US 2075408 A
Description (OCR text may contain errors)
March 30, 1937. J. a. sHoLEs v2 0 1 TRANSFER OF LIQUEEIED, GAS I Filed Sept. 17, 19:55 2 Sheets-Sheet 1 REF IGERATMG MACHINE March 30, 1937-- J. G. sHoLES I TRANSFER OF LIQUEFIED GAS 2 Sheets-Sheet 2 Aw 3 mm H Filed Sept. 1'7, 1935 INVENTOIR BY v vvr-w xmi- I ATTORNEYS Patented Mar. 30, 1937 PATENT OFFICE TRANSFER or momma!) GAS Justin Grant Sholes, Cleveland, Ohio, assignor to The Ohio Chemical and Manufacturing Com- .pany, Cleveland, Ohio, a corporation of Ohio Application September 17, 1935, Serial No. 40,887
This invention relates to the transfer of liquefied gas from one container to another, for example from a bulk container to others of smaller size for delivery to users, and its chief object is 5 to provide a method and apparatus for effecting such transfer in a rapid and convenient manner, with a minimum loss of gas and particularly with the least possible evaporation of the gas from the 20 particularly during the major part of the transfer operation, nor re-liquefying arrangements and devices. At the same time, especially where the invention is employed in packaging the liquefied gas for purposes of sale or like distribution, provision can be made for accurate measurement of the quantity of gas so packaged, forexample, where it is sought to fill each container with a predetermined weight of the liquefied gas.
Although the invention may be carried out in a number of ways, so as to achieve, in each instance, many or all of the foregoing objects and such additional objects and-advantages as will be hereinafter apparent, it is believed that the apparatus and methodof the invention, particularly in their presently preferred forms, will be best illustrated by the following description of a specific embodiment of them.
The drawings therefore show, by way of example, a suitable apparatus, constructed in accordance with the invention, and adapted for transferring liquefied gas from one or more bulk containers to a smaller container or conveniently to a large group of such smaller containers. Apparatus of the specific character show'n has been found highly satisfactory for use in effecting such a transfer of liquefied nitrous oxide. In fact, the invention, although applicable to many other uses, is of special value in handling liquefied gases of that order, particularly gases having physical characteristics generally similar to nitrous oxide; for convenience and by way of example, it will be assumed in the following description that liquefied nitrous oxide is the specific material to 55 be handled and transferred.
In the drawings:
Fig. 1 is a schematic view of the apparatus, generally in perspective, with certain portions broken away to showfeatures of internal construction as will be noted;
' Fig. 2 is a plan view of the cooling tank, with I the cover removed; and
Fig. 3 is a vertical section of the cooling tank, on lines 3-3 of Fig. 2. q
The apparatus shown is particularly adapted, among other purposes, for transferring liquefied gas from large bulk containers or cylinders III, to smaller containers or -cylinders l|,--the cylindersfias they are called in the industry, being of well-known construction in each instance. A manufacturer of liquefied gas, for example, may package his product in large'cylinders Ill, for convenient storage or Wholesale distribution, or the like, but it is often necessary "at a later time to transfer the liquefied gas to smaller cylinders ii, for delivery to the ultimate user, and with the present invention, this transfer can be achieved economically and rapidly, and without requiring any unusual knowledge or skill on the part of theoperator. In the case of one manufacturing plant where the invention has been so used for transferringliquefied nitrous oxide, a large cylinder l customarily contains from 50 to 60 lbs. by weight of the liquefied gas, whereas a small cylinder ll usually holds from 3 to '7 lbs. Of course, the capacity of the-cylinders or other containers from which liquefied gas is to be transferred, and of those which are to be filled with it, as well as the quantity of gas actually handled in any transfer operation, may vary widely, even with the specific apparatus here shown. 7
Referring to Fig. 1, a manifold, I2 is provided for receiving the liquefied gas from a plurality of large cylinders l0, through a corresponding plurality of inlets l3 (a convenient number, six, being here shown). Each inlet valve l4, for controlling or shutting off the fiow of gas through the inlet to the manifold l2 (without, of course, affecting the manifold itself, or the passage of gas through it, for example, from another inlet), andeach inlet also includes a pipe l, provided at its outer extremity with 'a yoke l3 includes a it of standard and well-known construction, for
70 the arrangement of the supporting tubes 33 and the manifolds 35 and 36 is such that when a.
