Title:
Delivery system for volatile liquids
United States Patent 2348478


Abstract:
This invention relates to apparatus for transferring and distributing liquid petroleum gases such as butane, propane, and the like, and more especially to an apparatus of this type having novel safety features incorporated therein. These gases are usually in liquid form when transferred from...



Inventors:
Jones, Nelson M.
Application Number:
US47355543A
Publication Date:
05/09/1944
Filing Date:
01/25/1943
Assignee:
GREEN S FUEL INC
Primary Class:
Other Classes:
62/48.1, 62/50.4, 62/53.1, 62/53.2, 137/614.04
International Classes:
B67D7/04; B67D7/36
View Patent Images:



Description:

This invention relates to apparatus for transferring and distributing liquid petroleum gases such as butane, propane, and the like, and more especially to an apparatus of this type having novel safety features incorporated therein.

These gases are usually in liquid form when transferred from a truck tank to an underground storage tank. When the liquid gas is delivered into an underground tank, the heat of the earth raises it to its boiling point, after which it flows from the tank to points of consumption in the form of a hydro-carbon gas.

When the liquid gas is piped from a truck tank into an underground tank, the displaced vapor should be piped back into the truck tank, for reasons of economy and safety. If the vapor is vented into open air, it is likely to become ignited through static discharge or careless procedure. In the patent to J. B. Green, Number 1,968,141 the liquid is transferred from the bottom of the truck tank into an underground tank by a suitable hose, and at the same time, the displaced vapor in the top of the underground tank is conducted to the upper portion of the truck tank by a separate hose. It has been found that some truck tank operators will negligently fail to properly connect the separate vapor hose, and proceed to fill the underground tank while venting the displaced vapor into the air.

It is an object of this invention to provide a novel single unit hose system wherein the vaporreturn and liquid-supply hose are so arranged that transfer of the liquid gas from the truck tank into the underground tank cannot be effected without venting the displaced vapor from the underground tank into the truck tank.

It is another object of this invention to provide a distributing system of the class described in combination with a single unit liquid and vapor hose, said hose having a quickly detachable coupling on each end thereof whereby one end of the vapor-return and liquid-supply hose can be simultaneously attached to the underground tank, and the other end of the vaporreturn and liquid-supply hose can be simultaneously attached to the truck tank. A valve system is employed so that when either end of the hose is attached to its respective tank, communication is automatically established. Likewise, when either end of the hose is detached, communication is automatically cut off. The purpose of this arrangement is to prevent the truck operator from attaching the liquid hose only to the underground tank and venting the displaced vapor into the atmosphere.

It is another object of this invention to provide an apparatus which will prevent overfilling of the underground tank to such a level that the required vapor space is filled with liquid. This overfilling often happens on conventional systems through inattention of the operator during filling.

It is further object of this invention to provide mechanism associated with the underground tank for automatically preventing the liquid within the tank from entering the house service line in case the tank should be overfilled with liquid on account of the vapor escaping as a result of poor connections, leakage of the tank, and the like.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which: Figure 1 is a view illustrating the combination of a supply tank, a storage tank, and a double hose connection between the tanks whereby the liquid is transferred; Figure 2 is an enlarged detail sectional view similar to the upper central portion of Figure 1, illustrating the details of a coupling and associated valves between the truck tank and the double hose; Figure 3 is a sectional view similar to the lower portion of Figure 2 but showing the positions of the parts when disconnected; Figure 4 is a sectional view taken along the line 4-4 in Figures 2 and 3; Figure 5 is a sectional view taken along the line 5-5 in Figure 3; Figure 6 is a sectional view taken along the line 6-6 in Figure 3; Figure 7 is an elevation taken along the line 7-7 in Figure 3; Figure 8 is a sectional view taken along the lines 8-8 in Figures 1 and 2; Figure 9 is a sectional view taken along the lines 9-9 in Figures 1 and 2; .

Figure 10 is an exploded isometric view of the parts in a pair of adjoining valves, said parts being shown in assembled position in Figures 2 and 3; Figure 11 is a vertical sectional view through the inlet to the storage tank together with a portion of the connecting double hose conduit which is detachably secured to the upper end thereof.

Referring more particularly to the drawings, the numeral 10 broadly denotes a truck having a tank II mounted on the rear portion thereof.

This tank is adapted to contain a supply of liquid 12 such as propane, butane, and the like. Usually the tank is not completely filled, but instead a certain amount of vapor space 14 is retained -in the upper portion thereof to allow for expansion and contraction as well as variation in liquid volume due to temperature changes.

