63 results about "Pipe in pipe" patented technology

The invention relates to the technical field of cable construction, in particular to a cable pipe penetrating device and a construction method thereof.The cable pipe penetrating device is characterized in that a pulling device and a clamping device form a whole, an advancing device is detachably and fixedly connected to one side of the clamping device, a winding roller is arranged on the pulling device, a pulling rope is wound around the winding roller, the pulling rope is connected with a clamp, and the clamping device is connected with the clamping device; the clamp is clamped and embedded in the edge of one end of the embedded pipe, the pulling device and the clamping device are driven to the other end of the embedded pipe through the clamping device, after the end of the cable is inserted and fixed to the clamping device, the pulling device is started to clamp the cable to return to the end, where the clamp is installed, of the embedded pipe, and cable pipe penetrating is completed. The device can thoroughly isolate a cable copper core from being in contact with a pipe wall, is suitable for embedded pipes with different pipe diameters, and effectively solves the three problems of pipe wall scratching, cable clamping stagnation and low efficiency in traditional pipe penetrating.

The invention relates to the technical field of geological exploration, and discloses a stratified sampling drilling device and a connecting piece and a drilling cylinder thereof, which are arranged at the top end of the device and used for providing rotation driving force. The multi-section drill pipe comprises a low pipe, a middle pipe and a deep pipe which are connected in sequence. According to the stratified sampling drilling device and the connecting piece thereof, the connecting piece adopts a circumferential positioning and radial limiting structure of an annular groove II and an annular positioning plate, and is matched with the axial locking design of a threaded rod and a nut, so that the coaxiality and the connection strength of adjacent drilling pipes are kept in the drilling process, and the impact of stratum stress is effectively resisted; the annular positioning plate is embedded into the second annular groove to achieve + / -0.05 mm-level coaxiality calibration, the pre-tightening force of the threaded rod can reach 50 kN, compared with traditional threaded connection, the torsional strength is improved by three times, the disassembly time is shortened to 5 minutes from 30 minutes, the detachable connection mode supports rapid assembly and disassembly, the number of drill pipe sections can be flexibly increased or decreased according to the drilling depth, and the drilling efficiency is improved. Meanwhile, the equipment maintenance and sample cylinder replacement processes after sampling are simplified, and the working efficiency is improved.

This invention discloses a waste transfer device for high-rise building construction, relating to the technical field of building engineering and related equipment. The invention includes a central pipe and a floor slab located inside it. A feeding pipe is provided below the front end face of the central pipe. Sliding grooves are provided on the upper and lower sides of the outer walls of the central pipe. Installation components are provided on the front ends of the outer walls of the central pipe. A first limiting component is provided inside the pressing groove, a rotating component is provided inside the adjusting groove, a second limiting component is provided inside the moving groove, and a crushing component is provided above the front end face of the central pipe. This invention improves the stability of the device through the installation components and the first limiting component, preventing thread stripping and reducing safety hazards. Simultaneously, the rotating component and the second limiting component facilitate quick installation, docking, and disassembly of the folded pipe by construction personnel, resulting in high work efficiency. The crushing component further improves the efficiency of waste transfer and avoids pipe blockage.

The utility model provides a conveying support for penetrating a steel pipe into a pipe jacking steel sleeve, the conveying support comprises a first support assembly and a second support assembly which are sequentially connected end to end, the first support assembly and the second support assembly are of the same structure, and support legs are arranged on the two sides of the bottom of the first support assembly and the two sides of the bottom of the second support assembly; the first support assembly comprises a first main beam and a second main beam, the first main beam and the second main beam are fixedly connected through a cross beam, upper supports are fixedly connected to the first main beam, the second main beam and the cross beam respectively, and the supports are welded to steel sleeves by manufacturing the supports. The support can be arranged according to the specific construction environment and the conveying length, full-pipeline track laying is omitted, the automatic distance measuring instrument installed at the end of the support can also measure the conveying distance, and after the support is installed, the steel pipe is arranged on the support and can be dragged away through small equipment. The construction method is simple and fast, low in cost and capable of providing reference for projects of the same type.

1. Name of the designed product: the main body of shower set (pipe-in-pipe). 2. Use of the designed product: overall use: shower set; partial use: the main body of shower set. 3. Design points of the designed product: in shape. 4. Picture or photo that best shows the design points: perspective view. 5. Other circumstances or explanations: the designed product is a partial design, wherein the solid line part in the view is the claimed part and the dotted line part is the unclaimed part.

