Abstract:
An adjustable jacket and method of covering an insulated conduit, the jacket having two parts which together form a cylindrical configuration over the insulated conduit. Overlapping flanges of the two parts equipped with grooves and ridges allow tightening of the two parts so that the jacket conforms to the underlying conduit having bends and curves.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to adjustable jackets for use over insulated fluid transporting pipes or tubes. More particularly, the invention relates to adjustable metal jackets and methods for covering insulated pipes therewith having fittings with various angles other than a right angle to prevent damage to the insulation from the environment. 
     2. Reported Developments 
     Industrial conduits, such as used in the chemical, petrochemical, power, pulp and refinery fields require insulation for temperature-controlled processes, energy conservation and safety. The insulation helps maintain a desired temperature of the medium carried by the conduits which is different from the temperature of the environment. Most of the industrial conduits are located outdoors and must be protected from water. The penetration of water and moisture from the air into an insulation system can cause loss of insulating performance and corrosion of the conduits. The loss of insulation property can also affect the contents of the conduit, such that a vapor component of the conduits contents may become condensed, i.e. the liquid may freeze and disrupt the fluid flow within the conduit or rupture the conduit. The partially frozen liquid may also be transferred through the conduit into processing equipment, thereby adversely affecting the operation of the equipment. 
     Typically, industrial pipe insulation is protected by jackets made of metal, such as aluminum and stainless steel, or flexible and semi-rigid materials, such as thermoplastics. It is relatively easy to install weather-tight jackets to straight run insulation by putting the overlap of the jackets in a watershed position in order to direct water away from the area of the overlap. Installing jackets, especially metal jackets, on fittings having elbows of 90°, 45° and Tees in a weather-tight fashion has been problematic. Conforming the shape of the jackets to elbow fittings covered with insulation is rendered rather difficult because of the various pipe diameters and the various outside diameters of the insulation covering the pipes. In practice it is economically disadvantageous to produce preshaped jackets for covering various pipe sizes covered by various thickness of insulations. 
     The prior art has provided, for pipe elbow insulations, a jacket comprising overlapping connecting flanges formed with interengageable ribs and grooves. The jacket is assembled around a fibrous insulation which is wrapped around a pipe elbow and angularly related pipes connected to the elbow. The grooves serve as interval moisture traps for condensation. 
     The prior art has also provided a method for the application of a protective cover around heat or cool insulated tube bends. In the method, a corrugated bend-form material is spirally wound into a tube and the adjoining tube edges are secured, such as by lapping, to form a non-slip joint. The corrugated tube is cut lengthwise into two or more parts which are then placed over the insulated pipe bend. The cut edges are re-joined to form the protective cover. 
     Still another approach of the prior art includes the provision of a jacket having a plurality of pleats that provide points of flexure so that the jacket can be conformed to the bends and curves in the underlying insulation. 
     Illustrative prior art approaches for providing protection jackets are disclosed, for example, in U.S. Pat. Nos. 3,153,546; 4,054,985; and 5,775,379. While these and other approaches and proposals of the prior art greatly improved the insulation systems around pipes and tubes, there exists a need to further improve such insulation systems. Accordingly, an object of the present invention is to provide an adjustable jacket which would enclose the insulation material over the bends and joints of pipes and tubes so that the jacket can be tightened and tensioned over insulation having various diameters. 
     Another object of the present invention is the provision of easily installable jackets which, by their orientation on pipes and tubes, will prevent entry of water and moisture into the underlying insulation. 
     A further object of the present invention is the provision of jackets which can be pre-fabricated and which can be installed at the site of application without cutting or other cumbersome steps. 
     A still further object of the invention is the protection from corrosion of the pipes and tubes transporting fluids thereby maintaining the integrity of such fluids. 
     SUMMARY OF THE INVENTION 
     The present invention provides adjustable jackets for insulated conduits which carry fluids therein. The invention consists of three embodiments. 
     In the first embodiment, the invention provides: a first section of semi-circular, cross-sectional configuration having flanges equipped with grooves; a second section of semi-circular cross-sectional configuration having flanges equipped with ridges. The flanges are incrementally adjustable over the insulated conduit by snap-fitting the ridges into the grooves. 
     In the second embodiment the invention provides for incremental adjustment of the first section to the second section on two opposite sides of the jacket. 
