WELDED NOZZLE FOR A TANK CAR

Abstract

A tank for a railway tank car includes an outer tank, a nozzle, a connecting plate, and a piping assembly. The nozzle protrudes through the outer tank, with one outer edge of the nozzle extending beyond the outer surface of the tank. An intersection between the nozzle and the outer tank defines an opening in the tank. The connecting plate is welded to the nozzle around its outer edge. The piping assembly passes through the connecting plate and into the outer tank via the nozzle. The piping assembly includes pipes for loading and / or unloading fluid from the tank.

Description

WELDED NOZZLE FOR A TANK CAR RELATED APPLICATIONS This application claims priority over U.S. Provisional Application Serial No. 62 / 962,624 entitled WELDED NOZZLE FOR A TANK CAR, filed on January 17, 2020, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD OF THE INVENTION This description generally refers to railway cars, and more particularly, to a welded nozzle for a cryogenic tank car constructed using a tank within a tank design. BACKGROUND OF THE INVENTION Rail tank cars are used to transport a variety of fluid products over long distances. While traditional tank cars typically consist of an insulated tank covered with a protective jacket, specialized tank cars also exist. For example, cryogenic tank cars are designed to transport cryogenic liquids (e.g., liquid nitrogen, liquid hydrogen, liquid oxygen, liquid methane, etc.). Such tank cars typically include an inner tank placed inside an outer tank. A vacuum is applied to the annular space between the two tanks to insulate the product being transported within the inner tank. BRIEF DESCRIPTION OF THE INVENTION According to one embodiment, a tank for a railway tank car includes an outer tank, a nozzle, a connecting plate, and a piping assembly. The nozzle protrudes through the outer tank, such that an outer edge of the nozzle extends beyond the outer surface of the outer tank. An intersection between the nozzle and the outer tank defines an opening in the outer tank. The connecting plate is welded to the nozzle around the nozzle's outer edge. The piping assembly passes through the connecting plate and into the outer tank via the nozzle. The piping assembly includes pipes for loading and / or unloading fluid from the tank. According to another embodiment, a method for manufacturing a tank for a railway tank car includes attaching a nozzle to an external tank. The nozzle is configured to protrude through the external tank, such that an outer edge of the nozzle extends beyond an outer surface of the external tank. An intersection between the nozzle and the external tank defines an opening in the external tank. The method also includes passing a set of pipes through the nozzle. The pipe set includes pipes for loading and / or unloading fluid from the tank. The method further includes placing a ORObCO / I 707 / 3 / Yl· Connection plate on the outer edge of the nozzle. The connection plate defines a set of openings. Each opening in the opening set is associated with a pipe in the pipe assembly. Placing the connection plate on the outer edge of the nozzle includes passing each pipe in the pipe assembly through its associated opening in the opening set. The method further includes welding the connection plate to the nozzle around the outer edge of the nozzle. According to another embodiment, a railway tank car includes an external tank, a nozzle, a connecting plate, a piping assembly, and a wheel assembly. The nozzle protrudes through the external tank, such that an outer edge of the nozzle extends beyond an outer surface of the external tank. An intersection between the nozzle and the external tank defines an opening in the external tank. The connecting plate is welded to the nozzle around the nozzle's outer edge. The piping assembly passes through the connecting plate and into the external tank via the nozzle. The piping assembly includes pipes for loading and / or unloading fluid from the tank. The external tank is coupled to the wheel assembly. Certain welded nozzle designs can provide one or more technical advantages. For example, one design can prevent virtual leaks from developing and reduce the vacuum present in a cryogenic tank car constructed as a tank within a tank. Another design can enable the transport of cryogenic liquids over long distances by rail. Yet another design can facilitate the easy detection of leaks that contribute to the vacuum in a cryogenic tank car. Finally, a design can reduce the cost and / or weight of conventional cryogenic tank cars by reducing the number of parts used in their manufacture. Certain designs may include none, some, or all of the above technical advantages.One or more additional technical advantages may be readily apparent to someone skilled in the art from the figures, descriptions, and claims included herein. