The present invention relates to a line element comprising a hooped tube provided at both ends thereof with two receptacles in which male and female end fittings made of high-strength steel are fastened. The invention also relates to a riser section comprising at least one auxiliary line element having such characteristics. Furthermore, the invention relates to a method for upgrading a riser pipe by replacing an auxiliary line element with a line element having such characteristics.

A corrosion inhibiting composition is provided which comprises a salt of a fatty acid-amine condensate and an aromatic solvent. The composition can be used in reducing, inhibiting or preventing corrosion of a metal surface used in recovery, transportation, refining or storage of a hydrocarbon fluid containing elemental sulfur or polysulfide.

A method for producing a matrix-containing dry film on a threaded tubular component for drilling or working hydrocarbon wells, by applying a mixture containing a dispersion or an aqueous emulsion of an acrylic copolymer with a solution of an alkaline polysilicate in a liquid state onto a threaded end of the threaded tubular component by spraying at a temperature of from 20 C. to 40 C. thereby obtaining a threaded end coated with a film; drying the threaded end coated with the film; and densifying the film.

A method for producing a matrix-containing dry film on a threaded tubular component for drilling or working hydrocarbon wells, by applying a mixture containing a dispersion or an aqueous emulsion of an acrylic copolymer with a solution of an alkaline polysilicate in a liquid state onto a threaded end of the threaded tubular component by spraying at a temperature of from 20 C. to 40 C. thereby obtaining a threaded end coated with a film; drying the threaded end coated with the film; and densifying the film.

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 automotive member or oil filler pipe includes: a member of ferritic stainless steel containing, in mass %, at most 0.015% of C, at most 0.015% of N, 10.5 to 18.0% of Cr, 0.01 to 0.80% of Si, 0.01 to 0.80% of Mn, at most 0.050% of P, at most 0.010% of S, 0.010 to 0.100% of Al, more than 0.3 to 1.5% of Mo, and one or both of 0.03 to 0.30% of Ti and Nb; and a metal fitting of an aluminized stainless steel sheet, which is attached to the member to define therebetween a gap structure to be exposed to a chloride environment, and has an Al-plating weight per unit area ranging from 20 to 150 g/m.sup.2 in the gap structure. Surfaces of the metal fitting and member not facing the gap are coated with a cation electrodeposition coating film having a thickness of 5 to 35 m.

An automotive member or oil filler pipe includes: a member of ferritic stainless steel containing, in mass %, at most 0.015% of C, at most 0.015% of N, 10.5 to 18.0% of Cr, 0.01 to 0.80% of Si, 0.01 to 0.80% of Mn, at most 0.050% of P, at most 0.010% of S, 0.010 to 0.100% of Al, more than 0.3 to 1.5% of Mo, and one or both of 0.03 to 0.30% of Ti and Nb; and a metal fitting of an aluminized stainless steel sheet, which is attached to the member to define therebetween a gap structure to be exposed to a chloride environment, and has an Al-plating weight per unit area ranging from 20 to 150 g/m.sup.2 in the gap structure. Surfaces of the metal fitting and member not facing the gap are coated with a cation electrodeposition coating film having a thickness of 5 to 35 m.

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.

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.