Abstract: An elongate deformable conduit and method of fabrication thereof adapted for the subterranean conveying of petroleum products and petrochemicals has an inner copper tube to which is bonded an outer layer of flexible polyvinyl chloride up to about one-third inch in radial wall thickness. In a preferred embodiment the polyvinyl chloride contains an ultraviolet stabilizer and is extruded in a wall thickness up to about one-tenth inch about the copper tube, and the copper tube has an outside diameter ranging up to about two inches and is sized to convey heating oil substantially below ground.

Abstract: A tube for fuel transportation according to the present invention includes an innermost layer comprising one selected from the group consisting of fluorine type resins and polyamide type resins, a middle layer comprising a polyalkylene naphthalate resin, an outer layer comprising a thermoplastic resin or a thermoplastic elastomer, and an adhesive layer formed between the innermost layer and the middle layer. Polybutylene naphthalate may be used as the polyalkylene naphthalate resin. The tube for fuel transportation according to the present invention has excellent barrier action against fuels and is highly kink-proof.

Abstract: A refrigerant conveying hose, being wholly made of a synthetic resin, is formed of an inner tube forming an inner side layer, an intermediate layer on the outer periphery surface of the inner tube, a fiber reinforced layer on the outer periphery surface of the intermediate layer and an outer tube forming the outer covering layer.

Abstract: A method and apparatus for relining, repairing or reconstructing existing infrastructure pipeline systems that are new, structurally deficient or experiencing an excessive amount of exfiltration or infiltration, or converting new or damaged pipelines into dual-containment pipelines. A plurality of stock, high density polyethylene lining pipes having a cylindrical cross-section with a diameter up to 36 inches and lengths of 40-50 feet are joined together to a job specific length. The lining pipe is then heated to its flex temperature and gradually deformed to a reduced diameter. At the job site, the deformed lining pipe is inserted into the existing pipe and a controlled, pressurized environment is created therein for a period of time dependent on the pipe's length. Pressurized steam is first inserted to provide heat and internal pressure to expand the pipe. Then, compressed air is inserted to cool the pipe while maintaining the internal pressure to complete the expansion and set the pipe.

Abstract: Polyamide-based petrol supply tube, especially for engines, characterized in that it comprises an outer layer of polyamide, a middle layer of fluoropolymer, preferably of PVDF, and an inner layer of polyamide, these layers being respectively bonded to each other by layers of adhesive bonding agent.

Abstract: A method of producing large-diameter helical pipes for plastic synthetic resins wherein the pipe has an outer layer comprised of a first plastic resin and an inner layer comprised of a second plastic resin. In a particularly preferred embodiment, a helical pipe having an outer layer which is an ultraviolet light-protective color and an inner plastic layer which is a light-reflecting color is provided.

Abstract: A multi-layer tube comprises a metal tube having an outer surface and a zinc layer bonded to the metal tube outer surface, wherein the zinc layer is selected from the group consisting of zinc plating, zinc nickel alloys, zinc cobalt alloys, zinc aluminum alloys, and mixtures thereof. A surface treatment layer is bonded to the zinc layer, wherein the surface treatment layer is selected from the group consisting of a zinc/aluminum/rare earth alloy, phosphate, chromate and mixtures thereof. A first polymeric layer is bonded to the surface treatment layer, wherein the first polymeric layer is selected from the group consisting of a thermoplastic elastomer, an ionomer, a nylon, a fluoropolymer, and mixtures thereof. A second polymeric layer is bonded to the first polymeric layer, wherein the second polymeric layer is selected from the group consisting of a nylon, a thermoplastic elastomer, a fluoropolymer, and mixtures thereof.

Abstract: An elongated multi-layer tubing is disclosed for connection to a motor vehicle system to handle fluids containing hydrocarbons. The tubing includes a first layer disposed radially innermost and having an inner surface capable of prolonged exposure to a fluid containing hydrocarbons and an outer surface spaced a first predetermined radial thickness from the inner surface, the first layer consisting essentially of an extrudable, melt-processible thermoplastic. The tubing also includes a second layer having a second predetermined radial thickness at most equal to the thickness of the first layer. The second layer is uniformly and homogeneously connected to or bonded to the first layer and consists essentially of an extrudable, melt-processible thermoplastic capable of sufficiently permanent laminar adhesion with the first layer to prevent delamination during a desired lifetime of the tubing. At least one of the first and second layers is resistant to permeation by hydrocarbons.