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: FIGURE 1 illustrates an exemplary cryogenic tank car. FIGURE 2 illustrates an exemplary conventional system for use with the cryogenic tank car of FIGURE 1, wherein the piping protrudes from the outer tank of the tank car through a plurality of individual pads welded directly onto a large reinforcing pad welded to the outer tank. FIGURE 3 illustrates an exemplary virtual leak that can develop in the conventional nRnnrn / iznz / q / Yi system of FIGURE 2. FIGURE 4A and FIGURE 4B illustrate an exemplary nozzle and welded connection plate of the present disclosure, for use with the cryogenic tank car of FIGURE 1. FIGURE 5 illustrates an example of the nozzle and welded connection plate of FIGURE 4A and FIGURE 4B, in which an assembly of cover plates is attached to the welded connection plate. FIGURE 6 presents a flow diagram illustrating an exemplary method by which a cryogenic tank car can be manufactured, including the welded connection plate of FIGURE 4A and FIGURE 4B. DETAILED DESCRIPTION OF THE INVENTION Rail tank cars are used to transport a variety of fluid products over long distances. Traditional tank cars typically consist of a metal tank, wrapped in insulating material and covered with a protective outer jacket. Such traditional tank cars may be suitable for transporting liquids such as oil or ethanol. However, when the product to be transported inside the tank car is a cryogenic liquid (e.g., liquid nitrogen, liquid hydrogen, liquid oxygen, liquid methane, etc.), the insulation provided by a traditional tank car may not be sufficient to maintain the product at the low temperatures characteristic of such liquids. Consequently, cryogenic tank cars have been designed to transport these products. Such tank cars typically consist of a thin inner tank placed inside a thicker outer tank.A vacuum applied to the annular space between the two tanks is used to provide a high degree of insulation to the product contained within the inner tank, allowing the tank car to transport extremely low temperature products over large distances, while helping to minimize heat leakage into the inner tank. Products are typically loaded into and unloaded from tank cars via inlet / outlet valves and piping that penetrates the tanks. In traditional tank cars, the product is usually loaded and / or unloaded from the top and / or bottom of the tanks. Nozzles are typically provided at the top of the tank cars, offering locations for piping to enter the tanks and connect to valves serviced from outside. Thick steel connection plates, designed to cover these nozzles, provide mounting locations for these valves and various other connections. These connection plates are typically secured to the nozzles using a set of mechanical fasteners, with O-rings placed between the nozzles and the connection plates to help seal the tank interior from the external environment. ORObCn / LZnZ / q / Yli Unlike a traditional tank car, where the product is typically loaded / unloaded from the top or bottom, a cryogenic tank car, constructed using a tank-within-a-tank design as described above, generally includes a cabinet on the side of the tank. This cabinet houses the valves and piping used for loading / unloading the tank. This allows an operator to load / unload the tank car while standing alongside it. Inside the cabinet, a large reinforcing pad is typically welded to the outer tank. A series of pipes, each associated with its own individual connection pad that attaches to the outside of the reinforcing pad, penetrate the tank at separate locations through the pad.Therefore, the reinforcing pad is welded not only around the outer edge of the pad, but also around the holes cut in the pad, through which the individual pipes pass. Undesirably, this configuration creates the possibility of a partial loss of vacuum in the annular space between the inner and outer tanks. Specifically, during the welding process, air can become trapped beneath the reinforcing pad, between the area defined by the weld around the pad's outer edge and the welds around the holes cut in the pad. Even if the weld around the outer edge of the reinforcing pad provides a good seal, a crack in any of the welds around the holes cut in the pad can allow air trapped between the pad and the outer tank to enter the annular space between the outer and inner tanks.The vacuum loss resulting from such a virtual leak can be sufficient to reduce the insulation provided by the vacuum below the range of values ​​suitable for use when transporting cryogenic liquids. This disclosure describes a welded nozzle for use in a cryogenic tank car that addresses one or more of the problems described above. In contrast to a conventional tank within a tank design, where the piping protrudes from the outer tank through a plurality of individual pads welded directly onto a large reinforcing pad welded to the outer tank, this description describes the use, in certain embodiments, of a single large nozzle with a connection plate welded to the nozzle, through which all the piping passes. The use of a single weld around the outside of the connection plate helps prevent the development of virtual leaks and reduces the vacuum in the annular space between the inner and outer tanks.In addition, welding the connection plate to the nozzle (rather than mechanically attaching the plate to the nozzle) helps