Abstract:
The present invention provides improved diverter assemblies ( 10 ) designed for installation on liquid-conveying conduit sections ( 12 ) having one or more joints susceptible to leakage of liquid. The assemblies ( 10 ) include a plurality of mating housing sections ( 34, 36 ) which are releasably interconnected and in surrounding relationship to the conduit sections ( 12 ) on opposite sides of the conduit joint(s) to form an overall housing ( 35 ) defining anon-sealed enclosure. The housing ( 35 ) is equipped with a sump ( 72 ) which gravitationally collects escaped liquid. The sump ( 72 ) includes a drain outlet ( 74 ) for conveying the collected liquid away from the conduit sections ( 12 ) for collection or reuse.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is broadly concerned with leak diverter assemblies used to divert and collect liquids escaping from a failed joint in a liquid-conveying conduit, pipe, or other structure (referred to generically herein as a “conduit”). More particularly, the invention is concerned with such assemblies, the combination thereof with jointed conduits, and corresponding methods, wherein the diverter assemblies include a housing installed on a conduit to provide a non-sealed enclosure about the conduit, and where the housing includes a drain sump for continuously diverting and collecting leaking liquid. The invention finds particular utility in the protection of jointed oil-conveying conduits associated with substation transformer oil tanks. 
     2. Description of the Prior Art 
     Substation electrical transformers include large tanks for holding oil used to cool the transformer during operation thereof. In order to maintain the oil temperature at an appropriate level, it is necessary to continuously circulate the oil from the tank to a heat exchanger. Consequently, conduits are provided between the oil tank and the heat exchanger for handling the flow of oil from the tank to the heat exchanger, and vice-versa. Such conduits typically include a short, flanged stub pipe extending from the oil tank and connected with similarly flanged conduits leading to and from the heat exchanger. These flanged connections or joints are sealed by use of elastomeric O-rings or similar expedients. 
     Over time, the joints tend to leak oil, usually owing to failure of the O-rings or other sealing devices. This presents a series of significant problems. For example, the leaking oil is an environmental hazard which must be controlled. The straightforward solution of replacing the joint seals is not a realistic proposition in the context of substation transformers. That is, these transformers cannot be easily taken out of service without significant disruptions in electrical output from the substation. Moreover, any effort to replace the joint seals necessitates some means of collecting the very large amount of oil within the transformer oil tank. As a consequence, utilities have not heretofore been able to effectively deal with oil conduit leaks, and have been forced to “live with” the problem. In one reported instance, a substation transformer has been leaking oil in this fashion since 1969, and the utility has been unable to adequately deal with the problem over four decades. 
     Efforts have been made in the past to provide a way of dealing with liquid-conveying conduit sections having one or more joints susceptible to liquid leakage, both in the context of transformer oil tank conduits and in other areas. Generally speaking, these efforts have been characterized by attempts to provide fully sealed structure which is mounted on the conduits in surrounding relationship to the leaking joint. The goal is thus to contain the leaking liquid in the belief that such would provide a permanent solution. 
     For example, AU 2009/100938 describes leakproof structure to be applied to an oil-conveying pipe. The intent is to thus contain leaking oil within a housing surrounding the conduit joint. However, this does not provide a permanent solution, inasmuch as the housing seals themselves will ultimately fail. Likewise, KR 2009/0038160 describes a pipe connection cover assembly designed to prevent escape of leaking fluid through use of an end-sealed housing disposed about a conduit joint. Other references of interest include U.S. Pat. Nos. 5,141,256, 6,305,719, 6,789,584, and 7,464,728, and U.S. Patent Publication No. 2004/0118467. 
     There is accordingly a need in the art for an improved apparatus and method for effectively dealing with liquid conveying conduits having joint(s) susceptible to leakage, and especially conduits which cannot readily be repaired, such as substation transformer oil-conveying conduits. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the problems outlined above and represents a marked departure from prior art efforts to contain liquids leaking from a jointed conduit. Rather than attempting to provide permanent sealing arrangements to confine or otherwise hold in leaked fluid from the conduit, the invention contemplates diverter assemblies which continuously divert leaking liquids in order to allow easy collection thereof without the need to provide a fully sealed enclosure; indeed, fully sealed enclosures are undesirable, inasmuch as such sealed arrangements are inherently subject to failure, and make access to the conduit and joint(s) more difficult. 