Abstract: A coated metal tubing arrangement comprises a metal tube. An inner layer of a first polymeric material is bonded to the tube to provide corrosion protection. The first polymeric material has a high crystallinity, a dampening factor of less than 0.05, and a flexural modulus of at least 100 MPa. An outer layer of a second polymeric material is extruded around the inner layer to absorb impact energies and to eliminate mechanical vibrations and acoustic noises. The second polymeric material has a dampening factor of at least 0.05 and a flexural modulus of less than 50 MPa. The second polymeric material is a multi-phase polymer having at least one polymer component with a glass-transition temperature below room temperature.

Abstract: An improved conduit for transporting fuel and/or fuel vapor or a motion transmitting member in an automobile comprising an inner tube comprised of fluorocarbon polymeric material and having an inner surface for contacting and containing fluids or a motion transmitting member, and a chemically etched outer surface having a substantial portion of the fluorine of the fluorocarbon polymer substituted by a polar moiety. The conduit further includes an outer tube comprising an inner surface comprised of polymeric material containing sufficient polar groups such that hydrogen bonding at the interface between the outer surface of the inner tube and the inner surface of the outer tube prevents substantial relative separation of or movement between the inner and outer tubes.

Abstract: A polymeric, multiple-layer tube suitable for use as a filler neck is disclosed. The tube is comprised of a generally cylindrical wall having an outer surface and an inner surface. The inner surface is approximately parallel to the outer surface and defines a generally cylindrical interior having a diameter D. The cylindrical interior, which provides a flow path for fuel, extends throughout the length of the tube. The tube is divided into one or more contiguous first and second longitudinal segments. In the first longitudinal segment, D is approximately constant along the length of the segment; in the second longitudinal segment, D varies with axial position. This variation defines a convolution, which allows the filler tube to be bent without crimping. The cylindrical wall of the multiple-layer tube further comprises an outer layer composed of a thermoplastic elastomer, and an inner layer composed of an extrudable melt-processible thermoplastic having an elongation of at least 150%.

Abstract: The composite duct system includes a first, duct portion; a second, duct foam portion; and, a third duct portion. The first duct portion has a first surface for permitting a flowable medium to be conveyed adjacent thereto, and a second surface. The first duct portion is formed with a first fiber reinforced resin system. The second duct foam portion has a first surface bonded to the second surface of the first duct portion. The foam portion is formed of fire retarding material derived from a resin system. The third duct portion has a first surface bonded to a second surface of the foam portion. The third duct portion is formed of a second fiber reinforced resin system. Thus, a system is created having an internally sandwiched foam insulation.

Abstract: The present invention provides a corrosion- and chipping-resistant resin coating structure for stainless steel pipes with a small diameter and thin wall. The coating structure comprises a stainless steel pipe (1) and a polyolefin or polyamide layer (4) formed on the outer surface thereof. In a preferred embodiment, the coating structure further comprises an adhesive layer (2), a fluoroplastic layer (3), and a polyamide adhesive layer (5). The coating structure exhibits good resistance to corrosion with mud and chipping by splashed pebbles.

Abstract: Provided is a pipe and pipe liner composition including PVC, a PVC-hydrogen bonding modifier and a PVC-polar bonding modifier.

Abstract: Tubular workpieces of oriented polymers such as polyethylene polyester and PVC are formed by drawing a workpiece over an expanding former in the absence of any force perpendicular to the axis of the workpiece. The processes do not require the use of any liquid lubricant. They enable greater degrees of expansion and hence orientation in the direction perpendicular to the axis to be achieved and result in products of improved appearance and strength.

Abstract: The invention relates to a high strength pipe of ethylene polymer having a bimodal molecular weight distribution. Such pipe has a stress cracking resistance of .gtoreq.1400 h, a fracture toughness of .gtoreq.7 mJ/mm.sup.2 and a modulus of creep in flexure, measured according to DIN 54852-Z4, of .gtoreq.1100 N/mm.sup.2. The pipe according to the invention is produced from an ethylene polymer in which the ratio of weight of the low molecular weight fraction to the weight of the higher molecular weight fraction is in the range from 0.5 to 2.0 and which has a melt flow index MFI.sub.5/190.degree. C. of .ltoreq.0.35 g/10 min. It is particularly suitable for the transportation of gases and water.