maintain the vacuum between the inner and outer tanks, while also allowing for easy detection of any actual leaks in the vacuum space that may develop. nRnbrn / iznz / q / Yi The terms of this disclosure and its advantages are best understood by referring to Figures 1, 2, 3, 4A, 4B, 5, and 6 of the drawings. Similar numbers are used for similar and corresponding parts of the various drawings. Additional information is disclosed in U.S. Patent Application No. ___ entitled “Internal Nozzle for a Tank Car” (Attorney File No. 091078.2325) and U.S. Patent Application No. ___ entitled “Access Release for a Tank Car” (Attorney File No. 091078.2327), which are incorporated herein by reference as if reproduced in their entirety.A railway tank car is used throughout this disclosure as an example, but the ideas presented herein may be applied to other cryogenic liquid storage tanks, including storage tanks for use on other types of vehicles or vessels. Figure 1 illustrates an exemplary cryogenic tank car 100 on which the welded connection plate of this disclosure may be installed. The cryogenic tank car 100 includes the storage tank 102 mounted on the wheel assemblies 135 and 140. The storage tank 102 is generally configured to store a cryogenic liquid, such as methane, nitrogen, hydrogen, oxygen, and / or any other liquefied gas. The storage tank 102 includes a generally elongated hollow cylinder, enclosed at one end by the tank head 110 and at one end by the tank head 115. This description contemplates that the storage tank 102 may have any suitable diameter and length. As illustrated in FIGURE 1, the storage tank 102 can be a double-walled cryogenic tank equipped with a vacuum jacket. For example, the storage tank 102 can include the outer tank 105 and the inner tank 120 placed inside the outer tank 105. The outer tank 105 and the inner tank 120 can be formed from any suitable material or combination of materials. For example, the outer tank 105 and the inner tank 120 can be made of steel or any other suitable metal. In some embodiments, the outer tank 105 can be formed from a different material than the inner tank 120. In certain embodiments, the thickness of the outer tank 105 is greater than the thickness of the inner tank 120. The outer surface of the inner tank 120 and the inner surface of the outer tank 105 define the annular space 125. The annular space 125 can be configured to maintain a vacuum. For example, the annular space 125 can be sealed from the outside of the outer tank 105 and the inside of the inner tank 120, so that air from outside the outer tank 105 and / or fluid from inside the inner tank 120 cannot enter the annular space 125. A vacuum can be established in the annular space 125 using one or more vacuum pumps, or any other suitable means. Once the vacuum is established, the annular space 125 can be used to provide insulation to the contents of the inner tank 120 by minimizing heat transfer from the outer tank 105 to the inner tank 120. Storage tank 102 may include piping circuits for loading / unloading products into or out of storage tank 102. For example, storage tank 102 may include a spray head, a sprinkler, a vent circuit, a fill and drain circuit, any other piping circuit, any other suitable component, and / or any number and combination thereof. Valves and / or fittings may be mounted on storage tank 102 to control the loading and unloading of products into and from storage tank 102. Such valves and / or fittings may be mounted anywhere on storage tank 102. For example, in certain embodiments, the valves and / or fittings may be mounted on the top and / or bottom of storage tank 102.As another example, in certain embodiments of cryogenic storage tanks 102, the valves and / or connections can be mounted on one side of the storage tank 102 and housed within the cabinet 130. As a further example, in certain embodiments of the cryogenic storage tank 102, the valves and / or connections can be mounted on one or both tank heads 110 and 115. Figure 2 presents an example illustrating portions of the interior of cabinet 130, which may be present on conventional cryogenic tank cars. As described above, cabinet 130 typically includes valves, connections, and / or piping used to control the loading and / or unloading of the storage tank 102. One or more cabinets 130 may be mounted on the side of the tank car 100 and / or on one or both tank heads 110 and 115. Such placement of cabinet 130 allows an operator to load / unload the storage tank 120 while standing beside the tank. As illustrated in FIGURE 2, conventional cryogenic tank car cabinets 130 typically include a large reinforcing pad 205 that is welded to the outer tank 105. The reinforcing pad 205 is typically formed from carbon steel. One or more pipes 215 penetrate the reinforcing pad 205 and are used to load / unload products to / from the inner tank 120. Each pipe 215 is associated with its own individual connection pad 210, which is welded to the reinforcing pad 205. The connection pads 210 are typically formed from stainless steel and cover holes in both the reinforcing pad 205 and the outer tank 105, through