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.

The invention relates to a screw element comprising an internal torque limitation for fastening a line, in particular a liquid-conducting line, to a counter-piece, in particular to a device connector or to a coupling for a further line, said screw element having a connection part, which preferably has a thread, and an actuation part; and having a torque limiting unit that limits a torque that can be transmitted from the actuation part to the connection part, wherein the torque limiting unit is arranged between the connection part and the actuation part and has a limiting element, in particular a separate limiting element, that can be assembled from at least two limiting element parts connectable to one another and that limits the torque limiting unit in an axial direction of a longitudinal axis of the screw element. The invention further relates to a system comprising at least one screw element and a line fastened to the screw element.

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.

The invention is a tapping assembly for use on a pipe or tank. It includes a hollow body that sits flush on the outer wall of the pipe or tank and includes a plurality of locking members that sit flush within the body and form a threaded portion into which a cap is insertable. Each locking member extends into the interior of the pipe or tank, and has an outwardly extending flanged portion that engages with the inner sidewall of the pipe or tank. When the cap is tightened against the body, it causes each of the locking member to retract, thereby causing the respective flange portions to lock the assembly against the pipe or tank wall. The assembly can be manufactured to provide either an orthogonal tap, or an angled tap, relative to the longitudinal axis of the pipe, or plane of the tank sidewall.

A double ball pipe coupling with two axes for connecting fluid pipes or conduits at eccentric angles while reducing or eliminating frictions loss. The coupling also provides movement of pipes or fluid pathways that are under low to high pressures. Two outer shell halves contain two ball joints with protruding connections and or outer fittings for most applications. The shell halves being mostly uniform or oblong or distorted for highly non-collinear connections. The ball joints containing pathways rotate within each shell half while permitting fluid flow as intended while greatly reducing restrictions.

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 dielectric fitting includes a nut having inner threads and an axial compression surface, and a hole having a first diameter. A mating component includes outer threads that engage with the inner threads including a second axial compression surface. A first fitting includes a circumferential flange captured between the first axial compression surface and the second axial compression surface, the first fitting having a first wall that extends axially and passes through the first hole and includes first fitting threads. A second fitting includes second fitting threads that engage with the first fitting threads, the second fitting having a second wall and a bulge portion that radially projects to a second diameter and includes an O-ring. The nut and the mating component are dielectrically isolated from the first fitting and the second fitting, and the second diameter is larger than the first diameter.

A fitting to interconnect water pipes or to connect pipes with valves or mountings. The connector housing has an O-ring seat, constituting two walls of a groove for an O-ring. The fitting comprises a clamping sleeve, having a first end provided with a flange, which forms a third wall of the O-ring seat groove. The flange is retained against the coupling housing by a nut screwed by hand onto outer threads on the coupling housing. The clamping sleeve is adapted to be clamped against a pipe which is inserted into the clamping sleeve, and the O-ring seals against the outer surface of the pipe.

A method for coating a screw element, in particular a screw element for connecting pipes, preferably motor vehicle pipes, wherein the screw element has at least one thread as well as at least one unthreaded contact surface. At least areas of the thread are provided with a first coating, and at least areas of the unthreaded contact surface are provided with a second coating. Both the first coating of the thread as well as the second coating of the unthreaded contact surface are applied to the thread or to the unthreaded contact surface via plasma coating.

Embodiments of the present invention include a tube connector assembly connectable to a fitting in an installed position. The tube connector assembly includes a tube with a retainer and nut received about the tube for engaging the retainer. The present invention also includes embodiments of a tube having a retainer and embodiments of a nut having a bend relief portion.