' l 9 to show this style of valve construction, whereby the liquefied gas can leave the cylinder only through the siphon tube 18, being forced out by the naturally high gas pressure above the liquid in the cylinder. Particularly efficient drainage of the liquefied gas is afforded by this expeditious arrangement for withdrawing it from the bottom of the cylinder. Of course, where the siphon construction is not employed, the inlet w yokes l6 and cylinders l0 can be inverted, so
that the cylinders are above the manifold and drain down into it; the siphon tube arrangement, however, is generally preferable for its conven- 0 ience and practicability.
' be filled with liquefied gas. These cylinder-holdand areconveniently so disposed that their bot- The manifold I2 is closed at its "left-hand end in Fig. l, and opens at its other end into a distributing head 20, through which the liquid gas may fiow into two separate pipes 2|, 22, respectively controlled by valves 23, 24. r A high pressure gauge 25, for'recording the gas pressure of the contents of the manifold l2 and connected parts of the system, is conveniently mounted in the manifold l2 intermediate the inlets l3 and the head 20. a
Pipe 22 extends into the cooling tank generally designated 26 through a suitable valve 21, conveniently described as the main transfer valve. Pipe 2| also extendsinto the cooling tank 26 through a valve 28, likewise mounted on the cooling tank and called, for convenience, the topping supply valve.
Referring now to Figs. 2 and 3, as well as Fig. 1, the cooling tank 26 comprises an inner tank 29 having heat-insulating walls 30, and
has a hinged cover 3| of like insulated construc- 'tion, which may be tightly closed to preserve the refrigeration effected in the tank. Carried by a plate32 in the'upper part of tank 29 and opening through suitably conforming apertures in that plate, as shown, a plurality of hollow metal- 110 tubes 33 are provided in each' of which there may be inserted one of the small cylinders II to ing; tubes 33 are closed at their lower ends against access of liquid contained in the tank 29,
toms are a substantial distance above the bottom of the tank 29. In some instances, additional supports 34 for the bottoms of the cylinder-receiving tubes 33 may be used, preferably two) to'each of which a distributing manifold 36. is removably attached. Each of these removable manifolds 36 has a plurality of outlet tubes 31, which may be flexible copper tubes, and each of which, in turn, is provided with a yoke of standard construction for removably connecting it to the valve-head of a'small cylinder I I, as will now be understood. It will be appreciated that 'number of small cylinders II are respectively plate 32, for ready attachment and connection of the yoke of the corresponding. flexible outlet tube 31 extending from the nearest manifold 36. In this way, with the yokes attached to the valve heads of the small cylinders, an unobstructed conduit for liquefied gas is provided from pipe 22 to all of the small cylinders ll, assuming, of course, that valve 21 is open, and that each of the individual valves on the small cylinders are likewise open.
In the present embodiment, the cooling tank is provided with sixteen of the supporting tubes 33, for receiving a corresponding number of small cylinders; and the removable manifolds are disposedas shown, with four outlets spaced 'along either side of each, affording satisfactory distribution to each of the small cylinders II. The number of supporting tubes 33 may of course be varied in accordance with requirements. and
corresponding changes effected in the arrange of the tank, conveniently as shown, to a suitable refrigerating unit, which may comprise the usual compressor 39, condenser 40, fan 4| and motor 42 (for operating the fan and compressor), and
the usual thermostatic control 43; as this refrigerating unit may beof any standard construction, it is only diagrammatically shown in the drawings. For example, in using the apparatus for' transferring liquefied nitrous, oxide, satisfactory results were obtained with a cooling coil 38 comprising a 200 foot coil of '7 mm. by 9 mm. copper tubing, connected (as shown) to a 75-lb. capacity ice machine of the standard make known by the trade name Kelvinator. In that case it was found that a non-freezing liquid placed in the tank 29, for circulation around the tubing 38 and supporting tubes 33, was cooled to plus 13 F., .and that the air in the tubes 33, and the small cylinders placed in them, were cooled toplus 25 F.
An additional coil of tubing 44is similarly disposed in the space intermediate the tubes 33 and the walls of tank 29, adjacent but preferably outside the refrigerating coil 38. The coil 44 may advantageously be made of tubing smaller in size than that in the coil '38, but with more convolutions about the interior of the tank. One end of the tubing 44 is connected through the topping supply valve 28 to pipe 2i and the other end is connected through a large valve 45, called the operating valve, to a pipe 46.