which the individual pipes 215 pass. Accordingly, the reinforcing pad 205 is welded not only around the outer edge 220 of the reinforcing pad 205, but also around the holes cut in the pad.Under normal operating conditions, the welds around the reinforcement pad noobm / i 707 / 3 / yl. 205 and the connecting pads 210 are configured to seal the outer tank 105, allowing a vacuum to be established in the annular space 125 between the inner tank 120 and the outer tank 105. As described above, this vacuum can be used to provide sufficient insulation to the inner tank 120 so that cryogenic fluids can be transported within the inner tank 120. However, cracks in any of the welds described above can lead to an actual and / or virtual leakage of atmosphere into the annular space 125, reducing the insulation provided by the vacuum. Figure 3 illustrates an example where multiple welds around the reinforcing pad 205 can lead to the development of a virtual leak of atmosphere into the annular space 125 between the inner tank 120 and the outer tank 105. Figure 3 shows a cross-section of the reinforcing pad 205, welded to the outer tank 105. Hole 315 has been cut in the reinforcing pad 205 to accommodate the passage of pipe 215 into the outer tank 105. The connecting plate 210 is welded to the reinforcing pad 205 and covers hole 315. As illustrated in Figure 3, during the welding process, air 310 can become trapped beneath the reinforcing pad 205, between the area defined by weld 305a around the outer edge of the pad and weld 305b around the hole 315 cut in the pad. 205 to accept pipe 215.Even if the weld 305a, around the outer edge of the reinforcing pad 205, provides a good seal (such that the atmosphere cannot pass through the weld 305a), a crack in the weld 305b, around the hole 315 (as illustrated in FIGURE 3), may allow air 310 trapped between the platform 205 and the outer tank 105 to enter the annular space 125 between the outer tank 105 and the inner tank 120. The loss of vacuum within the annular space 125 resulting from such a virtual leak may be sufficient to reduce the insulation provided by the vacuum below the range of values ​​suitable for use when transporting cryogenic liquids.For example, adding only 500 milliliters of atmosphere to an annular space of volume -35,000 L may be sufficient to reduce the insulation provided by the vacuum in the annular space below the range of values ​​suitable for transporting cryogenic liquids. The multiple welds 305 around the reinforcing pad 205 also make it difficult to discover the source(s) of any potential leaks. For example, as illustrated in FIGURE 3, each connection plate 210, welded to the top of the reinforcing pad 205 to cover the hole 315, also covers weld 305b around the hole 315. As a result, if a crack develops in weld 305b, it will be undetectable by mere visual inspection of the external tank 105 (including visual inspection of the reinforcing pad 205 and the connection plate 210). nRnnrn / iznz / q / Yi Rather, identifying crack 305b as the source of a virtual shunt may require removing the 210 connection plate from the 205 reinforcement pad. FIGURE 4A and FIGURE 4B illustrate an example of the nozzle and welded connection plate of the present disclosure, for use with the cryogenic tank car 100. FIGURE 4A presents a cross section of the welded connection plate 405 and nozzle 415, while FIGURE 4B presents a front view of the welded connection plate 405. As illustrated in FIGURE 4A and FIGURE 4B, in contrast to a conventional cistern within a cistern design, in which the pipe 215 projects from the outer cistern 105 through a plurality of individual pads 210 welded directly onto a large reinforcing pad 205 welded to the outer cistern 105, this disclosure contemplates the use of a large nozzle 415, with the connection plate 405 welded to the nozzle 405, through which all pipes 215a to 215g pass. The nozzle 415 may be formed from a hollow cylindrical pipe (or any other suitable elongated hollow structure) and defines an orifice / opening 420 in the outer cistern 105.Nozzle 415 extends from the outer cistern 105 in a direction generally opposite to the direction from the outer cistern 105 to the inner cistern 120, such that a first edge of nozzle 415 engages with the outer cistern 105 (and / or is located within the annular space 125), and a second edge of nozzle 415 is located at a distance d from an outer surface of the outer cistern 105. This description contemplates that the distance d can be any suitable distance. In certain embodiments, the first edge of nozzle 415 may be flush with the first cistern 105, so that the first edge does not extend into the annular space 125. In some embodiments, the first end of nozzle 415 may extend slightly into the annular space 125, so that the first edge of nozzle 415 is located within the annular space 125.In such embodiments, the nozzle 415 may be coupled to the outer tank 105 along one side of the nozzle 415 near the first edge. For example, the nozzle 415 may be welded or otherwise coupled to the outer tank 105 around the orifice / opening 410. A cross-section of the nozzle 415 may be circular, elliptical, or