According to the present invention, a suitable outlet 15 is provided near the lower portion of the tank I, said outlet having threadably secured therein a pipe 16, which pipe is adapted to receive a smaller pipe 17 when the distributing system is in operation. It will be noted by referring to Figures 2 and 3 that the pipes 16 and 17 have a gasket 18 disposed therebetween to prevent leakage at the coupling point, said gasket being- preferably made of a suitable material commercially known as "neoprene." The pipes 16 and II are detachably connected together by any suitable means such as by a nut 19, said nut being rotatably mounted around the smaller pipe 17 and is threadably secured to the end of the larger pipe 16 to couple the pipes together. Between the nut 18 and the end of pipe 16 is another neoprene gasket 20 which further serves to prevent leakage at the coupling point. It is therefore seen that pipes 16 and 17 may be quickly attached or detached from each other by merely manipulating the nut 19.

The pipe 17 in Figure 1 is disposed on one end 80 of a combined liquid and vapor conduit unit broadly designated by reference character 24, said pipe having one end of a hose 25 secured thereto. This hose or conduit 25 is preferably made of some flexible material such as rubber hose, however, it is to be understood that any suitable materal may be employed such as metal pipes, if conditions require such material to be used. The other end of the hose or conduit 25 is connected to another pipe 17, which is identical to the pipe 17 previously described. This second pipe 17 is illustrated in detail in Figure 11. It will be seen by observing Figure 11 that the pipe 17 is connected to a larger pipe 16 and detachably coupled thereto by means of a nut 19. Since the connection is identical to the connection adjacent truck tank I , a further description will not be made.

The lower end of pipe 16 (Figure 11) is threadably secured to a fitting 26, said fitting being threadably secured upon the upper end of a vertically disposed intake pipe 27. This intake pine has its lower end disposed in a storage tank 28 to substantially the allowable maximun liquid level. This liquid level will, of course vary, de- M55 pendent upon the capacity of the tank employed; however, it is well known that there must be a certain amount of vapor space left in the tank in order to insure the proper operation when the gas or vapor is being led from the tank through the supply lines into the burners where the gas is consumed. The pipe 27 has a collar or band 29 disposed around its intermediate portion, and this collar or band is threadably secured on opening 30 of tank 28. A lock nut 29a is threaded a. onto sleeve 29 for locking and positioning stand pipe 27, said lock nut being used in association with a gasket 29b.

The tank 28 is equipped with a standard content gauge of the offset stem type, comprising a gauge housing 32 and an associated stem 33a extending downwardly through a gauge pipe 33.

The lower end of the stem 33a has a gear 34 mounted thereon, which gear meshes with another gear 35 on a shaft 36, said shaft 36 being connected to the intermediate portion of a rod 37. One end of rod 37 has a float 38 connected thereto and the other end has a counterweight 38a thereon. The float 38 rises and falls with the level of the liquid 12 within the tank 28, and as this, rising and falling takes place, the gears 34 and 35, as well as the gauge stem 33a are rotated to thereby indicate by pointer and scale in the housing 32 the level of liquid within the tank.

As heretofore stated, the level of the liquid 12 within the tank 28 must not rise too high. Usually the lower end of the pipe 27 determines the maximum height to which this liquid should rise.

In any event, the vapor space 31 above the liquid level in the tank should not be less than a predetermined minimum.

When filling the tank 28 from a supply tank I the system is connected up in the manner shown in Figure 1. In other words, the single unit conduit 24 has the upper end thereof connected to the supply tank and its lower end connected to the inlet of the storage tank 28. Immediately upon the connection, the passageways are opened to permit the flow of liquid from the supply tank to the storage tank, but at the same time, means must be provided for venting the displaced vapor from the storage tank.

In order to effect the venting of the displaced vapor from the storage tank, a suitable vapor conduit has been provided inside of the exterior liquid supply pipes 16, 17, 25, 26, and 27 previously described. More specifically, the vapor conduit comprises a pipe 40 (see Figure 11), a pipe 41, a pipe 42, a pipe 43, a hose or pipe 44 (see Figures 1, 2, and 3) a second pipe 43, a second pipe 42, a second pipe 41, and a pipe 45, all of which are connected up in series in the order named, beginning at the storage tank 28 and ending at the supply tank 1.

