High-pressure vacuum-jacketed transfer lines

Abstract

Vacuum-jacketed transfer line includes a safety conduit system including a partly flexible hose assembly, a valve assembly at each longitudinal end thereof with a valve and valve seat, a connecting member connected to the valves and extending through the hose assembly, and a pipe stub connected to each valve assembly. A partly flexible vacuum-jacket assembly surrounds the hose assembly and is connected at ends to the pipe stubs and defines a space between the vacuum-jacket assembly and safety conduit system. The vacuum-jacket assembly includes a pump-out port through which air can be evacuated from the space between the vacuum-jacket assembly and safety conduit system to thereby provide a vacuum therein. The safety conduit system is configured to be capable of operating pressures of greater than about 24000 psi during use, for example, with cryogenic fluid such as liquid hydrogen passing through the transfer line.

Description

[0001] HIGH-PRESSURE VACUUM- JACKETED TRANSFER LINES

[0002] TECHNICAL FIELD

[0003] The present invention relates to vacuum-jacketed transfer lines with a built in safety shutoff system that is capable of tolerating relatively high fluid pressures, and a method for manufacturing vacuum-jacketed transfer lines.

[0004] BACKGROUND ART

[0005] Vacuum-jacketed or insulated transfer lines (often referred to as LH2 VIP) are used in almost every liquid hydrogen project in the energy sector, the mobility industry, and all other industries in which liquid hydrogen is transported, transferred, handled, processed, or otherwise used. The transfer lines form the connection, for example, between storage vessels and applications or between production sites and transportation vehicles.

[0006] Since liquid hydrogen must be transported at the extremely low temperature of about minus 252.9 degrees Celsius, the use of transfer lines with optimal insulation is essential. The technology that precisely provides the insulation value, quality, and safety required to transport liquid hydrogen is vacuum technology.

[0007] To this end, vacuum-jacketed transfer lines typically have a double tubular wall, with air between the walls being evacuated. Spacers are used between the tubular walls to keep them apart so that they never touch. This creates a vacuum space and a pressure difference between the vacuum and outside air. Use of vacuum technology keeps much of the surrounding heat out of a pipe or application, minimizing thermal heat losses of the fluid being conveyed through the pipe and preventing ice build-up.

[0008] Also, vacuum-jacketed liquid hydrogen transfer lines often include a rigid pipe with a slim design. All coils are prefabricated for fast and efficient installation. In addition, the pipes are made of stainless steel so that the structures will last for years without any problems.

[0009] Vacuum-jacketed transfer lines are also used for the transfer of liquified natural gas (LNG). Producers who want to switch from LNG to liquid hydrogen can therefore continue to use the same infrastructure. Of course, all the standards and requirements for liquid hydrogen must be met.

[0010] Of interest, U.S. Pat. No. 3,765,705 (Tantam) describes a vacuum-jacketed assembly for the transfer of such fluids that has prefabricated jacketed members each made up of a tubular pipeline and a coaxial tubular jacket. The jacket is attached in fluid-tight manner to the tubular pipeline to provide an insulating space, with tubular junction members having the same cross section as the tubular pipeline and joined to the ends of the pipeline. Each prefabricated jacketed member has two tubular sleeves joined to it, one at each end of the jacketed member. The tubular sleeves have a larger internal diameter than the external diameter of the jacketed members and provide an insulating space around the portions of the pipeline not enclosed within a tubular jacket, with these insulating spaces being evacuated of air.

[0011] Additional prior art relating to vacuum-jacketed conduits and / or methods for making them includes U.S. Pat. Nos. 1,140,633 (Trucano), 2,930,407 (Conley et al.), 3,360,001 (Anderson), 6,216,745 (Augustynowicz), 8,291,940 (Frohne et al.), 8,590,942 (Kouketsu et al.), and 9,261,206 (Soika et al.).

[0012] SUMMARY OF INVENTION

[0013] An object of at least one embodiment of the present invention is to provide new and improved vacuum-jacketed transfer lines, that have a built in safety shutoff system and are preferably flexible, capable of transferring liquid hydrogen and other fluids that have low handling temperatures, and relatively high pressure strength and methods for manufacturing vacuum-jacketed transfer lines.