of any other suitable shape. The nozzle 415 may be formed of the same material as the outer tank 105 or of any other suitable material. For example, in certain embodiments, the nozzle 415 may be formed of steel or of any other suitable metal. The connecting plate 405 is configured to rest on top of the second edge of the nozzle 415 and to cover the opening 420 in the external tank 105 defined by the nozzle 415. For example, the connecting plate may generally have the same shape as the cross-section of the nozzle 415. The connecting plate 415 may be formed of the same material as the external tank 105 and / or the nozzle 415, or any other suitable material. For example, in certain embodiments, the connecting plate 405 may be formed of steel or any other suitable metal. This disclosure contemplates that the connecting plate 405 may have any suitable thickness. For example, in certain configurations, the connection plate 405 may have the same thickness as the external cistern 105, be thicker than the external cistern 105, or be thinner than the external cistern 105.In certain configurations, the second edge of the nozzle 415 may include a groove which is configured to seat the connection plate 405. The connecting plate 405 is secured to the second edge of the nozzle 415 by welding around the outer edge 410 of the connecting plate 405. Using a single weld around the outer edge 410 of the connecting plate 405 helps prevent virtual leaks from developing and reduces the vacuum in the annular space 125 between the outer tank 105 and the inner tank 120. In addition, welding the connecting plate 405 to the nozzle 415 (rather than mechanically clamping the plate 405 to the nozzle 415) can help maintain the vacuum within the annular space 125, while also allowing for easy detection of any leaks that may develop in the annular space 125. This disclosure states that the connection plate 405 can accept any number of pipes 215a to 215f that run from the external environment of the outer cistern 105 into the annular space 125 and ultimately into the inner cistern 120. Such pipe 215a to 215f can extend through the holes 425a to 425f in the connection plate 405. To help prevent leaks from developing into the annular space 125 through these holes, the pipes 215a to 215f can be welded to the connection plate 405 around the holes 425a to 425f. For example, pipe 215a can be welded to connection plate 405 around an outer circumference of pipe 215a at the location where pipe 215a passes through hole 425a, pipe 215b can be welded to connection plate 405 around an outer circumference of pipe 215b at the location where pipe 215b passes through hole 425b, etc.Similar to the welding around the outer edge 410 of the connection plate 405, such welds between pipes 215a to 215f and the connection plate 405 can help maintain the vacuum within the annular space 125, while also allowing for easy discovery of any leaks into the annular space 125 that may develop. In certain embodiments, and as illustrated in FIGURE 4A and FIGURE 4B, the holes 425a to 425f are designed to provide a small clearance for the passage of the corresponding pipe 215a to 215f. In this way, welds can be used around the pipes 215a to 215f to provide seals around the holes 425a to 425f. In some embodiments, one or more of the holes 425a to 425f may be designed to provide a larger clearance for the passage of the corresponding pipe 215a to 215f. This may be desirable to provide a tolerance for manufacturing purposes. FIGURE 5 illustrates an example of such a modality. As illustrated in FIGURE 5, the holes 425a through 425c in the connection plate 405 can be designed to provide significant clearance for the corresponding pipe 215a through 215c. For example, the diameter of one or more of the holes 425a through 425c can be 1.27 cm (half an inch) or more larger than the diameter of the corresponding pipe 215a through 215c passing through the hole. In such embodiments, it may not be possible to use welding to seal the exposed space between the perimeter of each hole and the pipe passing through the hole. Accordingly, in certain embodiments, cover plates 505a through 505c can be installed on the connection plate 405. As illustrated in FIGURE 5, each cover plate includes a hole designed to accept the pipe.For example, cover plate 505a includes hole 510a to accept pipe 215a, cover plate 505b includes hole 510b to accept pipe 215b, and cover plate 505c includes hole 510c to accept pipe 215c. Each cover plate 505a through 505c can be used to cover the opening exposed by the corresponding oversized hole 425a through 425c. For example, cover plate 505a can be used to cover the opening in external cistern 105 exposed by hole 425a, cover plate 505b can be used to cover the opening in external cistern 105 exposed by hole 425b, and cover plate 505c can be used to cover the opening in external cistern 105 exposed by hole 425c.To achieve this purpose, each hole 510a to 510c in the cover plates 505a to 505c is designed to provide a smaller clearance for the pipes 215a to 215c than the corresponding hole 425a to 425c in the connection plate 405. For example, in