Abstract:
The present invention is directed to improved assembly for transporting flammable fluids. In an example, the assembly comprises a conduit, a liner, and a core. The liner comprises a material that contracts in response to an elevation in temperature. In an example, the liner comprises a material that expands in response to an elevation in temperature.

Description:
FIELD OF THE INVENTION 
     The present invention relates to conduit for flammable fluids. More specifically, the present invention relates to a conduit for flammable fluids designed to stop or limit flow of fluids in response to elevated temperature. 
     BACKGROUND OF THE INVENTION 
     Flammable fluids (such as methane gas or liquid gasoline) are used in both residential and industrial applications. Flammable fluids frequently enter or are stored in a system in one area, but are needed in a different area. Flammable fluids are therefore transported through the conduit, frequently piping, from the place the fluid enters the system to the place they are needed. If the conduit in which the flammable fluids are contained is exposed to a fire or increased temperatures, a dangerous situation exists because the conduit can become compromised, thereby allowing the flammable fluids to escape. For example, if the conduit is metal, and subject to a lightning strike, the conduit can become compromised, resulting a fire and explosion hazard 
     Therefore, a need exists for a way to shut off or limit the flow of flammable fluids in the event of an elevated temperature, such as caused by a fire or lightning strike. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an assembly for restricting fluid flow in response to elevated temperatures. The assembly comprises a conduit that can be configured to transport flammable fluids. The assembly can also comprise a liner located on an internal surface of the conduit. The liner can comprise a material that contracts in response to elevated temperatures. The liner can be configured to encircle a portion of the conduit. The assembly can also comprise a core within the conduit. When the assembly is exposed to an elevated temperature, the liner within the conduit can contract around the core such that flow of flammable gas through the conduit is substantially prevented. 
     In an embodiment, the assembly can include a liner that can be configured to expand in response to an increase in temperature, such as fire. When the liner is expanded, the liner can occupy the majority of the aperture along a cross-section, such that the flow of fluid is substantially terminated. 
     In an embodiment, the assembly can include a core. The core can be configured to expand in response to an increase in temperature, such as fire. When the core is expanded, the core can occupy the majority of the aperture along a cross-section, such that the flow of fluid is substantially terminated. 
     The above summary of the present invention is not intended to describe each discussed embodiment of the present invention. This is the purpose of the figures and the detailed description that follows. 
    
    
     
       FIGURES 
       The invention may be more completely understood in contestation of the following detailed description of various embodiments of the invention in connection with the accompanying drawings in which: 
         FIG. 1  is a simplified schematic of a system for fluid delivery. 
         FIG. 2  is an end cross-sectional view of conduit. 
         FIG. 3  is a side cross-sectional view of conduit shown in  FIG. 1 . 
         FIG. 4  is an end cross-sectional view of conduit with a liner in accordance with an implementation of the invention. 
         FIG. 5  is a side cross-sectional view of conduit with a liner shown in  FIG. 4 . 
         FIG. 6  is an end cross-sectional view of conduit with a liner and a core. 
         FIG. 7  is a side cross-sectional view of conduit with a liner and a core shown in  FIG. 6 . 
         FIG. 8  is an end cross-sectional view of conduit with a core integrally formed with the liner. 
         FIG. 9  is an end cross-sectional view of conduit with a liner and a foam insert. 
         FIG. 10  is a side cross-sectional view of conduit with a liner and a non-continuous core. 
         FIG. 11  is a side cross-sectional view of conduit with a non-continuous liner and a non-continuous core. 
         FIG. 12  is a side view of different types of conduit in series. 
         FIG. 13  is a side view of conduit that has been partially exposed to elevated temperatures. 
         FIG. 14  is an end cross-sectional view of conduit with a liner after it has been exposed to heat. 
         FIG. 15  is an end cross-sectional view of conduit with a liner and a core after it has been exposed to heat. 
         FIG. 16  is an end cross-sectional view of conduit with a liner and a core after it has been exposed to heat. 
         FIG. 17  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 18  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 19  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 20A  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 20B  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 20C  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 21  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 22  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 23  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 24A  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 24B  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 24C  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 25  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 26  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 27  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 28A  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 28B  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 28C  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 29  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 30  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 31  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 32A  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 32B  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 32C  is an end cross-sectional view of conduit with a core, according to an embodiment. 
         FIG. 33  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 34  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 35  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 36  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 37  is a side cross-sectional view of conduit, according to an embodiment. 
         FIG. 38  is a front view of a stent mechanism in a collapsed configuration, according to an embodiment. 
