Patent Publication Number: US-9897508-B2

Title: Leak detection system

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/020,105, filed on Sep. 6, 2013 and entitled Leak Detection System, now U.S. Pat. No. 9,291,521, which is a divisional of U.S. patent application Ser. No. 12/981,590, filed on Dec. 30, 2010 and entitled Leak Detection System, now U.S. Pat. No. 8,528,385. 
    
    
     FIELD OF INVENTION 
     The present application relates to the field of fluid lines and fluid line fittings. In particular, the present application relates to a leak detection system for a fluid line. 
     BACKGROUND 
     Fluid lines are known to leak at various location. Leaks may be caused, for example, by ordinary wear, temperature fluctuations, weathering, corrosion from the fluid being transported, and other internal and external degenerative factors. In particular, fluid lines may be prone to leakage at a location where a hose meets a fitting. 
     Certain leak detection systems are known. One known leak detection system includes a strain-sensing layer that detects strain in a hose. Another known leak detection system employs electrical leads. 
     SUMMARY OF THE INVENTION 
     In one embodiment a fluid line includes a conduit, a nipple received coaxially within an end of the conduit, a socket disposed coaxially about the conduit and the nipple, and a ring disposed coaxially about the nipple. The ring has at least one slot formed therein, defining a first slot wall and a second slot wall opposite the first slot wall. The ring further has a receiver disposed on at least one of the first and second slot walls. 
     In another embodiment, a hose leakage detection system includes a ring configured to be disposed within a hose. The ring has a lateral slot formed in an outer surface, defining a first slot wall and a second slot wall. A light receiver is disposed on one of the first slot wall and the second slot wall and a power source is electrically connected to the leakage detection system. 
     In yet another embodiment, a leak detection apparatus includes a ring having at least one lateral slot formed in an outer surface, each slot defining a first slot wall and a second slot wall. The apparatus also includes a light source and an optical fiber disposed within the ring in a circumferential direction. The optical fiber has a first end connected to the light source and a second end disposed on one of the first and second slot walls of the at least one lateral slot, thereby transmitting light across the at least one lateral slot. At least one optic fiber light receiver is circuit disposed on one of the first and second slot walls of the at least one lateral slot in a location opposite the second end of the optical fiber such that it receives the light transmitted across the at least one lateral slot. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings, structures are illustrated that, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. Like elements are identified with the same reference numerals. It should be understood that elements shown as a single component may be replaced with multiple components, and elements shown as multiple components may be replaced with a single component. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration. 
         FIG. 1  is a perspective view of an exemplary fluid line having a leak detection system; 
         FIG. 2  is a front view of a ring in the leak detection system; and 
         FIG. 3  is a partial cross-section of an alternative embodiment of a ring in the leak detection system. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of an exemplary fluid line  100  having a leak detection system. The fluid line  100  includes a hose  105  and a fitting  110 . The fitting  110  includes a nipple  115  and a socket  120 . The nipple  115  is received coaxially within an end of the hose  110 , and the socket  120  is disposed coaxially about the hose  110  and the nipple  115 . However, it should be understood that any fitting may be employed, such as a compression fitting or a push to connect fitting. Likewise, the leak detection system may be employed on any conduit conveying fluid and is not limited to use with hoses or flexible tubing. 
     The leak detection system includes a ring  125  connected to electronics  130 . The ring  125  may be dimensioned for any size fluid line. In one known embodiment, the ring  125  has a diameter of between 0.25 inches (0.6 cm) and 5 inches (12.7 cm). 
     The ring  125  includes at least one slot  135  that defines a first slot wall  140  and a second slot wall  145  opposite the first wall. The width of the slot is proportional to the size of the ring and can be varied to increase the intensity of light received at the receiver end. In the illustrated embodiment, the slot  135  is disposed in the external circumferential surface of the ring  125  and extends in a lateral direction. In other words, the slot  135  extends in a direction parallel to the direction of fluid flow in the hose  105 . In an alternative embodiment (not shown), the slot is disposed on an internal circumferential surface of the ring. In another alternative embodiment (not shown), the slot may extend at an acute angle with respect to the lateral direction of the ring  125 . Additionally, while the first slot wall  140  is shown as substantially parallel to the second slot wall  145 , it should be understood that the slot walls may converge or diverge. Further, the slot walls may be curved or have one or more bends. 
     In the illustrated embodiment, the ring  125  is disposed about the nipple  115  inside the hose  105 . If there is an inadequate seal between the nipple  115  and hose  105 , fluid may leak out of the fitting  110  by flowing along the external surface of the nipple  115 . The ring  125  is therefore positioned in the path of any fluid that leaks between the nipple  115  and the hose  105 . The external circumferential surface of the ring  125  may form a seal with the hose  105 , such that leaking fluid would pass through the slot  135 . A receiver  150  is disposed on one of the first and second slot walls  140 ,  145  that can be used to detect the leaking fluid that passes through the slot  135 . 
     Alternatively, the ring may be disposed about the hose inside of the socket. In such an embodiment, the ring is positioned in the path of any fluid that leaks between the hose and the socket. The external circumferential surface of the ring may form a seal with the socket, such that leaking fluid would pass through the slot in the ring. 