Abstract: A method for reducing the chemical vapor permeability of a polyfluoroorgano resin substrate by coating its surface with a vinylidene dichloride copolymer is disclosed. The method produces a polyfluoroorgano resin substrate-vinylidene dichloride copolymer composite, for example a Teflon PFA pipe having its surface immediate to the environment treated with a vinylidene dichloride/vinyl chloride copolymer.

Abstract: An elongate deformable conduit and method of fabrication thereof adapted for the subterranean conveying of petroleum products and petrochemicals has an inner copper tube to which is bonded an outer layer of flexible polyvinyl chloride up to about one-third inch in radial wall thickness. In a preferred embodiment the polyvinyl chloride contains an ultraviolet stabilizer and is extruded in a wall thickness up to about one-tenth inch about the copper tube, and the copper tube has an outside diameter ranging up to about two inches and is sized to convey heating oil substantially below ground.

Abstract: A flexible conduit for coolant having a high bursting pressure above 8 bar at 100.degree. C. and high hydrolysis resistance comprising an outer layer of a material selected from the group consisting of homopolyamides, copolyamides and mixtures thereof with an excess of amino terminal groups, a non-swelling inner layer made of a material selected from the group consisting of non-halogenated copolyolefins, non-halogenated homopolyolefins and mixtures thereof and a middle layer compatible with the inner and outer layers made of a homopolyolefin or a copolyolefin with grafted functional groups, the layers being coextruded and corrugated during coextrusion.

Abstract: The invention relates to a pipe for conveying fuel, in particular for motor vehicles, the pipe comprising a polyamide inner layer, an outer layer of vulcanized elastomer such as CSM, and a film of modified polyolefin forming an alcohol barrier and connecting the inner layer to the outer layer.

Abstract: Fire resistant pipes and pipe fittings include a structural pipe wall formed from helically wound reinforcing fiber that is bonded together with a thermoset polymer resin selected from the group consisting of phenolic resins, siloxane-modified phenolic resins, furan resins, and mixtures thereof. In a first embodiment, a resin rich fire resistant layer is applied to the surface of the structural pipe wall. The carrier is capable of accommodating a large amount of resin. The resin used to impregnate the carrier is selected from the same group of resins used to form the structural pipe wall. It is desired that both resins be compatible, and preferably be the same, to facilitate forming a bond between the structural pipe wall and the fire resistant layer during cure.

Abstract: An improved vehicle includes fluid conducting apparatuses such as tubing and fittings which make up a piping system installed on the vehicle. The material used to make the fluid conducting apparatuses satisfies a specified ratio between the modulus of elasticity and the yield strength of the material. When the fluid conducting apparatuses are filled with frozen water such that the internal volume of the apparatuses has expanded by 10%, if the material has a modulus of elasticity of less than 20.5 times the yield strength of the material, then the material will not yield but will return substantially to its original shape and dimensions when the stress of the frozen water is removed.

Abstract: A composite rubber article is obtained by joining a rubber composition based on a brominated p-methylstyrene/isobutylene copolymer to a different material such as a plastic, inorganic and metallic material through a di-, tri- or tetra-alkoxysilane compound. The copolymer is firmly joined to the different material. The invention is applicable to the manufacture of composite rubber articles such as tires, high-pressure hoses, and pneumatic springs.

Abstract: An improved vehicle includes fluid conducting apparatuses such as tubing and fittings which make up a fluid conducting system installed on the vehicle. The material used to make the fluid conducting apparatuses satisfies a specified ratio between the modulus of elasticity and the yield strength of the material. When the fluid conducting apparatuses are filled with frozen water such that the internal volume of the apparatuses has expanded by 10%, if the material has a modulus of elasticity of less than 20.5 times the yield strength of the material, then the material will not yield but will return substantially to its original shape and dimensions when the stress of the frozen water is removed.

Abstract: A fuel hose comprising an outer rubber layer wherein polysulfide is crosslinked so that polysulfide bonding density is not less than 4.times.10.sup.-5 mol/cm.sup.3 and phenol based resin is contained, and an inner polyamide resin layer which is laminated on the inside face of the outer rubber layer and bonded thereon by heat treatment. Since the polyamide resin powder is melted by the heat treatment and the polysulfide bonding decomposes so that the resultant residue after decomposition combines with polyamide molecules, resulting in a direct and strong bonding of the outer rubber layer and the inner polyamide resin layer. Moreover, since the phenol based resin is mixed therein, it is possible to set up the heat treatment condition at a rather mild one.