The application discloses a high-rigidity unbonded cooperative loading system and a construction method thereof, belongs to the technical field of structural engineering test, and is characterized in that opposite-side cooperative steel beams are arranged on opposite sides of a structure to be tested; top-loading steel beams are arranged in a cross shape in the opposite-side cooperative steel beams and are connected with the opposite-side cooperative steel beams at the ends; the top-loading steel beams are double-layer unbonded sleeve pipe assemblies, which comprise an inner square steel pipe and a peripheral round steel pipe sleeved outside the inner square steel pipe, and a preset gap is arranged between the inner square steel pipe and the peripheral round steel pipe; and horizontal prestressed tendons are arranged around the peripheral round steel pipe and are connected with the opposite-side cooperative steel beams at the ends. The high-rigidity unbonded cooperative loading system and the construction method thereof are adopted, the force transmission channel is separated from the fixed interface through the unbonded design of the pipe-in-pipe, and the problems of local buckling, deformation coupling and poor opposite-side cooperativeness of the traditional loading scheme in the super-large tonnage test are solved.

The invention relates to the technical field of pipe belt machines, in particular to a pipe twisting prevention method for a pipe belt machine, when the pipe belt machine operates, a support with a sliding seat is arranged at an opening section, a deviation switch capable of horizontally moving on the support is located at a V-shaped pipe belt of the opening section, and the bottom of a fastening bolt abuts against the surface of the support; the sliding seat and the support are relatively fixed, the deviation switch is fixed in the horizontal transverse direction, the deviation switch is located at the V-shaped pipe belt of the opening section of the pipe belt machine, and when the pipe belt on one side deviates, the deviation switch is extruded and contacted to trigger an alarm. When the pipe belt deviates, the deviation switch is triggered to give an alarm, and the phenomenon of further pipe twisting is prevented.

The utility model relates to a telescopic rod of one-key locking multi-section pipe, including telescopic pipe body of inner tube, middle tube and outer tube are successively sleeved, and locking mechanism is used for locking each pipe section of telescopic pipe body, locking mechanism includes the upper lock structure for locking and loosening the joint of inner tube and middle tube, the lower lock structure for locking and loosening the joint of middle tube and outer tube, the transmission bar for transmitting the kinetic energy of the locking action of upper lock structure and controlling the locking and loosening action of lower lock structure, the utility model has the advantages of: the kinetic energy of the locking action of upper lock structure is transmitted through transmission bar and controls the locking and loosening action of lower lock structure, namely one locking mechanism can lock three pipe bodies of upper, middle and lower adjacent to each other, simplifies the process of adjusting and locking of existing telescopic rod, and it is more convenient to use.

The utility model relates to a caterpillar type supporting structure used for a pipe-in-pipe, which solves the problems that when a large-depth single-well geothermal energy exploration and production well adopts a pipe-in-pipe or hole-in-pipe structure, the supporting and fixing of a central pipe not only need to ensure that the central pipe does not incline or deform, but also need to ensure the requirement of flexible adjustment. The structure comprises an outer pipe and an inner pipe, the inner pipe is arranged in the outer pipe in a penetrating mode, a gap is formed between the outer wall of the inner pipe and the inner wall of the outer pipe, a supporting mechanism is arranged between the outer wall of the inner pipe and the inner wall of the outer pipe and comprises a sleeve arranged on the outer wall of the inner pipe in a sleeving mode, at least three supporting feet are evenly arranged on the periphery of the sleeve, and the outer ends of the supporting feet abut against the inner wall of the outer pipe. Each supporting foot is sequentially provided with a first one-way joint and a second one-way joint from inside to outside, and the swinging directions of the first one-way joints and the second one-way joints are both in the axial direction of the outer pipe and are opposite. Stable supporting is formed in the static state, and when the inner pipe and the outer pipe are drawn relative to the axial direction, the first one-way joint and the second one-way joint can reduce drawing resistance bidirectionally and avoid obstacles.

The utility model belongs to the technical field of domestic water, and particularly relates to a diaphragm type balance valve core for a pipe-in-pipe and a balance valve. The balance valve is provided with a balance valve element and comprises a balance valve frame, a balance valve element and a balance valve element, the valve core seat is mounted on the balance valve frame; the diaphragm component is installed on the valve element seat or in the balance valve frame, and a balance channel is arranged between the valve element seat and the diaphragm component or between the balance valve frame and the diaphragm component; the diaphragm component can deform and change the sectional area of the balance channel according to the pressure of the first channel. The medium pressure is large, the deformation amount of the diaphragm component is large, and the backflow amount of the balance channel is small, so that the backflow amount of the branch away from the circulating pump is larger than or equal to the backflow amount of the branch close to the circulating pump, the effect that the backflow amount is small and large is achieved, and the circulating efficiency and the water quality of the branch at the far end are guaranteed.