     Generally speaking, the invention is implemented in the context of a liquid-conveying conduit section having a joint susceptible to leakage of liquid, and employs a diverter assembly operably coupled with the conduit section for diverting liquid leaked from the joint away from the conduit section. The diverter assembly comprises an elongated, hollow housing including a plurality of mating housing sections, the housing having a pair of opposed, open ends; usually, the length of the housing is greater than the maximum diameter thereof. The housing is positioned on the conduit section with the housing open ends in surrounding relationship with the conduit section, and with the conduit joint(s) located within the housing cavity between the housing ends. The housing also includes a sump oriented for gravitational collection of liquid leaked from the joint, with the sump having a diverter outlet allowing collected liquid to be drained from the sump. The housing sections are joined by connection structure operable to releasably interconnect at least one of the housing sections to the remainder of the housing so as to allow access to the conduit section and joint within the housing. Importantly, the housing defined by the housing sections creates a non-sealed enclosure about the conduit section and joint, apart from the diverter outlet. As used herein, a “non-sealed enclosure” refers to the fact that at least some or all of the junctures between the housing sections, and/or between the housing and the conduit itself, are not sealed and will, in and of themselves, allow passage of the conduit fluid therethrough. Normally, at least the elongated junctures between the housing sections are not sealed. 
     In many instances, the conduit section is generally horizontally oriented, and has at least a pair of mating, sealed conduit flanges along the length thereof and defining a conduit joint. Of course, one or more such joints can be present in a given conduit section. Preferably, the housing comprises a pair of generally semi-cylindrical, upper and lower housing sections, with each of the housing sections having a pair of opposed, outwardly projecting connection flanges extending along the lengths thereof. The connection flanges of the housing sections are in opposition to each other to define respective, non-sealed junctures between the housing sections and spaced from the conduit section. The connection structure interconnecting the housing connection flanges is advantageously of the quick-connect variety, e.g., one-quarter turn screw couplers. In such diverter assemblies, the sump would be located in the lower housing section for gravitational flow of leaked liquid into the sump. 
     The preferred diverter assemblies may also include an internal diverter shield secured to the inner face of the upper housing section and extending downwardly therefrom to cover each of the opposed junctures, whereby leaked liquid is prevented from passing through the junctures. This can be useful in the event that a leak is in the form of a low-velocity spray from the conduit section joint. In such a case, the leaked liquid could conceivably pass through the loosely interconnected housing sections at the junctures thereof. However, such a spray-leak would be readily contained by diverting the leaked fluid toward the lower sump of the diverter assembly. 
     One of the goals of the invention is to provide a diverter assembly which can be easily opened for visual inspection of the protected conduit section. In case of the preferred diverter assemblies, the lower housing section may be suspended from the conduit section using a hang strap or the like. In this manner, the upper housing section may be detached from the lower housing section to permit the desired inspection, without the need to hold the lower housing section in place. 
