Methods and apparatus are described for producing welded assemblies of plastic parts for use in fluid flow applications. A unit cell structure is disclosed for use in an assembly. One embodiment is an as-molded plastic unit cell structure for use in fabricating welded fluid flow assemblies, the cell structure comprising a hollow tubular body portion having opposed first and second axial ports, a first hollow tubular portion extending axially from a first end of the tubular body portion and defining the first axial port, the first hollow tubular portion having a tube or pipe end configured for welding to another plastic part in a fabrication process for an assembly, and wherein the first tubular portion has a length in a range of 1 mm to 40 mm.

A resin end-face butt joint, a method for welding the joints, and a piping member ensure a sufficient clamping margin with the clamp of an ordinary welding machine, and ensure an appropriate distance between the centers even when joints having short tubular welding ring parts are welded. It is also possible to align the centers by positioning the centers along the same axis. The resin end-face butt joint includes multiple welding ring parts which communicate with a flow path within a joint base part and which are provided on the joint base part. Fastening parts are coaxial with at least one of these welding ring parts at the outer end of the joint for the purpose of clamping a welding machine.

A machine for welding saddle connectors by polywelding, during pipe laying, includes a base which extends in a first direction, a clamp which can move along the base in the first direction, a bracket mounting means for detachably coupling the machine to a pipe arranged transversely to the first direction, and a means for detachably coupling the base to the bracket mounting means.

An internal boss can have an outer side surface shaped to match the bored opening of the DWV pipe, an inner side surface shaped to align with an interior pipe surface of the sanitary Tee or Wye fitting component, and an internal face surface of the boss extending between the side surfaces and shaped to align with an interior pipe surface of the DWV pipe when welded thereto. Snap-fit wings can hold the interior face surface of the sanitary Tee or Wye fitting component against an exterior face surface of the DWV pipe while the fitting component and DWV pipe are homogeneously weldable into a single DWV fitting using a solvent mixture including a common plastic material. Related methods and single homogeneous fittings are also provided.

A liner assembly and method for lining a damaged pipe junction between a main and lateral pipe is provided. The liner assembly includes a main liner member and a lateral liner tube. A collar disposed near the juncture between the main liner member and lateral liner tube is impregnated with a liquid hydrophobic or hydrophilic material capable of curing in a flexible or rigid state with the material expanding in the presence of water. The hydrophobic or hydrophilic material can also be applied without the use of the collar. When the liner assembly is pressed against the main and lateral pipes, a portion of the hydrophilic or hydrophobic material is forced into the damaged pipe junction.

Methods and apparatus are described for producing welded assemblies of plastic parts for use in fluid flow applications. A unit cell structure is disclosed for use in an assembly. In an exemplary embodiment, an assembly of welded plastic parts for a fluid flow application includes a plurality of as-molded plastic unit cell structures, each cell structure having a hollow tubular body portion, a first tubular portion extending axially from a first end of the tubular body portion, and second and third opposed transverse tubular portions extending from an intermediate portion of the tubular body portion transverse to the first tubular portion. The first tubular portion of a first unit cell structure is welded to the first tubular body portion of a second unit cell structure in an axially aligned configuration.

A positive crankcase ventilation system for an internal combustion engine routes blowby gases into the intake of the engine. Because the blowby gases have about 12% water vapor, during cold-weather operation, the water vapor may freeze in the PCV valve or in the port that couples the PCV duct with the intake manifold. In situations in which the PCV duct is pointing toward the direction of flow of the intake gases, a hood or cap is placed over the end of the tube according to the present disclosure. It can be as simple as a 90-degree elbow or multiple openings in the cap. A centerline of the openings is perpendicular or at an obtuse angle with respect to the direction of flow in the duct so that the intake gases do not directly access the openings and cause freezing in the openings (or ports).

A clamping ring that presses an end of a pipe against a connecting piece by back shrinkage. The clamping ring comprises a body comprising a plastic material having memory properties. The body has a first end to be positioned at a distance from the end of the pipe and a second end to be positioned close to the end of the pipe. The body of the clamping ring has a first position at the first end or at the distance from the first end having a first radial wall thickness. The body of the clamping ring has at least one second position between the first position and the second end such that the body of the clamping ring has a second radial wall thickness at the second position. The second radial wall thickness is smaller than the first radial wall thickness.

The polymeric pipes reinforced with a metal casing are used for transporting oil and gas, acids, alkali products, drinking water and industrial water, and also in the transportation of aggressive and neutral pulps. A metal-containing polymeric reinforced pipe includes a welded metal casing and a polymeric matrix having an amorphous-phase-based molecular structure. The metal-containing polymeric reinforced pipe is produced by extrusion moulding with simultaneous feeding of a polymer melt and the reinforcing metal casing into the mould cavity, followed by intensive cooling of the internal and external surfaces of the pipe being moulded. The invention increases the quality and endurance limit in the radial direction of the metal-containing polymeric reinforced pipe, productivity of the process for manufacturing the pipe, and also the strength and technological effectiveness of a pipeline constructed from the pipes produced.

A snap fitting far use in plumbing is provided. The snap fitting includes a main body formed of plastic and shaped to extend partially around a cylindrical pipe to snap over the pipe and an inset for extending from an interior side of the main body into a hole in the cylindrical pipe.