Abstract: Fire resistant pipes and pipe fittings include a structural pipe wall formed from helically wound reinforcing fiber that is bonded together with a thermoset polymer resin selected from the group consisting of phenolic resins, siloxane-modified phenolic resins, furan resins, and mixtures thereof. A jacket is disposed around the structural pipe wall and comprises alternating release layers and fiber-reinforced resin layers. The release layer is formed from a material that is incompatible with the resin of the structural pipe wall and fiber-reinforced resin layers, and is energy absorbing to improve impact resistance and reduce thermal stress. The jacket is formed having a sufficient number of alternating layers, having sufficient layer thicknesses, to protect the structural pipe wall from heat induced failure produced by exposing the outermost pipe wall to a 1,000.degree. C. flame for at least five minutes in a dry condition.

Abstract: A long tubular article characterized by having a smooth surface and a substantially uniform wall thickness in the circumferential direction and the longitudinal direction and by being produced by injection molding a thermoplastic resin and a method for the injection molding.

Abstract: A thermoplastic tube for in-field storage or packaging of bales of agricultural products is disclosed. The tube combines high puncture resistance with an exceptional stretchability, elasticity and good slip properties. The circumference of the tube can be expanded by at least 15% without tearing when stretched in the transverse direction. The tube also shows no substantial permanent deformation 2 hours after being so stretched for a period of time not exceeding 30 minutes and released. Before feeding a bale, the tube is stretched radially to facilitate the insertion and accommodate bales larger than original diameter of the tube. When regaining the original size, the tube wraps up tightly the bales reducing the amount of air trapped in the tube. Since the tube can be enlarged to a variable extent, it may accommodate bales of different shapes and sizes.

Abstract: Unreinforced or reinforced concrete moldings, for example concrete pipes, with improved corrosion resistance to acids and acidic sewage, improved permeation resistance to inorganic and organic liquids and gases and improved mechanical stability, produced by molding with machines, for example in press molding machines or extrusion machines or concrete pipe pressing machines, and allowing to harden plastic-viscous concrete mixtures of hydraulic inorganic binders, preferably cement, aggregates and water, where, in the preparation of the plastic-viscous concrete mixtures, to the latter has been added in a positive mixer an effective amount of an aqueous plastics dispersion based on anionic and hydrolysis-resistant copolymers of ethylenically unsaturated monomers, the minimum film forming temperature (MFT) of which is above the setting temperature of the concrete mixture, preferably above 23.degree. C.

Abstract: An ultra-high molecular weight polyethylene thin-wall pipe which is uniform in thickness and free from a folded mark as well as a method of and an apparatus for manufacturing the same. The ultra-high molecular weight polyethylene thin-wall pipe is manufactured by supplying ultra-high molecular weight polyethylene into and melting and kneading, continuously extruding the molten substance of the ultra-high molecular weight polyethylene from a die connected to a screw of the screw extruder to form a cylindrical roughly shaped article, and diametrically expanding the cylindrical roughly extruded article by means of a tapered core and taking up.

Abstract: A layered tubing for use in a motor vehicle composed of a thick outer tubing having an inner and an outer face, the outer tubing made of an extrudable thermoplastic such as a polyamide such as Nylon 6; a thin intermediate bonding layer bonded to the inner face of the thick outer layer, the bonding layer composed of an extrudable melt-processible thermoplastic capable of sufficiently permanent laminar adhesion to the polyamide outer tubing; and an inner hydrocarbon barrier layer bonded to the intermediate bonding layer, the inner layer composed of an extrudable, melt processible thermoplastic capable of sufficiently permanent laminar adhesion with the intermediate bonding layer, the thermoplastic containing as a major constituent a fluoroplastic such as polychlorotrifluoroethylene, ethylene tetrafluoroethylene copolymers and the like.