The upper end of the pipe 45, that is, the upper end of the vapor conduit, is disposed inside the vapor space 14 of the supply tank II, whereas, the lower end of pipe 40, which is the lower portion of the vapor conduit, is disposed substantially at the allowable high liquid level in the storage tank 28. Therefore, when the liquid is permitted to flow from the supply tank II through the members 16, 17, 25, 17, 16, 26, and 27 in the order named into the storage tank 28, the displaced vapor in space 31 of the storage tank will simultaneously flow upwardly through the vapor conduit comprising pipes 40, 41, 42, 43, 44, 43, 42, 41, and 45 in the order named into vapor space 14 of tank 1. Since the outside cross-sectional area of the vapor conduit at all points is substantially less than the inside crosssectional area of the liquid conduit, a space between the exterior of the vapor conduit and the interior of the liquid conduit is provided whereby the liquid may flow into the storage tank around the exterior of the vapor conduit.

Although in the drawings the vapor conduit is shown disposed on the interior of the liquid conduit, it is to be understood that the arrangement might be easily reversed; that is, the vapor conduit might be placed on the exterior of the liquid conduit without departing from the spirit of the invention. Also the two pipes could be placed side-by-side and have uniting fittings whereby when one pipe was connected to a tank, the other pipe would also be connected. One of the principal ideas in the present invention is providing a conduit within a conduit, so that one of the conduits may be employed for conducting liquid in one direction while the other said conduit conducts displaced vapor in the opposite direction.

Attention is called to the manner in which the inner vapor conduit is supported within the outer liquid conduit. For example, in Figure 2, a spider 48 is provided in the outlet 15, and this spider supports the pipe 45, so that its lower end will be disposed substantially in the center of the outlet. To the right-hand lower end of pipe 45, the pipe 41 is threadably secured, said pipe 41 having telescopically fitting thereover, the left-hand end of pipe 42. Pipe 42 has threadably secured in its other end a short pipe 43, which pipe 43 is supported by a spider 49, secured in pipe 17 by any suitable means such as a-snap ring 50. The right-hand end of pipe 43 (Figures 2 and 3) supports the left-hand end of vapor pipe 44, said vapor pipe being disposed on the inside of the outer liquid supply hose or pipe 25.

The lower end of the inner pipe 44 is connected in an identical manner to a second pipe 43 (see Figure 11), said pipe 43 being supported in a second p'pe 17 in the manner previously described. The lower end of the second pipe 43 in Figure 11, threadably supports a second pipe 42, which, in turn, has its lower end telescopically fitting over the upper end of a second pipe 41, and this last-named pipe 41 is threadably secured on the upper end of pipe 40.

In order to facilitate the transfer of liquid fuel 12 from the tank 14 to the storage tank 28 without loss of displaced vapor, suitable valves have been employed at each of the coupling points. In fact, there is a normally closed valve disposed in the outlet 15 which will prevent the liquid from escaping from the supply tank II and as also a companion normally closed valve in the vapor pipe at this same point which will prevent the vapor from escaping from the vapor space 14 in the supply tank II. A similar arrangement of normally closed valves is provided on each end of the single unit vapor and liquid conduit 24 for retaining the vapor and liquid therein when the' conduit is disconnected. Also a similar arrangement of normally closed valves is disposed in the upper end of the tank intake fitting 26, said lastnamed valve arrangement serving to prevent the escape of vapor from the vapor space 31 when the connecting combination hose is not connected and for closing the liquid intake.

The specific valve arrangement is shown in connected positions in Figures 2 and 11, and in a disconnected position in Figure 3. The valve parts are shown in exploded position in Figure 10. It can be seen by observing Figures 2 and 3 that when the combination single unit condu't 24 is connected to the supply tank, that all of the valves are in opened positions which permits flow of liquid from the tank II and also permits the flow of vapor into the vapor space 14. When the conduit 24 is disconnected from the tank I I the ends of the vapor and liquid pipes in conduit 24 are automatically closed, as well as the ends of the liquid and vapor pipes in the supply tank II.

Fundamentally, the construction of each of the valve arrangements at each coupling point is identical, therefore a description will be made of the arrangement at the lower coupling point (Figures 2, 3, and 10) and like reference characters will be applied to the valve arrangement at the upper coupling point, disposed adjacent the truck tank inlet, but without making an additional description. In general practice the hose remains attached at all times to the truck tank, and the hose is connected to and disconnected from the storage tank.