         FIG. 39  is a front view of a stent mechanism in an expanded configuration, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Now, in reference to the drawings,  FIG. 1A  shows a schematic of a system  100  comprising a fluid source  110 , a fluid destination  120 , a conduit  130 , and a wall  140  of a structure (such as a house). The wall  140  can represent the wall numerous environments such as a house, business, a combustion engine or any other structure or component that may use or contain flammable fluid. The system  100  can comprise a fluid source  110 , such as where fluid is produced, stored, or introduced into the system. Fluid can travel from the fluid source  110  through conduit  130 , such to transport the fluid from the fluid source  110  to the fluid destination  120 . In an embodiment, the fluid source  110  can be within the wall  140 . 
     The fluid traveling from the fluid source  110  to the fluid destination  120  through conduit  130  can include a gas, a liquid, or a combination of gas and liquid. In an embodiment, the fluid can be flammable. For example, the fluid can include a flammable gas such as natural gas (methane), propane, butane, or hydrogen. The fluid can include a liquid, such as gasoline, diesel fuel, lubricants, or hydraulic fluids (brake fluid, steering fluid, transmission fluid, etc. . . . ). It is understood that there are additional flammable gases and liquids that could travel through the conduit  130 . The conduit  130  can include corrugated stainless steel tubing (“CSST”). The conduit  130  can also include external gas risers, piping, or appliance connectors. An appliance connectors can couple piping to an appliance. 
     The system  100  can include one or more walls  140 , such as to enclose a space or define the boundary of the system. In some situations the walls  140  or other components of the system can catch on fire exposing the conduit  130  to flames and an increase in temperature. 
       FIG. 2  shows a cross-section view of the conduit  130  from an end.  FIG. 3  shows a cross-section view of the conduit  130  from a side. Conduit  130  can comprise different cross-sections and different materials. In some embodiments the cross-section of the conduit  130  is circular, such as shown in  FIG. 2 . The conduit can comprise an inner wall  210  and an outer wall  220 . The conduit  130  can comprise an aperture  200 , such as to allow fluid to pass through the conduit  130 . The fluid can pass through the conduit  130 , such as when the fluid is traveling from the fluid source  110  to the fluid destination  120 . 
       FIG. 4  shows a cross-section view of conduit with a liner  400 . The liner  400  can be disposed on at least a portion of the inside wall  210  of the conduit  130 . The liner  400  can encircle at least a portion of the aperture  200 . The inner surface  410  of the liner  400  can at least partially define the aperture  200 . 
     The liner  400  can comprise a heat sensitive polymer or a thermoplastic. A thermoplastic can become pliable or moldable above a specific temperature and then return to a solid state once it has cooled. The liner  400  can comprise, for example, a polyolefin. 
     In an embodiment, if the conduit  130  or a portion of the conduit  130  is exposed to an increase in temperature, such as if there is a fire, the liner  400  can shrink or constrict and at least partially close the aperture  200 , thereby at least partially restricting the flow of fluid through the conduit  130 . 
     In an additional embodiment, if the conduit  130  or a portion of the conduit  130  is exposed to an increase in temperature, such as if there is a fire, the liner  400  can constrict and completely close the aperture  200  along a portion of the conduit  130 . When the liner  400  constricts and closes the aperture  200 , the flow of fluid through the conduit  130  can be stopped or reduced. 
       FIG. 5  shows a side view of a cross section of the conduit  130  with a liner  400 . The liner  400  can be disposed on the inner wall  210  of the conduit  130 . The liner  400  can substantially cover the inner wall  210  of the conduit  130 . 
     In reference now to  FIG. 6 , a cross-section view of the conduit  130  with a liner  400  and a core  600  is shown. In various embodiments, a core  600  is disposed within the aperture  200 . The core  600  can be disposed on an inner surface  410  of the liner  400 . The cross section of the core  600  can have a similar shape as the aperture  200 , the inner wall  210 , or the inner surface  410 . The shapes can be similar, in that they have the same shape, but are of different sizes. The core  600  can comprise a material that substantially maintains its shape when exposed to an increase in temperature. The core  600  can comprise the same material as the conduit  130 , the liner  400 , or a different material. 
     In an embodiment, if the conduit  130  or a portion of the conduit  130  is exposed to an increase in temperature, such as if there is a fire, the liner  400  can separate itself from the inner wall of the conduit  210  as it contracts around the core  600 . When the liner  400  contracts around the core  600 , the liner  400  and the core  600  can at least partially block the flow of fluid through the aperture  200  (shown in  FIG. 13 ). The core  600  can assist the liner  400  in blocking the flow of fluid through the conduit  130  when the contracted liner  400  alone does not provide sufficient blockage of the aperture  200 , such as in high pressure environments or when the thermoplastic material does not contract in the proper manner to cover the aperture  200 . 
     Referring now to  FIG. 7 , the core  600  can continuously extend along the conduit  130 . The core  600  can have a substantially similar length as the conduit  130  or the aperture  200 . 