     In certain embodiments of the invention, structure is provided for inhibiting the ingress of water into the housing, which could otherwise dilute the conduit fluid being diverted. Such structure may include a bead of synthetic resin material at one or both of the ends of the housing sections, or an annular diverter assembly mounted on the conduit adjacent one or both ends of the housing. However, even with the use of such water ingress-inhibiting structure, the overall enclosure defined by the housing is non-sealed, apart from the diverter outlet; this condition normally obtains because of the non-sealed nature of the elongated juncture(s) between the housing sections. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary side view illustrating a transformer oil tank and external oil-conveying conduit section having a diverter assembly in accordance with the invention mounted on the conduit section; 
         FIG. 2  is a fragmentary perspective view of the conduit section and diverter assembly illustrated in  FIG. 1 ; 
         FIG. 3  is a fragmentary vertical sectional view of the conduit section and diverter assembly of  FIG. 1 ; 
         FIG. 4  is a vertical sectional view taken along the line  4 - 4  of  FIG. 3 ; 
         FIG. 5  is an exploded view illustrating the construction of the diverter assembly housing sections; 
         FIG. 6  is a fragmentary perspective view illustrating the use of a suspension strap to maintain the lower housing section on the conduit section; 
         FIG. 7  is a vertical sectional view illustrating the suspension strap depicted in  FIG. 6 ; 
         FIG. 8  is a fragmentary perspective view illustrating a modified diverter assembly having a viewing port in the upper housing section thereof; 
         FIG. 9  is a perspective exploded view illustrating the housing sections further depicting the use of synthetic resin beads at the ends of the sections to inhibit ingress of water into the diverter assembly; 
         FIG. 10  is a fragmentary elevational view of a modified diverter assembly mounted on a conduit and equipped with a water shedding ring also serving to inhibit the ingress of water into the diverter assembly; 
         FIG. 11  is a perspective view of the water shedding ring illustrated in  FIG. 10 ; 
         FIG. 12  is a fragmentary vertical sectional view further illustrating the water shedding ring; 
         FIG. 13  is a fragmentary perspective view depicting the use of a two-piece annular band of flexible material adjacent one end of the diverter assembly designed to inhibit water ingress; and 
         FIG. 14  is a fragmentary end view illustrating the use of a clamping band disposed about the annular segment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning now to the drawings, a diverter assembly  10  is illustrated in  FIG. 1 , applied to a conduit section  12 . The section  12  extends between a transformer oil tank  14  and a pump  16 , the latter serving to convey transformer oil through the conduit section  12  to a heat exchanger or other oil treatment device. 
     As best seen in  FIG. 3 , the conduit section  12  includes a short stub pipe  18  extending outwardly from tank  14  and having a flange  20 . An intermediate pipe section  22 , equipped with endmost connection flanges  24  and  26 , extends from pipe  18  and is coupled with the inlet of pump  16 , also having a connection flange  28 . Connection bolts  30  and  32  are used to interconnect the abutting flanges  20 ,  24 , and  26 ,  28 , respectively. Although not shown in detail, it will be appreciated that appropriate O-ring or other sealing structure is provided between the abutting flanges to complete the conduit joints. Nonetheless, the sealing structure is susceptible to leakage over time, especially in light of the anticipated long service life of conduit section  12 . In this instance, the intermediate pipe section  22  is also equipped with an upstanding gauge  33  allowing visual reading of pressure within the pipe section or other flow-related parameter. 
     The diverter assembly  10  in the depicted embodiment includes mating, integrally formed, synthetic resin upper and lower housing sections  34  and  36  which are designed to be installed on conduit section  12  to cooperatively define a housing  35 . The upper housing section  34  includes a primary semicircular wall  38  with a rightmost end wall  40 , as viewed in  FIG. 3 , which terminates with an arcuate lip  42 . The leftmost end of wall  38  has a inclined transition wall  44  and an axially projecting, semicircular wall  46 . The housing section  34  also has a pair of opposite outwardly extending connection flanges  48  and  50  at the opposed bottom margins of the walls  38 ,  44 , and  46 . As best seen in  FIGS. 2 and 5 , the outer ends of the flanges  48  and  50  have depending skirts  52  and  54 . Each of the connection flanges  48 ,  50  also have a series of spaced through-apertures  56  and  58 . The depicted embodiment also makes use of an optional spray-deflecting shield  60  secured to upper housing section  34  by means of connection strap  62 . As illustrated, the shield  60  is of frustocircular design, having downwardly extending segments  64  and  66  which extend below the connection flanges  48  and  50 , respectively. 
