reciprocably received in a closed-bottom guide-opening ISO in the stem I53 and is urged into contact with the seat II! by a spring ISI resting upon the shoulder I! at the bottom of an enlargement I63 made to receive the spring IiI in the body of the lower valve.

In this particular embodiment the valve areas are of different sizes but operate substantially in the same way as already described. I

As shown in Figs. 3 and 4 particularly, the threaded opening 6| may be left open, for some purposes, as where dry gas withdrawal is desired. On the other hand in some systems it is preferable to position a small pipe shown in broken lines Ill in the opening II and to have it extend downward into the liquid within the tank. The opening may, thus, be used exactly as shown or with a tube installed.

3? spouses @rdinarily, a pressure gauge is desirable. One such is shown in Fig. 2 as at 6138. It has a dial 989 and a needle or pointer I40. It is connected by means of a tube ill to the housing branch 32 in the wall of which an opening 882, as shown in Fig. 3, is termed in register with the pipe Mi.

Although several forms of the invention are shown and described, it will be understood by skilled in the art that many changes in the form. relative dimensions, shape and arrangement of parts might be made without de-' parting from the spirit of the invention, the scope of which is commensurate with the appended claims.

The use and operation of this device are as follows:

The closure plug 52 is removed. A hose connection, generally similar to that shown in Fig. 6, is connected. The other end 01' the hose is connected to a source of liquid; for example, to

a tank, truck tank, or tank car. Suitable valves are opened and the liquid flows through the hose and comes against the uppermost valve 46, opening it by compressing the spring 45. The stem of the valve N contacts the member 360. of the valve 36 and opens this valve, also, against the resistance of the spring 31, and the liquid flowing past both valves enters the tube 3| and flows to the bottom of the tank. Sometimes the weight of the liquid alone or the pressure of a warm service tank is sufilcient to open the valve and to cause the liquid' to how into the tank. Sometimes it is not sufficient, and a pump on the tank truck or elsewhere is used to force the liquid into the tank. Opening of the first valve 1 is followed by the opening of the second valve at times independently of each other without need for additional pressure. When a sufllcient quantity of liquid has been forced into the tank, further flow is stopped, the hose connection is removed, the valves will have been closed, either by vapor pressure within the tank or in response to their respective springs or in response to both of these effects. If the hose has been removed,

the closure plug is re-inserted. As a precautionary measure, the fitting 49 is undercut as at X; and should some unexpected breaking occur, the fitting will break at the point X above the valves and they will then automatically close to prevent discharge of liquid or any fluid from the tank.

With the tank now suitably filled with gas, some vapor will be present. Ordinarily, this vapor will pass up the standpipe 5 and outward through the opening GI and the passage lid. Usually, when the system is first installed, the valve 63 will be seated. After the tank is full and when the system is to be put into use, the valve will be opened, being backed away from the seat 62 and vapor then passes from the passage 60 to the passage l8, moving past the check valve ll, outward through the opening 68 and through the nipple of the swivel connection 83. If a pressure regulator is installed, the fluid moves to it from the nipple of the swivel connection 83 and from the regulator, it moves through the pipes 88 and 90 to the point of use. Theinvention is not limited to the use of a regulator, and in case one is used, the invention is not limited to any particular type. No regulator may be present, or several regulators may be used if desired.

For some purposes, it is desirable to permit liquid or a mixture of vapor and liquid to leave the system for use. Where that is done, a pipe is inserted in the opening at and extends downward into the liquid...

Vapor pressure within the tank will forcethis liquid upward through the pipe and into the passage to, and irom there it iollows the path above described tor the vapor alone. Where liquid is. thus, discharged irom the tank for using,

some means is provided tor accomplishing its vaporization before it reaches the point 01 use.

A number of such means are available and the invention is not limited to any particular one.

