563 results about "Double tube" patented technology

The utility model relates to the technical field of pipe cutting devices, in particular to an automatic cutting device for a three-way pipe fitting. According to the technical scheme, the device comprises a base, a sliding table is slidably mounted at the top of the base, a single-pipe-head clamping plate is fixedly mounted at the top end of the sliding table, a protective baffle is fixedly mounted on the side, away from the sliding table, of the top of the base, a transverse moving frame plate is slidably mounted at the top end of the sliding table, and a first rubber column head is clamped and inserted into the transverse moving frame plate; a double-pipe-head clamping assembly is fixedly installed at the top end of the base, two clamping plates are arranged on the double-pipe-head clamping assembly, and second rubber column heads are fixedly installed on the inner side walls of the clamping plates. By means of the single-pipe-head clamping plate and the double-pipe-head clamping assembly, any port of the three-way pipe can be clamped and fixed, the pipe positioning difficulty is reduced, the rubber column heads support the inner walls of the pipe heads, the deformation probability during pipe cutting can be reduced, cutting is convenient, and the production efficiency is effectively improved.

An internal floating piston (IFP) having circumferential seal groove 2 on its external surface between two walls 3, 4 of the external surface, and an anti-tipping feature 8 increasing a length of said

The invention discloses a suspended small cased well eccentric integrated double-pipe separated injection pipe column and a separated layer water injection method thereof, and aims to improve the later testing and adjusting success rate of small-diameter separated injection construction and prolong the separated injection validity period. The separate injection pipe column comprises an outer layer pipe and an inner layer pipe. The outer layer pipe comprises a conventional oil pipe, a double-flow-channel eccentric water distributor, an outer connecting sleeve, an adapter connector, a small-diameter oil pipe, a small-diameter packer, a double-acting injection valve, a small-diameter check valve, a screen pipe and a screwed plug which are sequentially connected from top to bottom. The inner-layer pipe comprises a first oil pipe connected to the lower inner end of the double-flow-channel eccentric water distributor and a rear-throwing ball type check valve. The layered water injection method comprises the steps of tripping in a tubular column, pressing and setting, measuring a water absorption index, putting a valve ball to control a water injection channel, and flushing a well. The method can achieve accurate layered water injection, improve the water injection efficiency and prolong the validity period of layered water injection, and is suitable for layered water injection operation of small cased wells.

A fluid damper having a damper housing with a first and a second fluid volume, and a damping piston located within the damper and separating the first and second fluid volume. The damper piston has a piston fluid pathway formed therethrough and between the first and second fluid volume. The fluid damper includes a fluid accumulator having a pressurizable gas volume and an accumulator fluid volume isolated from one another by a separation member. The fluid damper has a first fluid pathway extending solely between the first fluid volume and the accumulator fluid volume, and the fluid damper has a second fluid pathway extending solely between the second fluid volume and the accumulator fluid volume. A flow control valve is located in at least one of the first and the second fluid pathways, and the flow control valve has a non-zero threshold value.

A double pipe for heat exchange in which an inner pipe is inserted into an outer pipe to enable heat exchange among a fluid flowing through an inner flow path in the inner pipe and an outer flow path between the inner pipe and the outer pipe. In a straight pipe portion extending linearly in a pipe lengthwise direction, a pipe wall of the inner pipe has a plurality of convex portions in a circumferential direction so as to form a concave / convex cross-sectional shape, and in the pipe wall of the inner pipe, an inclined pipe wall portion whose convex portion extends spirally in the pipe lengthwise direction and a turbulence-generating pipe wall portion whose convex portion has a lead angle different from that of the inclined pipe wall portion are formed in series in the pipe lengthwise direction.