       FIG. 8  shows a cross-section view of conduit  130  with the core  600  integrally formed with the liner  400 . In an embodiment, the core  600  can be integrally formed with the liner  400 , such as if the core  600  and the liner  400  are extruded together. The core can be coupled to the liner, such as when the core  600  and the liner  400  comprise different materials or the core  600  is disposed within the aperture  200  after the liner  400  has been disposed within the conduit  130 . The core  600  can be coupled to the liner  400 , such as by welding, gluing, or fusing. Other options for coupling the core  600  to the liner  400  are available. The core  600  and the liner  400  can comprise the same material or different materials. 
       FIG. 9  shows a cross-section view of the conduit  130  with a liner  400  and a foam insert  900 . A foam insert  900  can be disposed within the aperture  200 . A foam insert  900  can be disposed on the inner surface  410  of the liner  400 . The foam insert  900  can comprise a foam that reacts to an increase in temperature, such as a foam that expands or changes shapes. In some instances the foam insert  900  can take a cylindrical shape, similar to the core  600  shown previously in  FIG. 6 . A foam insert  900  can block less of the aperture  200  in its original state than a standard core  600 , such as when the foam insert  900  expands when it is heated. A foam insert  900  can also take a different shape when it is heated, such as if a certain shape of the aperture  200  is desired during standard operation, but the shape is not desirable when restricting or stopping the flow of gas in an increased temperature environment. 
     The conduit  130  can include one or more segments of a core  600 , as shown in  FIG. 10 . A segmented core  600  can be continuous, such as when segments are linked to one another. A segmented core  600  can be non-continuous, such as shown in  FIG. 10  or when the core  600  comprises a plurality of beads. 
     Similar to the non-continuous core  600  segments shown in  FIG. 10 , the liner  400  can also be segmented and the liner  400  can be continuous or non-continuous. In  FIG. 11 , an embodiment is shown with a non-continuous segmented liner  400 . An embodiment with a non-continuous liner  400  can have a continuous core  600  or a non-continuous core  600  (as shown in  FIG. 11 ). 
     Portions of the conduit  130  can comprise different elements. In some embodiments a system  100  can include conduit  130 , and the conduit  130  comprises first conduit members  1200  and second conduit members  1210 , as shown in  FIG. 12 . The first conduit members  1200  can comprise conduit  130 , such as shown in  FIGS. 2 and 3 . The second conduit members  1210  can comprise one or more of the following conduit  130 , a liner  400 , a core  600 , and a foam insert  900 . 
     In some embodiments conduit  130  will comprise mostly standard pipe (represented by first conduit members  1200 ) and coupling portions (represented by second conduit members  1210 ). The coupling portions can couple portions of piping together, additionally the coupling portions could serve to prevent gas flow through the conduit  130  in the event of a fire. 
     In an embodiment with portions of first conduit members  1200  and second conduit members  1210  there can be an aperture  200  with a substantially consistent size, such as having a constant inside diameter along the conduit  130 . In this embodiment, the outside diameter of the second conduit members  1210  can be larger than the outside diameter of the second conduit  1210  members, such as to allow space within the second conduit members  1210  for one or more of a liner  400 , a core  600 , and a foam insert  900 . 
     In an embodiment with portions of first conduit members  1200  and second conduit members  1210  there can be a substantially consistent outside diameter of the conduit  130  even between the first conduit members  1200  and the second conduit members  1210 . In this embodiment, the aperture  200  of the second conduit members  1210  can be smaller than the aperture  200  of the first conduit members  1200 , such as if one or more of the following occupy space within the aperture  200  of the second conduit members  1210 : a liner  400 , a core  600 , and a foam insert  900 . 
     In an embodiment with portions of first conduit members  1200  and second conduit members  1210  there can be an aperture  200  with a substantially consistent size along the conduit  130 , as well as a substantially consistent outside diameter. In this embodiment, the distance between the inner wall  210  and the outer wall  220  can be smaller in the second conduit members  1210  than the first conduit members  1200 , such as to allow space for one or more of the following: a liner  400 , a core  600 , and a foam insert  900 . 
     As shown in  FIG. 13 , in certain implementations only a portion of the conduit  130  will be affected by a fire or increased heat. The portion of the conduit  130  to the left of reference line  1300  has been affected by a fire or increased heat, and the portion of the conduit  130  to the right of the reference line  1300  is unaffected by the heat. It should be noted that the gas could have been travelling in either direction through the aperture  200 , prior to the aperture  200  being closed. The portion of conduit between reference line  1300  and reference line  1310  has been affected by heat; however there has not been enough heat to contract the liner  400  to completely close the aperture  400 . The portion of the conduit  130  to the left of reference line  1310  has been affect by enough heat to completely close aperture  200 , such that gas would be prevented from flowing through the conduit  130 . 