The space in the tank 29 below the plate 32, around the coils 38 and 44, and around and under the supporting tubes 33 and each of them, is filled with a non-freezing liquid or solution, such as brine, or a solutionof calcium chloride, or
glycerine; that is, a solution which will not freeze at the low temperatures attained by the refrigerating coil 38. The refrigerating action of coil 38. is thus transmitted through the non-freezing solution or bath 41, to cool the supporting tubes 33, the cylinders I I inserted in them, and tubing 44; effective refrigeration is provided for the entire contents of tank 26. I
Pipe 46 extends through a suitable valve 48 to a yoke 49, similar to those on outlets 31 and adapted for connection with one of the small cylinders ll. This yoke 49 comprises part of a filling standwhich also includes a weighing device, such as the platform scale Ell upon which a cylinder ll rests, as shown in Fig. 1. It will be understood that the arrangement is such that a cylinder ll may be weighed on the scale, either standing alone, or as connected to the pipe 46 through yoke 49.
It will also be noted that valves (includingthe individual valves of all cylinders Ill, ll are provided throughout the system on each side of points where removable connections are made.
and at each end of every appreciably extensive section of manifold, pipe or tubing; in effecting transferring operations, every valve is preferably kept closed at all times, except when actual flow must be permitted through it. The arrangement and operation of valves in this manner is of distinct advantage in reducing loss of gas, or evaporation of gas from the liquefied state, during the manipulation of the apparatus and also during replacement or removal of parts of the apparatus,-for example, during connection or disconnection of cylinders Ill and H at various points, or connection of manifolds 36, or while one or more units of the system are changed, as they may readily be, for others of different character to accomplish different kinds of work.
As a specific example of the method of the inteen small cylinders, such as cylinders II, with liquefied. nitrous oxide, that each of them holds,
when full, 3 lbs. 12 oz. of the liquefied gas, that the transfer is to be made from large cylinders ill which contain 50 lbs. of liquefied nitrousoxide apiece, and that apparatus of the type shown in the drawingsis to be used for the procedure. All valves in the system are closed, and after the empty small cylinders have been suitably inserted in the supporting tubes 33 of the tank 26, the yokes of outlets 3'! are securely attached to the valveheads of the cylinders, and the removable manifolds 36 are in turn connected to manifold 35, as will now be understood. Six of the full large-sized cylinders l0 are connected respectively to the six inlet yokes iii of manifold l2.
With main transfer valve 21 closed, the in-. dividual small cylinder valves are now opened, and the cover 3| of the cooling tank 26 is tightly closed. until the temperature inside, as read upon a thermometer (not shown) which may extend through the cover into the air space abovethe cylinders, has dropped to a steady and preferably predetermined figure,--say, 25 to 30 F. where liquefied nitrous oxide,.or a like liquefied gas, is to be handled. During this time, all valves on the manifold I2, and elsewhere in the system should be closed.
The large cylinders to will be hereinafter identified by the Roman numeral characters (i. e. from I to VI) shown on the drawings.
the corresponding inlet are opened, and the gauge 25 now registers the pressure of gas in cylinder I. Valve 24 is then opened, and the operator cracks, i. e., opens very slightly, the main transfervalve 21. This last operation permits the liquefied gas from cylinder I to flow into the small cylinders II in the cooling tank, without setting up too large an accumulation of unliquefled gas (by immediate evaporation) and with- The cooling tank is allowed to stand- The valve ll of cylinder I and the valve l4 of i out causing freezing of the gas (and consequent clogging) anywhere in the part of the system now open, by reason of sudden expansion through valve 21 into the small cylinders. rush of liquid gas can now be plainly heard by the operator, and when it is no longer heard, he opens valve 21 wide and permits the apparatus to stand in this condition for a considerable period of time, such as about 12 hours,. or until the air temperature in the top of the cooling tank has again reached 25 to 30 F. and cylinder I has again attained room temperature. Valves l1 and I4 are thereupon closed for cylinder I.
