Abstract:
A blind assembly for use in a piping circuit that includes a blind element and an injection system. The blind element has a planar portion that is transversely mounted in the piping circuit to block flow through the piping circuit. When the blind element is installed, it has one or more flat surfaces that are in sealing contact with another component of the piping circuit, such as a flange face, to define a sealing interface. A primary seal is provided between the blind element and the other component of the piping circuit and which circumscribes at least a portion of the sealing interface. The injection system is in communication with the sealing interface, and selectively injects a sealant material into the sealing interface to form a redundant seal in the sealing interface and around the primary seal. An injection fitting can mount to the flange for injecting the sealant.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present disclosure relates in general to a redundantly sealing a line blind valve. More specifically, the present disclosure relates to a line blind valve with a redundant seal ring formed by injection of a sealant. 
         [0003]    2. Description of Related Art 
         [0004]    Fluids handling circuits in use in industrial facilities for transmitting fluids typically include lengths of piping and various pieces of fluids handling equipment, where the piping interconnects between the various pieces of the fluids handling equipment. The fluids handling equipment can range from multistory fractionation towers, storage tanks, pumps, compressors, and drums to much smaller items, such as specialty piping equipment, e.g. steam traps, strainers, and filters. What hardware is taken out of service depends on the specific situation, but the particularly hardware actually taken out of service can include a single component within a piping circuit, two or more components in the piping circuit, a section of the length of piping, or an entire circuit. The out of service time period can be as short as a few hours, can be months, or can be permanent. While out of service, the specific portion of a piping circuit is generally isolated from the rest of the piping circuit. Fluid within the out of service piping circuit is typically drained or vented from within the equipment. If required, personnel can safely perform maintenance on, or repair of, the hardware after the fluid has been removed. 
         [0005]    Usually included within most piping circuits are valves that can block or isolate portions of the piping circuit being isolated. These valves are sometimes also utilized to isolate the portion of the piping circuit being taken out of service. However, out of service isolation using valves is typically only done when the out of service time period is relatively short, i.e. less than a day. More typically, blinds, such as line blind valves, are used for isolating all or portions of a piping circuit. Blinds, which are usually planar members, have a solid portion that are transversely installed in a pipe and that block fluid communication through the pipe. Blind valve assemblies typically include a blind that can be swung between open and closed positions through different mechanisms that basically force the joint to relax and hence, allow blind to be swung. An O-ring seal is usually provided on the mating surfaces of the blind within the line blind valves and the flanges for preventing fluid from escaping across the blind to ambient. The O-ring seals though can become damaged, either over time or mechanically while being installed, thereby forming a leak path for fluid within a live portion of the piping circuit. 
       SUMMARY OF THE INVENTION 
       [0006]    Disclosed herein are examples of a blind valve assembly for use in a fluids handling circuit. In an embodiment the fluids handling circuit a flange mounted on an end of a tubular, and where the line blind valve assembly has a blind element with a planar surface in communication with an inside of the tubular and that has an outer periphery in sealing contact with the flange to define a sealing interface. The blind valve assembly also includes a seal provided along the circumference of the sealing interface and that defines a pressure barrier along a radial path, a recess on the planar surface along the sealing interface and that circumscribes the seal, and a sealant injection system in communication with the recess, so that when sealant is injected into the recess, a redundant seal is provided along the recess and that circumscribes the seal. The blind valve assembly can further include a passage through the flange that has an end in communication with the recess, and an opposite end in selective communication with the sealant injection system. In this example, the sealant injection system includes a sealant source that injects sealant into the passage; and can further include a fitting threaded into the passage for connecting to a line from the sealant source. In an alternative, the blind element includes a spectacle blind, having a substantially disk like planar blank portion, and a planar ring like spectacle portion that is coplanar and attached to the blank portion, and wherein both the blank portion and spectacle portion each have a sealing interface in selective sealing contact with the flange. In one example, the planar surface makes up a first surface and the flange makes up a first flange, the blind element can further include a second surface that is on a side opposite the first surface and that is in sealing contact with a second flange that is coupled to the first flange. In an embodiment, the tubular is a fluids handling element, such as a fluid flow line and a nipple connected to a vessel. In one alternative, the seal is an O-ring seal. 