       FIGS. 14, 15, and 16  show cross-sectional views of conduit that has been exposed to sufficient heat to completely close a portion of aperture  200 .  FIG. 14  has closed the aperture without a core.  FIG. 15  has closed the aperture with the liner  400  and the core  600 .  FIG. 16  has closed the aperture with the liner  400  and a core  600  that has changed shape and size because of exposure to heat. 
     In an embodiment, a component (such as a core or a liner) disposed inside the aperture  200  can be configured to expand when exposed to an elevated temperature, such as a fire. When the component expands it can interrupt, terminate, or at least partially impede the flow of fluid through the conduit  130 . 
     In an embodiment, a conduit  130  can include a core that expands when exposed to an increase in temperature.  FIG. 17  shows a cross-sectional view of conduit  130  with a core  1700  disposed within the conduit  130 .  FIG. 18  shows an end view of conduit  130  with a core  1700  disposed within the conduit  130 . The core  1700  can be configured, such that when the core  1700  is exposed to an increase in temperature, such as a fire, the core  1700  expands. When the core  1700  expands, the core  1700  can occupy the entire aperture  200  along a cross-section of the conduit  130 , or at least a significant portion of the aperture  200  along a cross-section, such that the flow of any fluid through the conduit  130  is substantially interrupted or terminated. 
     The core  1700  can include a heat activated blowing agent. The heat activated blow agent can be blended with a polymer, such as ethyl vinyl acetate or low density polyethylene. When activated by heat, the blowing agent can give off a gas, such as in the polymer that it is blended with. The gas can result in bubbles in the heat softened polymer. The bubbles can cause the polymer to expand, such as to limit the flow through the conduit  130 . 
     In an embodiment, the core  1700  can substantially return to its original shape and size when the elevated heat is removed, such that the core  1700  returns to its normal temperature. When the core  1700  is returned to its original shape and size, the aperture  200  can be reopened, such as to allow the flow of fluid through the conduit  130  to restart. In an embodiment, the core  1700  can include a liquid, that when heated expands the core  1700 . When the liquid included in the core  1700  is cooled, such as when the elevated temperature has dissipated, the liquid can contract and core  1700  can substantially return to its pre-expanded shape and size. The liquid can include a set point temperature, at which the liquid expands into a vapor, such as to stop flow of fluid through the conduit. 
     The core  1700  can include a material that is non-flammable and expands when subjected to an increase in temperature, as shown in  FIGS. 19 and 20A-20B . In FIG.  19  the portion to the left of reference line  1901  has been exposed to a sufficient amount of heat, such that the core  1700  has expanded to at least substantially occupy the aperture  200 , such as to terminate fluid flow through the conduit  130 . The portion between reference line  1901  and reference line  1902  has been exposed to an increase in temperature, such that the core  1700  has started to expand. However, the core  1700  does not occupy the entire aperture  200 , such that the flow of fluids is not entirely terminated. The portion to the right of reference line  1902  has not been subjected to a sufficient increase in heat to start to expand the core  1700 . 
       FIG. 20A  shows a cross section of a portion of the conduit  130  to the left of reference line  1901  in  FIG. 19 . The core  1700  has expanded to a sufficient size to substantially terminate the flow of fluid through the conduit  130 .  FIG. 20B  shows a cross section of a portion of the conduit  130  between reference line  1901  and reference line  1902  in  FIG. 19 . The core  1700  has expanded to partially impede the flow of fluids through the conduit  130 . However, the core  1700  (in  FIG. 20B ) has not expanded to a size that terminates the flow of fluids through the conduit  130 .  FIG. 20C  shows a cross section of a portion of the conduit  130  to the right of reference line  1902  in  FIG. 19 . The core  1700  has not been exposed to sufficient heat to expand the core  1700 . 
     In an embodiment, the conduit can include a liner disposed within the aperture, and the liner can be configured to expand in response to an increase in temperature.  FIG. 21  shows a cross-sectional view of conduit  130  with a liner  2100  disposed within the conduit  130 , such as around the inside wall  210  of the conduit.  FIG. 22  shows an end view of conduit  130  with a liner  2100  disposed within the conduit  130 . The liner  2100  can at least partially define the aperture  200  that extends along at least a portion of the conduit  130 . The liner  2100  can be configured, such that when the liner  2100  is exposed to an increase in temperature, such as a fire, the liner  2100  expands. When the liner  2100  expands, the liner  2100  can occupy the entire aperture  200  along a cross-section of the conduit  130 , or at least a significant portion of the aperture  200  along a cross-section, such that the flow of any fluid through the conduit  130  is substantially interrupted or terminated. 