     The lower housing section  36  is likewise integrally formed of an appropriate synthetic resin material, and has an elongated, transversely arcuate primary wall  68  with a central, laterally extending, stepped segment  70  defining a lowermost sump  72  extending along the length of the lower housing section  36 . A drain outlet is provided at the lowermost extent of segment  70 , in the form of a conventional drain fixture  74  secured to the segment  70 . A flexible drain line  76  is normally attached to the lower end of fixture  74 . The right-hand end of wall  68  includes an upwardly extending end wall  78  terminating in a lip  80 , whereas the left-hand end of wall  68  has an inclined transition wall  82  and an axially projecting, semicircular wall  84 . The upper ends of the walls  68 ,  82 , and  84 , and are equipped with laterally outwardly extending connection flanges  86  and  88 . These flanges have a plurality of through apertures  90  and  92  along the length thereof, and are moreover equipped with U-shaped connection clips  94 . 
     In the illustrated embodiment, the lower housing section  36  is equipped with an adjustable hanger strap  96  in the form of a pair of synthetic resin strap members  98  and  100 , respectively secured to the opposite sides of wall  68 , and having upper buckle connection structure  102  allowing the straps to be interconnected and adjusted. 
     Another option for diverter assembly is illustrated in  FIG. 8 , wherein the upper housing wall  38  is equipped with a sighting port  104  extending through wall  38 , shield  60 , and connection strap  62 . The port  104  is located directly above gauge  33 , allowing inspection of the gauge without removal of assembly  10  from conduit section  12 . 
     In the use of assembly  10 , the upper and lower sections  34 ,  36  thereof are installed on conduit section  12 . In those embodiments including hanger strap  96 , the lower section  36  is first installed, with the strap  96  serving to loosely hold the section  36  in place. If no hanger strap is used, the lower section  36  is merely temporarily held in place by the installer. At this point, the upper section  34  is installed over the conduit section  12 , by moving the housing sections  34 ,  36  together so that the connection flanges  48 ,  50  come into close, face-to-face adjacency with the lower connection flanges  86 ,  88  best seen in  FIGS. 2 and 4 . It will be observed that the skirts  52 ,  54  are slightly outboard of the outer edges of the flanges  86 ,  88 , in order to inhibit ingress of water into the housing while nonetheless maintaining the non-sealed nature of the elongated junctures between the connection flanges. This also serves to substantially align the apertures  56  and  58  with apertures  92  and  94 . The installation is completed by inserting conventional quick-connect screw couplers  106  through the aligned flange apertures with tightening of the couplers  106 . Preferably, the couplers  106  are conventional quarter-turn screw couplers, which interconnect the housing sections  34  and  36 . In this orientation, it will be appreciated that the lips  42  and  80  of the upper and lower sections engage the stub pipe  18 , such is merely a non-sealing abutment, and no effort is made to create a seal at this location. Similarly, the semicircular walls  46  and  84  are in loose contact with the interconnected conduit flanges  26  and  28  without any liquid-tight seal being established. The face-to-face engagement between the connection flanges  48 ,  50  and  86 ,  88  establishes elongated juncture lines  108  and  110  ( FIG. 4 ); again, these juncture lines are not sealed in any fashion. It will also be appreciated that the housing sections  34 ,  36  exert virtually no compressive forces on the conduit section  12 , apart form the weight of the housing  35 . 
     In the event that the pipe joint formed by the sealed interconnection of the flanges  20  and  24  develops a leak, it will be appreciated that the flow of liquid passes downwardly into sump  72  and then gravitationally flows through drain fitting  74  and line  76 . Such diverted liquid may then be collected in a suitable container (not shown) for disposal or reuse. Assuming that the assembly  10  is equipped with the optional shield  60 , any spray leakage from the leaking joint, which may otherwise escape through the juncture lines  108 ,  110 , is diverted downwardly into sump  72 . 
     It will thus be seen that the present invention provides a highly useful means of handling the problem of leaky joints in fluid-conveying conduits in a safe, environmentally friendly way. Moreover, the diverter assemblies of the invention provide an essentially permanent solution, meaning that the assemblies maybe maintained in place indefinitely without fear of failure owing to sealed connections. The loosely interconnected housing sections may also be readily separated for inspection of the protected conduit section and then reattached, without the need for dealing with sealing arrangements typical of prior art pipe joint covers. 
