387 results about "Double-walled pipe" patented technology

The double-walled pipe comprises a rigid internal tube 2 arranged in a rigid external tube 3, the tubes being separated by an annular space, centering elements holding the internal tube in position in relation to the external tube.

External tube 3 withstands alone an external pressure at least above 50 bars.

The mechanical resistance of the pipe to the external pressure is reinforced by placing centering elements 4 in contact with internal tube 2 and with external tube 3.

The invention relates to a double-wall pipeline for the connection of a fuel-gas valve set and an engine on an LNG ship, which comprises an internal pipe and an external pipe, wherein the internal pipe and the external pipe are coaxially sleeved and supported by a plurality of detachable clips, one end of the external pipe is fixed on the side wall of a fuel-gas valve set chamber provided with the fuel-gas valve set, one end of the internal pipe is communicated with the fuel-gas valve set by a transitional connection pipe, the other end of the internal pipe is communicated with the air inlet of a double fuel-gas engine by an internal corrugated pipe, the aperture of the internal pipe is the same as that of the air inlet of the engine, and a circular chamber is arranged between the internal pipe and the external pipe and communicated with the fuel-gas valve chamber to together realize air change. The double-wall pipe of the invention has simple and practical structure, uses common material of easy production and low cost, and can be rapidly and conveniently assembled and disassemble by using common tools when being applied on the LNG ship.

The invention discloses a double-layer pipe overall buckling simulation experiment device and method. The experiment device comprises a base, loading devices, a fixing device, a measuring device and the like. The double-layer pipe consists of an inner pipe and an outer pipe sleeved outside the inner pipe at an interval, and the tail end of the double-layer pipe is fixed by a fixing device; the axial loading device can axially slide and is connected to the base; the axial loading device is connected with the front end of the inner pipe; a pressure sensor is connected between the axial loading device and the inner pipe; two lateral loading devices are located on the two sides of the double-layer pipe respectively; and the two lateral loading devices are staggered.

The invention discloses a complicated-shape double-layer pipe manufacturing method and belongs to the field of double-layer pipe manufacturing technologies. The manufacturing method comprises the following steps: coaxially putting pipe blanks with different diameters, welding and reinforcing the two ends of the pipe blanks and a sealing device, then performing bending deformation; secondly, injecting a high-pressure liquid into an inner pipe and a gap between the inner pipe and an outer pipe, simultaneously pressuring in the inner pipe and the gap between the inner pipe and the outer pipe, increasing the gap between the inner pipe and the outer pipe by controlling the liquid pressure difference between the two so that the inner pipe reaches a needed shape; at last, releasing the high-pressure liquid, performing vacuum-pumping on the gap between the inner pipe and the outer pipe, simultaneously sealing the inner pipe and outer pipe at the two ends of the double-layer pipe to obtain the double-layer pipe. According to the complicated-shape double-layer pipe manufacturing method, by performing vacuum-pumping heat insulation on the gap between the inner pipe and the outer pipe, the weight of a heat insulation pipe is obviously reduced, the manufacturing cost is reduced, and various complicated-shape double-layer pipe fittings can be produced to be suitable for the requirements of different industries. The invention also discloses a sealing device for manufacturing the complicated-shape double-layer pipe.

A pipe joint assembly joins two double wall pipe sections together. The pipe joint assembly includes a first pipe section having at least one double wall corrugation on an end portion, a second pipe section having at least one double wall corrugation on an end portion and a joint formed by locating the first pipe section end portion and the second pipe section end portion in an overlapping relationship. The pipe joint assembly substantially increases the strength of the joint relative to conventional pipe assemblies.

The invention belongs to the field of a blowdown pipe and particularly relates to a modified polyethylene pipe and a preparation method thereof. The invention aims to solve the technical problems of poor ring stiffness, insufficient toughness, resource waste and increase of carbon emission of a double-wall pipe processed by polyethylene. To solve the technical problems, the adopted scheme is to provide the modified polyethylene pipe which comprises the following components by weight: 100 parts of polyethylene resin, 5 to 50 parts of chlorinated polyethylene, 5 to 50 parts of chlorinated polyvinyl chloride, 1 to 30 parts of chlorinated polypropylene, 1 to 50 parts of nano material, 0.1 to 3 parts of color masterbatch, 1 to 20 parts of processing aid, 0.1 to 5 parts of calcium stearate, 0.1 to 1 part of lubricant, 0.5 to 5 parts of light stabilizer, 0.5 to 5 parts of antioxidant, 1 to 15 parts of compatibilizer, 0.5 to 8 parts of lead-free stabilizer and 1 to 15 parts of anti-cracking resin. The invention also provides the preparation method of the modified polyethylene pipe. According to the modified polyethylene pipe provided by the invention, the ring stiffness is greatly improved and the modified polyethylene pip has good toughness and aging resistance.

A pipe element suitable for use in a fuel system of an aircraft comprises an inner pipe and an outer pipe sealingly surrounding the inner pipe and connected to the inner pipe. The pipe element is constructed in one piece and is produced by a 3D printing process.