A fluid damper having a damper housing with a first and a second fluid volume, and a damping piston located within the damper and separating the first and second fluid volume. The damper piston has a piston fluid pathway formed therethrough and between the first and second fluid volume. The fluid damper includes a fluid accumulator having an accumulator fluid volume. The fluid damper has a first fluid pathway extending between the first fluid volume and the accumulator fluid volume, and the fluid damper has a second fluid pathway extending between the second fluid volume and the accumulator fluid volume. A flow control valve is located in at least one of the first and the second fluid pathways, and the flow control valve has a non-zero threshold value.

The invention discloses a concentric double-pipe continuous negative pressure sand washing device and process. The device comprises a pump truck and a sand washing pipe column structure. The pump truck is used for providing sand washing liquid pressure and displacement for the sand washing pipe column structure; the sand washing pipe column structure comprises a concentric double pipe column, a process pipe, a negative pressure injection pump and a sand washing nozzle. A process pipe; wherein an annular liquid return channel is formed between the outer-layer oil pipe of the concentric double-pipe column and the inner-layer oil pipe of the concentric double-pipe column; a negative-pressure injection pump and a sand washing nozzle are mounted at the bottom of the inner-layer oil pipe; the sand washing fluid shunting channel is divided into two channels; one part of sand washing fluid enters the well bottom through the self-sealing well mouth and the inner-layer oil pipe in sequence, and the sand washing fluid makes contact with the sand surface of the well bottom through the sand washing nozzle; and the other part of the sand washing fluid generates negative pressure through the negative pressure injection pump to discharge the formation produced fluid and mixed fluid of the sand washing fluid and shaft sand grains out of the ground through the annular fluid return channel and the process pipe, and through the concentric double-pipe structure and the negative pressure injection pump, internal circulation of the sand washing fluid and continuous negative pressure sand washing are achieved.

The invention relates to a vacuum switch circuit breaker. The vacuum switch circuit breaker comprises a protective shell and a supporting shell, the double-tube vacuum bag is positioned in the shell and comprises a vacuum arc extinguish chamber and a vacuum insulation chamber; wherein the vacuum arc-extinguishing chamber comprises a static conducting rod and a movable conducting rod, the static conducting rod comprises a first penetrating end and a first contact end, the first penetrating end penetrates through one end of the vacuum arc-extinguishing chamber, the movable conducting rod comprises a second penetrating end and a second contact end, and the second penetrating end penetrates through the other end of the vacuum arc-extinguishing chamber and extends to the vacuum insulation chamber; the first contact end of the static conducting rod and the second contact end of the movable conducting rod are oppositely arranged and are spaced by a distance; the vacuum insulation chamber comprises an insulation push rod, one end of the insulation push rod penetrates through the other end of the vacuum insulation chamber, and the other end of the insulation push rod is connected with the second penetrating end of the movable conducting rod; and the transmission and control mechanism is connected with one end of the insulating push rod. By arranging the vacuum insulation chamber, the insulation push rod is packaged, and the insulation performance is better.

The invention discloses a fastening device for water conservancy and hydropower construction, relates to the field of water conservancy and hydropower construction auxiliary equipment, and aims to solve the problems of low pipeline butt joint precision, difficulty in parallelism control and poor distance adjusting efficiency in the existing two-group double-pipe parallel construction. The device comprises a bottom plate, a mounting frame, a sliding device, an adjusting device, a clamping device and a control panel, and buffer springs are arranged in supporting legs of the mounting frame. The adjusting device drives the clamping assembly through the bidirectional threaded rod, and coaxiality control over segmented splicing of the long pipeline is achieved. The sliding device is matched with an electric push rod through a sliding rail, and the parallel distance between the two spliced long pipes is adjusted in an electric control mode through a control panel. The device adapts to various common pipe diameters, can be assembled and disassembled by a single person, is stable in fixation, can resist construction vibration and pressure, conforms to related specifications, remarkably improves the construction efficiency, reduces the equipment cost, and is suitable for cooling pipes, water supply pipes, grouting pipes and other scenes.