[0014] Another object of at least one embodiment of the present invention is to provide new and improved vacuum-jacketed transfer lines that minimize and ideally avoid thermal heat loss of the fluid passing through the transfer lines, and / or are capable of enabling transfer of liquid hydrogen, liquid nitrogen, LNG and other fluids having a temperature substantially below ambient temperature.

[0015] In order to achieve one or more of these objects or possibly others, a vacuum-jacketed transfer line in accordance with the invention includes a safety conduit system including an elongate hose assembly, a valve assembly at each longitudinal end of the hose assembly, a connecting member extending through the hose assembly between the valve assemblies, and a pipe stub connected to each valve assembly. Each valve assembly includes a valve body having an open interior defining a flow passage, and a valve arranged in the open interior and being movable against a valve seat defined by the valve body to close the flow passage at least partly. The connecting member is connected at its ends to the valves. Each pipe stub is connected to the valve body of a respective valve assembly.

[0016] The transfer line also includes a vacuum-jacket assembly over the hose assembly and connected at ends to the pipe stubs and defines a space between the vacuum-jacket assembly and the safety conduit system. The vacuum-jacket assembly includes a pump-out port through which air is evacuated from the space between the vacuum-jacket assembly and the safety conduit system to thereby provide a vacuum in the space between the vacuum-jacket assembly and the safety conduit system. The vacuum-jacketed assembly may be connected to the safety conduit system such that the valve assemblies are inside the space defined inward of the vacuum-jacket assembly or outside of this space.

[0017] The safety conduit system may be configured to be capable of operating at pressures from about 3000 psi to more than about 24000 psi during use, or more particularly, capable of operating pressures of about 6000 psi during use.

[0018] The hose assembly of the safety conduit system may include a pipe connected to each valve assembly and a flexible braided hose connected at each longitudinal end to a respective pipe to thereby form an internal fluid conduit. The vacuum-jacket assembly can then include a flexible outer hose surrounding the flexible braided hose of the hose assembly.

[0019] The vacuum-jacket assembly may include a flexible outer hose having an inner outer hose braid and an outer braid sleeve, and seal plates each connected to a respective pipe stub with the pump-out port being in one of the seal plates. The seal plates can each include a tubular portion and an axial portion with at least part of the tubular portion being spaced apart from an underlying part of the safety conduit system. The axial portion of each seal plate is connected to the respective pipe stub.

[0020] The method of making a vacuum-jacketed transfer line includes providing an outer, elongate partly flexible hose assembly having an opening at each of its longitudinal ends and configured to withstand vacuum pressure, and a safety conduit system including a flexible elongate hose. The safety conduit system is positioned partly in the outer hose by passing the safety conduit system through the opening at one of longitudinal ends of the outer hose until the safety conduit system extends exterior of the opening at the other longitudinal end of the outer hose. Then, the longitudinal ends of the outer hose are sealed to the safety conduit system, for example, by crimping using ferrules, and a vacuum space is formed between the outer hose and the safety conduit system. Fittings are attached to longitudinal ends of the safety conduit system.

[0021] In some embodiments, a relief or pump-out port for the vacuum space is provided. The vacuum space may be formed while the outer hose having the safety conduit system sticking out is rolled up. The safety conduit system is provided with structure to enable passage of fluids therethrough having a temperature of about minus 252.9 degrees Celsius, and may include a metallic hose and specially engineered spring.

[0022] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0023] BRIEF DESCRIPTION OF DRAWINGS

[0024] Non-limiting examples of embodiments of the invention are described below with reference to figures attached hereto that are listed following this paragraph. Identical features that appear in more than one figure are generally labeled with the same label in all the figures in which they appear. A label labeling an icon representing a given feature of an embodiment of the invention in a figure may be used to reference the given feature. Dimensions of features shown in the figures are chosen for convenience and clarity of presentation and are not necessarily shown to scale.

