A pipe is used for control and forced circulation of corrosion-inhibiting fluids in an annulus thereof, the annulus located between an inner pressure barrier and an outer cover of the pipe and containing a number of layers. The pipe includes two layers of tensile armor within the annulus; at least one injection pipe laid helicoidally on the longitudinal extension of the pipe; at least one return pipe laid helicoidally on the longitudinal extension of the pipe; and a ventilation layer within the annulus, the ventilation layer being configured to facilitate the flow of fluids longitudinally through the annulus of the pipe.

A flexible tubular structure for oil exploitation, said flexible tubular structure having at least one reinforcing layer and at least one layer of a fluoropolymer compound, wherein said fluoropolymer compound has a composition including a polyvinylidene fluoride homopolymer and a vinylidene fluoride/fluorinated comonomer copolymer, and a plasticizer. The proportion by weight of hexafluoropropylene monomer in the copolymer is greater than 25%.

A non-penetrating multi-layer continuous hose and a preparation method thereof are provided. The hose includes an outer coating, a reinforcement layer, and an inner coating. The inner coating and the outer coating can have one or more layers with different materials and have an adjustable thickness. The hose is prepared by simultaneously performing extrusion coating inside and outside the reinforcement layer rather than penetrating the fiber reinforcement layer. The hose exhibits improved layer-to-layer adhesion and has high strength, and continuous production can be achieved to meet the length requirement in various kinds of construction, which has high applicability.

A multi-component extrusion die head for producing a composite tube comprises an extrusion nozzle, a main die head, and a melt flow distributor device. The main die head is configured to supply the extrusion nozzle with a first melt flow and a second melt flow, which are guided separately from one anther in the extrusion nozzle away from the main die head and toward a nozzle outlet of the extrusion nozzle. The melt flow distributor device is arranged in the extrusion nozzle outside of the main die head and is configured to split the first melt flow in a peripheral direction thereof, and to supply the second melt flow to the first melt flow such that at least one section of the second melt flow is arranged within the first melt flow in the peripheral direction.

A die has an inner die that has a straight portion of circular columnar outer shape and a convergent tapered portion provided closer to an extrusion port side than the straight portion and an outer die that houses the inner die. A first supply passage connecting a first valve and a flow passage, a second supply passage connecting a second valve and the flow passage, and a third supply passage connecting a third valve and the flow passage are provided inside the die. Downstream side end portions of the first supply passage and the second supply passage are connected to a portion of the flow passage formed between the straight portion and the outer die and a downstream side end portion of the third supply passage is connected to a portion of the flow passage formed between the tapered portion and the outer die.

Disclosed herein are abrasion resistant flexible hoses and methods for manufacturing such hose. The abrasion resistant elastomeric hose comprises an inner surface and an outer surface, and a abrasion resistant material embedded in the hose at a depth that imparts a three-dimensional pattern at the outer surface of the hose.

The present invention relates to a tube comprising polytetrafluoroethylene, and an object of the present invention is to provide a tube having an appropriate tensile strength and flexibility and being excellent internal insertion property. The object can he achieved by a tube comprising polytetralluoroethylene according to the present invention, in which, in a case where a surface shape of an inner surface of the tube is measured, when a direction of the measurement is parallel to a longitudinal direction of the tube and the measurement is performed in a forward direction and a reverse direction, a variation rate between a size of a periodic step measured in the forward direction and a size of the periodic step measured in the reverse direction is 5% or more.

A hose extrusion mandrel for manufacturing rubber hoses includes: a solid thermoplastic, elongate core; and a rubber compound outer layer covering a surface of the elongate core. A ratio between a diameter of the core and a thickness of the rubber compound layer may be between 8 and 11.

Provided is a composition for a highly elastic extruded foam. The composition includes a peroxide-crosslinkable thermoplastic polymer, an organic peroxide, thermo-expandable microspheres, and a silane coupling agent.

Damage of the outer surface of a rubber hose due to friction can be prevented while the sealing performance and the productivity are ensured. The following components are provided: a pipe 11 whose one end is connected to a vulcanization pipe and in which pressed liquid is pumped from an inlet 11a disposed at the side face of the other end side; an annular member 12 which is attached to the pipe 11 so as to close an opening of the other end side of the pipe 11, and includes a hole 12a whose diameter is larger than the outer diameter of a rubber hose and in which the rubber hose passes through; and a pump which pumps more liquid than the liquid discharged outside the pipe 11 through the gap between the hole 12a and the rubber hose into an inlet 11a.