         [0007]    One example of a fluids handling circuit is disclosed herein and that includes a tubular, a flange mounted to an end of the tubular, a blind element having a planar surface with an inner portion that is in communication with an inside of the tubular and that has an outer portion in sealing contact with the flange to define a sealing interface, a seal element disposed along the sealing interface and that circumscribes the inner portion and that defines an inner seal, a recess formed in one of the flange or the outer portion that circumscribes the seal element, and a passage formed through the flange having an end in communication with the recess and an opposite end in selective communication with a source of sealant, so that when sealant is provided by the source of sealant to the passage, a redundant seal is formed along the recess that defines an outer seal to block pressure communication along a radial path between the blind element and flange. The fluids handling circuit can further include a sealant injection system for injecting sealant from the source of sealant into the passage. A fitting can be included at an end of the passage on which an injection line that is part of the sealant injection system is attached. In one example, the tubular is a fluids handling element such as a fluid flow line or a nipple that attaches to a vessel. The blind element can further include a spectacle blind portion that is planar and has a mid-portion with an opening through the mid-portion, and an outer portion that circumscribes the mid-portion and that is in selective sealing contact with the flange to define a sealing interface. In one alternative, the planar surface is a first surface and the flange is a first flange, the seal element is a first seal element, the redundant seal is a first redundant seal, and wherein the blind element further includes a second surface that is planar and on a side opposite the first surface, and that is in sealing contact with a second flange by a second seal element that is circumscribed by a second redundant seal that comprises sealant selectively disposed in a recess formed on the second planar surface. 
         [0008]    Also disclosed herein is a method of forming a blind in a fluids handling circuit, and which includes providing a blind element having a planar surface with a seal element and a groove that circumscribes the seal element, mounting the blind element to a flange that connects to an end of a fluids handling tubular so that the seal element is in sealing contact with the flange to define a sealing interface, and injecting a sealant into the groove to form a redundant seal that blocks pressure communication along a radial path between the flange and the blind element. In one embodiment, a passage is formed through the flange. Further optionally, a sealant injection system can connect to the passage and inject sealant into the passage. In one example, the planar surface is a first surface, the flange is a first flange, and wherein the blind element has a second surface that is planar and opposite the first surface; in this example, the method further includes mounting the blind element to a second flange so that the second surface is in sealing contact with the second flange. In this example, the groove is a first groove, the redundant seal is a first redundant seal, and the seal element includes a second seal element, and wherein the second surface is a second groove in which sealant is injected to form a second redundant seal that circumscribes the second seal element. In an example, the fluids handling tubular can be a fluid flow line or a nipple that attaches to a vessel. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0009]    Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which: 
           [0010]      FIG. 1  is a schematic view of an example of a piping circuit having a line blind valve assembly. 
           [0011]      FIG. 2  is a side sectional view of an example of the line blind valve assembly of  FIG. 1 . 
           [0012]      FIG. 3  is a plan view of an example of a blind element for use in the line blind valve assembly of  FIG. 1 . 
           [0013]      FIG. 4  is a side sectional view of an embodiment of an injection fitting for use with the line blind valve assembly of  FIG. 1 . 
       
    
    
       [0014]    While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term “about” includes +/−5% of the cited magnitude. In an embodiment, usage of the term “substantially” includes +/−5% of the cited magnitude. 
         [0016]    It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation. 
         [0017]      FIG. 1  is a schematic example of a fluids handling circuit  10  shown including a line  12 , which in the illustrated example is a fluid flow line for transmitting fluid from a supply vessel  14  to a terminal point  16 . Terminal point  16  can be another vessel, a pump suction, a battery limit, or any other type of fluids handling equipment that is at a location different from supply vessel  14 . Line  18 , which also is a fluid flow line for transporting a fluid, branches from line  12  at branch-T  20  and terminates at a blind valve assembly  21 . Line  22  is shown mounted to the downstream end of line blind valve assembly  21 ; at an end distal from line blind valve assembly  21 , line  22  terminates at a discharge vessel  23  thereby completing communication between supply vessel  14  and discharge vessel  23 . A passage P ( FIG. 2 ) is formed within lines  18 ,  22 . Block valves  24 ,  25  are shown respectively in lines  12  and line  18 , and wherein block valve  24  is downstream of branch-T  20 . Selectively opening and closing block valves  24 ,  25  can be used for regulating flow through line  12  and  18 , and thus flow to one or both of terminal point  16  and discharge vessel  23 . As will be described in more detail below, line blind valve assembly  21  can be used to block flow communication through line  18 , and thus along passage P, for prolonged periods of time. In the illustrated example, line blind valve assembly  21  is schematically illustrated as a spectacle blind, and in the open position, thereby allowing flow through line  18 . As is known, line blind valve assembly  21  can be adjusted so that flow communication through line  18  is selectively blocked. 
