Abstract: An internal pipe powder coating system includes a nozzle having an attachment device to removably attach to a chamber; the nozzle having holes extending through a thickness of the body; a powder coating machine engaged with the chamber to deliver powder coating to the nozzle; the nozzle sprays the powder coating to an inside of a pipe.

Abstract: A tubing hanger assembly for suspending a tubing string within a wellbore. The tubing hanger assembly comprises a tubing head and a tubing hanger. The tubing hanger lands within the tubing head to gravitationally support a string of production tubing. The tubing hanger includes an auxiliary port extending from the upper end to the lower end. The auxiliary port receives unsheathed conductive wires from a power cable. To secure the conductive wires within the auxiliary port and to prevent shorting, the conductive wires are placed within a unique disc stack. The tubing hanger assembly further includes a bottom plate residing along the lower end of the tubular body and securing the disc stack. Thus, the tubing hanger assembly is arranged to receive a continuous power cable from a power source into the wellbore, through the auxiliary port, without the conductive wires being spliced.

Abstract: A pipe lining apparatus having a resin-impregnated reinforcement filament that is helically wound onto the inner surface of a tubular first lining layer disposed within a pipe by an inverted filament winding apparatus, the apparatus having a spring-loaded, articulated frame which maintains an orbiting applicator assembly.

Abstract: A pig system for transporting liquid or pasty substances two pig stations which are connected to one another by way of a pig line. The pig system includes a number of pigs. Accordingly, the two pig stations have a number of parking positions, to which a controllable media connection is respectively assigned. Appropriate activation of the media connections allows the effect to be achieved that only some of the pigs at a time shuttle back and forth between the two pig stations. Defective pigs or operational pigs that are being kept on standby in this case remain in corresponding parking positions of the two pig stations.

Abstract: A substrate processing apparatus includes a chamber including a process chamber for performing a process on a substrate by a gas introduced thereto and an exhaust chamber for evacuating the gas in the process chamber, a shield member for separating the process chamber from the exhaust chamber provided in at least a part of a neighborhood of a side wall of the chamber, and a hollow relay member penetrating through the shield member for communicating the chamber with a pipe connected to a pressure gauge outside the chamber. The relay member is configured to receive a first gas flowing from the chamber into the relay member. The first gas has a first conductance. The first conductance is greater than a second conductance of a second gas flowing from the exhaust chamber into a gap between the relay member and the side wall of the chamber.

Abstract: Described herein is a pipe cleaning apparatus of relatively uncomplicated construction. The apparatus includes a pipe support assembly having a number of cradles for supporting oilfield pipe. The cradles are positioned side-by-side with one pair of cradles supporting the opposite ends of each pipe. A number of lances are positioned side-by-side and are adapted to simultaneously penetrate the oilfield pipe in the pipe support. A mill is affixed to the free end of one of the lances. An air-driven tube cleaner is affixed to the free end of another one of the lances. A water jet nozzle is affixed to the free end of still another one of the lances.

Abstract: Processes and devices useful in the application of coatings (14) to the interior of tubes (10) are described. Such processes (40, 400) may include applying a layer (20) of coating fluid (18) to the internal surface (16) of the tube (10) and passing a smoothing member (22) through the tube (10) at a distance from the internal surface (16). The viscosity of the coating fluid (18) may be selected so that the layer (20) of coating fluid (18) has a thickness substantially equal to or in excess of a predetermined wet film thickness (Twf) correlated to a desired final thickness (Tf) of the coating (14). The distance between the smoothing member (22) and the internal surface (16) may substantially correspond to the predetermined wet film thickness (Twf). The smoothing member (22) may smooth the coating fluid (18) and remove coating fluid (18) in excess of the wet film thickness (Twf) from the internal surface (16).

Abstract: A pipeline pig for wetting the top inner surface of a pipeline comprising a pig body, one or more circular brushes attached to the pig body, and means for rotating the one or more circular brushes as the pig moves through the pipeline.

Abstract: Methods are provided for disinfecting water mains using ultraviolet (UV) light. One or more UV light sources are provided and secured to a movable device that moves axially in a pipe. The frequency and intensity of the UV light is determined based on characteristics of the pipe, such as its material and size. The rate at which the movable device moves through the pipe is also determined so that the interior surface of the pipe is properly disinfected. The movable device is remotely caused to move through the pipe.

