Abstract: The invention provides a composite protective coating applied to a steel pipe, the coating comprising an epoxy resin primer bonded to the outer surface of the pipe, a polyolefin outer sheath, and an interlayer consisting of a mixture of epoxy resin and polyolefin. The composition of the mixture forming the interlayer is graded throughout its thickness, being substantially all epoxy resin adjacent to the primer coating and substantially all polyolefin adjacent to the sheath.

Abstract: The invention relates to a method and apparatus for wrapping pipe with a cementatious material such as concrete. The material is conveyed to the pipe as a continuous strip provided with notches along one edge and complementary notches are formed at the other edge of the strip as the strip is wrapped spirally onto the pipe. The continuous strip is formed in a hopper having a number of sections of successively reduced widths and containing rollers by which successive superimposed layer portions of the strip are formed with reinforcing mesh embedded between successive layer portions.

Abstract: Two methods are provided for applying and forming a protective composite coating on a metallic substrate. In the first method, the substrate is heated to a temperature between about 175.degree. C. and 275.degree. C. and a powdered coating of epoxy resin between 100 and 400 microns thick is applied to the outer surface of the heated substrate. A premixed powder coating of epoxy resin and polyolefin is applied directly onto the epoxy resin coating, forming an interlayer of interspersed domains of epoxy and polyolefin between about 100 and 400 microns in thickness. On to this, powdered polyolefin is sprayed to produce a polyolefin sheath coating for the metallic substrate between 200 and 1000 microns in thickness. In the second embodiment of the method, the interlayer is formed by spraying pure epoxy resin powder and polyolefin powder from separate sources simultaneously onto the substrate. By these methods, a metallic substrate coated with a composite epoxy/polyolefin protective coating is produced.

Abstract: A longitudinally heat shrinkable closure sheet has a hold-down adhesive portion adjacent each longitudinal end for application on the exposed end portions a heat shrinkable wrap-around sleeve applied around a pipe or other article to be covered. Heat is applied to the closure sheet in order to weld the adhesive free portion of the underside of the closure sheet to the end portions of wrap-around sleeve. The initial shrinkage of the closure sheet between the hold-down adhesive portions draws it tightly into contact with the upper side of the end portions. Shearing forces are applied between the closure sheet and the end portions firstly as the closure sheet contracts relative to the end portions, and secondly, as the sleeve shrinks, develops hoop stress and stretches the closure sheet, and a high strength fusion bond is achieved between the closure sheet and sleeve.

Abstract: An improved spring spider for geophones is disclosed that has the desired ratio of spurious resonant frequency to the natural frequency of the geophone and can absorb the sharp lateral forces imposed on the geophone during destructive testing and hand usage.

Abstract: A heat shrinkable wrap-around sleeve comprises a heat shrinkable sheet with a heat stable strip welded on one end. The free end of the heat stable strip is overlapped on the outer side of the opposite end of the sheet and welded thereto by heating applied directly on the outer side. This allows a good quality welded connection to be formed without requiring the use of hold-down adhesives. The sleeve can be manufactured using induction welding or more preferably by heated wedged welding.

Abstract: A geophone is disclosed that has a cylindrical housing closed at one end by a bottom and at the other end by a top. A magnet assembly and a coil-mass are located in the housing. Springs support the coil-mass for axial movement relative to the magnet assembly along the longitudinal axis of the housing. A pair of coil terminals are mounted in the upper end of the coil-mass adjacent the top of the housing. A pair of eyelets extend through the top of the housing and outside geophone terminals are attached to and extend through the eyelets into the housing. A pair of pigtails connect the geophone terminals to the coil terminals.

Abstract: A welded pipe joint for pipes which are internally lined for carrying corrosive fluids is formed by an internally lined insert extending into the belled end sections of the pipes to be joined and engaging the belled end sections with a mechanical interference fit. The insert, which is provided with a heat shield to retard the transfer of heat during a subsequent welding operation, is held in coaxial alignment with the pipes while the adjacent ends of the pipes are brought together. The adjacent ends of the pipes are finally welded to complete the joint.

Abstract: A kelly valve includes a ball valve structure (10) having a ball valve member (40) with a central bore (42) therethrough mounted within a valve chamber (38) for rotation between open and closed positions. A fluid pressure equalizing opening or port (60) is provided in the quadrant of the ball valve member (40) exposed to the upstream flow passage (20) in closed position (FIG. 2) and exposed to the valve chamber (38) in open position (FIG. 1) thereby making the ball valve member (40) easy to rotate manually even at high downstream fluid pressures.

Abstract: An intermediate weight member (10) having a variable cross-section or bending moment of inertia as a function of member length is disclosed. At one end of the member (10) a slip and elevator section (14) is provided. A partially grooved section (16) of a diameter greater than that of the slip and elevator section extends between the slip and elevator section (24) and the other end of the member (10). The partially grooved section (16) includes two variable depth grooved sections (18, 20) separated by an ungrooved section (22). The ungrooved section (22) includes hardbanding rings (26, 28). The spiral grooves (30A, 30B, 30C) of variable depth grooved section (18, 20) vary in depth as a function of member length such that the bending moment of inertia varies as a function of length from the slip and elevator section (14) to the lower end of the member (10).