     The liner  2100  can include a heat activated blowing agent. The heat activated blow agent can be blended with a polymer, such as ethyl vinyl acetate or low density polyethylene. When activated by heat, the blowing agent can give off a gas, such as in the polymer that it is blended with. The gas can result in bubbles in the heat softened polymer. The bubbles can cause the polymer to expand, such as to limit the flow through the conduit  130 . 
     In an embodiment, the liner  2100  can substantially return to its original shape and size when the elevated heat is removed, such that the liner  2100  returns to its normal temperature. When the liner  2100  is returned to its original shape and size, the aperture  200  can be reopened, such as to allow the flow of fluid through the conduit  130  to restart. In an embodiment, the liner  2100  can include a liquid, that when heated expands the liner  2100 . When the liquid included in the liner  2100  is cooled, such as when the elevated temperature has dissipated, the liquid can contract and liner  2100  can substantially return to its pre-expanded shape and size. The liquid can include a set point temperature, at which the liquid expands into a vapor, such as to stop flow of fluid through the conduit. 
     The liner  2100  can include a material that is non-flammable and expands when subjected to an increase in temperature, as shown in  FIGS. 23 and 24A-24B . In FIG.  23  the portion to the left of reference line  2301  has been exposed to a sufficient amount of heat, such that the liner  2100  has expanded to at least substantially occupy the aperture  200 , such as to terminate fluid flow through the conduit  130 . The portion between reference line  2301  and reference line  2302  has been exposed to an increase in temperature, such that the liner  2100  has started to expand. However, the liner  2100  does not occupy the entire aperture  200 , such that the flow of fluids is not entirely terminated. The portion to the right of reference line  2502  has not been subjected to a sufficient increase in heat to start to expand the liner  2100 . 
       FIG. 24A  shows a cross section of a portion of the conduit  130  to the left of reference line  2301  in  FIG. 23 . The liner  2100  has expanded to a sufficient size to substantially terminate the flow of fluid through the conduit  130 .  FIG. 24B  shows a cross section of a portion of the conduit  130  between reference line  2301  and reference line  2302  in  FIG. 23 . The liner  2100  has expanded to partially impede the flow of fluids through the conduit  130 . However, the liner  2100  (in  FIG. 24B ) has not expanded to a size that terminates the flow of fluids through the conduit  130 .  FIG. 24C  shows a cross section of a portion of the conduit  130  to the right of reference line  2302  in  FIG. 23 . The liner  2100  has not been exposed to sufficient heat to expand the liner  2100 . 
     In an embodiment, a conduit  130  can include a core and a liner that both expand when exposed to an increase in temperature.  FIG. 25  shows a cross-sectional view of conduit  130  with a core  1700  disposed within the conduit  130 , such as within the aperture  200 , and a liner  2100  disposed within the conduit  130 , such as around the inside wall  210  of the conduit.  FIG. 26  shows an end view of conduit  130  with a core  1700  and a liner  2100  disposed within the conduit  130 . The core  1700  and the liner  2100  can be configured, such that when the core  1700  and the liner  2100  are exposed to an increase in temperature, such as a fire, the core  1700  and the liner  2100  expand. When the core  1700  and the liner  2100  expand, the core  1700  and the liner  2100  can occupy the entire aperture  200  along a cross-section of the conduit  130 , or at least a significant portion of the aperture  200  along a cross-section, such that the flow of any fluid through the conduit  130  is substantially interrupted or terminated. 
     The core  1700  and the liner  2100  can include a material that is non-flammable and expands when subjected to an increase in temperature, as shown in  FIGS. 27 and 28A-28B . In some embodiments, the core  1700  and the liner  2100  can include the same material(s). In  FIG. 27  the portion to the left of reference line  2701  has been exposed to a sufficient amount of heat, such that the core  1700  and the liner  2100  have expanded to at least substantially occupy the aperture  200 , such as to terminate fluid flow through the conduit  130 . The portion between reference line  2701  and reference line  2702  has been exposed to an increase in temperature, such that the core  1700  and the liner  2100  have started to expand. However, the core  1700  and the liner  2100  do not occupy the entire aperture  200 , such that the flow of fluids is not entirely terminated. The portion to the right of reference line  2702  has not been subjected to a sufficient increase in heat to start to expand the core  1700  or the liner  2100 . 
       FIG. 28A  shows a cross section of a portion of the conduit  130  to the left of reference line  2701  in  FIG. 27 . The liner core  1700  and the liner  2100  have expanded to a sufficient size to substantially terminate the flow of fluid through the conduit  130 .  FIG. 28B  shows a cross section of a portion of the conduit  130  between reference line  2701  and reference line  2702  in  FIG. 27 . The core  1700  and the liner  2100  have expanded to partially impede the flow of fluids through the conduit  130 . However, the core  1700  and the liner  2100  (in  FIG. 28B ) have not expanded to a size that terminates the flow of fluids through the conduit  130 .  FIG. 28C  shows a cross section of a portion of the conduit  130  to the right of reference line  2702  in  FIG. 27 . The core  1700  and the liner  2100  have not been exposed to sufficient heat to expand the core  1700  or the liner  2100 . 