The present invention discloses an inner-rotating and outer-braking double-tube drilling device, which belongs to the drilling machinery for pile foundation engineering; the inner drill rod of the braking device is connected to the power head of the ground drilling rig, and is connected to the hydraulic down-the-hole hammer drill bit at the bottom, so as to transmit the torque to the hydraulic down-the-hole hammer drill bit; the outer brake pipe is connected to the outer ring of the central swivel joint, connected to the ground section by section, and stopped by the stop frame on the power head. When the inner drill rod rotates, the inner ring of the central swivel joint rotates, and the outer ring of the central swivel joint does not rotate due to being connected to the outer brake pipe, so that the hydraulic oil pipe outside the outer brake pipe does not rotate, so that the hydraulic oil pipe does not entangle the drill tool, and the hydraulic down-the-hole hammer drill bit can continuously rotate in one direction for drilling. The present invention has a simple structure and is easy to operate. It solves the directional problem that the functional hydraulic pipeline outside the drill tool in the hole does not entangle the drill tool when the drill tool continuously rotates in one direction during drilling, and fills the world gap in this industry.

The utility model belongs to the technical field of optical gauges, and particularly discloses a device for calibrating the optical axis of a binocular telescope. A double-tube front lens of the device is fixed on the upper portion of an adjusting frame, a collimator, a supporting seat and the adjusting frame are sequentially arranged on a workbench, a cross reticle I is arranged in the collimator, cross reticles II are arranged in lens bodies of the double-tube front lens, and a supporting flat plate for placing a binocular is arranged at the top end of the supporting seat. Three adjusting screws I in threaded connection are evenly distributed on a base I of the adjusting frame in the circumferential direction, a bottom sleeve is vertically fixed to the middle of the upper surface of the base I, the lower portion of a lifting rod extends into the bottom sleeve in a sliding mode, a set screw is arranged on the side wall of the bottom sleeve to lock the lifting rod, and a double-tube front mirror is detachably and fixedly connected to the top end of the lifting rod. According to the utility model, the binocular telescope can be directly placed on the supporting flat plate of the supporting seat to directly detect the optical axis deviation, and the device has the characteristics of simple structure, convenient detection, flexible adjustment and low cost.

The invention relates to a suspension tunnel, and discloses a double-pipe suspension tunnel vehicle-rail-pipe-cable coupling system dynamic response analysis method, which comprises the following steps of: constructing a space vehicle subsystem motion equation, establishing a rail-pipe-anchor cable subsystem motion equation, constructing a wheel-rail contact equation, and solving to obtain a vehicle transmission load borne by a rail; a double-pipe suspension tunnel vehicle-rail-pipe-cable coupling system dynamic model is constructed; and calculating a wave load by utilizing a Morrison equation, establishing a vehicle-rail-pipe-cable coupling system kinetic equation under the action of the wave load, and solving by adopting a separation iteration method to obtain the dynamic response of the pipe body, the anchor cable and the vehicle of the double-pipe suspension tunnel. According to the method, the enhancement effect of the double-pipe linkage structural component on the transverse rigidity of the double-pipe suspension tunnel and the train eccentric load of the suspension tunnel are fully considered, the dynamic equation of the coupling system is established, the dynamic response of the system can be accurately calculated, the calculation precision and efficiency are both considered, and theoretical support and a technical path are provided for design and construction of the suspension tunnel.

The invention discloses a heat pump type efficient dehumidification device with a waste heat recovery function, and belongs to the technical field of efficient dehumidification devices. A temperature locking cavity is formed in the center of the interior of a dehumidification base, a first hot-pressing dehumidification box and a second hot-pressing dehumidification box are symmetrically arranged at the two ends of the temperature locking cavity, heat pump storage boxes are arranged at one ends of the hot-pressing dehumidification boxes side by side, and a flow guide center frame is arranged in the center of the interior of the second hot-pressing dehumidification box; the device has the remarkable advantages that firstly, a high-temperature primary dehumidification and low-temperature secondary dehumidification grading mode is adopted, the design of a zigzag flow channel and a symmetrical cavity is matched, the dehumidification efficiency is high, continuous operation can be kept during cavity dehydration, and constant temperature and low humidity of the environment are ensured; secondly, a whole-process waste heat utilization system is constructed, cold water is converted into hot water through cold water spraying, heat exchange arc piece circulation and the like, meanwhile, waste heat of a temperature locking cavity is recycled, and energy waste is reduced; and hot water and waste water are treated in order through the double-pipe hot drain valve, and environmental protection and economical efficiency are both considered.

