Abstract: A modular pipeline pig is formed of one or more driving cups and one or more scrapers, all joined together by flexible polymeric spool pieces. The scrapers include notches or cut-outs along their peripheral edges to bypass fluid. The driving cups, scrapers, and flexible spool pieces are joined together by metal bolts, the only metallic part of the pig. A flow path is provided through and around the pig to flush paraffin away from the pig when it is resident within a receiver so that the pig can be easily removed from the receiver without the laborious manual removal of the paraffin.

Abstract: A pipeline pig includes a plurality of inserts in spaced apart relationship around the periphery of a disk or a cup. The inserts are formed of a material that is compatible with the material of the pig, either the same material or a different material. Molded within the inserts are a random distribution of wear resistant material elements, i.e. a material that is harder than the material from which the insert is molded and harder than the material of the disk or the cup.

Abstract: A modular pipeline pig provides scraping cup having holes therethrough, adapted to retain a plurality of scraper studs. Positioned a well-defined distance behind the scraping cup is a driving cup defined by a slightly larger diameter than the scraping cup. The studs in the scraping cup may be of any appropriate shape or material, depending in the particular job. The driving cup is preferably mounted on the forward end of a mandrel, and another driving cup mounted to the back end of the mandrel. The pig is modular, so that other scrapers and or cups may be mounted to suit the needs of a particular job.

Abstract: A method of forming a pipeline pig in two or more steps is provided. Selected disks and/or cups, of selected size and hardness, are first formed. These disks and/or cups may include scraper disks, seal disks, flower petal disks, and/or cups in various sizes and hardnesses, in any desired permutation of these characteristics. The preformed pig components are then arranged with a plurality of mold pieces placed between the various disks and/or cups and then a second molding step is performed. The pig components which are formed in the first step preferably include a large central hole through which polyurethane will flow in the second molding step to form the mandrel. The pig components also preferably include a plurality of smaller holes radially spaced around the large central hole. The smaller holes serve to form a mechanically robust coupling between the pre-formed pig components and the polyurethane mandrel.

Abstract: A method of forming a pipeline pig in two or more steps is provided. Selected disks and/or cups, of selected size and hardness, are first formed. These disks and/or cups may include scraper disks, seal disks, flower petal disks, and/or cups in various sizes and hardnesses, in any desired permutation of these characteristics. The preformed pig components are then arranged with a plurality of mold pieces placed between the various disks and/or cups and then a second molding step is performed. The pig components which are formed in the first step preferably include a large central hole through which polyurethane will flow in the second molding step to form the mandrel. The pig components also preferably include a plurality of smaller holes radially spaced around the large central hole. The smaller holes serve to form a mechanically robust coupling between the pre-formed pig components and the polyurethane mandrel.

Abstract: The present disclosure sets forth a pipeline pig which is formed of two primary dimensions and two primary components. It is made with a set of N disks where N is preferably 6, 7, or 8 and the disks are all provided with a common thickness and common diameter. The thickness is about 10% of the pipe ID while the diameter is about 105% to about 110% of pipe ID. The excess size enables wiping of the inside surface of the pipeline. Importantly, when the disks are folded back, they are spaced sufficiently along the pig so that folded back disks each individually flatten and do not overlap so that folded disks are doubled; this avoids building up the diameter excessively during transition through a small ID opening.

Abstract: A bendable, unicast pig formed of polyurethane is disclosed. It has symmetrical front and rear end discs, seal discs there between and can wipe paraffin from a pipe. The body is devoid of intermediate discs to bend about 15.degree. or more.

Abstract: The present disclosure is directed to a pig for cleaning thin wall tubes in a heat exchanger which are subjected to internal deposits which become very hard with heating during use. The pig comprises an elongate central mandrel between front and back end pieces and supports a structurally defined carefully positioned disk. The disk in turn has a plurality of radially directed tapped holes evenly spaced therearound and the holes enable threading of a set of headed bolts in them. The length of the bolts is precisely controlled so that the outer exposed tip of the bolt head contacts the tube to scratch the interior to break the hard deposits without denting the surrounding tube.

Abstract: A tension leg platform in deep water over an underwater wellhead system supports an upstanding pig riser. The riser ID is smaller than the shoreline ID delivering produced oil to shore. The shoreline is pigged by a tapered nose pig inserted into the bell nipple at the top, open end to enable pig passage down the riser compressing the pig body. The body is formed of N discs and N foam donut spacers to clean the shoreline ID.