Should the flow of fluid through the passages M, 14 be too rapid or otherwise unsatisfactory, the check valve 18 will be moved upward against the spring 18 and will be seated upon the upper surface of the member 80, thus stopping the flow. Occasionally it is necessary to empty a tank by withdrawing the liquid from it. Where that is necessary, the closure plug 52 is removed, as it would have been for filling, and a member suchas the member l2! 0! Fig. 6 is inserted with the connections there shown, a hose having been previously connected to the member I33. At its other end, the hose is connected to a suitable receptacle into which the liquid is to be deposited. When the member I25 is put into position and the hose connection is tightened upon it, it contacts the screw 48 on the valve 44 and moves that valve open. The stem 43 contacts the projection 36a of the valve 86 and opens it. The two valves are, thus, held open while the member I25 is inplace, and liquid may now be pumped out of the tank through the pipe 3i until the tank is wholly or substantially empty. Then the member 525 and the hose connection are re-' moved and the empty tank may be repaired or removed or otherwise treated. It will be noticed that the connector I29 has a relatively narrow section at the point Y; and should side pressure occur on the connections, it will break at that point rather than at the point X on the member 49. When that occurs, there is nothing to hold the member H5 down in the valve opening position, and the valves will thereupon close either in response to their springs or to pressure from within the tank or in response to both.

Installations of the type shown in the first iour figures ordinarily require a pressure release or safety valve mechanism. Figs. 3 and 4 show such a mechanism. Excess pressure will be efiective on the valve i5 and will cause it to yield outwardly againstthe resistance of the spring 26 and, thus, pressure is released from the system. As above mentioned, more than 'one pressure release valve may be installed. This will be done where a greater pressure release ca-= pacity is required than could be conveniently furnished by means of -a single valve.

Ordinarily, some sort of liquid level gauge is provided. The opening 58 and the pipe 59 merely indicate diagrammatically a suitable location for such a gauge, which may be of any desired type-mechanical, electrical, slip-tube or other type.

What is claimed is:

1. In combination with a tank, a hollow housing formed of a unitary member and connected to said tank in communication with its interior, parts of said unitary member defining an inlet and a discharge passage for moving fluid into and withdrawing it from said tank, a pipe secured in communication with said passage and extending into said tank, a plurality of valves in said housing opening in the direction of the flow of fluid introduced into the tank under I accuses "with its interior, parts or said unitary member deiining an inlet and a discharge passage tor moving fluid into and withdrawing itirom said tank, a pipe secured in communication with said passage and extending into said tank, a plurality of valves in said housing disposed-in said passage for controlling the flow oi 'fluid therethrough, means normally holding them closed, parts on the valves adapted to contact each other whereby opening movement of the outermost valve accomplishes opening or any adjacent valve,

and a removable connector assembly adapted to adapted to contact each other whereby opening movement of the outermost valve accomplishes openi aoi an adjacent valve, and a removable connector assembly adapted to be secured to said housing and including a hollow valve-operating member which moves said outermost valve to the open position.

6. In combination wiith a tank, a valve hous- I a ing formed ota unitary member secured in sealed communication with the interior of said tank, there being within said housing a plurality of valve' seats and valve-supportingmeans connected by .a passage, and a plurality ofvalves movably mounted therein, means for each valve be secured to said housing and including a ho1- 1 low valve-operating member which moves; said outermost valve to the open position. Y

3. In combination with a tank, a' hollow hous ing formed of a unitary member secured .to the tank in communication with its interior,'parts of said unitary member defining an inlet and a discharge passage for moving fluid into and withdrawing it from said tank, a pipe'secured in communication with said passage and extending into said tank to a point adjacent the bottom of the tank, a plurality of valves in said housing for controlling the flow of fluid through the pas:-

sage, means normally holding them closed; parts on the valves adapted to contact each other whereby opening movement of the outermost valve accomplishes opening of an adjacent valve, and a removable connector assembly adapted to be secured to said housing and including a hollow valve-operating member which moves'said outermost valve to the open position.

4. In combination with a tank buried in the ground, a standpipe extending upwardly to a point accessible above the ground, a hollow housing' formed of a unitary member and secured to the upper end of said standpipe and in communication with its interior, parts of said unitary member defining an inlet and a discharge passage for moving fluid into and withdrawing it from said tank, a pipe secured in communication with said passage and extending through said standpipe into said tank to a point adjacent to the bottom'of the tank, a plurality of valves in said housing disposed in said passage to control the flow of fluid through the passage, means normally holding them closed, parts on the valves adapted to contact each other whereby'opening movement of the outermost valve to a predetermined degree accomplishes opening of an adjacent valve.