Abstract: A silicon focus ring in a processing chamber of a plasma etching apparatus is provided. The silicon focus ring comprises: silicon wastes an amount of which is determined based on a content of impurity in the silicon wastes and a target value of an electrical resistance of the silicon focus ring; a silicon source material an amount of which is determined based on the content of impurity in the silicon wastes and the target value of the electrical resistance of the silicon focus ring; and impurity an amount of which is determined based on the content of impurity in the silicon wastes and the target value of the electrical resistance of the silicon focus ring. The target value of the electrical resistance of the silicon focus ring is about 2?.

Abstract: The present invention relates to coating of tubes, and more particularly to a system and method for coating and/or renovating deteriorated or pitted tubes to extend tube life and enhance performance. Using this system and method a thin coating is applied to the interior of a tube such that the coating is uniform in thickness and covers all regions of the tube. The coating material may be selected to minimize changes in heat transfer or may be selected to provide for the change in working fluid within the tube such that the working fluid does not negatively interact with the tube material.

Abstract: A focus ring is shaped by cutting off a silicon carbide body formed by a sintering method or a CVD method. The shaped focus ring is exposed to a plasma generated from at least one of a carbon tetra fluoride gas and an oxygen gas for producing impurities, and the impurities are introduced to void-like defects existing in the vicinity of a surface of the focus ring. Subsequently, positrons are injected in the vicinity of the surface of the focus ring into which the impurities are introduced, and the defect density in the vicinity of the surface of the focus ring is detected by the positron annihilation method.

Abstract: Methods and apparatus for applying a uniform application of an appropriate quantity of lubricant to the internal threads of a pipe. In general, the apparatus includes a high pressure supply of lubricant and a high speed, rotating centrifugal applicator for evenly applying the lubricant to internal threads. The system also includes a dosing system to regulate the distribution of lubricant by dispensing a consistent volume of lubricant at each application. Potential advantages of the embodiments include the repeatability and consistency of amount of lubricant on pipe threads (e.g. thickness).

Abstract: A method and apparatus is disclosed for remotely and robotically installing an organic, monolithic, structural and non structural, circumferential and partial radius membranes in conduits, pipelines or passageways. The included apparatus has the mechanical function to manually or automatically center the liner dissipation device in any geometrical shape. The included apparatus possesses the remote controlled capability to manipulate centrifugal dissipation of the liner to afford consistent thickness on any shaped profile or flat surface of the pipe wall surface. The apparatus includes a manual or automatic mechanical scissoring device for elevation changes and a manual or automatic rotational table for shaft alignment. The apparatus includes a means of automated self alignment by way of proximity sensors. The pendulum oscillation bracketing incorporates a fluid driven motor assembly communicating with a bored shaft and integrates as many as two offset dissipation devices.

Abstract: The present invention relates to coating of tubes, and more particularly to a system and method for coating and/or renovating deteriorated or pitted tubes to extend tube life and enhance performance. Using this system and method a thin coating is applied to the interior of a tube such that the coating is uniform in thickness and covers all regions of the tube. The coating material may be selected to minimize changes in heat transfer or may be selected to provide for the change in working fluid within the tube such that the working fluid does not negatively interact with the tube material.

Abstract: A method is provided for forming coatings on stents. The method comprises applying a coating composition to the stent; followed by terminating the application of the coating composition; followed by inserting a temperature adjusting element within the longitudinal bore of the stent to change the temperature of the stent.

Abstract: A method of manufacturing a reinforced tubular membrane comprises the steps of manufacturing the tubular support from monofilament thread, impregnating the support with membrane dope and adjusting the inner and the outer diameter of the membrane. A coating apparatus comprises a casting bob and an orifice to adjust respectively the inner and outer diameter of the membrane. A tubular reinforced polymeric membrane comprises a tubular support and membrane substance. The tubular support is made of monofilament thread and has a sufficiently open structure (openings larger than 0.1 mm). Touching and/or engaging parts of the thread may be linked prior to impregnating the support with membrane dope. The support may comprise loops of the monofilament thread, which are also linked.