A double-walled pipe with integrated heating capability for an aircraft or spacecraft includes a pipe body rigidly formed from plastic in one piece with an inner wall, with an outer wall and with a plurality of wall supports, the wall supports connecting the inner wall to the outer wall, the inner wall and the outer wall defining an intermediate space. The double-walled pipe further includes an electrically conductive coating surrounding the inner wall within the intermediate space and configured to heat up under application of an electric current such that heat is transferred to the inner wall.

The invention discloses a liquefied natural gas power driving vessel gas supply system double-wall pipe construction process. An internal field construction process includes the steps: 1) completing a construction design scheme and drawing according to a liquefied natural gas supply system drawing; 2) purchasing right-angled bends and manufacturing inner pipes, outer pipes and supporting devices according to the construction design drawing; 3) manufacturing double-wall pipe right-angled bend prefabricated parts. An external field construction process includes the steps: 1) manufacturing double-wall pipe straight sections by a pre-nesting process; 2) welding and closing the double-wall pipe right-angled bend prefabricated parts and the inner pipes of the double-wall pipe straight sections, and performing 100% radiographic inspection for welds; 3) performing air pressure test under design pressure; 4) actually measuring inner pipe closure welds and the length of a shooting position, manufacturing outer pipes at the shooting position, mounting the outer pipes, welding joints and performing routine inspection for the welds. Reworking is decreased, vessel construction efficiency is greatly improved, and construction cost is reduced.

Device for arresting the propagation of a buckle in a double walled pipe. The device comprising an outer pipe wall having a defined external diameter and placed around an inner pipe wall, defining an annular space between the said outer and inner walls; providing predetermined regions in the annular space which are bounded between two sealing blocks with radially opposed faces which are in contact with the outer and inner pipes; placing a curable compound in each region and curing it the length of each region is at least equal to 0.5 times the external diameter of the outer wall.

The invention discloses a double-flow-channel direction control short connection device. The device is connected to the lower ends of an inner-layer pipe and an outer-layer pipe of a double-layer pipe. The device comprises an outer-layer flow channel one-way valve, a fluid steering short connector and an inner-layer flow channel one-way valve, wherein the outer-layer flow channel one-way valve comprises a valve core A, an outer-layer sealing ring A, an inner-layer sealing ring A and a spring A, and can be used for realizing direction control of fluid in an outer-layer flow channel; the fluid steering short connector can be used for realizing communication of an inner-layer flow channel with an annulus space; the inner-layer flow channel one-way valve comprises a valve core C, a valve seat C, a valve body C and a spring C, and can be used for realizing direction control of fluid in an inner-layer flow channel. By adopting the device, fluid entering the annulus space through the outer-layer flow channel can be guided into the inner-layer flow channel, and isolation of the inner-layer flow channel and the outer-layer flow channel from the shaft bottom fluid can be realized. The device has the advantages of simple structure, reliability in direction control and reduction of shaft bottom pressure fluctuation during pump opening.

The invention provides an LNG single-fuel ship and belongs to the technical field of ship engineering. According to the structure of the LNG single-fuel ship, a hole is formed in a main deck of a storage tank cabin, the storage tank cabin is designed to be of a sunken structure, one part of a gas storage tank is located above the main deck, the other part of the gas storage tank is located below the main deck, a double-wall pipe in an engine room is adopted as a fuel gas delivery pipe, a rectangular ventilation guide pipe is arranged on the periphery of the tail segment, close to an engine, of the fuel gas delivery pipe, and a round ventilation guide pipe is arranged on the periphery of the segment, on the upstream of the rectangular ventilation guide pipe, of the fuel gas delivery pipe; a liquid outlet pipe on the downstream of a flowmeter is divided into a main path and an auxiliary path, wherein the main path is finally connected to a mixer, and the auxiliary path is connected to the portion, between a second-stage pressure reducing valve and a downstream manual drainage pipe, of the main path through a fault opening type electromagnetic pneumatic valve and an auxiliary path safety valve; the mixer is connected with a supercharger, and the supercharger is connected with the fuel gas delivery pipe. Due to the design, the strength and the stability of the LNG single-fuel ship are improved; fuel adding, fuel feeding and safety protection are achieved, and the safety of a ship power system is guaranteed.

The invention relates to a bending process of a double-layer pipe, which comprises the following steps that: an outer layer pipe is fed; an inner layer pipe is fed; one end of the inner layer pipe is made into a flared end; the other end of the inner layer pipe is plugged to form a plugging end; the inner and the outer layer pipes are assembled and welded; special solid stuffing for bending pipe is filled inside the pipes; the inner and the outer layer pipes are bent; the special solid stuffing for bending pipe is dissolved; the pipes are cut; and the double-layer pipes are examined. The bending process has the advantages that the solid stuffing is filled between the two layers of pipe, so the stuffing between the two layers of the pipe is free from being smashed during the pipe bending process, effective supporting between the two layers of the pipe can be realized, a satisfactory distance between the outer side surface of the inner layer pipe and the outer layer pipe after the pipe is bent can be maintained, the shape of the bending part is smooth and aesthetic, and the function of the double-layer pipe can be adequately played in the application.