         [0018]      FIG. 2  shows in a side partial sectional view details of an embodiment of line blind valve assembly  21 , and which includes a blind element  30  mounted in a body  31  of the line blind valve assembly  21 . In the example of  FIG. 2 , the body  31  includes a pair of annular body members BM 1 , BM 2 ; inner flanges  32 ,  33  are formed respectively on annular body members BM 1 , BM 2 . As shown in the illustrated example, inner flanges  32 ,  33  are coaxially coupled to one another thereby affixing together annular body members BM 1 , BM 2 . Further illustrated is that the blind element  30  is coaxially mounted between flanges  32 ,  33 . Fasteners  34 , shown as a combination of nuts  35  and bolts  36 , are used for fastening together the flanges  32 ,  33  in a coaxial fashion. When fastened between flanges  32 ,  33 , blind element  30  and flanges  32 ,  33  are in sealing contact to prevent fluid within lines  18 ,  22  from escaping between flanges  32 ,  33  and opposing planar surfaces of the blind element  30 . As illustrated, blind element  30  is put into a blocking configuration thereby blocking fluid communication across flanges  32 ,  33 . Flanges  37 ,  38  are shown respectively on the ends of annular body members BM 1 , BM 2  distal from flanges  32 ,  33 . Flanges  37 ,  38  respectively couple to flanges  39 ,  40  shown on ends of lines  18 ,  22  adjacent the line blind valve assembly  21 ; thereby affixing the line blind valve assembly  21  to the lines  18 ,  22 . 
         [0019]    Referring now to  FIG. 3 , shown is one example of the blind element  30  in a plan view wherein the blind element  30  includes a blind  42  or blank shown as a substantially solid planar member with a disk-like shape and circular outer circumference. A ring spacer  43 , also having a generally planar configuration and circular outer shape, is attached to blind  42  by a connector  44 . In the example, connector  44  is generally rectangularly shaped. In an embodiment, blind  42 , ring spacer  43 , and connector  44  are all generally co-planar. A bore  45  extends axially through the mid-portion of ring spacer  43 . Accordingly, selectively disposing the ring spacer  43  between flanges  32 ,  33  instead of blind  42 , allows, rather than blocks, fluid communication through line  18  and across flanges  32 ,  33  and within bore  45 . Referring back to  FIG. 2 , bolt  36  is shown projecting through an opening  46  formed through connector  44 . Thus, by loosening nuts  35  and bolts  36  from one another, the blind element  30  can be rotated about bolt  36  and changed from a blocking configuration, as shown in  FIG. 2 , to an open configuration as shown in  FIG. 1 , which allows flow through line  18  and into line  22 . In the open configuration, fluid can flow through the bore  45  of ring spacer  43  rather than being blocked by the solid blind  42 . 
         [0020]    Shown in both  FIGS. 2 and 3  are inner recesses  48  formed a radial distance into, and along circumferences of planar surfaces of blind  42 , where the planar surfaces are on opposite sides of the blind  42 . Each inner recess  48  is circumscribed by an outer recess  50  on both planar sides of blind  42 , where outer recess  50  is also formed a radial distance into the body of the blind  42 . Although shown as having a generally rectangular cross-section, recesses  48 ,  50  can also have other shapes, such as round or elliptical. Similarly, the solid portion of the ring spacer  43  includes inner recesses  52  each shown circumscribing bore  45 , and on planar sides of ring spacer  43  that are on its opposing sides. Each inner recess  52  is circumscribed by an outer recess  54  that also extends a radial distance into ring spacer  43 . Inner O-rings  56  are shown set in inner recesses  48 , and which provide primary seals between the blind  42  and flanges  32 ,  33  when blind  42  is mounted within flanges  32 ,  33 . Outer sealant ring  58  are shown set inside of outer recesses  50  and as shown in  FIG. 2 , provide an outer or redundant sealing interface between blind  42  and flanges  32 ,  33 . Ring spacer  43  includes inner O-rings  60  set inside of inner recesses  52  and when ring spacer  43  is set within flanges  32 ,  33  a primary sealing interface between ring spacer  43  and flanges  32 ,  33  is provided along inner O-rings  60 . Outer sealant rings  62  are shown set in outer recesses  54  on both sides of ring spacer  43 , and which provide an outer and redundant seal between ring spacer  43  and flanges  32 ,  33 . 
