FOR PROTECTING COATED PIPE

INVENTOR(S)

[0001] Christopher L. Work, Kevin B. Inglehart, and M. Derek Birdwell, all residents of the City of Jacksonville, in Cherokee County, Texas, United States of America, and all citizens of the United States of America.

TECHNICAL FIELD OF THE INVENTION

[0002] The present invention relates in general to protective coverings for underground pipes, and in particular to a protective wrap for protecting buried coated pipe.

CROSS-REFERENCE TO RELATED APPLICATION

[0003] The present application is a continuation-in-part of U.S. patent application Serial No. 14/807815, filed July 23, 2015, and entitled "Covering for Underground Pipes and Related Methods." BACKGROUND OF THE INVENTION

[0004] Protective wraps have been provided for covering buried pipes to prevent damage to coatings for the pipes caused by crushing against rocks in the soil or rubbing against abrasive bedding materials. A problem arises with protective wraps used in underground installations for protecting coated when the protective wraps interfere with cathodic protection systems deployed to prevent pipe corrosion. In such systems, conductive metal pipes are included as cathodes for electrolytic cells and are electrically connected to sacrificial anodes. Such cathodic protection systems require that an electric circuit be completed from the sacrificial anodes, through the metal pipes, and back to the anodes through the soil. A non-conductive wrap can act as a moisture barrier, breaking a cathodic protection circuit by preventing current from flowing through the soil between the protected metal pipe and the sacrificial anode, defeating

conventional cathodic protection systems. Pipes used for underground installation are typically coated with an epoxy or plastic material. If the coating delaminates from the surface of the pipe, moisture will typically migrate between the delaminated coating and the surface of the pipe setting up a small electrolytic cell and corrosion of the pipe will occur when cathodic protection systems are rendered ineffective. A need exists for a protective wrap for underground pipes that is inexpensive and can be readily installed at a job site, and which does not interfere with conventional cathodic protection systems.

SUMMARY OF THE INVENTION

[0005] A protective wrap-type covering for underground pipes is provided by a rectangular sheet of a flexible waterproof protective material capable of being wrapped around a pipe. The rectangular sheets have markings near the edges of the length of the rectangle which are fixed and equidistance from one another. In a preferred embodiment, the rectangular sheets are 22 to 26 feet wide, cut to a desired diameter in the field, 400 feet (122 meters) long, 80 mils (2.03 mm) thick, with perforations having a diameter of approximately 3/16 inches (4.8 mm). The rectangular sheets are preferably formed of 40 mil (1.02 mm) to 120 mil (3.05 mm) low density polyethylene sheets and have fluid communication perforations on 25 mm (one inch) centers, both longitudinally and laterally spaced, and preferably ranging in diameter from approximately 1/16 inch to 5/16 inch (1.5 mm to 8 mm), allowing moisture to contact the coated pipe to provide current paths between the coated pipe, the soil and sacrificial anodes of cathodic protection systems. For thicker sheets, perforation diameters may be sized to approximately ½ inch (12 mm). A method is provided for protecting an underground pipes comprising:

unrolling a roll of a flexible covering; placing the unrolled flexible covering adjacent to the pipe to be wrapped; wrapping the flexible covering around the pipe so that the diameter of the pipe is perpendicular to the length of the covering; securing the covering to the pipe using cable ties to wrap around a respective circumference of the pipe. Mounting holes are provided in the protective cover for receiving the cable ties, preferably with respective rows of mounting holes extending around a respective circumferences of the pipe for weaving cable ties through mounting holes in a selected row and about a respective circumference of the pipe.

DESCRIPTION OF THE DRAWINGS

[0006] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying Drawings in which FIGS. 1 through 4 show various aspects for a protective covering with moisture apertures for underground pipes devices made according to the present invention, as set forth below:

FIG. 1 is a partial perspective view of a protective cover that has been laid flat;

FIG. 2 is a partial perspective view of a pipe that has been wrapped with the protective cover;

FIG. 3 is an environmental view of a coated pipe wrapped with the protective covering; and

FIG. 4 is a perspective view of a cable tie used to secure the protective cover.

DETAILED DESCRIPTION OF THE INVENTION

[0007] FIG. 1 is a partial, perspective view of the preferred embodiment of a protective covering 100. FIG. 1 shows the covering 100 after it has been unrolled and laid flat. The covering 100 preferably will be made and sold in rolls, so it can easily be transported to and from a job site, with te rolls suspended from yokes which allow the protective covering to be applied to a long pipe section, up to 400 feet (122 meters) long. A longitudinal axis 114 runs the length of the covering 100, perpendicular to a later direction or width of the covering 100. The covering 100 is preferably a sheet of low density polyethylene, but may also be a different pliable polymer, such as high density polyethylene. In some embodiments, the covering 100 may be provided by composite layers of polyethylene, or other flexible polymer, having a central layer providing a pliable core, such as that provided by having a honeycomb structure. Preferably, the protective cover 100 is a layer of low density polyethylene having a thickness of 80 mils (2.03 mm), but other thicknesses maybe provided such as those within a range of 40 mils (1.02 mm) to 120 mils (3.05 mm). The width of the cover 100 is based on the diameter of the pipe to be covered, which often range in size from sixteen inches (40 cm) to forty-two inches (107 cm). The width is cut from rolls of polyethylene sheets measuring from 22 feet to 26 feet (6 meters to 8 meters), by 400 feet (122 meters) in length.