     In an embodiment, a conduit  130  can include a core that expands when exposed to an increase in temperature and a liner that shrinks or collapses when exposed to an increase in temperature.  FIG. 29  shows a side cross section of conduit  130  with liner  400  that shrinks and core  1700  that expands, such as to interrupt or terminate the flow of fluid through the conduit  130 . In an embodiment, a liner  400  can be disposed around the inside wall  210  of the conduit  130 . As described above in reference to  FIG. 13 , the liner  400  can shrink or collapse to close off at least a portion of the aperture  200 , such as to interrupt or terminate the flow of fluid through the conduit  130 . In an embodiment, a core  1700  can be disposed in the conduit  130 . As described in reference to  FIGS. 17-20 , the core  1700  can expand to close off at least a portion of the aperture  200 , such as to interrupt or terminate the flow of fluid through the conduit  130 . 
     In an embodiment, the conduit  130  can include a core  1700  that expands and a liner  400  that shrinks or collapses, disposed in the aperture  200 . The core  1700  and the liner  400 , in concert, can block the flow of fluids through the aperture  200 , such as when the conduit is exposed to an increase in temperature. 
       FIG. 30  shows an end view of a cross section of conduit  130  with liner  400  that shrinks and core  1700  that expands. As discussed above, the liner  400  can be disposed on the inside wall  210  or inner surface of the conduit  130 . The liner  400  can define at least a portion of the aperture  200 . In normal conditions, prior to being exposed to an increase in temperature, fluid can flow through the aperture  200 . When the liner  400  or the core  1700  is exposed to an increase in temperature, the liner  400 , the core  1700 , or both the liner  400  and the core  1700  can close off the aperture  200  to stop the flow of fluid through the conduit  130 . In an embodiment, the liner  400  can shrink or collapse to close off at least a portion of the aperture  200  and a core  1700  can expand to close off at least a portion of the aperture  200 . 
     In  FIG. 31 , the portion to the left of reference line  3101  has been exposed to a sufficient amount of heat, such that the core  1700  has expanded and the liner  400  has shrunk or collapsed to at least substantially occupy the aperture  200 , such as to terminate fluid flow through the conduit  130 . The portion between reference line  3101  and reference line  3102  has been exposed to an increase in temperature, such that the core  1700  has started to expand and the liner  400  has started to collapse or shrink. However, the core  1700  and liner  400  do not occupy the entire aperture  200 , such that the flow of fluids is not entirely terminated. The portion to the right of reference line  3102  has not been subjected to a sufficient increase in heat to start to expand the core  1700  or shrink or collapse the liner  400 . 
       FIG. 32A  shows a cross section of a portion of the conduit  130  to the left of reference line  3101  in  FIG. 31 . The core  1700  has expanded and the liner  400  has shrunk or collapsed to a sufficient size to substantially terminate the flow of fluid through the conduit  130 .  FIG. 32B  shows a cross section of a portion of the conduit  130  between reference line  3101  and reference line  3102  in  FIG. 31 . The core  1700  has expanded and the liner  400  has shrunk to partially impede the flow of fluids through the conduit  130 . However, the core  1700  has not expanded and the liner  400  has not shrunk to sizes that terminate the flow of fluids through the conduit  130 , such that at least a portion of the aperture  200  remains open.  FIG. 32C  shows a cross section of a portion of the conduit  130  to the right of reference line  3102  in  FIG. 31 . The core  1700  and liner  400  have not been exposed to sufficient heat to expand the core  1700  or shrink the liner  400 . 
     In an embodiment, a conduit  130  can include an inner conduit and an outer conduit, with a liner disposed between the inner conduit and the outer conduit.  FIG. 33  shows a cross section of conduit  130 , according to an embodiment. Conduit  130  can include an inner conduit  3310  and an outer conduit  3320 . In an embodiment, a liner  3330  can be disposed between the inner conduit  3310  and the outer conduit  3320 . The inner conduit  3310  can define the aperture  200 . The aperture  200  can be configured to allow fluids to pass through the conduit  130 . 
     The inner conduit  3310  can be weaker than the outer conduit  3320 , such as the outer conduit  3320  can withstand more force than the inner conduit  3310 . The inner conduit  3310  can be weaker than the outer conduit  3320 , such as the inner conduit  3310  can have a lower failure point than the outer conduit  3320 . The failure point can reference an amount of force, such as pressure, that causes a portion of conduit to collapse, fracture, burst, crack, expand, shrink, or otherwise fail to maintain its previous shape or configuration. 