The utility model relates to the technical field of plastic pipe fitting production, and discloses a continuous pipe feeding pipe cutting machine for plastic pipe fitting production, which comprises a base, the outer wall of the upper end of the base is rotatably connected with a cutting arm, one end of the cutting arm far away from the base is rotatably connected with a cutting wheel, and the outer wall of the upper end of the base is fixedly connected with a fixed push rod. And the output end of the fixed push rod is fixedly connected with a fixed plate, a cutting groove is formed in the outer wall of the upper end of the base, and a material continuing assembly is arranged outside the base. According to the pipe cutting machine capable of continuously feeding the pipes for plastic pipe fitting production, multiple sets of plastic pipes are placed in the pipe storage groove, at the moment, when the electric push rod drives the barrier strip to move, one ends of the plastic pipes in the pipe storage groove can stretch out of the discharging groove, and when the barrier strip moves along with the electric push rod, the plastic pipes can be disengaged from the discharging groove; the plastic pipes in the pipe storage groove can be continuously pushed out when the electric push rod reciprocates, time and labor are saved, and the efficiency of the pipe cutting machine is higher.

The present invention provides a simulation test system and method for a laser-mechanical combined high-efficiency drilling and rock-breaking platform, comprising: a laser-mechanical combined drill tool, a drive device, a drill tool mounting device, a position adjustment device, and a confining pressure loading device. The drive device is used to rotate and propel the drill tool to achieve rock-breaking. The drill tool is fixed to the position adjustment device via the mounting device, enabling adjustment of the borehole space and relative angle. The confining pressure loading mechanism is used to apply confining pressure to the specimen, simulating a realistic geostress environment. The present invention achieves all-round and multi-angle continuous drilling through a displacement adjustment device; simulates a realistic geostress environment through the confining pressure loading device, and increases the combined rock-breaking efficiency by offsetting the laser. The multi-tube-in-tube structure solves the design challenges of the laser-mechanical integrated mounting system. Optimizing the pipeline layout within the drill pipe solves the problems of laser energy transmission and laser head cleaning and protection.

The invention belongs to the technical field of domestic water, and particularly relates to a diaphragm type balance valve element for a pipe-in-pipe, a balance valve and a pipe-in-pipe circulation system. The pipe-in-pipe circulation system comprises a plurality of branches, each branch is provided with a balance valve element, and the pipe-in-pipe circulation system comprises a balance valve frame installed at the tail end of a pipe-in-pipe pipeline; the valve core seat is mounted on the balance valve frame; the diaphragm component is installed on the valve element seat or in the balance valve frame, and a balance channel is arranged between the valve element seat and the diaphragm component or between the balance valve frame and the diaphragm component; the diaphragm component can deform and change the sectional area of the balance channel according to the pressure of the first channel. The medium pressure is large, the deformation amount of the diaphragm component is large, and the backflow amount of the balance channel is small, so that the backflow amount of the branch away from the circulating pump is larger than or equal to the backflow amount of the branch close to the circulating pump, the effect that the backflow amount is small and large is achieved, and the circulating efficiency and the water quality of the branch at the far end are guaranteed.

The utility model relates to the technical field of pipeline control valves, in particular to a pipe-in-pipe control valve and a pipe-in-pipe control valve assembly, which are used for controlling an inner flow channel or an outer flow channel of a pipe-in-pipe and comprise a mounting base, a control assembly is arranged on the mounting base, and the mounting base and the control assembly are matched to form a mounting cavity; the mounting base is provided with a mounting part, a liquid inlet channel and a liquid outlet channel which are used for being communicated with the inner flow channel / the outer flow channel are formed in the mounting part, the liquid inlet channel and the liquid outlet channel are communicated through the mounting cavity, and the control assembly is used for connecting or disconnecting the liquid inlet channel and the liquid outlet channel; wherein a check valve assembly is arranged in the liquid outlet channel, and the check valve assembly is used for preventing backflow. Preferably, the check valve assembly comprises an annular check seat, a valve rod and a valve rod, and a through hole is formed in the check seat; the non-return ball is arranged between the liquid outlet of the liquid outlet channel and the non-return seat; when liquid at the liquid outlet of the liquid outlet channel flows back, the check ball can block the through hole, and therefore series flow is prevented.

