Provided is a pipe detachment preventing device for a union nut pipe fitting that can keep a temporarily-assembled state and enables tightening work to be performed uniformly, while having a simple structure. A protruding portion has at least a flange portion 75 having a through hole 76 through which tightening means penetrates, and a wall portion 77 extending from the flange portion 75. An end portion 77a of the wall portion 77 opposed to another divisional component is formed so as to protrude toward the other divisional component relative to an end portion 73a of an arm 73 and a hook 72 opposed to the other divisional component. A retaining ring 7 has a compressively-deformable held member 8 through which the tightening means is inserted and which is held between the flange portions 75 opposed to each other. The compressively-deformable held member 8 forms a gap S between the end portions 77a of the wall portions 77 when a pair of divisional components are coupled by the tightening means and latched to a union nut 4 in a loose-fit state. The tightening means is tightened until the end portions 77a of the wall portions 77 come into contact with each other, thus tightening and fixing the pair of divisional components to an outer-peripheral surface of a pipe.

A tube nut and a brake tube assembly are provided. A pipe is disposed within the bore of the nut. A first coating is disposed on an outer surface of the nut. The first coating has a corrosive resistance greater than the bore so as to promote corrosion within the bore. The corrosion forms a seal which is pinched between the bore and the pipe. The tube nut and brake tube assembly may include a second coating disposed on the bore. The first coating has a corrosive resistance greater than the second coating so as to promote corrosion within the bore.

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.

Systems and methods of the inventive subject matter are directed to components that are used to form lengths of conduit. Such a system can include a male component and a female component, where the male component has a male conical tapered surface on a threaded end and the female component comprises a female conical tapered surface on a threaded end. A B nut can be slid over the male component so a sleeve can be screwed onto the threaded end of the male component, and the B nut can then screw onto the threaded end of the female component, thereby pulling on the sleeve to bring the male component and the female component toward each other. Systems of the inventive subject matter are made from non-metal materials such as machinable ceramics, plastics, polymers, and the like.

This invention relates to a partially carbonitriding heat treated stainless steel ferrule, having a first region with a first hardness and a second region with a second hardness, wherein the first region includes a nitrogen layer having a nitrogen concentration higher than a carbon concentration, and a carbon layer formed under the nitrogen layer and having a carbon concentration higher than a nitrogen concentration, so that the first hardness is greater than the second hardness. Thereby, partial heat treatment is effective at preventing rotational torque of the region, except for the portion to be heat treated, from increasing due to the total hardening.

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.

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 union screw (1) for pipes (2) provided with at least one flare (21) comprises a metal base body (10) which accommodates the pipe (20). The union screw (1) further comprises a screw head (12), a threaded portion (13), a contact portion (15) which is configured to abut the flare (21) of the pipe (20), and a functional layer (40) with which the base body (10) is coated at least in the region of the threaded portion (13) and the contact portion (15). The functional layer (40) is multi-layered and consists of at least one base coat (41) and a top coat (42) applied to the base coat (41) at least in some areas. The base coat (41) forms a structure for creating corrosion protection and a far-reaching invariance with regard to the material of the usual friction partners of the union screw (1) which, in addition to a binder, also contains zinc in the form of zinc-containing lamellae (43), which are oriented to lie substantially flat on the base body (10).