     The liner  3330  can expand when it is exposed to an increase in temperature, such as a fire. The liner  3330  can apply a pressure to the inner conduit  3310  and the outer conduit  3320 , such as when the liner  3330  is expanding. The outer conduit  3320  can withstand more force than the inner conduit  3310 , such that the liner  3330  is forced to expand inward. The liner  3330  can crush or collapse the inner conduit  3310 , such that the liner  3330 , when expanded, can interrupt or terminate the flow of fluid through the conduit. 
     In  FIG. 34  the portion to the left of reference line  3401  has been exposed to a sufficient amount of heat, such that the liner  3330  has expanded and the inner conduit  3310  has collapsed to at least substantially occupy the aperture  200 , such as to terminate fluid flow through the conduit  130 . The portion between reference line  3401  and reference line  3402  has been exposed to an increase in temperature, such that the liner  3330  has started to expand and the inner conduit  3310  has started to collapse. However, the liner  3330  does not occupy the entire aperture  200 , such that the flow of fluids is not entirely terminated. The portion to the right of reference line  3402  has not been subjected to a sufficient increase in heat to start to expand the core  1700  or shrink or collapse the liner  400 . 
     In  FIG. 35 , the top portion of the conduit  130  has been exposed to more heat than the bottom portion of the conduit  130 . Portions below reference line  3503  have not been exposed to sufficient heat to expand the liner  3330 . Some portions above the reference line  3503  have been exposed to an increase in temperature. The portion to the left of reference line  3501  has been exposed to a sufficient amount of heat, such that the liner  3330  has expanded and the inner conduit  3310  has collapsed to at least substantially occupy the aperture  200 , such as to terminate fluid flow through the conduit  130 . The portion between reference line  3501  and reference line  3502  has been exposed to an increase in temperature, such that the liner  3330  has started to expand and the inner conduit  3310  has started to collapse. However, the liner  3330  does not occupy the entire aperture  200 , such that the flow of fluids is not entirely terminated. The portion to the right of reference line  3502  has not been subjected to a sufficient increase in heat to start to expand the core  1700  or shrink or collapse the liner  400 . 
     In an embodiment, a conduit can include a core  3600  that expands when exposed to an increase in temperature.  FIG. 36  shows a cross-sectional view of conduit with a core  3600  disposed within the conduit. The core  3600  can be configured, such that when the core  3600  is exposed to an increase in temperature, such as a fire, the core  3600  expands. When the core  3600  expands, the core  3600  can occupy the entire aperture  200  along a cross-section of the conduit, or at least a significant portion of the aperture  200  along a cross-section, such that the flow of any fluid through the conduit is substantially interrupted or terminated. 
     The core  3600  can include a plurality of segments  3610 . Each segment  3610  can be isolated from the other segments, such that they do not have fluid communication. The segments  3610  can be isolated at isolation points  3620 . In an embodiment, the isolation points  3620  can be connections between segments  3610 , such as when each segment  3610  is separate from the other segments  3610 . In an embodiment, the isolation points  3620  can be separations between segments  3610 , such as when the segments are all part of a single component. 
     Each segment  3610  can include an elastic casing, such as a shell or housing that can expand or contract. Each segment  3610  can include liquid disposed inside of the casing. As the core  3600  is exposed to an increase in temperature, the liquid inside of the casing can be converted into a vapor and expand the casing. In an embodiment, a segment  3610  can include a stent mechanism, such as to aid in keeping the casing expanded. 
     The core  3600  can include a material that is non-flammable and expands when subjected to an increase in temperature, as shown in  FIG. 37 . In  FIG. 23  the portion to the left of reference line  3701  has been exposed to a sufficient amount of heat, such that the core  3600  has expanded to at least substantially occupy the aperture, such as to terminate fluid flow through the conduit. The portion between reference line  3701  and reference line  3702  has been exposed to an increase in temperature, such that the core  3600  has started to expand. However, the core  3600  does not occupy the entire aperture, such that the flow of fluids is not entirely terminated. The portion to the right of reference line  3702  has not been subjected to a sufficient increase in heat to start to expand the core  3600 . 
       FIG. 38  shows a stent mechanism  3800  in a collapsed position.  FIG. 39  shows a stent mechanism  3800  in an expanded position. The stent mechanism  3800  can go from a collapsed position (as shown in  FIG. 38 ) to an expanded position (as shown in  FIG. 39 ). The stent mechanism  3800  can be in a collapsed position, such as when fluid is flow through the conduit, such as prior to the core  3600  being exposed to an increase in temperature. When the core  3600  is exposed to an increase in temperature, the core  3600  can expand. When the core  3600  expands, the stent mechanism  3800  can go from a collapsed position to an expanded position, such as to aid in keeping the core  3600  expanded. 