[0025] FIG. 1 is a longitudinal cross-sectional view of a vacuum-jacketed transfer line in accordance with the invention;

[0026] FIG. 2 is a side view, partly cut-away of another vacuum-jacketed transfer line in accordance with the invention;

[0027] FIG. 3 is a perspective view of a model of another vacuum-jacketed transfer line in accordance with the invention;

[0028] FIGS. 4-6 show a vacuum-jacketed transfer line in accordance with the invention; and

[0029] FIGS. 7-23 shows steps in the manufacture of a safety conduit system particularly suited for the vacuum-jacketed transfer line in accordance with the invention.

[0030] A better understanding of the disclosed technology will be obtained from the following detailed description of the preferred embodiments, taken in conjunction with the drawings and the attached claims.

[0031] BEST MODE FOR CARRYING OUT THE INVENTION

[0032] A vacuum-jacketed transfer line 10 for fluid in accordance with the invention is shown in FIG. 1 and includes a safety conduit system 12 and a vacuum-jacket assembly 14 over part of the safety conduit system 12 to define a space 16 between the vacuum-jacket assembly 14 and the safety conduit system 12. The vacuum-jacket assembly 14 is connected to the safety conduit system 12. Prior to use of transfer line 10 for fluid transfer, air is evacuated from the space 16 between the vacuum-jacket assembly 14 and the safety conduit system 12 to thereby provide a vacuum in this space 16. Generally, the safety conduit system includes a built-in safety shutoff system, whether having the construction described herein or another different construction.

[0033] The safety conduit system 12 includes at each longitudinal end of a partly flexible hose assembly 18, a valve assembly 20 having a valve body 22 with an open interior forming a flow passage for the fluid. Valve body 22 extends in an axial or longitudinal direction about a central axis. Each valve assembly 20 also includes a valve 24 arranged in the open interior of the valve body 22 and is movable against a valve seat 26 defined by the valve body 22 to close the flow passage, or in the opposite direction to open the flow passage. When the valve 24 is against the valve seat 26, the flow passage may be entirely closed thereby preventing all fluid flow therethrough or only partly closed allowing weep or a limited amount of fluid therethrough, depending on the construction of the valve 24. When the valves 24 are apart from the respective valve seat 26, fluid flow through the valve assemblies 20 is permitted.

[0034] The valve 24 of each valve assembly 20 may be a plunger valve having a receptacle at one end region, i.e., the end region including the end facing the valve seat 26, into which a respective end of a valve cable 28 is fixed. The valve cable 28 extends through the hose assembly 18 between the valve assemblies 20. Valve cable 28 is an example of a connecting member that connects the valves 24. Instead of a valve cable 28, a spring may be used as the connecting member, such as shown in FIG. 8. Instead of a plunger valve, a flapper or other seating type of valve may be used, one such flapper valve being shown in FIG. 7.

[0035] A valve guide ring 30 is provided as part of each valve assembly 20 for positioning the valve 24. With a valve 24 at each end of the safety conduit system 12, the safety conduit system 12 would prevent flow of fluid regardless of the site of the break in the flow structure. The pressure differential causes by any such break would cause the valve 24 in one or both the valve assemblies 20 to move against its respective valve seat 26, and stop outflow of fluid.

[0036] A cylindrical pipe stub 32 is connected to or formed integral with each valve body 22, extending in a direction away from the center of the transfer line 10. Hose assembly 18 includes a pipe 34 connected to or formed integral with each valve assembly 20 and a flexible braided hose 36 is connected at each longitudinal end to a respective one of the pipes 34 to thereby form an internal fluid conduit. A rear end region of each of the pipe stubs 32 is exposed, i.e., pipe stubs 32 are partly exposed and thus available for connection to or integration with fluid handing structure or conduits or other fluid couplings. Coupling structure can be formed on or integrated with the exposed end regions of the pipe stubs 32. Pipe stubs 32 and pipes 34 may be rigid, along with valve body 22. Adapters or fittings, such as fittings 54, 56 described below, may be connected to or formed integral with the pipe stubs 32, e.g., with the exposed portions thereof. Safety conduit system 12 may be any safety conduit system but is especially one of those manufactured by the applicant herein, LifeGuard Technologies.