As a means for normally closing the vapor conduit which extends upwardly from vapor space 31 of storage tank 28, a suitable spider 56 is provided in the pipe 41 (Figure 11). This spider has slidably mounted therein a valve stem 5Ta having a valve head 57 on one end thereof, said head 51 being adapted to normally fit against a valve seat 58 also disposed within the pipe 41 to thereby close the vapor conduit when the combination single unit conduit 24 is disconnected from tank 28. A spring 58 normally urges the valve head 57 toward closed position, that is, in contact with seat 58.

Pipe 42 likewise has a spider 56, a valve stem 57a, a valve head 57, and a seat 58 therein, but the parts are arranged so that the ends of the valve stems 57a of the respective valve heads will abut when in an assembled position as shown in Figure 11. When this abutment takes place and the pipes 41 and 42 are in connected position, the respective springs 59 on the valve stems will be simultaneously comtpressed to thereby open the valve heads 57 and permit the flow of vapor through pipes 41 and 42.

As a means for insuring that both of the valves will be opened when the pipes 41 and 42 are connected in the manner shown in Figure 11, a suitable pin 60 is provided on the interior of each pipe 41 and 42, there being a pin 60 disposed in spaced relation to each valve seat 58 and in the path of movement of each valve head 57. When the proximate ends of the valve stems 57a abut each other upon the connection of the pipes 41 and 42, the associated springs 59 will be compressed. If one spring 59 should be slightly stronger than the other, then there will be a tendency for one valve to remain closed while the other valve is being opened; however, by providing the pins 60 at the proper points, the movement of each valve head 57 is limited.

Therefore. when one valve has opened a predetermined amount, it will be stopped by its associated pin 60, after which the other valve will begin to open. Ordinarily, the pins 60 are not necessary, because the springs 59 have substantially the same strength and, therefore, both valves will open simultaneously.

By observing Figures 2 and 3, it will be seen that a similar valve arrangement is employed at the outlet of the truck tank II. In other words, a valve head 57 is disposed in the pipe 42, which pipe forms a portion of the vapor line within the combination liquid supply and vapor conduit 24. This valve head is al3o normally closed, that is, when conduit 24 is disconnected, the head will automatically close to prevent escape of vapor.

00 In a similar manner, the valve head 57 in the adjacent pipe 41 of the vapor line will automatically close upon disconnecting the conduit 24 from the supply tank, and thus prevent the vapor from escaping from space 14.

f5 The liquid within the supply tank 11, as well as the vapor in storage tank 28, is prevented from c caping by means of a suitable valve 62, when conduit 24 is disconnected, said valve 62 being disposed inside the pipe 16 (Figures 2, 3. and 11) and having a bore 63 therein which slidably fits around the exterior of pipe 41. This valve 62 is adapted to fit against valve seats 64 and 65 to close the liquid conduit in pipes 27 and 16. A suitable compression spring 68 i3 provided for normally urging the valve 62 in the close position and against the valve by means of a nut 69. Nut 69 is threadably secured upon threads 70 of the pipe 41.

Extending from the upper face of the valve 62 in pipe 16 (Figure 11) is a pair of rods 72, said rods having disposed on the upper ends thereof a suitable ring 73. The liquid valve structure designated by reference characters 62 to 73 inclusive are located on the inside of the pipe 16, which forms an orifice for the liquid flowing from the tank I into tank 28.

The adjoining detachably connected pipe 17 of conduit 24 has an identical arrangement of valve parts therein; however, it will be noted that the parts are oppositely positioned so that the proximate faces of rings 73 will abut each other when the conduit 24 is coupled to the tank 28. When coupled, both of the valves 62* will be simultaneously opened to permit liquid to flow from the tank II through the liquid conduit and around the exterior of the vapor conduit.

The springs 68 are preferably of substantially the same strength so that both valves will open simultaneously when the pipes 16 and 17 are connected; however, if there should be some slight difference in the strength of the springs, the valves will still open where the pipes 16 and 17 are coupled, because the end of the hub 62a of each valve 62 is adapted to be disposed in close proximity to the nut 69 at the time the valves are in opened position. "If one spring should be weaker than the other, then the valve associated with the weaker spring would open first until its associated hub contacted or abutted the nut 69, and then the opposite valve would be opened.