     The stent mechanism  3800  can include a plurality of stent segments  3810 . A stent segment  3810  can be coupled to another stent segment  3810 , such as at joints  3840 . The stent segments  3810  can pivot with respect to other stent segments  3810 , such as at joints  3840 . 
     The stent mechanism  3800  can include a locking leg  3820 . The locking leg  3820  can pivot with respect to a stent segment  3810  such as at joint  3830 . The locking leg  3820  can pivot to be perpendicular to the wall of the conduit, when the stent mechanism  3800  is in an expanded position, such as to provide additional support for the stent mechanism to stay in an expanded position. 
     The liner or the core can include a cross-linked binding agent, such as allow the core or liner to adhere to the conduit. The liner or the core can include a flexible material, such as rubber or a flexible polymer. The flexible material can be carried by expanding the liner or the core and pressed or positioned against the walls of the conduit, such as to fill, occupy, or seal, a crack or other hole in the conduit. Sealing a crack or hole in the conduit can prevent fluid from flowing out of the conduit. 
     The liner or the core can include a fuse mechanism, such that once the fuse mechanism is exposed to a certain temperature, the fuse mechanism can initiate or propagate the liner or the core to expand, shrink, or collapse. In an embodiment, the liner or the core can start to expand, shrink, or collapse at a temperature below 200° C., such as 190° C., 180° C., 170° C., 160° C., 150° C., 125° C., 100° C., or 75° C. The fuse mechanism can be activated at a lower temperature, such as to start the production of gas to expand the core or liner earlier. The fuse mechanism can include single or multipart exothermic chemical reactions or the rapid oxidation of materials within the conduit. 
     In an embodiment, the core or the liner can include a thermal set component. The thermal set component can be configured to harden with an increase in temperature. In an embodiment, the thermal set component can be configured to harden at a temperature greater than temperature at which the core or liner starts to expand, shrink, or collapse. 
     In an embodiment, the liner can be monolithic, such that it contains a consistent material throughout the liner. In an embodiment, the liner can include multiple layers. In an embodiment, the liner can be laminated. 
     The liner can include multiple layers and the layers can have different characteristics. In an embodiment, a layer, such as the outer most layer (the layer in contact with the inside surface of the conduit) can be a self-healing layers, such as a layer that can seal a puncture or a breach in the conduit. A second layer can include a thermoset polymer, such as a layer that can solidify at elevated temperature. Additional layers, with different characteristics are also possible. 
     EXPERIMENTS 
     In order to evaluate the performance of an expandable liner made in accordance with an embodiment, experiments were conducted to determine how the expandable liner would perform under different conditions. 
     In a first test, a 0.04 inch expandable liner was disposed along the length of a 4 foot section of ¾ inch corrugated stainless steel tubing (“CSST”). The tubing was placed in a test fixture that was constructed like a wood wall made of wood 2×4s and ½ inch of SHEETROCK (a plasterboard made of gypsum layered between sheets of heavy paper) on both sides. The tubing was connected to a propane gas supply at a pressure of 13 inches water column. The outlet of the tubing was connected to an atmospheric burner with an input of 60,000 BTU/hr. 
     The burned was positioned, such that when lit, its flame impinged on the wall where the tubing ran. The burner was allowed to continue to burn. When the temperature of the surface of the tubing reached 154° C. the liner expanded and completely stopped the flow of propane to the burner. 
     In a second test, a fiberglass reinforced expandable liner was disposed within an 8 inch length of ¾ inch CSST. The tubing was plugged at one end and pressurized with propane gas to 13 inches water column. A wire feed welder was used to arc holes in the CSST. The expandable liner inside of the CSST expanded out of the holes, effectively plugging the holes and preventing gas from leaking out of the CSST. 
     In a third test, a 0.04 inch expandable liner was disposed within and along the length of a 4 foot section of ¾ inch SST. The tubing was connected to a propane gas supply at 13 inches water column. The outlet of the tubing was connected to a 60,000 BTU/hr burner. The burner was lit. A propane torch, using a separate fuel source, was used to apply direct heat on the tubing. The liner expanded, completely stopping the flow of propane to the burner. 
     A fourth test was conducted to evaluate the performance of a fuse mechanism. In the fourth test, a ⅛ inch and a 1/16 inch fuse cord were wrapped in a spiral fashion around portions of expandable material, such as expandable material used for an expandable core or an expandable liner. These portions of material were placed in 1 inch diameter pipes that were 4 inches long. The fuses were lit and allowed to burn. It was found that the expandable material partially reacted in the areas adjacent to the fuse mechanism. When the portions of expandable material were re-exposed to prolonged heat, the material fully expanded. 
     The fuse mechanism had a burn rate of 2 second per inch. In other embodiments, a fuse mechanism with a slower burn rate could be used. The expandable material can react and expand when in the presence of heat generated by the fuse mechanism.