certain embodiments, the holes 425a to 425c and the holes 510a to 510c may be circular. In such embodiments, the diameter of each of the holes 510a to 510c is smaller than the diameter of the corresponding hole in holes 425a to 425c. The cover plates 505a to 505c may be welded to the connection plate 405 around their outer perimeters 515a to 515c. Additionally, the cover plates 505a to 505c can be welded to the corresponding pipe 215a to 215c around the perimeter of the holes 510a to 510c.Unlike conventional 210 bonding pads (described above in the discussion of FIGURE 3), 505a through 505c cover plates are not designed to cover any solder joints. Therefore, the use of 505a through 505c cover plates does not carry the risk of virtual leakage. The 505a through 505c cover plates can have any suitable geometry. For example, as illustrated in Figure 5, the 505a through 505c cover plates can be circular. As another example, the 505a through 505c cover plates can be elliptical or any other suitable shape. The 510a through 510c holes can be placed anywhere on the 505a through 505c cover plates. For example, in certain ORObm / l 7O7 / 3 / Yl· In certain configurations, one or more of the holes 510a to 510c may be located in the center of the corresponding cover plate 505a to 505c. As another example, and as illustrated in FIGURE 5, each hole 510a to 510c may be located slightly off-center from the corresponding cover plate 505a to 505c. This may be desirable to help ensure that a given cover plate of the cover plates 505a to 505c does not interfere with any of the other cover plates and / or holes 425a to 425f in the connection plate 405. This disclosure states that any number of cover plates 425a to 425c may be installed on the connection plate 405. For example, as illustrated in FIGURE 5, in certain configurations, cover plates 505a to 505c may be used for the larger pipe 215a to 215c passing through the connection plate 405, but not for the smaller pipe 215d to 215f. This may be desirable when the flexibility of the smaller pipe is such that it can be easily accommodated to manufacturing tolerances. The connection plate 405 may additionally include any number of valves and / or other connections used to control fluid flow into / out of the inner tank 120 through the pipes 215. Furthermore, this description assumes that any number of connection plates 405 may be installed in a given storage tank 102, and that the connection plates 405 may be installed in any suitable location in the storage tank 102. For example, a pair of connection plates 405 may be installed on each side of the storage tank 102. FIGURE 6 presents a flow diagram illustrating an exemplary method 600 by which a cryogenic tank car 100 can be manufactured, including a welded connection plate 405. In step 605, the nozzle 415 is coupled to the outer tank 105. In certain embodiments, the nozzle 415 is manufactured separately from the outer tank 105. For example, the nozzle 415 can be formed from a hollow metal cylinder. In such embodiments, coupling the nozzle 415 to the external tank 105 may include creating an opening 420 in the external tank 105 and welding the nozzle 415 to the external tank 105 around the perimeter of the opening 420. In some embodiments, the external tank 105 may be manufactured to include the nozzle 415 (for example, the external tank 105 and the nozzle 415 may be manufactured integrally together). In stage 610, pipe 215a to 215f passes through nozzle 415. In stage 615, each pipe 215a to 215f is passed through a corresponding hole 425a to 425f in the connection plate 405, and the connection plate 405 is placed on top of the nozzle 415. In certain embodiments, placing the connection plate 415 on top of the nozzle 415 may include resting the connection plate 415 in a groove on the upper edge of the nozzle 415. In stage 620, the connection plate 415 is welded to the nozzle 415 around the upper edge of the nozzle 415. In certain embodiments, the connection plate 415 is also welded around of the perimeters of one or more holes 425a to 425f. In some embodiments, one or more cover plates 505a to 505c are placed over the holes 425a to 425c in the connection plate 415.The cover plates 505a to 505c are then welded to the connection plate 415 around their outer perimeters 515a to 515c. The cover plates 505a to 505c can also be welded to the pipes 215a to 215c, around the perimeters of the corresponding holes 510a to 510c through which the pipe passes. Modifications, additions, or omissions may be made to Method 600, as depicted in Figure 6. Method 600 may include more, fewer, or other steps. For example, the steps may be performed in parallel or in any suitable order. One or more steps may be performed by an individual, a machine, any other device, or a combination thereof. Although this disclosure includes several embodiments, many changes, variations, alterations, transformations and modifications may be suggested to a person skilled in the art, and it is intended that this disclosure covers such changes, variations, alterations, transformations and modifications that fall within the scope of the appended claims.