Abstract: The present disclosure sets forth both a method and apparatus for molding a unitary pig formed of two types of material, one being a light weight foam, and the other being a harder polymeric material thereby yielding a unitary harder material in the cast pig. The finished product involves N discs having parallel end faces and a central drilled core; the unitary cast harder material defines end located discs located adjacent to said foam core and a central core therein so that the end located discs adjacent to the foam donut are unitary with the core and bonded thereto.

Abstract: A foam pig body supports one, two or three helical coil strips. Each strip is formed of a backing and supports plural ridges. The ridges extend radially outwardly to clean the pipeline. The ridges are at right angles to the centerline axis of the foam pig body.

Abstract: The present disclosure sets forth a method of pigging a paraffin coated pipeline. It is scrubbed to dislodge a paraffin coating by sequentially passing through the pipeline subject to flowing oil pressure a sequence of pigs. The first pig has an elongate cylindrical body formed of very light foam of open cell construction, typically polyurethane, and subsequent pigs are formed of the same external pig body. In sequence, the pigs are provided with increasingly large central cores formed of a heavier foam so that the first central core has a diameter of about ten percent of diameter and the last approaches about seventy, but not one hundred percent of the diameter.

Abstract: A pipeline pig is disclosed, the preferred embodiment incorporating all plastic components including a central elongate mandrel being hollow along the middle to a forward transverse partition, a nut which threads to the forward end of said mandrel, said nut and mandrel locking together to secure components on said mandrel. The device further supports N cups, the cups preferably backed by adjacent discs for stiffening purposes and being spaced along the mandrel by spacer means. Scrapper discs can be used with the leading disc being harder & smaller while scrapping discs are softer and larger.

Abstract: A method and apparatus for installing optical fibers on a leader in plastic pipe are disclosed. In the preferred and illustrated embodiment for one type of plastic pipe having transverse corrugations, a pig is set forth which has a eyelet for connection with a towed leader, the eyelet being anchored at the nose. The pig body is constructed so that the nose is deformed as loading increases with length of leader, thereby swelling. This reduces blow-by and increases thrust force acting on the pig to overcome the increase in drag with leader length. An alternate embodiment shows an outer layer incorporating graphite or Teflon.RTM. particles in the outer layer to reduce friction. The pigs of this disclosure are adapted to be used in procedures involving corrugated plastic pipe and also plastic pipe having a smooth wall and spaced welded internal beads.

Abstract: Parafin scrapping, disc equipped, unitized pigs are disclosed. The leading disc is undergage by 0.01 to 0.05" and has a durometer of 85 to 95. N scrapper discs are included and have hardness between 65 and 75, and are overgage by a specific size. The pig is equipped with a rear disc similar to the leading disc.

Abstract: In the preferred and illustrated embodiment, an improved pig is set forth. The preferred version includes a body with a hollow cavity filled with foam. The body supports a number of encircling ribs for wiping the inside pipe surface. The internal foam filled cavity is exposed to pipeline pressure which enters through a constricted opening at the rear. In the event of a pressure surge, the fluid enters the pig with a pressure wave front, the pressure wave front being slowly propagated through the foam body. As the retarded pressure wave front moves through the body, the pig has sufficient time to move. Failure to incorporate this retardation of the propagated pressure wave front risks blowing out the nose of the pig.

Abstract: For use with a mandrel supporting a plurality of cups, an improved pipeline pigging cup is set forth in the preferred and illustrated embodiment. The cup is equipped with a large protruding lip around the periphery, and has a reinforcing member in the lip to secure the lip in a resilient fashion against the surrounding pipeline. The reinforcing member is formed of a strip of cloth backing with upstanding staples in the form of a multitude of small staple tips; the tips are arranged at or near the surface of the lip, thereby defining an abrasion resistant surface.

Abstract: An improved pipeline pig is described, there being alternate embodiments. The illustrated and preferred embodiment is a pipeline pig made of a foamed polyolefin, bullet-shaped body having a cylindrical outer wall and a strip of heavier density resilient material across the outer cylindrical wall. A stud having the form of an inverted screw or bolt with a pointed tip is placed in the pig body and protrudes at the strip. The strip reinforces the stud and helps hold it in position. The stud preferably has an enlargement near the bottom portions thereof which enables the stud to be firmly anchored in position. The tip of the stud breaks hard deposits accumulated on the wall of a pipeline and enables the pipeline pig to sweep the deposits away.