Abstract: A method for continuously coating the inside of a continuously extruded hollow profiled bar made of elastic material and a liquid wiper and a device for removing excess coating agent from the chambers of a hollow profiled member. A hollow profiled bar is directed through a stationary supply of a liquid coating agent on a bent, arc-shaped track, whereby inner walls of the hollow profiled bar are moistened with coating agent, and the hollow profiled bar is guided along a rising track directly after running through the coating agent supply. Excess coating agent is wiped off one or plural inner walls with the aid of liquid wipers mounted inside the hollow chambers, the hollow profiled bar being continuously moved relative to the liquid wipers. The liquid wipers include at least one magnet or magnetizable material and a wiping lip that touches the inner walls while being located downstream of the coating agent supply in a zone of a sloped track of the hollow profiled bar.

Abstract: In a stator core having a plurality of teeth, which elongate in an inner radial direction and slots, which are configured among the teeth, powder is caused to adhere to the stator core, the powder adhering to an inner peripheral face of the stator core is removed, and the stator core is heated to melt and harden the powder.

Abstract: The invention concerns a pig scraper for cleaning the inside wall of a coating agent conduit. The pig scraper includes a body insertable in the conduit and at least one sealing lip that seals against the inside wall of the conduit and extends parallel to a longitudinal axis of the body. A space is defined between the sealing lip and the body to form a pocket for enhancing the sealing of the sealing lip with respect to the conduit. The length of the sealing lip substantially prevents the lip from folding over on itself in response to a change in the direction of movement of the pig scraper in the conduit.

Abstract: A pig for use with a tubular bore wherein the pig is comprised of a body which supports a plurality of turbine blades wherein the blades mechanically break down and remove debris from the tubular bore. The blades have a profile which allows forward movement and rotation about a longitudinal axis when acted upon by a propulsion fluid traveling through the tubular. In an alternative embodiment the blades are mounted on a stabilizer body to allow simultaneous centralization and cleaning.

Abstract: The inventive method for protecting from corrosion and scale deposit and restoring tubes of heat-exchanging equipment consists in applying a polymeric coating on the internal surface of tubes by gradually and rotationally moving an excessive volume of polymeric material therealong and in hardening said material. A polymeric compound having an at-rest viscosity ranging from 1000 to 1200 poises and a thixotropic viscosity reduction during the displacement thereof is used as a polymeric material. The inventive device for carrying out said method comprises a loading chamber (2), a connecting washer (12), a unit for progressively displacing the polymeric material provided with spaced rigid washers (4,5,6) fixed to a metallic rod (7), an elastic screw (8) having a conical shape whereby the conicity thereof ranges from 5 to 10° on the side which is opposite in relation to the connecting washer.

Abstract: A cleaning brush and method for removing a coating solution from the inner end of a flexible, tubular substrate to be fitted over a mandrel or drum. After a tubular substrate is dipped endwise in a coating solution, some solution coats the inner face of the substrate at one end. By using moderate deformation of the substrate, changes to the profile of the cleaning brush, or both, the cleaning brush is fitted inside the end of the tubular substrate without damaging the substrate. The cleaning brush engages and cleans the substrate's inner surface. The substrate is then free from any coating so as to readily fit on the mandrel or drum.

Abstract: An improved shaft is described with which a sponge saturated with carbon coating can be pushed through the narrow neck of a cathode ray tube funnel to fully coat the interior of the neck with the carbon coating. The improved shaft is made of a plastic composite material. The preferred material for the improved shaft is garolite. This improved shaft is much less expensive that previous stainless steel shafts and has enough flexibility that it is not easily bent when plunged into a funnel that is not properly aligned and centered under the shaft.

Abstract: An inside wall of an elongated syringe body is coated by supplying at least an outer surface of an applicator ring with a coating of silicon oil while displacing a rod carrying the coated ring from a rear end to a front end of the body with the ring in continuous annular engagement with the inside wall thereof so as to transfer the oil from the ring to the inside wall. Thereafter a scraper ring also carried on the rod is displaced from the front end to the rear end of the body with the scraper ring in continuous annular engagement with the inside wall so as to scrape excess silicone oil from the inside wall.

Abstract: Device for introducing a coating into pipes and pipe bends and, more generally, into rotationally symmetrical bodies open at only at least one end, with an elastic, elongate, inflatable core (12), the so-called “variocore”.