[0037] Preferably, the safety conduit system 12 is configured to be capable of withstanding pressures of about 6000 psi during use, for example, with liquid hydrogen as the fluid passing through the transfer line 10. A range of pressure for the safety conduit system 12 in the transfer line 10 that it is capable of withstanding, or operating at, before burst may be from about 3000 psi to about 24000 psi. Incorporation of such high pressure safety conduit systems into a vacuum-jacketed transfer line is not believed to have been considered before. In addition to liquid hydrogen, the transfer line 10 could be used to transfer any cryogenic or extremely low temperature fluid.

[0038] Vacuum-jacketing is provided to the transfer line 10 by the vacuum-jacket assembly 14 which includes a flexible outer hose 38 having an inner outer hose braid 40 and an outer braid sleeve 42, which may be coextensive, and define a portion 16A of the space 16 radially inward. At one end, the outer hose 38 is connected to a first seal plate 44 having a pump-out port 46 and the other end, the outer hose 38 is connected to a second seal plate 48 without any port. The seal plates 44, 48 each have a tubular portion and an axial portion with at least part of the tubular portion being spaced apart from an underlying part of the safety conduit system 12, i.e., the valve body 22, the pipe stub 32 and / or the pipe 34. The axial portion of each seal plate 44, 48 is attached to the respective pipe stub 32 at a location to enclose with valve assemblies 20 inward of the vacuum-jacket assembly 14. Seal plates 44, 48 may be made of rigid materials.

[0039] For use of the transfer line 10, after the vacuum-jacket assembly 14 is connected to the safety conduit system 12, air is evacuated from the space 16 between the safety conduit system 12 and the vacuum-jacket assembly 14 through the pump-out port 46, e.g., by attaching a suction machine to the pump-out port 46 and activating it. The pump-out port 46 may include a one-way valve to prevent inflow of air into the space 16, which would now be a vacuum space.

[0040] Pump-out port 46 can have a structure that differs from that shown. For example, it may be oriented parallel with a longitudinal direction of the transfer line 10 at an end of the transfer line 10, such as disclosed in U.S. Pat. No, 7,093,619 (Watanabe et al., which is incorporated by reference herein) to achieve the identified advantages thereof.

[0041] Connections in the transfer line 10 may be welds or integral formation of the components being connected. Since the vacuum-jacket assembly 14 include the flexible outer hose 38 and the hose assembly 18 includes the flexible braided hose 36, the vacuum-jacketed transfer line 10 is thus partly flexible. FIG. 2 shows another embodiment of a transfer line 50 including a safety conduit system 52 and a vacuum-jacketed assembly 54 integrated therewith. The safety conduit system 52 includes a fitting or valve assembly 56, 58 at each end, each with a valve body 60 housing a valve 62 and a valve guide ring 64, and a connecting member 66 connecting the valves 62, i.e., a cable as shown or a spring. A breakaway assembly 68 is associated with one of the valve assemblies 56. The safety conduit system 52 also includes a hose assembly 52A including a pipe stub 70 connected to each end of a flexible inner hose. The vacuum-jacketed assembly 54 includes a partly flexible outer hose 54A, with the inner and outer hoses being convoluted to form a convoluted internal and external hose 72, and a wire braiding 74. The vacuum-jacketed assembly 54 also includes a rigid tubular component 76 with a pump-out port 78. In this embodiment, the vacuum-jacket assembly 54 does not overlie and enclose the valve assemblies 56, 58 or valve body 60 thereof, but rather is connected to the pipe stubs 70 and / or the valve assemblies 56, 58 themselves on an inner side.

[0042] Transfer line 10 may be manufactured essentially as described below with respect to FIGS. 7-23. Manufacturing transfer line 10 when in the rolled state is often advantageous.