Under the specific conditions hereinabove stated for this example, there should now be from 4 to 6 lbs. of liquefied nitrous oxide remaining in cylinder I, and from 44 to 46 lbs. of the liquid gas deposited in all of the small cylinders H taken together. .For economical results with this type of apparatus, the small cylinders should be preferably about 75 to filled at this stage of the operation. If there is not enough. gas in cylinder I to fill the small cylinders to this extent, cylinder II may be opened (at its valves i l and I1) after cylinder I has been shut off, and following gas may be allowed to flow from cylinder II into the small cylinders, and cylinder II may then be shut oif. On the other hand, if cylinder I contains more than enough gas to fill thesmall cylinders to about of their proper capacity,
care should preferably be taken to close the valves of cylinder I before the small cylinders have been more than 85% filled. Any possibility of overfilling the small cylinders, occasioned by the low temperature to which they are subjected in tank 26, can be readily. avoided with simple and moderate care on the part of the operator. For example, readings of gauge 25 will give a rough indication of the quantity of gas in the large cylinder l0 which is in use at a given time,not only at the beginning of operations, but also, if valve 24 is temporarily closed, at any subsequent stage.
In fact, the actual weight of gasin each of the large cylinders at the start will usually be known, and the arrangement shown is such that any one of them can be easily removed for re-weighing at any time. In fact, a modicum of experience will enable the average operator to control the transferas'accurately asdesired, without any intermediate weight-checking at all. The suggested safety limit of about 85% or less, for the initial filling step may vary somewhat with conditions, but for economy, and particularly for accuracy of filling each cylinder, an underfilling of this order is advisable at this stage in the pro- It will be remembered that valves 2-3, 28, 45, and 48 have been closed during theforegoing steps. Valves 24 and 21 are now closed (as well as all 'inlet valves for the large cylindersiso as to prevent wasting gas in line 22, as already'explained.
If cylinder II has not as yet been used, its valve H and corresponding. inlet valve l4 are now opened; if considerable gas has been removed from cylinder II it may be advisable to use cylinder III instead, at this point. Valves 23 and 28 are also now opened, valves 45 and 48 remaining closed, and the coil 44 in the refrigerating bath is always be keptclosed, to conserve refrigeration) all of the individual small cylinder valves are closed and the removable manifolds 36 taken out. One of the small cylinders is also taken out and placed on the scale 50 of the filling stand. As-
suming that the gross weight which the small cylinder will have when ultimately filled is known,
the weight of the smallcylinder (and its present" contents) just placed on the scale is now read and '15 stand valve 48 are opened. The weight of the cylinder as it now stands, with the yoke and valve attached, is noted; as will now be understood, additional liquefied gas must be introduced in the cylinder to increase this present reading of the scale.by the difference previously obtained, 1. e., by the amount of gas needed to complete the filling.
The operating valve 45 is thereupon opened and is kept open until suilicient liquefied gas has fiowed into the small cylinder, while it stands on the scale, to bring it up to the desired weight, as just determined. The operating valve 45, valve 48 and the small cylinder valve are then closed, and the filling stand yoke 49 is removed from the cylinder. The weight of the small cylinder and its contents, as now read on the scale, should be identical with the predetermined gross weight for a completely filled cylinder.
The same operations are repeated for each of the other small cylinders remaining in the cooling tank until all of them have been completely filled. After this topping step has been performed on the last of the group, and valves 45 and 48 have been closed for such final operation, the topping supply valve 28 is closed, and likewise valve 23 and the valves l1 and ll of the large cylinder (presumably cylinder II) used for the topping operation. It will now be appreciated that in the specific example here described (where the small 5 cylinders require 3 lbs. 12 oz. of liquefied gas apiece, or a total of 60 lbs., for filling) about 14 to 17 lbs. of gas will have been required from the large cylinder for actual toppin in addition to that needed to fill the coil 44. I 50 If the procedure is to be repeated the cooling tank may be refilled with an additional group of sixteen empty small cylinders, the removable manifolds connected and replaced and the entire operation carried out in the same way. In
. 55 the first or main filling stage (as distinguished from the topping operation), cylinder I may again be opened at the outset. Assuming that it had left from the previous operation about 4 to 6 lbs. of gas and thatthe capacity of the small 60 cylinders is as previously stated, opening of the valves in the lines I2, 22, 35, and 31 should reduce the quantity of gas in cylinder I to about 2 to 3 lbs. after pressure is equalized between cylinder I and the small cylinders; the difference 65 has thus been transferred to the small cylinders. To continue filling the latter in this stage of the operation as far as possible, say toabout 80%, 'one or more of the other large cylinders must be opened. For example, the remainder of the 70 gas in cylinder II (left from the previous topping operation) may now be transferred to the small cylinders, to leave a residue of about 4 lbs. of liquid gas in this large cylinder II, upon equalization of pressure; and additional gas may be 75 taken from cylinder III, as needed. The topping be left in it of about 2 lbs.
operation, for which cylinder III is again put to use, then follows in the manner described above, and the second set of small cylinders is thus completely filled.