The invention belongs to the technical field of sealing parts, and particularly discloses a polyurethane sealing part and a production process thereof.The polyurethane sealing part comprises a first connecting pipe and a second connecting pipe, and the end, close to the first connecting pipe, of the second connecting pipe is fixedly connected with an inserting ring. The problems that a traditional sealing piece is small in contact area and poor in coating performance are solved, a first connecting pipe and a second connecting pipe are positioned through an inserting ring to form mechanical embedding, a protruding ring of a sealing connecting ring is matched with an annular groove of an elastic ring and an expansion rubber ring to construct a physical sealing barrier, the contact area is increased, and when an extrusion assembly applies pressure, an external supply set injects viscoelastic fluid of an outer bag body into an inner cavity of the elastic ring; the driving elastic ring and the expansion rubber ring are internally expanded and externally hooped to doubly wrap and fill the interface gap, so that the plane-to-three-dimensional contact upgrade is realized, the stress is uniformly dispersed, and the expansion rubber ring can compensate the gap through elastic deformation to improve the sealing performance even if the pipeline is rusted and displaced.

1. The name of the design product: cosmetic packaging bottle (JY42 double tube bottle E-F series). 2. The use of the design product: for a cosmetic bottle. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: design 1 perspective view. 5. Design 1 is designated as the basic design.

The utility model discloses a concentric double-pipe leather cup type composite gas anchor, which relates to the field of oil exploitation, and comprises a centrifugal mechanism and a separation mechanism, the centrifugal mechanism comprises a plug, a lower joint, a centrifugal body and a cone, and the plug, the lower joint, the centrifugal body and the cone are sequentially connected through threads; the separating mechanism comprises an inner pipe, an outer pipe, an outer sleeve, a separating body and an upper connector, the lower end of the inner pipe is in threaded connection with the cone, the upper end of the inner pipe is freely suspended, the upper end of the outer pipe is in threaded connection with the separating body, the other end of the outer pipe is freely suspended, two ends of the outer sleeve are in threaded connection with the centrifugal body and the separating body respectively, and the upper connector is in threaded connection with the separating body. The underground gas-liquid separation device has an underground gas-liquid separation function, prevents gas from entering an oil well pump, reduces pump efficiency, avoids gas locking, and improves oil extraction efficiency.

The invention provides a double-pipe self-locking type gas spring and relates to the technical field of double-pipe self-locking type gas springs, the double-pipe self-locking type gas spring comprises a sleeve, a lubricating structure, a connecting structure and a safety structure, a sliding rod is installed on the inner wall of the sleeve, a connecting piece is arranged at the end, away from the sliding rod, of the sleeve, and a connecting piece is arranged at the end, away from the sleeve, of the sliding rod; the connecting piece and the joining piece are connected with the sliding rod and the sleeve respectively through connecting structures, and a lubricating structure is arranged at the upper end of the sleeve. The problems that when a double-pipe self-locking type spring is used, a lubricating device is arranged in the double-pipe self-locking type spring, but in the actual using process, lubricating oil is troublesome to add and replace, continuous and stable lubrication of sliding parts in the double-pipe self-locking type spring is difficult to achieve, and the service life of the double-pipe self-locking type spring is affected are solved. The problem that the normal use and the service life of the double-tube self-locking spring are affected due to the fact that the sliding rod and the sleeve are prone to being blocked and even abraded due to the fact that friction is too large is solved.