Abstract: A system for removing resin from the stator core of a stator of a motor involves means for removing resin (1) from an inner circumferential surface surrounding the bore of the stator core; (2) from the outer circumferential surface of the stator core; and (3) from between the windings along the end surfaces of the stator core. The circumferential surfaces have resin removed from them by moving the surfaces relative to a series of wipers. The wipers push the resin off the surfaces as they sweep the surfaces. Resin is removed from the end surfaces by blowing the resin radially inward, where it either drips off the core or is deposited on the inner circumferential surface, from which it is removed by wipers.

Abstract: Tubelining device and technique using a coating-applicator for slip-casting a fluent liner coating onto the internal surface of a tube.

Abstract: A segmented squeegee blade is provided for optimizing the flow of a depositable material such as viscous liquid or flowable medium such as solder paste, adhesive, or the like through a stepped stencil onto a substrate. The blade has a plurality of segments adapted for substantially independent deflection with respect to each other. The blade segments deflect and conform to a stepped surface or stencil to provide for more consistent deposition of flowable material. The squeegee blade also is adapted for use with stencils having more than two step levels. The segmented squeegee blade enables component density to be increased as compared to conventional methods.

Abstract: An increased efficiency method and apparatus for lining a section of pipe with a cement mortar. After a wet cement mortar has been applied to a cleaned interior surface of a pipe, carbon dioxide is introduced into the freshly lined section of the pipe in such quantity that a crust of calcium carbonate will be formed on the interior surface of the wet cement mortar lining as the carbon dioxide reacts with calcium compounds of the wet cement mortar in a relatively short period of time. This crust is provided to protect the underlying mortar from scouring, while tolerating a low-velocity flow of water, until the normal hardening of the underlying mortar through hydration can take place so as to substantially reduce the out-of-service time of the section of pipe which is being lined.

Abstract: An improved method for impregnating a tubular lining material with a hardenable liquid resin employed in a pipe repair operation by lining the pipe internally with the lining material; the method comprises (a) supplying about the same amounts of the same hardenable liquid resin to two mixing baths, (b) mixing the hardenable liquid resin with an agent to retard hardening and another agent selected from catalyst to facilitate hardening and hardener in one of the mixing baths, and, at the same time, mixing the hardenable liquid resin with a hardening accelerator in another one of the mixing baths, (c) supplying predetermined amounts of these mixtures to a static mixer from the respective mixing baths, (d) mixing these mixtures together in the static mixer to obtain a final mixture of hardenable resin, (e) supplying the final mixture to the tubular lining material, and (f) impregnating the tubular lining material with the final mixture.

Abstract: The invention relates to a chimney lining device which includes a shell member which telescopically embraces the exterior of a bell member. A shell member of desired dimensions may be used in conjunction with a standard sized bell member for the lining of various sized chimneys. Both the bell member and the selected shell member are formed of one-piece construction enhancing the durability and performance of the chimney lining device. During use, the invention is generally lowered to the bottom of a chimney whereon a masonry mortar compound is deposited within the chimney covering the chimney lining device. The chimney lining device is then activated causing the vibration of the bell member and the shell member. The chimney lining device is then slowly raised within the chimney, which causes a uniform and compacted thickness of masonry mortar compound to be deposited to the interior walls of the chimney.

Abstract: There is disclosed a method for coating an interior surface of an elongated pipe member. The method uses a first plug member having a resilient cylindrical body with an outer diameter close to an inner diameter of the pipe member, and a second plug member having a cylindrical body of an outer diameter smaller than the inner diameter of the pipe member and a brush provided at an end portion of the body of the second plug member, the brush having radially outwardly extending fibers having radial outer ends defining a cylindrical surface of which diameter is close to the diameter of the pipe member.

Abstract: A method for forming cementitious material, such as gunite or the like, to a desired cross-sectional profile for an interior structure such as a swimming pool, skateboard bowl or the like. A forming assembly includes a cutting edge, which is formed so as to correspond to the final desired profile of the structure. The forming assembly is mounted so as to be pivotable about a pivot axis substantially coincident with the center of the structure being formed. In this manner, when the cementitious material is applied to the side walls and bottom of the excavation to a depth slightly greater than that as finally desired, and the forming assembly pivoted 360.degree. about its pivot axis, the final desired cross-sectional profile of the structure is attained due to the action of the forming assembly striking off the excess material applied to the excavation.

Abstract: A system for pipe lining including a forward seal and a following spreader defining a chamber therebetween for receiving flowable lining material. The spreader is immediately followed by a cylindrical elongate platen formed of radiant-energy transparent material. A radiant energy source is mounted in the platen for transmission of radiant energy through the platen and into the lining material simultaneously with the forming of the lining material into position by the platen as the apparatus moves along the interior of the pipe.