For a third lot of small cylinders, cylinder I is again used at the outset, and equalization of pressure after opening the valves to the small cylinders in the cooling tank should leave about one pound of, gas in'this large cylinder. Cylinder II which, it will be remembered, now contains about 4 lbs. of gas, is also used, and a residue may then Other large cylinders are used in succession, as needed to fill the group of small cylinders to the requisite extent, and the topping operation is carried out as before.
I On a fourth lot of small cylinders, cylinder I is opened for the last time, as in this operation the amount of gas remaining in it should be reduced to much less than one pound. When cylinder II is in turn opened for this transfer operation, its gas content may be reduced to about one pound, and corresponding reductions may be made in other cylinders in succession. Cylinder I can now be removed from the manifold I2 and refilled, or a full cylinder substituted for it. In other words, by thus discharging cylinder I into four lots of small cylinders in succession, the gas remaining in it has been reduced to a convenient minimum; justifying refilling. On the succeeding, i. e., fifth lot of small cylinders, large cylinder II will reach the same condition and may be removed for refilling or for substitution of a full cylinder. This cycle, it will now be seen, repeats itself'for each of the large cylinders in turn so that each of them becomes ready for refilling or replacement after it has been used for enough principal transfer operations, or topping operations, or both, to deplete it to whatever may be the predetermined minimum,--in the example chosen, less than one pound of liquefied gas.
In these respects the process is continuous and cyclical, and it will now be understood that preferably a sufficient number of large cylinders are employed so that there will be no actual interruption of operation for refilling or substitution. That is, in the example just given, six large cylinders are connected to the manifold, and in general, in any of a series of transfer operations to small cylinders of the assumed capacity,
there will never be more than two or three of the large cylinders fully depleted in immediate succession. Actual gas transfer can always proceed from one or more other cylinders of the set of six while the depleted units are being replaced, and at no time is there any interruption of either the principal filling operation or the topping operation at all.
It should now be appreciated that the procedure and apparatus of the invention areboth expeditious and economical, not only in attaining a relatively rapid transfer to a large number of small cylinders with a. minimum loss of liquefied gas, but also in achieving high accuracy in filling each of the small containers with a predetermined quantity of the gas. Flexibility and ease of operation are also inherent advantages of the described arrangements; for example, in order to fill a group of less than sixteen cylinders with the specific apparatus shown, it is only necessary to insert blank valves in the unattached yokes of the removable manifolds 36. As explained, the operations are cyclical in nature when repeated for successive groups of receiving containers, and are adapted to effect an expeditious transfer of liquefied gas from oneplurality of containers to another plurality of containers without interruption for refilling or replacing the constituent units of the group of containers from which the transfer is made.
It is to be understood that the invention is not limited to the specific procedure and apparatus hereinabove described and shown, but may be carried out in other ways without departure from its spirit as defined by the following claims. I claim? 1. A method of transferring liquefied gas from one container to another, comprising partially filling the second container by causing liquefied gas to flow from the first container directly into said second container, cooling said second container during said flow of liquefied gas-and thereafter completing the desired filling of said second container without cooling the same, by passing additional gas into said second container and cooling said additional gas during itspassage to maintain it in liquefied form.
2. A method of transferring a predetermined quantity of liquefied 'gas to a'container, comprising passingliquefied gas, in less than the predetermined quantity, into said container, cooiing said container during said passage-of gas thereinto. liquefied gas into said container while weighing the latter and while cooling said additional gas while en route to the container to maintain the gas in liquefied form, and controlling said addi-' tional passage of gas in accordance with the weight of the container and its contents.