The invention discloses a double-pipe drilling double-power drilling machine system, which belongs to the technical field of drilling rods, and comprises an outer drilling rod, a spiral inner drilling rod is rotatably arranged in the outer drilling rod, the outer drilling rod is in threaded connection with a pipe drill bit, a PDC drill bit is arranged at one end, far away from the outer drilling rod, of the pipe drill bit, and a plurality of liquid holes are formed in the PDC drill bit; a composite slice drill bit is arranged on the periphery of the end, away from the outer drill rod, of the pipe drill bit, and a deslagging channel is formed between the composite slice drill bit and the PDC drill bit. And a central channel communicated with the liquid hole is formed in the central position of the spiral inner drill rod. According to the double-pipe drilling and double-power drilling machine system, scour and damage of drilling cuttings to a drilling hole wall are fundamentally eradicated, the drilling cuttings carrying efficiency of a medium is greatly improved through the spiral stirring and vortex effect generated by reverse rotation of the inner drill pipe and the outer drill pipe, the stubborn problem that a slag discharging channel is blocked is effectively solved, and the service life of the drilling cuttings is prolonged. And continuous and efficient operation under complex and deep hole working conditions is ensured.

A double-tube packaging container bottle comprises an outer bottle body, an inner bottle body and a rotating cover, a first assembly head is arranged at a bottle neck of the inner bottle body, a second assembly head is arranged at a bottle neck of the outer bottle body, a first clamping cavity is formed in the inner side of the second assembly head, the first assembly head is clamped in the first clamping cavity from the interior of the outer bottle body, and the rotating cover is arranged on the inner side of the second assembly head. The rotating cover is rotatably installed on the second assembling head, a first liquid outlet communicated with the interior of the inner bottle body is formed in the edge of the top of the first assembling head, two liquid distribution openings are formed in the second assembling head, one liquid distribution opening is communicated with the inner bottle body, and the other liquid distribution opening is communicated with the outer bottle body; in addition, a rotating cover is rotationally mounted on the second assembly head, and the second liquid outlet is communicated with one of the liquid separation openings by rotating the rotating cover, so that the substances in the inner bottle body and the outer bottle body are respectively guided out, and the flexibility and the practicability are improved.

An ultrasonic liquid level sensor probe using a piezoelectric plate FPC module which has a simple configuration, is small and easy to handle, requires no wiring of lead wires, and is easily assembled into a probe. For the piezoelectric plate FPC module, there are a single-sided arrangement, in which an FPC is bonded to one-side surfaces of two or more piezoelectric plates, and a double-sided arrangement, in which two or more piezoelectric plates are sandwiched between two FPCs that are an FPC for individual electrodes and an FPC for a common electrode. The ultrasonic liquid level sensor probe has the piezoelectric plate FPC module stored in a double pipe serving as an insertion portion of the ultrasonic liquid level sensor probe.

The utility model belongs to heat exchanger technical field, concretely relates to a heat exchanger double tube plate welding structural member. Heat exchanger double tube plate welding structural member includes: the tube side tube plate is provided with the boss at the right end part of the tube side board tube, is provided with the boss ring main part at the left end part of the shell side tube plate, is provided with the boss ring step at the left end part of the boss ring main part, the right end surface of the boss is with the left end surface of the boss ring main part coaxial contact, the inner side surface of the boss ring step is with the outer side surface of the boss adapts, the outer side surface of the boss ring step and the outer side surface of the boss are the welding position.