The invention discloses a welding method for a double-layered tube. The welding method comprises the following specific steps of preparing the double-layered tube, wherein the double-layered tube comprises an inner tube and an outer tube, the outer tube is sleeved with an outer tube sleeve, the inner tube comprises a left inner tube and a right inner tube, and the outer tube comprises a left outer tube and a right outer tube; attaching and aligning end faces of the left inner tube and the right inner tube, reserving a gap between the left outer tube and the right outer tube, moving the outer tube sleeve onto the left outer tube or the right outer tube, and exposing the gap between the left outer tube and the right outer tube; performing application for inspection before welding on the left inner tube and the right inner tube according to the butt welding requirement; welding a connected part of the left inner tube and the right inner tube; polishing and cleaning a weld joint of the welded inner tube; performing application for inspection before welding on the left outer tube and the right outer tube according to the overlap welding requirement; moving the outer tube sleeve to the outer side of the gap in the first step, and separately welding a connected part between the left outer tube and the outer tube sleeve as well as a connected part between the right outer tube and the outer tube sleeve; and separately polishing and cleaning a weld joint between the left outer tube and the outer tube sleeve as well as a weld joint between the right outer tube and the outer tube sleeve.

An arrangement is disclosed for connecting at least one double-walled pipe of stainless steel to a LNG tank having an inner shell of stainless steel and an outer shell spaced at a distance from the inner shell, the inner and outer shells defining an isolation space therebetween. The at least one double-walled pipe includes a common outer wall and at least one inner pipe. The outer wall of the pipe is connected to the inner shell of the tank in such a way that the outer wall and/or a pipe fitting of cold resistant material between the inner shell and the outer wall is arranged to compensate for changes in the length of the outer wall of the pipe and/or of the pipe fitting due to temperature differences between the outer wall of the pipe and the inner shell of the tank.

A flowing wet ¿C steam humidity measurer of double layer tube direct ¿C heating type is prepared as connecting inlet section to heating section being connected to outlet section, setting middle layer heating tube in outer jacket of internal layer heating tube at heating section, setting external layer support tube in outer jacket of middle layer heating tube, insulating said tubes to each other and holding gap between them, connecting inlet section to one end of heating section by left connection component and outlet section to another end of heating section by right connecting component, setting directional needle tube in inlet section and connecting said needle tube to piping connection box of outlet section.

The present invention relates to a fixation device for fixation of a position of an inner pipe of a double-walled pipe with respect to a pipe laying structure and/or an outer pipe of said double-walled pipe, said fixation device comprising: an inner pipe gripping device (23) configured to grip said inner pipe, and a connection device (24,25,2S) configured to connect said inner pipe gripping device with said pipe laying structure and/or said outer pipe, said connection device having a flexible state in which, during use, the inner pipe gripping device is movable with respect to said pipe laying structure and/or said outer pipe, and a fixation state in which, during use, the inner pipe gripping device is fixated with respect to the pipe-laying structure and/or said outer pipe.

The invention provides an electron field emission cathode of a single carbon nanotube and a method for the preparation thereof, belonging to the application field of the carbon nanotubes. The nanotube used as the field emission cathode is provided with a cone-shaped end part that is in structure of a sealed sing-wall or double-wall pipe; multi-wall pipe structure is arranged at the lower part of the cone-shaped structure. The manufacturing method of the carbon nanotubes comprises the steps as follows: a multi-wall carbon nanotube is acquired through a metal wire; one multi-wall carbon nanotube on the metal wire is contacted through a metal needle tip; evenly increasing voltage is added between the metal wire and the metal needle tip, which leads the single carbon nanotube to become thinner and even to break up as a result of the electric current effects, so as to obtain the carbon nanotube with the cone-shaped end part. The carbon nanotube, with the advantages of the single-wall tubes and the multi-wall tubes on the emission performance, also has the advantages of stable emission, and low threshold voltage, can bear higher electric current and is also relatively easy to obtain. In addition, the curvature radius of the cone-shaped tip is controllable and can be enlarged; therefore, the corresponding maximum electric current to be borne can be increased constantly.

The invention discloses a water-controlling sand prevention device and method used for a fracturing horizontal gas well. The water-controlling sand prevention device comprises a double-layer tube, a supporting agent, a first packer and a second packer, wherein the double-layer tube comprises an inner layer tube body and an outer layer tube body sleeving the exterior of the inner layer tube body, an annular space is formed between the inner layer tube body and the outer layer tube body, and tube holes are formed in the tube walls of the inner layer tube body and outer layer tube body respectively; the supporting agent is arranged in the annular space and is a hydrophobic supporting agent, and the maximum particle size of the supporting agent is smaller than the average value of stratum separated particle sizes; the first packer and the second packer are annular and are arranged at the two ends of the double-layer tube respectively to close the supporting agent in the annular space. Withthe water-controlling sand prevention device and method, stratum particles and the supporting agent are controlled to enter a shaft, at the same time, water production of the gas well is controlled,production among all fracturing layers is not affected, and continuous efficient production of the horizontal gas well is guaranteed.