3. A method of transferring a predetermined I amount of liquefied gas to a receiving container therefor, comprising; establishing a direct line between a supply container'of liquefied gas to a cooled receiving-container and thereby causing liquefied gas to fiow directly from the supply 40 container, and in quantity less than the prede-' termined amount, to the receiving container while cooling the latter to maintainthe received gas in liquefied form, and thereafter completing the desired filling of the receiving container without cooling the latter, by causing additional gas containers in which the gas is to be received,
causing the gas to flow directly to said cooled receiving containers from the original containers thereof and in quantity about 15% to 25% less than desired in the receiving containers, maintaining the latter in cooled condition during said flow, thereafter completing transfer to each of the receiving containers, without cooling them, by causing additional liquefied nitrous oxide gas to fio'w directly thereto from the original con- 5 tainers and cooling said additional liquefied gas to about 25 to 30 F.'during said flow.
5. A method of transferring liquefied gas from one container to a receiving container, comprise ing cooling the receiving container, causing the liquefied gas to flow from the first container directly into the receiving container by siphoning liquefied gas from the first container under the pressure of the evaporated gas confined above the liquefied gas in said first container, while maintaining the receiving container in cooled and thereafter passing additional condition during said fiow of liquefied gas into it, to keep the introduced gas in liquefied condition, and controlling said fiow of liquefied gas to prevent complete filling of the receiving container therewith.
6. In a method of transferring of liquefied gas between containers therefor, wherein a receiving container has been. partially filled with liquefied gas, the procedure of completing the filling of said receiving container with a predetermined amount of liquefied gas, comprising causing additional gas to pass directly to said container from a supply container of liquefied gas,-while cooling said additional gas during its flow to maintain it in liquid form and while weighing said receiv: ing container to determine that the predetermined amount of gas has been transferred there- 7. Apparatus for transferring liquefied gas between containers therefor, comprising means for selectively receiving liquefied gas from a plurality of containers containing the same,'means for Y conducting the'liquefied gas from said first mentionedmeans to a refrigerated container, refrigeluted-conduit means. through which liquefied go's canalso be conducted from the receiving means, means for connecting said last mentioned conduit means to a container for transferring gasfrem said conduit means into the container, and means for selectively controlling the fiow of liquefied gas from the receiving means into thefirst mentioned conducting me'ans or the refrigeratedconduit means.
8. Apparatus for transferring liquefied gas to receiving containers therefor, comprising means for containing a supply of liquefied gas, means for conducting the liquefied gas from said first mentioned means to a refrigerated receiving container, refrigerated'conduit means through which liquefied gas 'can also be conducted from the first mentioned means, means for connecting said refrigerated conduit means to a receiving container for transferringgas from said conduit means into the container, and means for weighing the receiving container while it is connected by said connecting means to said refrigerated conduit means.
9. Apparatus for transferring liquefied gas to *containers therefor, comprising a. transfer line for conducting liquefied gas to a container, means for supporting said container while receiving gas from said transfer line, a second transfer line for conducting liquefied gas to a container, and common means for simultaneously cooling both the first mentioned container while it is supported by the supporting means, and the liquefied gas passing through the second mentioned transfer line.
10. In apparatus for transferring liquefied'gas and in position to be cooled bythe cooling bath,
refrigerating means for maintaining the cooling bath at a predetermined low temperature, means for conducting liquefied gas to the containers retained in the supporting means, and supplementary gas-handling means disposed in the cooling bath in the tank for cooling liquefied gas re- 5 ceived by said supplementary means.
12. Apparatus for transferring liquefied gas from cylinders thereof to receiving cylinders therefor and for minimizing loss of gas during such transfer, comprising manifold means for '10 receiving liquefied gas from a plurality of the 15 for removably supporting a plurality of receiving cylinders for cooling action thereon by said cooling means, means for conducting liquefied gas from the output of the manifold means to said receiving cylinders while supported ,by said supporting means. valve means for controlling passage of liquefied gas from said conducting means to the receiving cylinders, means including a cooling coil disposed for cooling action thereon by the cooling means, for receiving and I cooling liquefied gas from the output of the manifold means, valve means for controlling fiow of liquefied gas into and out of said cooling coil, valve means for controlling output of liquefied gas from said manifold means to the conducting means and to'the cooling coil, means for weighing a receiving cylinder, means for conducting liquefied gas from said cooling coil to a receiving cylinder while it is being weighed by the weighing means, and valve means for controlling fiow of liquefied gas from the last-mentioned conducting means to said last-mentioned receiving cylinder. v JUSTIN GRANT SHOLES.