Likewise, at the connection of the conduit 24 with the truck tank, a similar set of valves are employed (Figures 2 and 3), one set of said liquid valves being provided to normally close the ends of the vapor and liquid lines in conduit 24, and the other set of said valves being adapted to normally close the liquid and vapor lines leading from the truck tank II when the conduit 24 is disconnected from the tank. In both cases the valves are automatically closed upon disconnecting conduit 24, and automatically opened upon the connection.

As heretofore stated, there is a decided advantage in providing this hose within a hose arrangement, because the operator cannot negligently fail to disconnect the vapor return hose when fuel is being transferred from the supply tank to the storage tank. Also upon disconnecting the hose from the storage tank, the liquid and vapor within the hose and within the storage and supply tanks will automatically be captured in the respective conduits, and therefore cannot escape to form a hazard, or permit loss of the fuel.

When filling the storage tank 28 with liquid 12, it is not necessary for the operator to maintain a constant vigilance of the indicator 32 to see whether or not the proper amount of fluid is denosited in the tank, because when the tank is filled to a prescribed level, the lower end of the vapor pipe 40 will be closed by the rising liquid level thereby preventing 'escape of vapor from the vapor space 31. The closing of the vapor pipe will prevent the further flow of liq,,id into the tank through the liquid con- 7 duit. In this manner the allowable vapor space within the tank is automatically maintained.

Leading from the vapor space 31 in the tank 28 at a level somewhat above the allowable high liquid level, is a vapor service pipe 75. This pipe extends upwardly on the interior of previously described pipe 27, and then passes through the fitting 26 to the exterior, after which it leads to a point of consumption such as a building 77. The vapor service pipe has disposed therein a conventional excess flow valve 78, a shut off valve 79, and a regulator 80. The lower end of the pipe 75 is disposed within the vapor space 31 in storage tank 28, and is adapted to be automatically closed when the liquid within the tank substantially exceeds the allowable high level as determined by the lower ends of pipes 27 and 40. Sometimes on account of leakage of the storage tank, as at point 30, or at other points during filling, more vapor is permitted to escape from the tank than is permissible, and consequently, a greater amount of liquid will be permitted to flow from the supply tank into the storage tank than is desired. An excess amount of liquid in the tank will sometimes result in the liquid being forced through the vapor supply line and into the burners: By providing an automatic means for closing the lower end of the pipe 75, however, this possibility is 2a eliminated.

The means for automatically closing pipe 15 comprises a valve 82 having a suitable neoprene valve seat 83 on cne face thereof, which seat is adapted to fit against the lower open end of vapor supply pipe 75. tihe valve 82 is pivotally secured intermediate its ends as at 84 to a collar 85 which collar is disposed around the pipe 75. As a means for limiting the clockwise rotation of the valve 82 when in an opened 3: position, a suitable leg 82a is provided integral with the valve 82, the end of said leg being adapted to contact the exterior of the pipe 15 to limit the clockwise rotation of the valve.

The valve 82 also has extending from the 4o free end thereof a rod 86, which, in turn, supports a float 87. This float is adapted to be contacted by the rising liquid within the storage tank; that is, when the liquid rises above the *allowable level. When the liquid does exceed the allowable level, the float continues to rise until the valve entirely closes thi opening in the lower end of the vapor supply pipe 75, and" thus prevents any liquid from entering the vapor service line 75.

It is therefore seen that a novel method and apparatus has been employed for filling the underground tank 28 from the truck tank II by means of a new hose system 24 in which the liquid supply hose and the vapor return hose are arranged one within the other to form a single unit that can be connected to the tank 28 through a common coupling as shown in*Figure 1 of the drawings, as well as to tank II through an identical coupling. The purpose of this arrangement, as previously stated, is to prevent the truck operator from attaching the liquid hose only to the underground tank, and venting the displaced vapor into the atmosphere to cause a fire hazard, and waste fuel.

05 Another safety feature employed, resides in the special arrangement of the lower ends of pipes 40 and 27- within the tank 28 to insure that a filling of the tank will automatically cease when a predetermined level of liquid h-s been attained 0O in the supply tank.

Still another safety feature has been incorporated, namely, that of preventing the liquid within the tank from rising above the allowable prescribed level and being forced into the vapor service line on account of a vapor leak during a filling operation. The latter safety feature is shown in detail in Figures 1 and 11, and designated by the reference characters 75 to 81, inclusive.