[0043] FIGS. 3 and 4 show another transfer line 80 that includes an inner hose assembly or internal fluid conduit 82, a pair of adapters, valve assemblies or fittings 84, 86 each at a respective end of the internal fluid conduit 82, and an outer hose 88 extending between ferrules, end caps 90, 92, and spaced radially apart from the internal fluid conduit 82. There may be pipe stubs between the internal fluid conduit, and the fittings 84, 86. Internal fluid conduit 82 is made of metal and configured to allow for flow of a cryogenic fluid such as liquid hydrogen, liquid nitrogen and LNG, while the fittings 84, 86 are connected to the internal fluid conduit 82 to provide for a secure coupling to connectors leading to storage vessels, and the like. The fittings 84, 86 are preferably of a type sold by the assignee, Lifeguard Technologies.

[0044] A vacuum is generated in a space 94 between the internal fluid conduit 82 and the outer hose 88 in the radial direction and between the end caps 90, 92 in the longitudinal or axial direction, to minimize and potentially avoid thermal heat loss of the fluid passing through the internal fluid conduit 82. Vacuum space 94 thereby provides an insulating effect to the fluid operatively passing through the internal fluid conduit 82.

[0045] To provide intended flexibility for the transfer line 80, both the internal fluid conduit 82 and the outer hose 88 are flexible between the end caps 90, 92, and may be flexible hoses. This is represented by the accordion-type folding of the internal fluid conduit 82 and the outer hose 88. However, this type of folding is not required and any structure for the internal fluid conduit 82 and outer hose 88 that enable them to be flexible, and not rigid, may be used in the invention. This flexibility is an important aspect of the transfer line 80. The material of the outer hose 88 must be such that it is strong and capable of withstanding and holding vacuum pressure.

[0046] End caps 90, 92 may be a crimping of the longitudinal end regions of the outer hose 88 to the internal fluid conduit 82. The end caps 90, 92 surround the internal fluid conduit 82, and are spaced apart from the fittings 84, 86 to leave a portion of the internal fluid conduit 82 exposed between the end caps 90, 92 and the fittings 84, 86. This is not an essential feature though of the invention.

[0047] The structure shown in the middle region of the transfer line 80 is not required to be present in a commercial embodiment.

[0048] As with transfer lines 10, 50, the transfer line 80 may include an internal fluid conduit 82 that is manufactured to withstand or operate at significantly high pressures, relative to fluid conduits in existing vacuum-jacketed transfer lines. Specifically, the pressure threshold for the internal fluid conduit 82 in the invention may be about 6000 psi. A possible range of the operating pressure threshold is from about 3000 psi to more than about 24000 psi, which would be close to the burst pressure of the internal fluid conduit 82. The pressure capability of fluid conduits in existing vacuum-jacketed transfer lines is much less, for example, only about 350 psi.

[0049] In the method for manufacturing the transfer line 80, an existing hose to be used as an internal fluid conduit 82 is taken and placed inside of the outer hose 88 and then the vacuum is formed between longitudinal areas of the existing hose (to be internal fluid conduit 82) and the outer hose 88, which outer hose 88 thus forms an external hose inside of which there is the vacuum space 94. Vacuum-jacketing is thus not undertaken at the time of manufacture of the internal hose. The vacuum-jacketing may be formed while the hoses are in a rolled state.

[0050] An exemplifying method of manufacture is therefore to pass the internal fluid conduit 82 (of the safety conduit system of which it is the main part of) through an open longitudinal end of the outer hose 88 until both end regions of the internal fluid conduit 82 are exterior of the outer hose 88. The cross-sectional size or diameter of the open end regions of the outer hose 88 must be larger than the larger cross-sectional size or diameter of the internal fluid conduit 82 and its added structure to enable passage through the outer hose 88. The outer hose 88 is then crimped at its longitudinal end regions, preferably using ferrules, to the internal fluid conduit 82 to form the end caps 90, 92 while the air inside the space between the internal fluid conduit 82 and the outer hose 88 is removed to create the vacuum, e.g. the space 94 is evacuated. To this end, a relief or pump-out port 96 is provided in a casing 98 for the outer hose 88 to evacuate the space 94 prior to use.