Claims

1. A tank for a railway tank car, characterized in that it comprises: an external tank; a nozzle projecting through the external tank, wherein: an outer edge of the nozzle extends beyond an outer surface of the external tank; and an intersection between the nozzle and the external tank defines an opening in the external tank; a connecting plate welded to the nozzle around the outer edge of the nozzle; and a pipe assembly passing through the connecting plate and into the external tank through the nozzle, the pipe assembly comprising at least one of the pipes for loading fluid into the tank and the pipes for unloading fluid from the tank.

2. The tank according to Claim 1, further characterized in that it comprises an inner tank placed within the outer tank, the inner tank being configured to store a cryogenic fluid, wherein an annular space defined by an inner surface of the outer tank and an outer surface of the inner tank is configured to maintain a vacuum.

3. The cistern according to Claim 2, characterized in that each pipe of the pipe assembly travels at least a distance in the annular space between the inner cistern and the outer cistern, in a direction that is not substantially perpendicular to a surface of the inner cistern through which the pipe enters.

4. The cistern according to Claim 1, characterized in that the nozzle is placed on one side of the external cistern.

5. The tank according to Claim 1, further characterized in that it comprises: a second nozzle projecting through the outer tank, wherein an outer edge of the second nozzle extends beyond the outer surface of the outer tank; a second connecting plate welded to the second nozzle around the outer edge of the second nozzle; and a second set of pipes passing through the second connecting plate and into the outer tank through the second nozzle, the second set of pipes comprising at least one of the pipes for loading fluid into the railway tank car and the pipes for unloading fluid from the railway tank car.

6. The cistern according to Claim 1, further characterized in that it comprises a cover plate, wherein: the connection plate defines a set of openings, each opening of the connection plate being associated with a pipe of the pipe assembly passing through the opening; the cover plate defines an orifice, wherein: a pipe of the pipe assembly passes through the orifice; and a diameter of the opening of the set of openings through which the pipe passes is greater than the diameter of the orifice; and the cover plate is welded to the connection plate around an outer perimeter of the cover plate.

7. The cistern according to Claim 6, characterized in that a center of the hole is displaced from the center of the cover plate.