Abstract: An improved conduit for transporting fuel and/or fuel vapor or a motion transmitting member in an automobile comprising an inner tube comprised of fluorocarbon polymeric material and having an inner surface for contacting and containing fluids or a motion transmitting member, and a chemically etched outer surface having a substantial portion of the fluorine of the fluorocarbon polymer substituted by a polar moiety. The conduit further includes an outer tube comprising an inner surface comprised of polymeric material containing sufficient polar groups such that hydrogen bonding at the interface between the outer surface of the inner tube and the inner surface of the outer tube prevents substantial relative separation of or movement between the inner and outer tubes.

Abstract: A hose capable of exhibiting increased flexibility and lubricity. The hose is made of soft synthetic resin containing a slidability providing silicone resin material. In particular, the slidability providing silicone resin material contained in a surface layer of the hose or ribs formed on a surface of the hose. In production of the hose, re-dispersion of the resin material and forcing of layers of the hose against each other are carried out. Alternatively, a layer containing the resin material and a layer free of the resin material are co-extruded.

Abstract: A flexible partition member for a hydraulic accumulator, which divides an interior of a shell of the accumulator into two sections that provide a gas chamber and a liquid chamber, respectively. The flexible partition member includes an integrally layered composite portion which includes at least one gas-barrier layer and at least one elastic layer, each gas-barrier layer containing a copolymer of ethylene and vinyl alcohol, and each elastic layer containing as a major component thereof a polyamide resin selected from the group consisting of nylon 6, nylon 66, nylon 6-10 and nylon 6-12. The integrally layered composite portion includes two adjacent layers which include a gas-barrier layer and an elastic layer.

Abstract: A method for manufacturing a double jacketed fire hose, and a double jacketed fire hose comprising an inner jacket and an outer jacket, the inner jacket being encapsulated with polyurethane, the inner jacket residing within the outer jacket, the inner and outer jacket having a controlled net twist.

Abstract: Unreinforced or reinforced concrete moldings, for example concrete pipes, with improved corrosion resistance to acids and acidic sewage, improved permeation resistance to inorganic and organic liquids and gases and improved mechanical stability, produced by molding with machines, for example in press molding machines or extrusion machines or concrete pipe pressing machines, and allowing to harden plastic-viscous concrete mixtures of hydraulic inorganic binders, preferably cement, aggregates and water, where, in the preparation of the plastic-viscous concrete mixtures, to the latter has been added in a positive mixer an effective amount of an aqueous plastics dispersion based on anionic and hydrolysis-resistant copolymers of ethylenically unsaturated monomers, the minimum film forming temperature (MFT) of which is above the setting temperature of the concrete mixture, preferably above 23.degree. C.

Abstract: A coolant conduit, which is an elongate tubular article for an apparatus requiring cooling by a cooling agent, includes a plurality of layers which are provided by, in combination, discharging a co-axial melt hose, 3D tubing manipulation, and blow molding thereof, each layer of the plurality being composed of a polymeric material which is thermoplastically processable. The plurality of layers preferably includes at least one inner layer which is composed of a polymeric material which is substantially inert to the cooling agent and which is substantially non-swelling; and an outer layer which is composed of at least one polyamide and which has a high pressure resistant which conveys a high bursting strength.

Abstract: Filled compositions having good low temperature impact performance made from a thermoplastic (e.g., a polyolefin such as polypropylene) and either at least one linear ethylene/C.sub.5 -C.sub.20 .alpha.-olefin or at least one substantially linear ethylene/C.sub.3 -C.sub.20 .alpha.-olefin polymer are disclosed. The compositions are easily molded and have particular utility in making automotive facia, parts and other household articles.

Abstract: A molding process includes flowing a polymer melt into the cavity of a mold which includes a core pin. After the mold is filled and skin layers of solidified polymer have formed adjacent the mold wall and core pin wall, the core pin is spun transversely to the direction of polymer melt flow. The invention includes hollow articles of improved mechanical properties made by the process.

Abstract: A coolant conduit which is an elongate tubular article for an apparatus requiring cooling by a cooling agent, such as an engine, for example, an internal combustion engine, includes a plurality of layers which are provided by sequential coextrusion thereof and which are adjoined thereby, each layer of the plurality being comprised of a polymeric material which is thermoplastically processable. The plurality of layers may include an inner layer which is composed of a polymeric material which is substantially inert to cooling agent and which is substantially non-swelling, and an outer layer which is composed of at least one polyamide and which is pressure resistant. The coolant conduit may include a plurality of longitudinal sections, and at least one layer of the plurality of layers may then be composed of a polymeric material which differs between longitudinal sections thereof as is made possible by sequential coextrusion thereof.