As a general rule, the truck tank has heretofore been equipped with two separate hose with manually operated valves in the lower end thereof which are closed before the liquid supply hose and vapor return hose are disconnected from the storage tank to prevent escape of fluid from the two lose. In practice, these hose are never disconnected from the truck tank, and in the present invention, the hose are rarely disconnected from the truck tank, but it is thought advisable to provide a similar coupling at each end of the hose to permit ease of coupling the hose to the truck tank when installing the same. In operation, the present invention would be connected to the truck tank and carried in this connected condition from one place to another and when a customer's premises are reached, the outer end of the hose is connected to the storage tank stand pipe which automatically establishes communication between the hose and the storage tank. Then the communication being held open, at all times between the truck tank and hose, the liquid proceeds to flow into the storage tank, and the vapor to return into the truck tank.

Although I have shown the connection at each end of the hose as being of the screw type, it is evident that any suitable form of connection, such as a snap or bayonet connection could be likewise used. It is also evident that by use of a snap connection, the vapor return hose and the liquid hose do not necessarily have to be one inside the other, but they could be placed alongside each other, and connected to a common fitting, which when fitted to a tank, would automatically open in the same manner as shown and described. This could easily be done by having two adjacent openings in each tank so spaced as to coincide with the openings in the fittings communicating with the liquid hose and the vapor return hose.

An additional safety feature is shown in Figures 1 and 11 whereby the valve 82 will be automatically closed when the liquid within storage tank 28 is exhausted or falls below a predetermined level. This safety feature is adapted to work in association with the previously described automatic closing feature of this same valve when the tank is over-filled. This closing feature of the valve 82, when the contents within tank 28 approaches exhaustion, is desirable because there must be a prescribed minimum amount of liquid in the tank in order for enough gas to be formed to maintain the burner or appliance flame at the point of consumption. If the liquid level is allowed to fall below this prescribed minimum, sufficient vapor will not be formed to maintain' the flame, resulting in the flame at the burners going out and permitting gas to escape through the unlighted orifices into the room.

The valve closing structure comprises a vertically disposed rod 90 having its intermediate portion slidably mounted in a bearing 91, supported by pipe 33. The upper end of the rod 90 is pivotally secured as at 82 to arm 82a of the valve 82 and the lower end of the rod 88 (see Figure 1) has secured thereto a bucket 84 which is normally submerged in the liquid 12 within the storage tank 28. Therefore, the bucket 94 at all times will be filled with liquid. When the liquid within the tank reaches the dotted line predetermined low level 12a the weight of the liquid within the bucket 94 will pull the rod 90 downwardly, thereby rotating the valve structure 82 about pivot point 84 to close the end of service pipe line 75. When the bucket falls to its dotted line position, the valve float 81 will also be raised to its dotted line position, and in this position, the valve will be closed.

In the design of the crank 82a of the valve structure these parts will be proportioned so as to provide an accelerated closing action during the last phase of main tank emptying.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim: 1. In a coupling for connecting one pair of concentric pipes to a second pair of concentric pipes comprising two connector members meeting endwise, means for detachably securing the two connecting members together, each connecting member having a spider member therein for rigidly supporting an inner pipe, the proximate 0 ends of the inner pipes being adapted to telescope relative to each other, and having spring-pressed valves therein based normally to closed position. each of said valves having pins extending towards each other, so that the ends of the pins 8 will engage each other when the two ends of the inner pipes are telescoped relative to each other, a pair of valves slidably mounted on the inner pipes and biased to normally close the passageways between the inside walls of the connector members and the inner pipes, the latter valves having pins extending towards each other, so as to engage each other to move the last-named valves to open position when the connector members are secured together.

S 2. In a coupling for connecting one pair of concentric pipes to a second pair of concentric pipes comprising two connector members meeting endwise, means for detachably securing the two connecting members together, each connecting member having a spider member therein for rigidly supporting an inner pipe, the proximate ends of the inner pipes being adapted to telescope relative to each other, and having spring-pressed valves therein biased normally to closed position, each of said valves having pins extending towards each other, so that the ends of the pins will engage each other when the two ends of the inner pipes are telescoped relative to each other, a pair of valves slidably mounted on the inner pipes and biased to normally close the passageways between the inside walls of the connector members and the inner pipes, the latter valves having pins extending towards each other, Sso as to engage each other to move the lastnamed valves to open position when the connector members are secured together, and stop means for limiting the amount each of said valves can be opened, so when one valve is opened Sa predetermined amount, its opening movement will be stopped, and its companion valve in the other connector member will be moved to opened position, NELSON M. JONES.