[0051] Accordingly, a very advantageous transfer line 80 is obtained since it is now possible to use a pre-formed safety hose, preferably with modifications as described below, and then essentially build the vacuum-jacket around it by inserting it into an outer casing and forming the vacuum between the outer casing and the safety hose. This order differs from prior art constructions wherein the internal hose is formed at the same time as the transfer line in its entirety.

[0052] The invention therefore allows for unrestricted use of a variety of existing or future internal hoses, which are capable of transfer of fluids having desired properties such as an ability to contain and pass low temperature fluid, and different outer casings that may have properties, such as their size, to surround the internal hoses and then form a vacuum to create the vacuum-jacketed transfer line.

[0053] One manner in which the transfer line 10, 50, 80 may be obtained is described with reference to FIGS. 7-23. The steps identified below are considered important and critical steps in order to manufacture a preferred embodiment of an internal safety conduit system including the internal hose to be used in the transfer line 80. This does not in any way limit the method disclosed above. Also, advancements in technology may enable omission of some steps so that the steps should not be considered essential. Also, the provided order of the steps is not necessarily critical and the steps may be performed out of the order set forth below to the extent they involve different components. Even further, there may be other methods of manufacture any or all of the transfer liens 10, 50, 80 and the disclosed method in no way limits the transfer liens 10. 50 80 to being manufactured thereby.

[0054] Necessary parts and materials include fittings, ferrules (for rubber or PTFE hoses), an engineered compression spring, hinge pins, flapper valves, hinge pins, O-rings, fittings plugs, l / 8thinch pipe thread, cable connectors, rivets, and TEFLON® paste or equivalent. Preferred and possibly necessary tools include a crimper (where necessary), needle nose pliers, an assembly table, a screwdriver, a center punch, a hex wrench (Allen wrench), a hammer, a hose reel machine, and cable or wire cutters.

[0055] An initial step is to cut the hose to the proper, desired length. In the case of a metallic hose, this includes cutting the tube and the exterior braid.

[0056] Flapper subassemblies, such as shown in FIG. 7, should be completed prior to the following step. The flapper subassemblies will form part of or constitute the valve assemblies, since each flapper can function as a valve.

[0057] One fitting is attached to one side of the respective hose, which will be referred to as side A following proper crimping or welding procedures.

[0058] An engineered compression spring (ECP) is inserted into the bore of the hose, and which will be used as the connecting member to connect two flappers on opposite sides of the transfer line together through the hose assembly. The coil side of the spring should be nearest side A. This appears as shown in FIG. 8, which shows side A. A unique spring is preferably used, such as one from a specific alloy that is needed in view of the intended use of the hose, i.e., for flow of very cold or ultra-low temperature liquid materials, such as cryogenic fluids including liquid hydrogen, liquid nitrogen and helium, and liquified natural gas. In addition, since the hose has far less flexibility, the spring is constructed, configured, or selected to have additional flexibility to enable its insertion into and within the hose. One possible material for the spring is 712 stainless steel.

[0059] With the spring sitting inside of the hose, attach side B. The spring will be sticking out of the hose as shown in FIG. 9.

[0060] Then, the flapper valve is attached to Side A of the hose, and spring is inserted about 1 Vi inches into the spring connector to provide the state shown in FIG. 10.

[0061] An alternative method of inserting the spring into the bore or hollow cylindrical interior of the hose is to start by inserting one end of the spring into the hose while twisting the spring slightly to help it slide in. Then, one side of the spring is locked into the hose by attaching to the internal valve, e.g., a flapper valve as shown in FIG. 7. Then, a spring compressor is attached to the other, exposed end of the spring, and the spring is then slowly and evenly compressed. As the spring is compressed, it is gently pushed further into the hose continuously compressing and pushing until the spring is fully inside the hose. Once the spring is fully inserted, the spring compressor is released slowly to ensure the spring stays in place inside the hose and is locked in place by the internal retainer within the fitting.

[0062] Since the spring connector is not permanently attached to the spring, it is necessary to compress the connector to the spring. This can be achieved simply by, for example, using the hammer to hammer a center punch to the spring connector as seen in FIGS. 11 and 12.