     In the third embodiment there are provided two adjustments of the first and second sections on opposite sides of the jacket. One adjustment is incremental, and the other adjustment on the opposite side of the jacket is slideable. The incremental adjustment is made first, followed by the slideable adjustment so that the jacket tightly conforms to the configuration of the underlying insulated conduit. 
     The embodiments of the invention include adjustable jackets for straight and bend configurations of conduits. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary perspective view of a horizontal straight run conduit covered by an insulation and a jacket, 
     FIG. 2 is a cross-sectional view of the horizontal straight run conduit covered by an insulation and a jacket, taken along the line  2 — 2  of FIG. 1; 
     FIG. 3 is a side-elevational view of a conduit covered by insulation and a jacket wherein the conduit the insulation and the metal jacket form a fitting of less than a straight angle, such as an angle of 45°; 
     FIG. 4 is a side-elevational view of a conduit covered by insulation and a jacket wherein the conduit, the insulation and the metal jacket form a fitting of less than a straight angle, such as an angle of 45°, and the jacket is provided with grooves and ribs to guide water away from the overlaps of the jacket; 
     FIG. 5A is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises two rounded grooves in the top layer of the overlap and one rounded ridge in the bottom layer of the overlap; 
     FIG. 5B is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises three rounded grooves in the top layer of the overlap and two rounded ridges in the bottom layer of the overlap; 
     FIG. 5C is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises two inverted V-shaped grooves in the top layer of the overlap and one inverted V-shaped ridge in the bottom layer of the overlap; 
     FIG. 5D is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises three inverted V-shaped grooves in the top layer of the overlap and two inverted V-shaped ridges in the bottom layer of the overlap; 
     FIG. 6 is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises a generally flat, extended groove in the top layer of the overlap and a round ridge in the bottom layer of the overlap; and 
     FIG. 7 shows in side-elevational view the combination of the jacket overlap design of FIG.  5 A and FIG.  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In one aspect the present invention provides jackets having novel closure systems which surround insulated conduits, such as pipes and tubes. Such conduits are used extensively in industrial piping systems such as in various refineries, petrochemical, power, and pulp and paper plants. The conduits require insulation for process control, energy conservation and safety. In another aspect the present invention provides a method of installing jackets over conduits covered by insulations. 
     The majority of industrial conduits are located outdoors or in washdown areas and, therefore, the insulation must be protected from water and weather penetrations. The penetration of water or moisture into the insulation can cause problems such as process disruption due to the loss of insulating performance caused by the wet insulation and the accelerated corrosion of the metal conduits. 
     The type of insulation used on metal conduits include but are not limited to: rigid insulations, such as made of calcium silicate, perlite silicate, cellular glass, Styrofoam and polyisocyanourate/urethane; semi-rigid insulations, such as made of high density mineral wool; and soft insulations, such as made of soft fiberglass and soft elastomeric materials including elastomeric foams. 
     One of the most commonly used materials used to make jackets of industrial conduit is metal, such as aluminum and steel, since the metal is rugged and durable. It is relatively easy to apply a weather-tight metal jacket to straight run insulation that is horizontal by putting the jacket in a watershed position as shown in FIGS. 1 and 2. 
     In FIG. 1 there is shown in a fragmentary prospective view a horizontal straight run conduit covered by an insulation and a jacket, wherein: the numeral  10  generally denotes the assembly of the metal pipe  12 , numeral  14  denotes the insulation and  16  generally denotes the metal jacket covering the insulation. Jacket  16  comprises two parts  16 A and  16 B wherein  16 A overlps  16 B at area P. The overlap P is located at about 3 o&#39;clock to shed water running down from portion  16 A and is about 0.5 to about 1.0 inch on each side. 
     FIG. 2 is a cross-sectional view of the horizontal straight run conduit covered by an insulation and a jacket, taken along the line  2 — 2  of FIG.  1 . 
     The fittings of sections of conduits shown in FIGS. 1 and 2 is accomplished by simply inserting one section of a conduit into a similar conduit section of another conduit in a male/female relationship. 
     Installing metal jackets on fittings having less than straight angles, such at 45°, 90° and Tees is rather difficult. In order to provide conformity between the insulation  14  and metal jacket  16  in a conduit having a fitting of less than a straight angle, such as shown in FIG. 3, the lower half  16 B of metal jacket  16 , which is the inside radius of the metal jacket, is kept straight, while the upper half  16 A of metal jacket  16 , which is the outside radius of the metal jacket, is slightly bent inward. This inward bend is designed to help the metal “lay down”, giving the appearance of a tight seal. This seam, however, was observed to be penetrated by water from storms and moisture from wet atmospheric conditions; water moves under the overlap and into the insulation on both the inside and outside radius of the overlaps. 