The invention belongs to the technical field of testing and sampling, and particularly discloses a semi-closed tube type static and dynamic triaxial undisturbed sample cutting ring soil sampler. Two ends of an upper joint of the soil sampler are respectively provided with interfaces connected with a drill rod and fixed with a waste soil pipe, and the bottom end of a pipe boot is provided with a cutting edge I; an outer soil sampling pipe of the soil sampling pipe is of a tubular structure formed by buckling two semi-closed pipes, external thread sections are arranged at the two ends of the outer soil sampling pipe respectively, the two ends of the outer soil sampling pipe are in threaded connection with a waste soil pipe and a pipe shoe through the external thread sections, a cutting ring support is of a double-pipe structure formed by buckling two omega-shaped semi-closed pipes, the cross section of the cutting ring support is in a transverse 8 shape, and the cutting ring support can be embedded into the outer soil sampling pipe and is provided with a fixing groove. The cutting ring is of a tubular structure formed by buckling two semi-closed tubes and can be embedded into the fixing groove. The cutting ring support of a semi-closed double-pipe structure is arranged in the soil sampling pipe, and two cutting rings can be fixed through the fixing grooves in the cutting ring support respectively, so that four tailing undisturbed samples can be sampled at a time to meet the requirements of a group of samples for a triaxial compression test, and the device has the characteristics of simple structure, easiness in disassembly and assembly and small disturbance.

A slit nozzle having a double-tube structure and a method for manufacturing a high-silicon steel strip having a small variation in Si concentration depending on the position in the width direction of the steel strip. The slit nozzle has a double-tube structure, in which a flow-control plate which closes a gap between an inner tube and an outer tube is disposed between an open end of the inner tube and an end of a delivery port, and in which an opening is formed in a plane in which the flow-control plate is disposed only in a range of the flow-control plate of 27.5° or more and 332.5° or less in terms of a central angle with respect to a reference line L1 passing through the axis of the outer tube and the central position in the width direction of the delivery port.

The invention provides a double-pipeline laying method capable of welding while construction, which belongs to the technical field of marine oil and gas engineering and comprises the following steps: step 1, executing a dynamic welding and double-pipeline collaborative laying method; 2, executing a mechanical and deformation control method of the pipeline structure; and step 3, executing the land-sea collaborative operation and partition management and control method. The defect that in the prior art, due to the fact that the working space of a pipe laying ship is relatively narrow, the high-efficiency and high-quality double-pipe welding requirement is difficult to meet through traditional welding equipment and technology is effectively overcome.

The utility model discloses a ventilation pipe with a dry-wet separation structure, and particularly relates to the technical field of ventilation pipes, the ventilation pipe comprises an outer pipe structure, a primary filter, an inner pipe structure and a secondary filter, the left side of the outer pipe structure is provided with a wet air inlet, and the inner pipe structure is arranged in an inner cavity of the outer pipe structure; by means of the inner and outer double-pipe structure composed of the outer pipe structure and the inner pipe structure, indoor humid air can be exhausted, meanwhile, dry air is introduced, the indoor relative humidity is controlled within a proper range, the indoor air quality is improved, and the stability of the environment is guaranteed; by means of the inner and outer double-pipe structure composed of the outer pipe structure and the inner pipe structure, the situation that wet air and dry air permeate mutually can be effectively avoided, the inner and outer double-pipe structure prevents the wet air and the dry air from being mixed, the purity of the dry air entering a processing area is ensured, meanwhile, the wet air containing pollutants can be safely exhausted, and the processing efficiency is improved. And secondary pollution to the indoor environment is prevented.

The present invention discloses a segmented water control and sand prevention completion string and method for cementing and isolating open-hole horizontal wells, comprising an outer string and an inner string. The outer string is provided with casing, a cementing device, a sand filter, an external packer, a blind pipe, an external packer, a sand filter, and a well flushing valve in order from top to bottom, and the inner string is provided with a first packer, a cementing external blind pipe, a second packer, a cementing external blind pipe, an upper switch, a first protective packer, a lower switch, a second protective packer, and a plug in order from top to bottom. The invention adopts a double-tube structure, with the string provided with a cement injection port and a cement return port, to achieve cyclic injection of cement slurry and improve the quality of cementing. After cementing is completed, the inner injection port and the cement return channel are provided with an automatic closing mechanism, which automatically closes after the cementing pump is stopped to prevent the injected cement slurry from being spitted back.