[0063] Thereafter, the flapper valve is inserted into the fitting and the hinge pin is inserted into the hinge pin slot thereby locking the flapper valve in place (see FIG. 13).

[0064] This is a very critical and difficult part of the assembly process as it is vital to ensure that the valve is inserted and locked into position properly. To this end, the fabricator will need to hold the valve with the needle nose pliers while aligning the flapper holes with the hinge pin hole. If it is not done correctly, the flapper may be seen out of its proper position (FIG. 14 shows the out of position flapper while FIG. 15 shows the correct position of the flapper). Once the flapper valve has been locked into position, the 1 / 8 inch plug is screwed into the hinge pin hole. The plug threads are coated with TEFLON® paste to assure a complete seal (see FIGS. 16 and 17).

[0065] Since all springs are made to a standard length, it is necessary to cut the spring to the proper length to achieve the maximum compression (about 80% of force). To determine the proper length, it is possible to create the maximum compression and then measure the necessary length of the cable for each length to be used in future assemblies. To obtain the maximum compression, one technique is to roll-up the hose with the spring inside while maintaining the force on the cable (see FIG. 18).

[0066] Once the hose has been compressed with the above rolling-up method, the cable is cut with the cable or wire cutters at a location that is exterior of the hose, e.g., along the portion outside of the hose shown in FIG. 19.

[0067] The flapper on the other side, side B, is then installed. The hose must be kept in the rolled-up position while the side A flapper is installed. Once the flapper on side B is installed, the unit is complete and ready for flapper tension testing, pressure testing and certification.

[0068] For flapper tension testing, i.e., to test the proper tension in each flapper valve, a screw driver is slid under the flapper valve and tension is applied trying to lift the valve (see FIG. 20). More specifically, the screw driver is inserted immediately under the lip of the flapper and checked for tension. This should be extremely difficult to achieve if at all. The shorter the length, the easier it will be to lift it up from its down position. It should be virtually impossible to lift up the valve. Anything more than a slight lift with it snapping back into position once the screw driver is removed is unacceptable and the spring’s length should be revaluated as well as the position of the hinge pin.

[0069] Once the spring has been installed, the hose is ready for pressure testing. Note that it is not uncommon to have hose distortion due to the spring’s axial force. The hose will appear as shown in FIG. 21.

[0070] For pressure testing, separate procedures should be followed in accordance with the pertinent industry standards. In general, a working pressure is applied for about 5 minutes and then the working pressure is increased by about 50% for another approximately 5 minutes. The gauges used for an ultra-high pressure metallic hose as shown in FIGS. 22 and 23.

[0071] All hoses should be shipped with the operational guidelines booklet and pressure certification.

[0072] The invention therefore combines in a unique and novel manner safety technology for transfer of fluid and vacuum-jacketing technology and provides a transfer line with both safety features and the ability to be used for ultra-low temperature liquids.

[0073] Descriptions of embodiments of the invention in the present application are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments utilize only some of the features or possible combinations of the features. Variations of embodiments of the invention that are described, and embodiments of the invention comprising different combinations of features noted in the described embodiments, will occur to persons of the art. The scope of the invention is limited only by the claims.

Claims

CLAIMS1. A vacuum-jacketed transfer line, comprising: a safety conduit system including an elongate hose assembly, a valve assembly at each longitudinal end of said hose assembly, an elongate connecting member extending through said hose assembly between said valve assemblies, and a pipe stub connected to each of said valve assemblies, each of said valve assemblies comprising a valve body having an open interior defining a flow passage, and a valve arranged in said open interior of said valve body and movable against a valve seat defined by said valve body to at least partly close said flow passage, said connecting member being connected at its ends to said valves, each of said pipe stubs being connected to said valve body of a respective one of said valve assemblies; and a vacuum-jacket assembly over said hose assembly and connected at ends to said pipe stubs and defining a space between said vacuum-jacket assembly and said safety conduit system, said vacuum-jacket assembly comprising a pump-out port through which air is evacuated from the space between said vacuum-jacket assembly and said safety conduit system to thereby provide a vacuum in the space between said vacuum-jacket assembly and said safety conduit system.