     The prior art has proposed a simple but effective solution for the problem of water penetration into the jacket covering the insulation. For example, U.S. Pat. No. 3,153,546 discloses a jacket whose sections have overlapping connecting flanges formed with inter-engageable ribs and grooves, which direct water away from the insulation. This approach to solving the water penetration problem into the insulation is illustrated in FIG.  4 . 
     Grooves and ribs  18  and  20  conform to each other. When water gets under the overlaps, it runs into the ridge formed by the grooves and ribs and is guided down and out of the jacketing at the bottom. 
     In installing a jacket over an insulated conduit, it is important that the jacket tightly conform to the insulation. Whether the insulation is soft, semi-rigid or rigid, it has a large tolerance in its diameter. In order to tightly adjust the jacket over the insulation, the jacket also must have a large tolerance. A simple ridge system, such as illustrated in FIG. 4, does not allow for any adjustment of the jacket circumference and, therefore, cannot be used on rigid insulation. Even on soft fibrous insulation which can be somewhat compressed, the circumferential dimension of the jacket must be about the same as the circumferential dimension of the underlying insulation. 
     I have now discovered that adjustability can be built into jackets whereby the jackets can be tightly conformed to the underlying insulation. 
     FIGS. 5A-5D schematically show overlaps of jacket fittings having built-in ridges and matching grooves therein. The ridges and grooves allow incremental adjustments of the jackets. 
     FIG. 5A is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises two rounded grooves  2 A and  2 B in the top layer  22  of the overlap and one rounded ridge  32  in the bottom layer  30  of the overlap. Incremental tightening of the jacket is accomplished by sliding and moving either the top layer  22  or the bottom layer  30  so that ridge  32  is positioned into groove  28 . The distance denoted by the numeral  26  between grooves  25  and groove  28  can be of from about 0.25 to about 1.0 inch or more depending on the quality of firmness and diameter of the underlying insulation. This embodiment allows for only one incremental adjustment of the overlapping jacket. 
     FIG. 5B is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises three rounded grooves  36 ,  40  and  41  in the top layer  34  of the overlap and two rounded ridges  44  and  48  in the bottom layer  42  of the overlap. Incremental tightening of the jacket is accomplished by sliding and moving either the top layer  34  or the bottom layer  42  so that ridge  44  is positioned into groove  41 . It is to be noted that this embodiment of the invention includes, in addition to what is shown in FIG. 5A, a plurality of grooves and matching ridges so that the incremental adjustment of the overlap can be repeated several times as desired. 
     Similarly to that described in FIG. 5A, the distance between grooves, denoted by the numerals  38  and  39 , can be of from about 0.25 to about 1.0 inch or more depending on the quality of firmness and the diameter of the underlying insulation. The distance between ridges  44  and  48  is approximately the same or slightly less than the distance between the grooves. Also, as will be appreciated by those skilled in the art, it will be recognized that the ridges matching the corresponding grooves are just slightly less in size than the grooves so that the matching of the grooves and corresponding ridges will be easy. The height of the grooves and ridges are typically in the range of from about 0.125 to about 1.5 inches or larger, which is mostly by dependent on the environment in which the jacket is used: in an environment where heavy rain is prevalent, the grooves and ridges should be larger in size in order to direct large amounts of water away from the fitting. 
     FIG. 5C is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises two inverted V-shape grooves  52  and  56  in the top layer  50  of the overlap and one inverted V-shape ridge  60  in the bottom layer  58  of the overlap. Incremental tightening of the jacket is accomplished by sliding and moving either the top layer  50  of the bottom layer  58  so that ridge  60  is positioned into groove  56 . The distance denoted by the numeral  54  between grooves  52  and  56  can be of from about 0.25 to about 1.0 inch or more, depending on the quality of firmness and the diameter of the underlying insulation. This embodiment, similarly to the embodiment described with respect to FIG. 5A allows only for one incremental adjustment of the overlapping jacket. 
     FIG. 5D is a schematic representation of a jacket fitting having an overlap, wherein the overlap comprises three inverted V-shape grooves  64 ,  68  and  72  in the top layer  62  of the overlap and two inverted V-shape ridges  76  and  80  in the bottom layer  62  of the overlap. Incremental tightening of the jacket is accomplished by sliding and moving either the top layer  62  or the bottom layer  74  so that ridge  76  is positioned into groove  41 . It is to be noted that this embodiment of the invention, similarly to that described in FIG. 5B, includes a plurality of grooves and matching ridges so that the incremental adjustment of the overlap can be repeated several times as desired. 