5. In combination with a buried tank, a standtary member defining an inlet and a discharge passage for moving fluid into and withdrawing it from said tank, a pipe secured in communication with said passage and extending throughsaid standpipe into said tank to a point adjacentthe bottom of the tank, a plurality of valves r in said housing disposed in said passage, means normally holding them closed, parts on the valves tending to seat it, when free to do so, said valves provided with portions which, when the one valve is opened by positive displacement, will contact each other and will transmit opening movement from the one valve to the other valve to open the latter, and a connector assembly adaptedto be removably secured to said valve housing, said connector assembly including a hollow valve opening member adapted, when seated, to open the outermost valve to such degree as to cause opening or an adjacent valve.

, '1. In combination with a tank for storing liquefied gas having a'standpipe or the like, an integral hollow unit secured to the standpipe in communication with the interior or the tank, a passageway through a wall of the unit defining a conduit through which fluid may be moved, means" for conducting fluid from the tank to the passageway, a safety. check valve in the passageway closing with the flow oi fluid irom the tank,

a self closing check valve in the passageway opening with the flow oi fluid into the tank, means interconnecting the valves including a lost motion device permitting said valves to operate independently oi." each other at times when the tank is receiving liquefied gas and one dependently upon the other when the tank is being emptied 8. In combination with a tank having a standpipe or the like, a unitary housing on the standpipe having a cavity in communication with the interior of the tank, said housing having a service outlet and a filling passageway independent of one another, an excess flow. check valve in the outlet, a safety check valve in the passageway closing with the flow of fluid from the tank,

a self closing valve inthe passageway opening with the flow of fluid into the tank, and removable connector device for withdrawing fluid from the tank so constructed and arranged as to force said self closing valve and safety check valve open by simultaneous positive displacement of the valves cooperatively whenever the device is attached to the housing.

9. In combination with a tank, a unitary housing mounted on the tank and having a cavity in sealed communication with the interior of the tank, said housing having a service outlet and a fllling passageway independent oi. one another, an excess flow check valve in the outlet to control educti'on from the. tank under service conditions, tandem valves opening at times independently oi each other'under fluid pressure and co operatively ,with each other when positively displaced, a removable connector device for withdrawing fluid from the tank so constructed andarranged as to positively displace said valves cooperatively whenever the device 'is attached to the housing.

liquefied petroleum gas, a unitary housing having a cavity therein, means for securing the housing to the tank including an element providing a conduit communicating with the cavity at one end and opening near the bottom of the tank at the other end, a filling passageway through a wall of the housing and opening into the cavity, a safety check valve in the cavity closing with the flow of liquid from the tank, a second valve in the cavity controlling the flow of fluid out of the tank, manual means for positively displacing the second valve, and means for opening the first valve by the second valve when the second valve is opened beyond the predetermined minimum.

11. In a liquefied petroleum gas dispensing system, the combination of a tank for storing gas under pressure, a fitting connected to the tank and having a space in the body portion thereof in communication with the tank, a passage through the wall of the fitting, a conduit extending to the bottom of the tank connected to one end of the passage, a plurality of safety check valves in tandem in said passageway, means for connecting a conduit to the fitting at the other end of the passage, and a service conduit communicating with the interior of the tank and having a manual control valve therein and an excess flow checkvalve therein.

12. In a liquefied petroleum gas dispensing system, the combination of a tank for storing gas under pressure, a fitting connected to the tank and havinga space in the body portion thereof in communication with the tank, a passage through thewall of the fitting, a conduit extending to the bottom of the tank connected to one end of the passage, asafety check valve in said passageway closing against one seat, a second safety check valve carried by the first valve and closing against a second seat, means for connecting a conduit to the fitting at the other end of the passage, a service conduit communicating with the interior of the tank and an excess flow check valve in said conduit.