     In certain instances, it may be desirable to inhibit ingress of water into the housing  35  so as to prevent dilution of the diverted liquid from conduit section  12 . In the case of transformer oil leakage, for example, the diverted and collected oil may be reused in the transformer oil tank  14 , and therefore water dilution of the oil is to be avoided. To this end ( FIG. 9 ), the inner faces of the semicircular walls  46  and  84  and the adjacent ends of the flanges  48  and  50  may be provided with respective beads  112 ,  114  of appropriate synthetic resin sealant. The sealant engages the corresponding areas of conduit section  12 . In like manner, the arcuate lips  42  and  80 , and the adjacent ends of the flanges  86  and  88 , may be similarly equipped with sealant beads  116 . The provision of the beads  112 - 116  serves to substantially prevent ingress of water into the confines of housing  35 . However, this is not designed to provide pressure seals at the ends of the housing  35 , but merely to inhibit the passage of water into the housing. Accordingly, even with the provision of these beads, the overall enclosure defined by the housing  35  is non-sealed as defined above, owing to the non-sealed, elongated juncture line  108  and  110  between the connection flanges  48 ,  50  of section  34 , and the mating connection flanges  86 ,  88  of section  36 . 
       FIGS. 10-12  illustrate the use of another type of structure for inhibiting ingress of water into the housing  35 , in the form of a diversion ring assembly  118 . As illustrated, assembly  118  includes upper and lower mating sections  120 ,  122 , which cooperatively define a radially enlarged cup-like ring  124  which has the closed end thereof adjacent one or both of the ends of the housing  35 , such that water passing along the exterior surface of conduit section  12  or blown towards the adjacent end of the housing during heavy rainfall is diverted from the housing end(s). In more detail, the upper section  120  includes a semicircular flange  126  and an outwardly flared semicircular wall  128  presenting an outermost lip  130 . The mating lower section  122  has a semicircular flange  132 , an outwardly flared semicircular wall  134  presenting an outermost lip  136 . As best seen in  FIGS. 11 and 12 , the sections  120 ,  122  are positioned in abutting contact about the conduit section  12  by means of a conventional clamping ring  138 . Although the ring assembly  118  is illustrated with ring  124  in an upwardly open position, such position could be reversed to a downwardly opening orientation if desired. 
       FIGS. 13-14  illustrate another type of water ingress-inhibiting structure  140 . The structure  140  includes modified semicircular wall sections  142 ,  144  used in lieu of the semicircular walls  46  and  84  of the embodiment of  FIGS. 1-8 . In particular, the wall section  142  is an integral extension of the housing section  34  and includes a semicircular wall  146  presenting an internal recess  148  which is axially spaced from the flanges  26  and  28 . The recess  148  receives a semicircular segment  150  of flexible synthetic resin material. Similarly, the wall section  144  is integral with housing section  36  and has a semicircular wall  152  presenting an internal recess  154 . The recess  154  likewise receives a semicircular segment of material (not shown). When the modified housing sections are installed on conduit section  12 , the flexible material housed within the recess  148  and  154  come into abutting, endwise engagement to create a water ingress barrier about the section  12 . If desired, a circular clamp  156  may be applied to the external surfaces of the semicircular walls  146  and  152  to augment the effect of the structure  140 . 
     While a representative diverter assembly has been illustrated in the context of a transformer oil-conveying conduit section, those skilled in the art will appreciate that the invention is not limited to any specific embodiment. For example, the diverter assemblies of the invention may be mounted on other types of jointed conduit sections oriented to various angles, including vertically. The assembly housings may be designed to protect multiple conduit joints, or joints of very different designs. The low cost of the diverter assemblies hereof also makes it possible to custom-design and fabricate unique diverter assemblies for individual jointed conduit sections at a reasonable cost. Additionally, while in preferred forms the diverter assemblies hereof are fabricated from synthetic resin materials, other materials including metal or elastomerics may be used, depending upon the diverter design in question and cost considerations.