The utility model belongs to the technical field of water conservancy facilities, and particularly relates to a reservoir water intake pipe system which comprises a main pipe gallery, a standby pipe gallery and a water supply three-way pipe, the standby pipe gallery and the main pipe gallery are consistent in structure, the two ends of the water supply three-way pipe are communicated with the main pipe gallery and the standby pipe gallery respectively, and when the main pipe gallery is not maintained, the standby pipe gallery is started, and the water supply three-way pipe is started. The main pipe gallery comprises a pipe gallery body, a PVC foaming floating platform, an L-shaped water taking pipe and a counterweight ball, the L-shaped water taking pipe is movably inserted and mounted at one end of the pipe gallery body, the PVC foaming floating platform and the counterweight ball are assembled at the top end of the L-shaped water taking pipe and connected with the L-shaped water taking pipe through ropes, the PVC foaming floating platform is used for lifting the top end of the L-shaped water taking pipe, and the counterweight ball is used for lifting the top end of the L-shaped water taking pipe. The top end of the water taking L-shaped pipe is always close to the water surface, and turbid water at the bottom of the reservoir is prevented from entering the water taking L-shaped pipe; and the counterweight ball is used for pulling the water taking L-shaped pipe downwards when the water surface is lowered, so that the water taking L-shaped pipe can take water all the time, and the water taking is more reasonable.

The hollow drill rod comprises a rod body and a hollow drill bit installed at the lower end of the rod body, the rod body comprises an inner pipe, a middle pipe and an outer pipe which are sequentially arranged together in a sleeved mode, an inner cavity of the inner pipe forms a slurry cavity, an air cavity is formed between the inner pipe and the middle pipe, and the outer pipe is connected with the inner pipe. A slurry cavity is formed between the middle pipe and the outer pipe; the inner pipe abuts against the inner wall of the center hole in a sealed mode, so that the water cavity is communicated with the center hole of the hollow drill bit. An injection cavity communicated with the air cavity and the slurry cavity is formed between the lower ends of the middle pipe and the outer pipe and the inner wall of the central hole; the hollow drill bit is provided with a jet hole communicated with the jet cavity, and cement paste and compressed air can be mixed in the jet cavity and then jetted outwards through the jet hole. According to the hollow drill rod, reinforcing parts such as the cement soil expansion head and the anchor rod wrapping body can be formed on the core rod, the reinforcing parts and an original structure are integrated, the construction cost can be reduced, and the connecting strength of the reinforcing parts and an existing high-pressure jet expansion head anchor rod can be improved.

The silencing air pipe comprises a pipe shell and a flow guide body, the pipe shell has a front pipe, a middle pipe and a tail pipe, a plurality of flow guide holes are arranged in the front pipe, the inner wall of the middle pipe near one end of the front pipe has a first conical surface, the inner wall of the middle pipe near one end of the tail pipe has a second conical surface, the first conical surface and the second conical surface are coaxial with the pipe shell, a plurality of through holes are densely arranged on the side wall of the tail pipe, a sound absorption layer is arranged on the outer wall of the tail pipe, the outer part of the flow guide body is a cylindrical structure, the front end of the flow guide body has an outer conical surface, the flow guide body is coaxially arranged in the tail pipe, a gap is formed between the outer wall of the flow guide body and the inner wall of the tail pipe, the rear end of the flow guide body is directed to the rear end of the tail pipe, the outer conical surface is arranged in the middle pipe, and the outer conical surface is located at the same position as the second conical surface in the axial direction of the pipe shell, and the projection of the flow guide hole and the outer conical surface in the axial direction of the pipe shell partially overlaps.

The utility model discloses a building foundation pit spraying dust fall device, which relates to the technical field of building construction and comprises a first limiting frame and a second limiting frame, mounting seats are fixedly connected above and below one end of the first limiting frame, and two adjacent mounting seats are fixedly connected through bolts. A first limiting frame and a second limiting frame are arranged on the base, a rotating wheel seat is rotatably connected between the first limiting frame and the second limiting frame, a middle pipe is fixedly connected into the rotating wheel seat, one end of the middle pipe is fixedly communicated with a connecting port, and the other end of the middle pipe is fixedly connected with an atomizing nozzle. Meanwhile, the design structure is simple, use is convenient, the first limiting frame and the second limiting frame are designed in a split mode, the rotating wheel base can be conveniently detached, taken out and replaced, meanwhile, the swing frequency of the middle pipe can be adjusted according to the rotating speed of the driving motor, and use is convenient.