13. In a liquefied petroleum gas dispensing system, the combination of a tank for storing gas under pressure, a fitting connected to the tank and having a space in the body portion thereof in communication with the tank, a passage through the wall of the fitting, a conduit extending to the bottom of the tank connected to one end of the passage, a plurality of safety check valves in said passage normally closing in the direction of flow of gas from the tank, means for connecting a conduit to the fitting at the other end of the passage, and an angular service conduit communicating with the interior of the tank, a manual control valve therein upon one side of the angle,'and an excess flow check valve therein upon the other side of the angle.

14. In a liquefied petroleum gas dispensing system, the combination of a tank for storing gas under pressure, a fitting connected to the tank and having a space in the body portion thereof in communication with the tank, a passage through the wall of the fitting, a conduit extendin to the bottom of the tank connected to one end of the passage and extending through said space, a plurality of check valves in said passage closing in the direction of fiow of fluid from the tank, means for connecting a conduit to the fitting at the other end of the passage, a service conduit communicating with the interior of the tank through said space, a manual control valve in said conduit and an excess 11 W check valve in said conduit between the manual control valve and said space.

15. In a' liquefied petroleum gas dispensing system, the combination of a tank for storing gas under pressure, a fitting connected to the tank and having a space in the body portion thereof in communication with the tank, a passage through the wall of the fitting, a conduit extending to the bottom of the tank connected to one end of the passage and extending through said space, a plurality of check valves in tandem in said passage closing in the direction of flow of fiuid from the tank, means for connecting a conduit to the fitting at the other end of the passage, a service conduit communicating with the interior of the tank and terminating in a threaded opening adapted to receive a liquid eduction tube, a manual control valve and an excess fiow check valve in said conduit.

16. In a liquefied petroleum gas dispensing system, the combination of a tank for storing gas under pressure, a fitting connected to the tank and having a space in the body portion thereof in communication with the tank, a pinrality of passages through the wall of the fitting, a conduit extending to the bottom of the tank connected to the inner end of. one of the passages, a, plurality of check valves in said one passage closing in the direction of flow of fiuid from the tank, means for connecting a conduit to the fitting at the outer end of one passage, an excess fiow check valve proximate said space and a manual control valve in another of said passages, a safety relief valve in another passage,-

and a manually opened check valve in another of said passages for venting the tank from said space.

17. In combination with a tank; a hollow valve housing formed of a, unitary member secured in sealed communication with the interior of said tank, there being disposed within said hollow housing a valve seat and .valve supporting means; a removable hollow section secured to the housing,-said removable section including a valve supporting member; a second removable section adapted to be Joined to the opposite end of said hollow valve housing and having a valve seat formed therein; said valve housing, valve supports and hollow section comprising a passageway placin the interior of the tank in communication with the outside: a valve in said valve housing; means tending normally to move said valve to its closed position when free to do so; a valve in said first-mentioned removable section; and yielding means tending normally to close thelast said valve, when free to do so; the two valves having parts adapted, when the outermost valve is opened to a predetermined degree, to cause opening of the adjacent valve in response to opening of the outer valve.

18. In combination with a tank; a valve housing formed of a unitary member and secured in sealed communication with the interior of said tank, there being within said housing a passage, a valve seat and valve supporting means; a removable hollow section secured to the valve housing, said removable section including a valve supporting member; a second removable section adapted to be joined to the opposite end of said valve housing and having a valve seat formed therein; a valve in said valve housing; means tending normally to move said valve to its closed position, when free to do so; valve in said firstmentioned removable section; and yielding means tending normally to close the last said valve.

accuses 7 when free to do so; the outer or said valves being opened by pressure and positive displacement and the inner oi said valves checking the outflow of said fluid from the tank, the two valves having parts adapted, when the outerinost valve is opened to a predetermined degree by positive displacement, to contact each other and to cause opening or the adjacent valve in response to opening of the outer valve.

in. in combination with a tank for storing linuitied gas, a unitary fitting, secured in sealed communication with the interior of said tank and having a passageway tlierethrough defining a conduit through which iiuid may be moved, means for conducting fluid iroin the tank to the passageway, a client; valve in the passageway closing with the flow oi fluid from the tank, a sell" r-iosmg check valve in the passageway opening with the how or fluid into the tank, means interconnecting the valves including a lost motion device providing independent movement between said valves at times when the tank is being nlled and dependent movement between the valves when the tank is being emptied, in which dependent movement the movement of one valve to its open position operates to hold the other valve open.