The application discloses an adjustable double-pipe welding table, which comprises a table top, a supporting frame, an adjusting device and a to-be-welded part positioning device, the to-be-welded part positioning device is installed on the table top, the to-be-welded part positioning device can stop and position each to-be-welded part, the table top is hingedly arranged on the supporting frame and can rotate around a horizontal rotating shaft, and the adjusting device can stop and position the table top and the supporting frame which are rotated to any angle, the to-be-welded part can be opposite to different welding directions through the rotation of the table top around the horizontal rotating shaft on the supporting frame, and the worker can accurately weld all welding positions of the part without changing the welding position around the to-be-welded part during the welding process, the to-be-welded part positioning device can accurately position the upper pipe, the lower pipe and the connecting plate in all directions, the synchronous welding of multiple parts of the cantilever can be realized at one time, the welding efficiency is high, there is no repeated positioning error, and the welding precision is high.

The application relates to a double-pipe booster which comprises a container body and a boosting piece, and relates to the technical field of oral care products and auxiliary equipment thereof. The container body comprises at least two pipe bodies, the multiple pipe bodies are arranged in parallel and side by side, the adjacent two pipe bodies are fixedly connected, one end of the pipe body is a discharging port, and the other end is a pushing port; a sliding seat is arranged in each pipe body, the outer wall of the sliding seat is attached to the inner wall of the pipe body, and the sliding seat is slidingly connected to the pipe body along the pipe length direction of the pipe body; the boosting piece is arranged correspondingly to the pipe body, the boosting piece slides in parallel to the pipe length direction of the pipe body, the multiple boosting pieces are arranged in parallel and at intervals, the adjacent two boosting pieces are fixed through a first connecting piece, so that the adjacent two boosting pieces have a gap, one end of each boosting piece is located in the pipe body and slides along the pipe length direction of the pipe body, and one end of the boosting piece abuts against one side of the sliding seat close to the pushing port. The application has the effects of improving product proportioning accuracy and being simple to operate.

The present invention provides an inner pipe support unit having a brace of a leaf spring structure for supporting an inner pipe disposed in an inner space of an outer pipe constituting a double pipe that may be provided in a gas transfer system or the like of a ship using LNG, LPG, or the like as fuel gas. The inner pipe support unit for a double pipe according to the present invention, as described above, provides: 1) a structure in which a pair of braces surrounding the inner pipe are connected by direct wide-area surface contact in a predetermined area range; 2) a structure in which the pair of braces are fastened to each other by bolts and nuts coupled to each other outside the braces through fastening holes formed only on both ends of fastening guides having a width greater than that of the braces; and 3) a structure in which the pair of braces surround the inner pipe with a pair of bushings disposed therein. Accordingly, structural stability and material mechanical stability are maximized, deformation / cracking / twisting / fatigue failures are minimized / suppressed by high durability, and manufacturing / assembly / installation works are facilitated.

The application discloses a kind of test pile double-tube pile sleeve and preparation method thereof, including inner cylinder body, inner support component, closed component, positioning assembly, middle outer tube, bottom outer tube, first limit block, second limit block, top outer tube, reinforcing support and third limit block, the bottom of the middle outer tube is welded with bottom outer tube, and the inner wall top end of bottom outer tube is uniformly provided with first limit block, first limit block is slidably connected on inner cylinder body, the present application, positioning assembly is positioned to inner cylinder during hoisting, and the installation quality of pile sleeve is guaranteed;The gap between top outer tube and inner cylinder body is closed using closed component, improve the sealing effect of pile sleeve, prevent soil and gravel from falling into the gap between outer tube and inner cylinder during construction, guarantee the actual effect of pile sleeve clearance friction;Inner cylinder body is assisted and supported using the inner support component, to avoid deformation of inner cylinder body during hoisting, improve the practicability of pile sleeve.