Abstract: Multilayer plastic pipes having at leastI. a layer based on a molding composition of polyamide; andII. a layer adjacent to layer I and based on a molding containing a mixture of(a) from 97.5 to 50% by weight of polyvinylidene fluoride; and(b) from 2.5 to 50% by weight of an acrylate copolymer,with the layers adhering to one another, are provided. These pipes exhibit improved resistance to chemical agents such as, methanol-containing fuels, without the loss of typical properties of polyamide and polyvinylidene fluoride.

Abstract: A reinforced rubber hose having a layer of ethylene-propylene rubber outside or inside a fiber-reinforcing layer. The two layers are firmly bonded to each other by an extruded adhesive layer of butyl rubber which exhibits a high bond strength after vulcanization. This obviates the necessity of treating (usually by dipping) the fibrous reinforcement with an adhesive before its braiding or knitting.

Abstract: Porous pipe formed of particles of vulcanized rubber dispersed in a binder resin such as linear low density polyethylene preferably having a Melt Index below 1.0 and a broad distribution of molecular weights, is stabilized to reduce degradation by ultraviolet light by dispersing in the binder resin an effective amount of an ultraviolet stabilizer such as 0.1 to 10% by weight of carbon black.

Abstract: A plastic pipe having improved resistance, inter alia, to methanol-containing fuels and improved mechanical properties comprising:(I) an outer layer made of a moulding compound based on polyamide,(II) an intermediate layer adjacent to the outer layer and made of a moulding compound based on a mixture of:(a) of from 95 to 99% by weight of a linear crystalline polyester, and(b) of from 1 to 5% by weight of a compound having at least two isocyanate groups,wherein the isocyanate groups originating from component (IIb) are present in the mixture of (IIa) and (IIb) in a concentration of from 0.03 to 0.

Abstract: A multi-layer tube suitable for use on motor vehicles composed of a cylindrical wall having an outer surface, and an inner surface essentially parallel to the outer surface. The cylindrical wall has a first region having an essentially uniform cross-sectional diameter and a second region which has a cross-sectional diameter differing from the essentially uniform cross-sectional diameter of the first region. The second region has at least one convolution or corrugation contiguously adjacent to the cylindrical wall of the first region.

Abstract: Improved thermoplastic adhesive liquid coatings adapted for use as a primer coating for inground pipelines, which coatings include an amphipathic metal complexing reagent in an amount effective to provide protection against cathodic disbondment, the improvement being the bonding to the thermoplastic moiety of an anhydride in an amount sufficient to provide still further protection against degradative environmental forces; and novel protective pipewrap systems including same.

Abstract: Multilayer plastic pipe comprising at least one outer layer based on polyamide and at least one layer of a linear, crystalline polyester modified by means of an isocyanate mixture exhibits improved resistance, inter alia, to methanol-containing fuels and improved mechanical properties.

Abstract: The present invention is a thermoplastic pipe nipple for connecting a flexible fluid conduit to a tank, comprising a first elongated tubular portion with a first end for engaging the conduit, and a second end for engaging a second portion of the nipple. The second portion is attached to the tank. The first part preferably consists of a reinforced polyamide, and the second part preferably consists of a non-reinforced high density polyethylene. The first part has a lower tendency to deform under load than the second part.

Abstract: A multilayer plastic pipe having improved barrier action against diffusion of the substance being transported, particularly methanol-containing fuels, dimensional stability, resistance to mechanical stress, and particularly improved adhesion between layers is provided comprising:(A) an inner layer and an outer layer, each of which comprise a polyamide-based molding composition, wherein the inner layer and outer layer may be the same or different, and (B) at least one intermediate layer comprisinga) 95 to 60% by weight of a linear, crystalline polyester andb) 5 to 40% by weight of a polymer containing reactive groups other than epoxide groups,wherein the reactive groups are contained in a concentration of from 4 to 95 mmol/kg based on the total amount of component (B); and wherein the layers are intimately bonded to one another.

Abstract: A centrifugally cast plastic pipe comprised of a polymer derived from monomers polymerized in bulk is provided. A pressurized cylindrical mold provides smooth inner and outer surfaces. Pipes with a wall thickness of from 1/8 inch to 3 inches and an outer diameter of 1 inch to 12 feet are provided.