         [0021]    Referring back to  FIG. 2 , an injection system  64  is shown for forming outer sealant rings  58 ,  62 . In an embodiment, outer sealant rings  58 ,  62  are formed after the blind element  30  has been installed between flanges  32 ,  33 ; and which can be done through any mechanical force that relaxes joint tightness. In this example, a sealant source  66  is shown as having a container with sealant  68  disposed therein, and an injection line  70  for transmitting sealant  68  into the outer recesses  50 ,  54  in order to form the outer sealant rings  58 ,  62 . An end of injection hose  70  distal from sealant source  66  connects to an injection fitting  72  shown mounted on an outer surface of flange  32 . A passage  74  is bored through flange  32  from its outer surface and projects radially inward to be in registration with outer recess  50 . Accordingly, by forcing (pumping) sealant  68  into injection line  70  and through fitting  72 , such as by an injection pump (not shown), sealant  68  makes its way through passage  74  where it is injected into the outer recess  50  and flows circumferentially through recess  50  and to form outer sealant rings  58 . In this fashion, a redundant and safety backup seal can be formed along blind element  30  after blind element  30  has been installed. In one example, the secondary seal is formed after detection of a leak through the line blind valve assembly  21 . Similarly, an injection fitting  76  is mounted onto an outer surface of flange  33  and which allows for communication of sealant  68  into a passage  78 , shown projecting through flange  33  and into registration with outer recess  50  adjacent flange  33 . In a similar fashion, injecting sealant  68  through fitting  76  and passage  78  forms a redundant seal and outer sealant ring  58  on a surface of blind  42  facing flange  33 . For purposes of clarity, although ring spacer  43  of  FIG. 2  is shown set outside of flanges  32 ,  33  and outer sealant ring  62  is illustrated set within outer recess  54 . Examples exist wherein formation of outer seal ring  62  is formed in much the same way as outer seal ring  58  as described above. 
         [0022]      FIG. 4  shows in a side sectional view one example of injection fittings  72 ,  76 . Here, a tap  80  is shown drilled into the outer surface of flanges  32 ,  33  and which may be threaded so that fittings  72 ,  76  may be threadingly attached to flanges  32 ,  33 . Fittings  72 ,  76  are shown made up of a generally elongate body  82  having threads on its lower end as described above and a bore  84  formed through an axis A X  of the body  82 . Bore  84  enlarges at roughly a midpoint of body  82  to form a downward facing shoulder  85 . A spring  86  is shown set within the enlarged portion of bore  84  and below shoulder  85 . A ball check  88  is depicted on top of spring  86  and being urged by the spring  86  against the shoulder  85 . The combination of the spring  86  and ball check  88  forms a check valve which prevents egress of fluid within passage  74 ,  78  from escaping from fitting  72 ,  76  through bore  84 . By applying sealant  68  at a pressure that exerts a force onto ball check  88 , which exceeds the strength of string  86 , can force ball check  88  downward to compress spring  86 , thereby allowing sealant  68  to flow through bore  84  and past ball  88  and spring  86 , and through passages  74 ,  78  for creation of sealant rings  58 ,  62  ( FIG. 2 ) within recesses  50 ,  54 . In the example of  FIG. 4 , sealant  68  is shown in recesses  50 ,  54  and prior to being cured or otherwise transitioned from a flowable substance to the pressure resistant material that makes up the sealant rings  58 ,  62 . Curing of the sealant  68  to form the sealant rings  58 ,  62  can take place at ambient conditions over time, or with the addition of heat. Further included with the fittings  72 ,  76  is a cap  90  for covering the bore  84  and further preventing egress of sealant  68 , or other fluid, from exiting bore  84 . 
         [0023]    The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. Optional embodiments exist where one or both of flanges  32 ,  33  are axially retractable so that loosening of the fasteners  34  is unnecessary for moving the blind element  30  between its open and closed configurations. For example, a cam (not shown) can be used to move one of the flanges  32 ,  33  along an axis A X  of the passage P. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.