     Similarly to that described in FIGS. 5A-5C, the distance between grooves denoted by the numeral  66  between grooves  64  and  68 , and the distance denoted by the numeral  70  between grooved  68  and  72  can be of from about 0.25 to about 1.0 inch or more, depending on the quality of firmness and the diameter of the underlying insulation. 
     FIG. 6 is a schematic representation of another embodiment of the present invention of a jacket fitting having an overlap, wherein the overlap comprises a generally flat, extended groove  84  in the top layer  82  of the overlap and a generally round ridge  88  in the bottom layer  86  of the overlap. This overlap allows for exact tensioning of the overlap over the insulation. The exact tensioning is accomplished by sliding the top layer  82  or the bottom layer  86  of the overlap so that ridge  88  moves within groove  84 . While this design allows for exact tensioning of the jacket, it does not provide for a wide range of tolerance. The range of tolerance of ridge  88  within groove  84  is typically of from about 1.5 to about 3.5 inches. This jacket design can, of course, be used on both sides, i.e., both halves of the jacket to allow double sliding movement of ridge  88  within groove  84 . 
     It is, however, preferred to use a combination of jacket design described in FIGS. 5A-5D with the jacket design described in FIG.  6 . The combination allows tightening of the jacket in large increments using the design of FIGS. 5A-5D, and then finally tensioning the jacket using the design described in FIG.  6 . The design of FIGS. 5A-5D is positioned on one side of the jacket and the design of FIG. 6 is positioned on the other side of the jacket. 
     The combination of the two types of design is shown in FIG.  7 . Forming the overlap with the combination of the designs, the jacket provides both a superior weather barrier and allows the jacket to be tightened snugly over the insulation. The combination design can be used for all types of insulation, including rigid insulation which has no “give” and requires the jacket to accommodate both large and small circumferences. By having the jacket fit snugly over the insulation, the rigid insulation is contained and supported by the jacket and better survives foot traffic without bending or denting the jacket. For maintenance purposes of industrial conduit when walking on the insulated and jacketed conduit, the jacket should be of metal, such as stainless steel or aluminum. 
     The method of installing jackets, metal or plastic, over insulations includes the step of: securing the jacket with sheet metal screws, evenly spaced in the overlaps, while the jacket is tightly held in place with “bungee type cords” or other devices that will tightly adjust the flaps of the jacket. 
     The jacket can also be held in place with metal bands or straps which are properly tensioned to tighten the jacket around the insulation. Both methods can be used singly or is in combination. 
     While the designs of jacket fitting illustrated in the drawings show fitting having approximately 45° angles, the designs include jacket fitting of 90°, Tees and vertical and horizontal straight run jacketings. 
     Having described the invention, it will be obvious to those skilled in the art that various modifications of the invention can be made without departing from the spirit and scope of the invention. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 PARTS LIST 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Assembly of metal pipe, insulation and 
                 10 
               
               
                 metal jacket (generally designated) 
               
               
                 Metal pipe 
                 12 
               
               
                 Insulation 
                 14 
               
               
                 Metal jacket 
                 16 
               
               
                 Metal jackets comprising two halves 
                 16A &amp; 16B 
               
               
                 Point of overlap between two halves 
                 P 
               
               
                 Grooves and ribs in jacket (prior art) 
                 18 &amp; 20 
               
               
                 Top layer of overlap 
                 22, 34, 50, 62 
               
               
                 Bottom layer of overlap 
                 30, 42, 58, 74 
               
               
                 Grooves 
                 24, 28, 36, 40, 
               
               
                   
                 41, 52, 56, 64, 
               
               
                   
                 68, 72 
               
               
                 Ridges 
                 32, 44, 48, 60, 
               
               
                   
                 76, 80 
               
               
                 Distance between grooves 
                 26, 38, 39, 54, 
               
               
                   
                 66, 70 
               
               
                 Distance between ridges 
                 46, 78 
               
               
                 Top layer of overlap 
                 82 
               
               
                 Flat, extended groove 
                 84 
               
               
                 Bottom layer of overlap 
                 86 
               
               
                 Round ridge to slide within flat, extended groove 
                 88