Abstract: A method for lining the inner surface of a generally cylindrical member or domed cylindrical member with an elastomeric material. A let-off head is provided within the member for applying a continuous strip of tacky elastomeric material to the inner surface thereof as it rotates. The head is moved axially as the strip is applied to form a layer of elastomeric material over the inner surface. After the head is removed, the applied elastomer material is cured.

Abstract: A method of lining a pipe comprises the steps of laying hose means along the bottom of a pipe to be lined, the hose means having been filled with a predetermined quantity of settable lining composition, anchoring the hose means at each end along the bottom of the pipe, advancing a centrifugal lining machine along the length of the hose means, slitting the hose means in front of the advancing centrifugal lining machine to permit egress of the lining composition from the hose means, and delivering the admixed settable composition to a centrifugal impellor of the centrifugal lining machine for application of the settable composition to the pipe wall as the centrifugal lining machine advances along the pipe. The method is characterised by the step of guiding the slit and emptied hose means through an axial bore in the centrifugal lining machine to lie in a flattened condition on the bottom of the lined pipe wall rearwardly of the centrifugal lining machine.

Abstract: The device consists of a mastic material-filled pipe (27) set in a cylinder (24) which is revolvable around its longitudinal axis and secured there against displacement by means of locks (30). Inside the pipe (27) is a piston (31) which is acted upon by a conduit (33) with compressed air. On the free end of the pipe (27) is a mastic spreading device (41) which is locked to the pipe. The piston (31) forces the material out of the pipe into the mastic spreading device which is revolvable together with the pipe around the longitudinal axis thereof. Once the mastic spreading device (41) has been fully emptied, it is removed from the pipe (27) and the latter is separated from the cylinder (24). The empty pipe is replaced by a full pipe and the mastic spreading device is again attached to the latter. In this way the device is again ready for use within a short time.

Abstract: A carriage (1) is guided coaxially to the axis (11) of a pipe (9) to be repaired by two sets (2, 3) of sprung rollers (4, 5). The carriage supports a drive motor (28), on the drive shaft (29, 30) of which is fixed a distributor means in the form of rollers (41). Coating material, for example a pressure setting plastic, is applied via a supply pipe (45) to the underside of the pipe wall (8) and is distributed by the turning rollers (41) over the circumference. In this way damaged sewer pipes can be correctly coated with small effort.

Abstract: A device for coating the internal surface of a pipeline with a cement-sand mixture, includes a mechanism (1) for applying a coating, systems (2 and 3) of feeding the cement-sand mixture and the working medium, hoses (4 and 5) a pull rope (6) and a winch (7). Wound on the shaft (8) of the winch drum (7) are the pull rope (6) and the hoses (4 and 5), some ends of which pass through the cavity of the shaft (8) and communicate through the supporting assemblies (11) of the shaft with respective systems (2 and 3) for feeding the mixture and working medium, and the other ends of which are connected to the mechanism for applying a coating. A joint winding or reeling off of the hoses (4 and 5) and the pull rope (6) make it possible to substantially streamline the maintenance of the device, as well as freely pass the working medium and the cement-sand mixture and water for washing the hose (5) through the hoses.

Abstract: A method of lining pipes comprises the steps of laying along the pipe (56) hoses (63) filled with constituent components of a settable resinous lining composition, axially slitting the hoses, conveying the constituent components to a mixing chamber (65), and centrifugally impelling the mixed lining composition against the wall of the pipe (56). A lining apparatus (50) for carrying out the method is advanced along the pipe (56) and comprises delivery tubes (62) with slitting blades (70) at their leading ends which are pushed through the holes (63) and which communicate with a mixing chamber (65) which, in turn, is open to a centrifugal impeller (57) of a lining machine. The slit and emptied hoses (63) may be left in situ in the pipe (56) or removed therefrom in advance of the lining apparatus (50). A trowelling arrangement using a thin-walled, flexible tube (112) of, for example, a cellulose polymer and a conical trowel (112) is employed to smooth the pipe lining.