2. The vacuum-jacketed transfer line of claim 1, wherein said safety conduit system is configured to be capable of operating pressures from about 3000 psi to more than about 24000 psi during use.

3. The vacuum -jacketed transfer line of claim 1, wherein said safety conduit system is configured to be capable of operating pressures of about 6000 psi during use.

4. The vacuum-jacketed transfer line of claim 1, wherein said connecting member comprises a cable having opposed longitudinal ends, and said valve in each of said valve assemblies is a plunger valve having a receptacle at one end region into which a respective one of the longitudinal ends of said cable is fixed to thereby connect said cable to said plunger valves.

5. The vacuum-jacketed transfer line of claim 1, wherein said hose assembly comprises a pipe connected to each of said valve assemblies and a flexible braided hose connected at each longitudinal end to a respective one of said pipes to thereby form an internal fluid conduit.

6. The vacuum-jacketed transfer line of claim 5, wherein said vacuum-jacket assembly further comprises a flexible outer hose surrounding said flexible braided hose of said hose assembly.

7. The vacuum-jacketed transfer line of claim 1, wherein a portion of said pipe stubs is exposed and available for connection to fluid handing structure or conduits.

8. The vacuum-jacketed transfer line of claim 1, wherein said vacuum-jacket assembly further comprises a flexible outer hose having an inner outer hose braid and an outer braid sleeve.

9. The vacuum-jacketed transfer line of claim 8, wherein said vacuum-jacket assembly further comprises first and second seal plates each connected to a respective one of said pipe stubs.

10. The vacuum-jacketed transfer line of claim 9, wherein said pump-out port is in one of said first seal plate.

11. The vacuum-jacketed transfer line of claim 9, wherein said first and second seal plates each comprise a tubular portion and an axial portion with at least part of the tubular portion being spaced apart from an underlying part of said safety conduit system, the axial portion of each of said first and second seal plates being connected to the respective one of said pipe stubs.

12. The vacuum-jacketed transfer line of claim 1, wherein said vacuum-jacket assembly further comprises a flexible outer hose and said hose assembly comprises a flexible braided hose connected at each longitudinal end to a respective one of said pipes to thereby form an internal fluid conduit, whereby the vacuum-jacketed transfer line is thus partly flexible.

13. The vacuum-jacketed transfer line of claim 1, wherein said vacuum-jacket is connected to said pipe stubs at locations axial rearward of said valve assemblies such that said valve assemblies are inside the space defined inward of said vacuum-jacket assembly.

14. A method of making a vacuum-jacketed transfer line, comprising: providing an outer, elongate flexible hose, the outer hose having an opening at each of its longitudinal ends and being configured to withstand vacuum pressure; providing a safety conduit system including a flexible elongate hose; positioning the safety conduit system partly in the outer hose by passing the safety conduit system through the opening at one of the longitudinal ends of the outer hose until only a part of the safety conduit system extends exterior of the opening at the other longitudinal end of the outer hose; then sealing the longitudinal ends of the outer hose to the safety conduit system; then forming a vacuum space between the outer hose and the safety conduit system; and attaching fittings to longitudinal ends of the safety conduit system.

15. The method of claim 14, further comprising: providing a pump-out port for the vacuum space; and forming the vacuum space by applying suction to the pump-out port.

16. The method of claim 14, wherein the vacuum space is formed while the outer hose having the safety conduit system is rolled up.

17. The method of claim 14, wherein the safety conduit system is provided with structure to enable passage of fluids therethrough having a temperature of about minus 252.9 degrees Celsius.

18. The method of claim 14, wherein the safety conduit system comprises a flexible metal hose.

19. The method of claim 14, wherein the step of sealing the longitudinal end regions of the outer hose to the safety conduit system comprises crimping the longitudinal end regions to the outer hose.

20. The method of claim 14, wherein the step of sealing the longitudinal end regions of the outer hose to the safety conduit system comprises crimping the longitudinal end regions to the outer hose using ferrules.

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