8. A method for manufacturing a tank for a railway tank car, characterized in that it comprises: coupling a nozzle to an external tank, wherein: the nozzle is configured to project through the external tank, such that an outer edge of the nozzle extends beyond an outer surface of the external tank; and an intersection between the nozzle and the external tank defines an opening in the external tank; passing a set of pipes through the nozzle, the pipe set comprising at least one of the pipes for loading fluid into the tank and pipes for unloading fluid from the tank;placing a connection plate on the outer edge of the nozzle, the connection plate defining a set of openings, each opening of the set of openings being associated with a pipe of the pipe set, wherein placing the connection plate on the outer edge of the nozzle comprises passing each pipe of the pipe set through the associated opening of the set of openings; and welding the connection plate to the nozzle around the outer edge of the nozzle.

9. The method according to claim 8, characterized in that: the outer tank encloses an inner tank configured to store a cryogenic fluid; and an annular space defined by an inner surface of the outer tank and an outer surface of the inner tank is configured to maintain a vacuum.

10. The method according to Claim 9, characterized in that each pipe of the pipe assembly travels at least a distance in the annular space between the inner cistern and the outer cistern, in a direction that is not substantially perpendicular to a surface of the inner cistern through which the pipe enters.

11. The method according to Claim 8, characterized in that attaching the nozzle to the external tank comprises attaching the nozzle to one side of the external tank.

12. The method according to claim 8, further characterized in that it comprises: attaching a second nozzle to the outer tank, wherein: the second nozzle is configured to project through the outer tank, such that an outer edge of the second nozzle extends beyond an outer surface of the outer tank; and an intersection between the second nozzle and the outer tank defines a second opening in the outer tank; passing a second set of pipes through the second nozzle, the second set of pipes comprising at least one of the pipes for loading fluid into the tank and pipes for discharging fluid from the tank;placing a second connecting plate on the outer edge of the second nozzle, the second connecting plate defining a second set of openings, each opening associated with a pipe of the second set of pipes, wherein placing the second connecting plate on the outer edge of the second nozzle comprises passing each pipe of the second set of pipes through the associated opening of the second set of openings; and welding the second connecting plate to the second nozzle around the outer edge of the second nozzle.

13. The method according to claim 8, further characterized in that it comprises: placing a cover plate on the connection plate, the cover plate defining an orifice, wherein: placing the cover plate on the connection plate comprises passing a pipe of the pipe assembly through the orifice; and a diameter of the opening of the pipe assembly associated with the pipe is greater than the diameter of the orifice; and welding the cover plate to the connection plate around an outer perimeter of the cover plate.

14. The method according to Claim 13, characterized in that a hole center is displaced from the center of the cover plate.

15. A railway tank car, characterized in that it comprises: an external tank; a nozzle projecting through the external tank, wherein: an outer edge of the nozzle extends beyond an outer surface of the external tank; and an intersection between the nozzle and the external tank defines an opening in the external tank; a connecting plate welded to the nozzle around the outer edge of the nozzle; a pipe assembly passing through the connecting plate and into the external tank through the nozzle, the pipe assembly comprising at least one of the pipes for loading fluid into the tank and pipes for unloading fluid from the tank; and a wheel assembly, wherein the external tank is coupled to the wheel assembly.

16. The railway tank car according to Claim 15, further characterized in that it comprises an inner tank placed within the outer tank, the inner tank being configured to store a cryogenic fluid, wherein an annular space defined by an inner surface of the outer tank and an outer surface of the inner tank is configured to maintain a vacuum.

17. The railway tank car according to Claim 16, characterized in that each pipe of the pipe assembly travels at least a distance in the annular space between the inner tank and the outer tank, in a direction that is not substantially perpendicular to a surface of the inner tank through which the pipe enters.

18. The railway tank car according to Claim 15, characterized in that the nozzle is placed on one side of the external tank.

19. The cistern according to Claim 15, further characterized in that it comprises a cover plate, wherein: the connection plate defines a set of openings, each opening of the connection plate being associated with a pipe of the pipe assembly passing through the opening; the cover plate defines an orifice, wherein: a pipe of the pipe assembly passes through the orifice; and a diameter of the opening of the opening set through which the pipe passes is greater than the diameter of the orifice; and the cover plate is welded to the connection plate around an outer perimeter of the cover plate.

20. The cistern according to Claim 19, characterized in that a center of the hole is displaced from the center of the cover plate.

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