20. In combination with a tank for storing liquefied petroleum gas having a boiling point below the freezing point of water, a unitary housing secured in sealed relationship with the tank and having a cavity therein in communication with the interior of thetank, said housing having a filling passageway through which fluid may move, a check valve in the passageway closing in the direction of flow of fluid from the tank, a self closing check valve in the passageway opening with the flow of fluid into the tank, said valves opening independently of each'other at times when fluid is forced into the tank, conduit means connecting the cavity with the bottom of the tank, and means for opening the valves in a predetermined relationship i'or withdrawal of liquid from the tank through said conduit means.

21. In a hollow valve housing, a. plurality of valve seats and valve-supporting means, and a plurality of valves movably mounted therein, means for each valve tending to seat it, when free to do so, said valves provided with portions which, when the one valve is opened, will transmit opening movement from the one valve to the other valve to open the latter, a connector assembly for a filler conduit adapted to be removably secured to said valve housing, said connector assembly including a removable hollow valve opening member adapted, when seated, to open the outermost valve by mechanical displacement and thereby to cause opening of an adjacent valve, and a fitting supporting said filler conduit and detachably receiving said valve opening member.

22. In a coupling for servicing a storage tank, a valve housing having a passage therethrough. a plurality of valve seats and valve supporting means in the passage, and a plurality of valves movably mounted therein, means for each valve tending to seat it, when free to do so. said valves positonecl adjacent each other, and provided with portions which, when the one valve is opened, will transmit opening movement from the one valve to the other-valve to open the latter, and a connector assembly adapted to be removably secured to said valve housing, said conmotor assembly including a fitting for supporting a flexible conduit and a hollow valve opening member detachably received upon the fitting and adapted, when seated, to open the outermost valve and thereby to cause opening of an adiacent valve.

23. in a hollow valve housing, a plurality of valve seats and valve-supporting means, and a plurality of valves movably mounted therein, means for each valve tending to seat it, when free to de so, said valves provided with portions which, when the one valve is opened, will contact each other and will transmit opening movement trout the one valve to the other valve to open the lutter, and a connector assembly adapted to he re inovably secured to said valve housing, said connector assembly including a hose connecting element with. a coupling nut thereon, a coupling member receiving said nut in threaded relation, a second coupling nut carried by the coupling member, and a hollow valve opening member extending beyond the second coupling nut secured in place by the first coupling nut and coupling member, said hollow valve opening member adapted under force exerted by the second coupling nut to open the outermost valve and thereby to cause opening of an adjacent valve.

24. Means for filling and rapidly emptying a storage tank which has been placed in operation comprising a portable connector nipple, a housing member adapted to be secured to the tank and having a tube extending to the bottom of the tank, said housing being provided with independent valves and valve seats adapted to be held open conjointly when one of the valves is forced open by insertion of the connector nipple whereby the contents of the tank are forced out by pressure present in the tank, said one of the valves being removable from outside the tank while the tube is in the tank, resilient means disposed inwardly of the respective valves for holding the valves closed against their respective seats, said resilient means being of such strength that when fluid is injected into the tank to fill it, the resistance of the resilient means is overcome by the pressure of the filling fluid.

25. In a device of the class described for filling and emptying an underground tank having liquefied petroleum gas present therein in both its liquid and vapor phases, the combination of a housing member secured to the tank and adapted to be accessible from above the ground, conduit means extending through the housing member and including a pipe which opens at its lower end at a. point close to the bottom of the tank, independent valves and valve seats mounted in said conduit means and so constructed and arranged as to be opened conjointly when the outer valve is forced inwardly and open by the insertion of a. nipple into the outer end of said conduit means, whereby the contents of the tank in the liquid phase thereof are forced out by the pressure in the tank of the contents present in the vapor phase, means located inwardly of the valves for normally holding the valves closed against their respective seats including resilient elements, the last said means being of such strength as to yield to permit the valves to open under the pressure of inflowing filling fluid when the filling fluid is forced into thetank, and said outer valve being removable from outside the tank for repair and replacement,

' HAROID L. NORWAY.