     To increase the likelihood that leaking fluid passes through the slot  135 , a plurality of slots  135  may be disposed about the ring  125 .  FIG. 2  illustrates a front view of the ring  125 . In this embodiment, the ring  125  includes five slots  135 . In alternative embodiments (not shown), any number of slots may be employed. 
     The ring  125  may be an O-ring and have sealing properties. The ring  125  may be constructed of metal or a polymeric material. Exemplary construction materials include, without limitation, polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) rubber, nitrile rubber, a thermoplastic elastomer such as HYTREL, stainless steel, aluminum, and titanium. 
     In one embodiment (as shown in  FIG. 1 ), the ring  125  has a substantially flat profile. Alternatively, the ring may have a tapered or a concave profile. For example,  FIG. 3  illustrates a partial cross-section of an alternative embodiment of a ring  125 ′ having a curved taper  300 . In another example (not shown), the ring may have a straight taper. A tapered ring may be positioned such that it tapers towards the end of the hose. Alternatively, the tapered ring may be positioned such that it tapers away from the end of the hose. 
     With continued reference to  FIGS. 1-3 , the ring  125  includes one or more optical fibers  155  (i.e., one or more fiber optic cables) disposed therein. The optical fiber  155  is connected to a light source  160 , such as a light emitting diode (LED), laser diode, infrared diode, or other light source. The optical fiber  155  may be directly connected to the light source  160  or indirectly connected (e.g., through one or more additional optical fibers). 
     An end of the optical fiber  155  is disposed on one of the first and second slot walls  140 ,  145  such that light travels from the light source  160 , through the optical fiber  155  to one of the slot walls  140 ,  145 . The light is then transmitted across the slot  135  to the opposite slot wall  140 ,  145 . In the illustrated embodiment, the end of the optical fiber  155  is disposed on the first slot wall  140  and the receiver  150  is disposed on the second slot wall  145 . In this embodiment, the receiver  150  is an optic fiber light receiver  150 . The-optic fiber light receiver  150  is positioned such that it is ordinarily in the travel path of the light transmitted by the end of the optical fiber  155 . 
     If leaking fluid flows through the slot  135 , it blocks the light being transmitted by the end of the optical fiber  155  and prevents some or all of the light from reaching the optic fiber light receiver  150 . When light is partially or fully blocked or deflected from reaching the optic fiber light receiver  150 , a leak detection sensor  165  that is placed in a location outside the fluid conveying zone raises an alarm. Exemplary sensors include photodiodes, photovoltaic cells, photo resistors, infrared receivers and other light receptor circuits. The alarm may be an audio and/or visual alarm. The alarm may include a local indicator. The alarm may also be transmitted to a remote station, such as a computer, a mobile phone, or other station. Such transmission may be a wired transmission or a wireless transmission. 
     The leak detection system raises an alarm when the light received by the optic fiber light receiver  150  falls below a selected threshold. An appropriate threshold may be selected such that normal fluctuations in light transmission would not cause an alarm to be raised. An algorithm may also be employed to determine when the light pattern deviates from its normal conditions. The algorithm may be embedded as a part of the leak detection sensor  165 . 
     In the illustrated embodiment, the light source (also called the light transmitter)  160  and the leak detection sensor  165  are external to the fluid line  100 . A power source  170  is also external to the fluid line. Together, the light transmitter  160 , the leak detection sensor  165 , and the power source  170  are designated as electronics  130  in  FIG. 1 . The electronics  130  may also include logic, such as a microprocessor, a display for displaying an alarm, an audible alarm, and another transmitter for remotely transmitting an alarm. In one embodiment, the electronics  130  may be mounted to one or more of the hose  105 , the nipple  115 , and the socket  120 . In an alternative embodiment, the electronics may be spaced apart from the fluid line  100 . While the electronics  130  are schematically designated by a box in  FIG. 1 , it should be understood that the electronics  130  need not be contained in a housing and different components may be in different locations. 
     Positioning the electronics  130  external to the fluid line will prevent the fluid being conveyed from damaging the electronics  130 . Further, if a combustible fluid is being conveyed, positioning the electronics  130  externally would reduce the chance of a spark causing a combustion. However, there are also advantages to employing internal electronics, such as a smaller footprint, and limiting exposure of the electronics to external elements. Therefore, in an alternative embodiment (not shown), the electronics may be housed inside the fitting. 
     The power source  170  includes an optical driver circuit that drives the light source  160 . In one embodiment, the power source  170  also drives the leak detection sensor  165 . Exemplary power sources include batteries. In an alternative embodiment, the transmitter light source  160  and the leak detection sensor  165  is not driven by the power source  170 . Instead, it uses energy harvesting devices that derive power parasitically. An energy harvesting device is a parasitic power source that may employ external disturbances, such as vibration, fluid pressure, flow velocity, fluid or ambient temperature, or electro magnetic radiation to generate power. Alternatively, the leak detection system may not include a power source, but instead include an AC power plug configured to draw power from an electrical outlet. 
     To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.” Furthermore, to the extent the term “connect” is used in the specification or claims, it is intended to mean not only “directly connected to,” but also “indirectly connected to” such as connected through another component or components. 
     While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.