A system for making a connection between a first tubular member and a second tubular member having coincident bores for conveying a fluid, the connection having an axis in the general direction of flow of said fluid therethrough, the system comprising a connection (1) and a tensioning tool (100), the connection having a first tubular end (6) comprising a first end flange (16) having an end face (17) and a collar (20) comprising a sleeve (21) and an end stop (30) fixed to the sleeve (21), said sleeve (21) arranged about said flange (18) and said end stop (30) arranged about said tubular end (6), said collar (20) slideable along said tubular end (6), the connection further having a second tubular end (7) comprising a second end flange (43) having an end face (45) and a locking nut (50) about and slideable along said first tubular end (7), the tensioning tool (100) for applying axial tension to said collar (30) relative to said second tubular end (7) characterised in that at least one of said sleeve (20) and said second tubular end (7) has a set of parallel circumferential grooves (23,47) therein and said tensioning tool (100) has a set of ridges (142), the system comprising the steps of moving said set of ridges (142) into said set of grooves (23,47) and applying an axial tension to said collar (20) relative to said second tubular end (7).

A fastener for connecting a coated conduit to a fitting comprises: a locking nut having a first end, a second end, and internal threading extending between the first end and the second end; a gasket formed at the first end of the locking nut by coating the locking nut with a polymeric material; and a flexible sleeve extending from the second end of the locking nut that is formed by coating the locking nut with the polymeric material. The internal threading of the locking nut is threaded onto exposed threading of the coated conduit such that the flexible sleeve fits over a circumference of the coated conduit and the gasket forms a sealed connection with the fitting when the exposed threading of the coated conduit is connected to the fitting.

Disclosed herein is a resin-coated aluminum pipe connector for the outdoor unit of an air conditioner. The resin-coated aluminum pipe connector includes: a refrigerant pipe made of aluminum, and configured such that an expanded portion is formed at one end thereof; a service valve including a connection port in which a first inclined surface is formed at an end of the connection port and a first screw portion is formed on the outer circumference of the connection port; a first compression ring configured such that an inclined surface is formed at one end of the inner circumference thereof and a first stop protrusion is formed at the other end of the inner circumference thereof; a second compression ring configured such that a second-first inclined surface is formed on the inside thereof and a receiving side wall extends upward from the second-first inclined surface; a sealing material; and a fastener.

Provided herein is a resin-coated aluminum pipe connector for the outdoor unit of an air conditioner. The resin-coated aluminum pipe connector includes: a resin-coated refrigerant pipe made of aluminum, and configured such that an expanded portion is formed at one end thereof; a service valve including a connection port in which a first inclined surface is formed at an end of the connection port and a first screw portion is formed on the outer circumference of the connection port; a first compression ring configured such that an inclined surface is formed at one end of the inner circumference thereof and a first stop protrusion is formed at the other end of the inner circumference thereof; a second compression ring configured such that a second-first inclined surface is formed on the inside thereof and a receiving side wall extends upward from the second-first inclined surface; a sealing material; and a fastener.

A tube fitting is provided with a resin coating layer over a coated region surfaces of a threaded portion and a contact portion. The resin coating layer includes a polyethylene based substance, a lubricant, and solid particles. When mass per unit area w (g/m.sup.2) is defined as a value obtained by dividing the mass difference between a state with the resin coating layer and a state without the resin coating layer by the surface area of the coated region, the mass per unit area w satisfies a relation 0.79<w<10.07.

A tube fitting is provided with a resin coating layer over a coated region surfaces of a threaded portion and a contact portion. The resin coating layer includes a polyethylene based substance, a lubricant, and solid particles. When mass per unit area w (g/m.sup.2) is defined as a value obtained by dividing the mass difference between a state with the resin coating layer and a state without the resin coating layer by the surface area of the coated region, the mass per unit area w satisfies a relation 0.79<w<10.07.

An axial force measurement device includes a frame, a tightening actuation unit that performs tightening operation upon a screw type tube fitting installed upon a tube upon which is formed an annular portion projecting in the radially outward direction from the tube, a testing member, and a mating member holding unit that holds the testing member into which the tube fitting is screwed and that is coupled to the tube. The tightening actuation unit and the mating member holding unit are provided to the frame in line along the direction of a reference axis that extends in the direction of the center line of the tube fitting and the tube axis of the tube. The testing member has a first part that engages with the tube fitting, and a second part against which the annular portion of the tube is pressed.

A method for manufacturing a tube fitting includes steps of: preparing the tube fitting; and forming a resin coating layer upon a coated region provided upon the surface of the tube fitting. Forming the resin coating layer includes: dipping the tube fitting into a coating material that includes as components a polyethylene based substance, a lubricant, and solid particles and having viscosity within a range of 4.24 to 5.27 mPa.Math.s at 25? C., and adhering the coating material to the coated region; and, drying the coating material which is adhered to the coated region of the tube fitting. In the dipping step, the mass per unit area w is controlled within a range 0.79<w<10.07 by dipping the tube fitting while regulating a temperature of the coating material within a range of 30? C. to 40? C.

A system for making a connection between a first tubular member and a second tubular member having coincident bores for conveying a fluid, the connection having an axis in the general direction of flow of said fluid therethrough, the system comprising a connection (1) and a tensioning tool (100), the connection having a first tubular end (6) comprising a first end flange (16) having an end face (17) and a collar (20) comprising a sleeve (21) and an end stop (30) fixed to the sleeve (21), said sleeve (21) arranged about said flange (18) and said end stop (30) arranged about said tubular end (6), said collar (20) slideable along said tubular end (6), the connection further having a second tubular end (7) comprising a second end flange (43) having an end face (45) and a locking nut (50) about and slideable along said first tubular end (7), the tensioning tool (100) for applying axial tension to said collar (30) relative to said second tubular end (7) characterised in that at least one of said sleeve (20) and said second tubular end (7) has a set of parallel circumferential grooves (23,47) therein and said tensioning tool (100) has a set of ridges (142), the system comprising the steps of moving said set of ridges (142) into said set of grooves (23,47) and applying an axial tension to said collar (20) relative to said second tubular end (7).

A tube fitting includes: a zinc-based plated layer; and a resin coating layer that is positioned at an outermost surface at an outer side of the zinc-based plated layer and includes a polyethylene substance, a lubricant, and solid particles. When a fitting average plating thickness t relating to the thickness of the zinc-based plated layer is defined, 2.1<t<19.7 is true.