Abstract: A method of cladding an internal cavity surface of a metal object is disclosed. The method includes the steps:(a) applying a powder metal layer on said internal surface, the metal powder including metal oxide or oxides, borides and carbides,(b) filling a pressure transmitting and flowable grain into said cavity to contact said layer,(c) and pressurizing said grain to cause sufficient pressure transmission to the powder metal layer to consolidate same.

Abstract: A linear material 20 is once wound on a winding drum 22, and then wound on a winding core 11a by a winding disk 21. The winding disk 21 periodically reverses the direction of rotation. During the winding operation, the linear material is impregnated with a synthetic resin.

Abstract: A system for repairing joints in pipes laid underground, such as gas pipes, in their buried state, from their inside, to ensure their sealing.The system, in the process of pushing the resin used for repairing along the inside of the pipes by the pig, is to fill and seal the sealing material with the resin through gaps in numerous pipe joints inside of the pipes. In order to guarantee insertion of resin into gaps in the pipe joints (sealing material) whether or not the pipe joint has developed a leak, the system comprises a substitution pig, and a means whereby the pig pushes the resin placed ahead of it along the pipe, and further, a means whereby the filling amount of the resin does not change even if the amount of resin present in front of the pig differs between the early and later stages of the repairing operation, gaps in the pipe joints will be uniformly filled.

Abstract: The invention relates to a method of coating a surface of a fiber blanket comprising forcing a plurality of probes through the fiber blanket until the probes extend beyond the surface to be coated, so that holes are formed in the fiber blanket, applying fluid coating material on the surface to be coated, retracting the probes from the fiber blanket, allowing the coating material to flow into the holes during the retraction of the probes, forming heads of the coating material at the uncoated surface of the fiber blanket, and allowing the coating material to harden. The invention relates moreover to an apparatus for carrying out this method. The coated fiber blanket obtained by the method according to the invention has the advantage that the hardened layer of coating material is firmly anchored to the blanket.

Abstract: A trowel for smoothing mortar coated on the interior wall of a pipe, including an elastic member for receiving pressurized air and inflating to a diameter less than the interior of the pipe. A blade assembly is connected to and extends from the elastic member, and defines an outer circular surface substantially corresponding to the coated interior diameter of the pipe for engaging and smoothing said mortar. The blade assembly is constructed and arranged to accommodate variances in the inner diameter of the pipeline.

Abstract: Apparatus for gripping a tire bead, moving the tire vertically and axially over an extruder nozzle die to a position within the tire chamber where a continuous extruded strip is applied to an inside surface of the tire as the tire is rotated. The extruded strip may be applied in a plurality of side-by-side turns connected by angular portions provided by axial indexing of the tire in a predetermined amount for a predetermined time. Means are also provided for spreading the tire beads and pressing the strip against the tire surface without interfering with the movement of the tire over and around the extruder nozzle die.

Abstract: A process and apparatus for coating the interior of a fiber-reinforced tube formed of cellulose hydrate in which a tube filled with a coating liquid is passed through a special conveying and pumping device which also serves to replenish the coating liquid. Above the level of the coating liquid, the tube is inflated with a support gas and is gradually flattened. The flattened tube then travels through a metering device made up of wipers in the form of doctor blades or rollers, which retain the major quantity of the coating liquid which is present on the inside surface of the tubing so that a thin, uniform film of the coating liquid is formed. The tubing is thereafter dried to remove the volatile constituents of the coating liquid, and is subsequently wound up.

Abstract: An apparatus and method for applying an adhesive to the edge of the can by inserting the can into the adhesive to its top surface and rotating the can 360.degree. or more, then past the edge of a doctor roll to remove excess adhesive in a selected region and then advancing the cans through an induction heater in a continuous motion until the can reaches a discharge station where it is released.

Abstract: A pipeline pig for lining pipe lines with an internal coating of a solidifying plastic composition with which the pipe line is spread by means of the pig, the pipeline pig having at least one spreader body and at least one forward and one rear guide body. The guide body comprises at least three narrow, resiliently elastic guide pieces bent into U-form comprising a middle part with forward and rear U-legs at the ends and rounded transitions from the middle part to the U-legs, the middle parts extending in the axial direction of the pipeline pig for guidance of the pipeline pig in the pipe line by abutment on the inner wall of the pipe line and being offset in relation to one another in the circumferential direction, the forward U-legs being non-displaceably secured in the axial direction in the pig and the rear U-legs being displaceably mounted in the axial direction in the pig and secured to a common bearing.