Abstract: A method and apparatus are described, for extruding a thermoplastic protective jacket onto a steel pipe. The pipe is first coated with a layer of epoxy which is partly cured, and then is conveyed through a cross-head extruder where a layer of copolymer or other suitable adhesive is applied. The outermost thermoplastic jacket may be co-extruded with the adhesive layer or laid down onto the pipe as it passes through a second cross-head extruder. Radial pressure is applied to a band of surface about the jacketed pipe which has been cooled to a stage such that the outer surface of the thermoplastic is hardened while the inner portion thereof remains above the softening temperature, thereby achieving good adhesion of the jacket to the pipe, without dislocating or blemishing the thermoplastic protective jacket.

Abstract: A self-propelled pipe cleaning machine as disclosed for use in removal of deteriorated coatings, such as coal tar or tape, from pipelines and providing a degree of surface preparation suitable for recoating. The machine comprises a travelling frame for motion along the pipe and an oscillating carriage bearing a plurality of counter-rotating cylindrical cutting tools which are urged toward the pipe surface by constant-force pneumatic cylinders. Variation in the pressure of cutters against the pipe surface during oscillation of the cutter head is avoided by counterbalancing of the pivotally-mounted cutters and their associated drive means.

Abstract: An electrical connector is disclosed having an elongated conductor housing of non-conducting material with two electrical connector conductors embedded in and extending lengthwise of the housing. Each connector conductor has a socket at one end and a pin at the other. A sleeve of elastic material positioned on the housing so that a portion of the housing extends beyond the sleeve to serve as a male plug and a portion of the sleeve extends beyond the other end of the housing to combine with the housing to form a female plug. The sleeve has an integral elongated boot in the side through which a geophone cable extends. The conductors of the geophone cable are connected to the conductors embedded in the housing of the connector.

Abstract: In a concrete-wrapped pipe having an inner water-impermeable resinous coating, the concrete wrapping is formed with a continuous inner portion covering the resinous coating and a helically slotted outer portion, the helical slot extending at least to the depth of a mesh reinforcement embedded in the concrete. The structure is characterized by the fact that the inner portion of the concrete wrapping is formed with one or more helically extending zones of reduced compressive strength, radially aligned with the helical slot or slots in the outer portion. The helical configuration breaks the continuityof the concrete wrapping in the longitudinal direction of the pipe and, even with pipe of relatively large diameter, enables the wrapping to accommodate limited bending of the pipe.

Abstract: In a concrete-wrapped pipe having an inner water-impermeable resinous coating, the concrete wrapping is formed with a continuous inner portion covering the resinous coating and a helically slotted outer portion, the helical slot extending at least to the depth of a mesh reinforcement embedded in the concrete. The structure is characterized by the fact that the inner portion of the concrete wrapping is formed with one or more helically extending zones of reduced compressive strength, radially aligned with the helical slot or slots in the outer portion. The helical configuration breaks the continuity of the concrete wrapping in the longitudinal direction of the pipe and, even with pipe of relatively large diameter, enables the wrapping to accommodate limited bending of the pipe.

Abstract: A method of forming an impact-resistant, moisture impermeable coating on the surface of an object, such as a pipe, comprises heating the object to a temperature above which a thermosetting resin applied to the heated surface will fuse, so that the resin forms a continuous layer. Before the layer of resin has gelled, a second layer consisting of a finely divided particulate mixture of the resin and a solid such as glass fiber or mica is applied over the first layer. The two layers are fused together to form a homogeneous resin covering with one layer reinforced by the above solid. The resin coating is then cured and the object allowed to cool. An apparatus for carrying out the method is also described.

Abstract: Prefabricated insulated pipeline section having a one-piece cast cured and dried insulative liner formed of lightweight aggregate in a foamed portland cement paste binder bonded to the inner surface of a tubular outer casing. The liner composition may be cast, in place between the liner and the pipe, and wet cured at elevated temperature. Bonding between the pipe and the liner composition is avoided by employing a cement cure retarder on the outer surface of the pipe or by mechanically debonding the pipe from the liner during curing. After curing, the pipe is withdrawn to expose the inner surface of the liner to permit rapid drying at elevated temperature. The prefabricated insulated sections permit simplified pipeline construction at reduced cost as compared with traditional methods of applying half shells of insulation to the pipeline on site.

Abstract: In a concrete-wrapped pipe having an inner water-impermeable resinous coating, the concrete wrapping is formed with a continuous inner portion covering the resinous coating and a helically slotted outer portion forming a helical wrap, the helical slot extending at least to the depth of a mesh reinforcement embedded in the concrete. The concrete wrapping serves as a water-permeable impact resistant barrier while permitting limited bending of the pipe.

Abstract: The invention relates to a method and apparatus for wrapping pipe with a cementatious material wherein the wrapping strip is provided with notches along the edges thereof which interlock along the wrapping seam about the pipe to provide an even coating. Where reinforcing mesh is provided within the coating material the mesh also overlaps at the wrapping seam to give greater strength to the coating. Compacting of the coating material is accomplished after the pipe is wrapped by means of a vibrating shoe.

Abstract: A heat shrinkable covering in the form of a sheet which is heat shrinkable in a longitudinal direction, and a stiffening member connected at each of two longitudinally spaced transversely extending superimposable zones of the sheet. One stiffening member has holes and the other studs in the form of arm portions which are insertable through the holes to secure the stiffening members together. The arm portions can be flattened down onto the outside of the covering to retain the stiffening members together while reducing risk of the studs interfering with items such as cables adjacent the covered article. Preferably the studs have a resiliently compressible head portion which snap fits into holes formed through the sheet adjacent the holes in the stiffening member to facilitate locating the overlapped zones of the sheet relative to one another. In use, the sheet is wrapped around an article, the stiffening members are engaged together, and the sheet is then heat shrunk.