A method of connecting together two unit elements (4, 4′) of a fluid transport pipe, each unit pipe element being covered in an outer insulating coating (6, 6′) made of a thermoplastic material, with the exception of an end portion that does not have an outer insulating coating. The method includes: a step of welding together two abutting unit pipe elements; a step of positioning an annular sleeve (14) around a cut-back and in part around the outer insulating coatings of the two unit pipe elements, the sleeve being made of a thermoplastic material; a step of fastening the sleeve in sealed manner by weld bonding on the outer insulating coatings; and a step of applying an external pressure on the sleeve to enable it to be deformed elastically and match the shape of the respective end portions of the two unit pipe elements.

A connection, and methods of making an using such a connection, the connection comprising a first layer; a second layer concentrically disposed about the first layer; and a laser-induced seal between portions of the first and second layers; wherein the laser-induced seal provides a fluid-tight engagement between the first and second layers. As to particular embodiments of the connection, the first layer can be incorporated into a first conduit and the second layer can be incorporated into a second conduit.

A connection, and methods of making an using such a connection, the connection comprising a first layer; a second layer concentrically disposed about the first layer; and a laser-induced seal between portions of the first and second layers; wherein the laser-induced seal provides a fluid-tight engagement between the first and second layers. As to particular embodiments of the connection, the first layer can be incorporated into a first conduit and the second layer can be incorporated into a second conduit.

A flow rate sensor includes: a housing made from a resin material and having a bottom base portion and a side wall, at least one surface side of the housing being open; a cover made from a resin material, covering the one surface side of the housing, welded to an upper surface of the side wall of the housing, and defining, with the bottom base portion and the side wall of the housing, an auxiliary passage within which a gas to be measured flows that is taken in from a main passage; and a flow rate detection unit disposed within the auxiliary passage. A protruding portion for height control is provided to one of the housing and the cover at least in a vicinity of the side wall around the flow rate detection unit so as to suppress sinking in of the cover during welding.

A method and apparatus for manufacturing a welded resin article which includes (a) bringing first and second resin members to come into contact with each other; (b) applying laser light to the first and second resin members while moving the laser light relative to the first and second resin members; (c1) obtaining a value corresponding to the intensity of infrared light from a plurality of locations on a surface; (d) successively calculating, as a section average, the average of a predetermined number of successive values, among those obtained from the plurality of locations corresponding to the intensity of the infrared light; (e) a step of successively calculating a deviation judgment value; and (f) a step of successively judging whether or not the deviation judgment value falls within a predetermined judgment threshold range.

The present invention relates to a method for producing a container which consists of a thermoplastic at least to some extent and comprises at least a first compartment element and at least a second compartment element joined to the first compartment element in a joining region by thermoplastic welding. The invention also relates to a plastic container which can be, and preferably is, produced according to said method.

A method for producing a resin joined body in which a specific region L1 of a welding portion of a second resin member (21) is provided to form a low-laser-light-transmissible portion, and the low-laser-light-transmissible portion has a laser light transmissibility lower than that of a region of the welding portion other than the specific region L1. Welding is carried out so that a portion between points S2 and F2, serving as a weld overlap portion (112), is present in the specific region L1 forming the low-laser-light-transmissible portion. Also disclosed is a resin joined body.

A resin pipe 30 and a resin member 31 are fixed to a setting portion 5 provided on the front side of a base 6, and a timing pulley 13 which is provided on the back side of the base 6 and to which a light emission unit 3 is attached is rotated. As a result, the light emission unit 3 applies laser light 20 to a junction 32 between the resin pipe 30 and the resin member 31 while revolving around the junction 32. This makes it easy to fuse and join the entire outer circumferential surface of the resin pipe 30 with the entire inner circumferential surface of the resin member 31, which are variously shaped and sized.

A machine for making a protective joint has a guide system, which is selectively clampable about a pipeline on opposite sides with respect to the annular junction portion and configured for defining an annular path about the annular junction portion; at least one heating unit moveable along the annular path and configured for heating the annular junction portion and moveable along the annular path; at least one spray unit moveable along the annular path and configured for applying at least one polymer material to the annular junction portion; and an extrusion die moveable along the annular path and configured for applying a protective foil about the annular junction portion.

A resin pipe 30 and a resin member 31 are fixed to a setting portion 5 provided on the front side of a base 6, and a timing pulley 13 which is provided on the back side of the base 6 and to which a light emission unit 3 is attached is rotated. As a result, the light emission unit 3 applies laser light 20 to a junction 32 between the resin pipe 30 and the resin member 31 while revolving around the junction 32. This makes it easy to fuse and join the entire outer circumferential surface of the resin pipe 30 with the entire inner circumferential surface of the resin member 31, which are variously shaped and sized.