[0008] Still referring to FIG. 1, the preferred embodiment of the covering 100 features mounting holes 110 which are preferably 5/8 inches (16 mm) in diameter and spaced apart in rows 6 inches in a lateral direction, which defines the width of the covering 100, which is perpendicular to the longitudinal axis 114. The rows are preferably spaced apart 3 feet along the longitudinal axis 114 of the protective cover 100. The mounting holes 110 assist with the installation process and accommodate cable ties (see FIG. 2, element 200; see also FIG. 4, element 200). Cable ties 200 are woven into respective ones of the rows of mounting holes 110, alternative passing above and beneath the protective covering 100 at adjacent ones of the mounting holes 110 in a row circumferentially extending around the coated pipe being covered. The mounting holes 110 may be located on one end or both ends of the covering 100. In some embodiments, instead of holes, the covering 100 may feature guide markings preprinted on the covering. In other embodiments, the covering 100 may feature extruded holes or an adhesive for zip ties to be inserted into the covering 100. The covering 100 may also be clear and

transparent to see engineering numbers and locations of welds.

[0009] The protective cover 100 is preferably a rectangular sheet which is perforated with an array of fluid communication perforations 112 to allow moisture to pass for completing an electric circuit for cathodic protection. The perforations 112 preferably through-holes, extending fully through the protective cover 100, and have a diameter of approximately 4.8 mm (3/16 inches). The rectangular sheets 100 are preferably formed of 40 mils (1.02 mm) to 120 mils (3.05 mm) low density polyethylene sheets and have perforations on approximately 25 mm (one inch) centers, both longitudinally and laterally spaced, and preferably ranging in diameter from approximately 1/16 inch to 5/16 inch (1.5 mm to 8 mm), allowing groung moisture to pass through the protective cover and contact the coated pipe to provide current paths between the coated pipe, the soil and sacrificial anodes of cathodic protection systems. For thicker sheets, perforation diameters may be sized to approximately ½ inch (12 mm). In some circumstances, larger spacings may be use between the fluid communication perforation 112 than one inch (24 mm) centers.. In some embodiments, interior layers of the rectangular sheets are conductive, provided by mixing graphite or carbon black with the polyethylene resins during manufacture, and larger spacing and smaller holes may be used. In some embodiments, the rectangular sheets may be formed of two more plies of low density polyethylene sheeting, with one of the layers being expanded or of a honeycomb shape to provide resiliency to protect against the pipe coating being crushed.

[0010] FIG. 2 is a perspective view that shows that covering 100 after it has been applied to a pipe 300. In the preferred embodiment, the covering 100 fully surrounds the diameter of the pipe 300 with little or no overlap. The covering is held in place with the use of cable ties 200. The cable ties 200 are inserted into the holes 110 of the covering 100 and fastened securely

[0011] FIG. 3 shows an environmental view of a covered pipe 300 in the ground 400. As depicted in FIG. 3, the ground 400 features hazards such as rough terrain and rocks that can potentially damage the pipe 300.

[0012] FIG. 4 is a perspective view of a cable tie 200. The cable tie 200 features a strip 220 and a clasp 210. The strip 220 is preferably made from nylon, but can be made from another polymer. In the preferred embodiment, the strip 220 is 0.036 inches thick and one half inch wide. The strip 200 preferably is made in fifty, one hundred, or two hundred foot rolls and can be cut to a custom length. The cable tie 200 features a clasp 210. The clasp 210 is preferably a one-way double locking head with stainless steel locking teeth that offers four hundred pounds of tensile strength. The cable tie 200 will lock the covering 100 tightly in place and will not stretch or slide.

[0013] In an alternate embodiment, the cable ties may be embedded along the covering 100 or pre-installed into the holes 110 of the covering 100 in order to make installation easier. A protective cover 100 with an array of fluid communication perforations 112 may also be used for non-coated conductive pipe protected by cathodic protection systems.

[0014] In one embodiment, the protective covering 100 is applied to a pipe 300 by a user first rolling out the covering 100 so that it is laid flat. If needed, the user may have to cut the covering 100 to the desired length. The user then wraps the covering 100 around the diameter of a pipe 300. The protective cover 100 may be laid over the pipe to be covered in roll form, using a yoke suspended from a crane, host, or the like, to hold the roll above a section of the pipe and spool the protective covering 100 out over the pipe. The user secures the covering 100 to the pipe 300 by encircling the covered pipe 300 with a strip 220 and tightly securing the strip 220 with a clasp 210. In some embodiments, the user will weave the strip 220 through at least one hole 110 on one or both sides of the covering 100. The user will continue to secure the covering 100 onto the pipe 300 by placing cable ties 200 approximately every three feet (91 cm) until the user reaches the end of the pipe 300.

[0015] Although the preferred embodiment has been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.