The present invention provides a blowing and filling system between the casing and the inner pipe in pipe jacking construction, comprising an external concrete casing, an inner steel pipe, a sand blowing system, a top sliding track system, and a pipeline sliding system; the sand blowing system is installed on the top sliding track system through the pipeline sliding system; wherein, the top sliding track system is arranged on the top of the inner wall of the external concrete casing. Beneficial effects of the present invention: the blowing and filling system between the casing and the inner pipe in the present invention, through the top sliding track system and the pipeline sliding system, enables the sand blown out from the pipe mouth of the sand blowing pipe to be evenly filled from bottom to top along the two side arc surfaces of the inner steel pipe, thereby effectively reducing the number of sand blowing pipes used and reducing the installation and disassembly time while ensuring the safety of blowing and filling and improving the quality of blowing and filling, while improving the blowing and filling effect and reducing the cost of the sand blowing project.

Techniques for implementing and / or operating a system that includes an outer pipeline, an inner pipeline, and an outer pipeline sealing mechanism. The outer pipeline includes an outer pipe fitting to be secured to an end of an outer pipe segment. The inner pipeline includes an inner pipe fitting to be secured to another end of an inner pipe segment. The outer pipeline sealing mechanism includes a sealing plate to be secured to the outer pipe fitting; a sealing stem that extends out axially from the sealing plate, in which the sealing stem is to be secured to the inner pipe fitting to facilitate sealing an inner pipeline bore from an outer pipeline bore; and a seal ring to be compressed between the sealing plate and the outer pipe fitting to facilitate sealing the outer pipeline bore of the outer pipeline from external environmental conditions.

A device for sealing off a segment of pipe-in-pipe pipeline including an inner pipe and an outer pipe between which an insulating material is interposed, and including a water detector. The device includes: a first plug for closing off the inner pipe, a tubular extension welded to the end of the outer pipe, the free end of the extension extending beyond the first plug and being closed off by a second plug, and a means for fixing the position of the inner pipe and outer pipe, integral with the extension.

Disclosed in the present invention are a rotating structure and a hinge comprising the structure. The rotating structure comprises an upper tube, a middle tube, a lower tube, six spacers, two spring plates, a hinge pin, and a plurality of bearing balls, wherein the upper tube, the middle tube and the lower tube are each provided with a mounting hole on a side surface thereof along its length for assembling a hinge leaf; the spacers are assembled and welded at two ends of each of the upper tube, the middle tube and the lower tube, and a recess is formed at each of the two ends of the middle tube; the upper tube, the middle tube and the lower tube are sequentially arranged on the hinge pin through center holes of the spacers, such that two raceways are respectively formed between the two recesses and the hinge pin; a set of bearing balls is arranged in each of the two raceways; the two spring plates are mounted on the hinge pin and located between the upper tube and the middle tube and between the middle tube and the lower tube, respectively, such that the two spring plates are in contact with the two sets of bearing balls, respectively; and the spacer at the top end of the upper tube and the spacer at the bottom end of the lower tube are both welded and fixed to the hinge pin, such that the upper tube and the lower tube compress the two sets of bearing balls in the raceways by means of the two spring plates respectively. By means of the structure and the hinge comprising the structure, a friction force generated during use can be reduced, wear of the spring plates in use is reduced, and higher requirements for use are met.

1. The name of the design product: hook for pipe spraying. 2. The use of the design product: used for hanging pipes in pipe spraying operation. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: front view.

The utility model discloses an integrated joint steel belt winding pipe, which comprises a bellmouth, a spigot and a pipe body, the bellmouth is arranged at the front end of the pipe body, the spigot is arranged at the rear end of the pipe body, and the bellmouth is matched with the spigot in shape, the integrated joint steel belt winding pipe is characterized in that a reinforcing steel belt is arranged in the pipe body, the reinforcing steel belt is spirally embedded in the outer wall of the pipe body along the length direction of the pipe body, and the spigot is arranged at the rear end of the pipe body. The longitudinal section of the reinforcing steel strip along the axis is wavy; and the bellmouth and the spigot are respectively welded with the front end and the rear end of the pipe body. According to the integrated connector steel belt winding pipe, the connecting positions of the pipe body and the inserting opening and the connecting position of the pipe body and the bellmouth are not prone to deformation and breakage, and the water leakage phenomenon is avoided.

The present application relates to the technical field of workshop storage equipment, in particular to a kind of pipe production workshop storage rack for temporarily storing pipe in production workshop, comprising: fixed frame group, including first side plate, second side plate and top plate, first side plate, second side plate and top plate are enclosed to form the workspace of half covering, first side plate is provided with discharging opening;Movable frame group is set in workspace, including frame body and the movable frame plate of multiple groups corresponding discharging opening, frame body and movable frame plate are enclosed to form the cavity of placement;Movable frame plate slides along support assembly and embeds fixed frame group rear support assembly jacking contact plate, so that movable frame plate is inclined;Support assembly according to the gravity of the activity frame plate received controls the start-stop of overturning component.The pipe production workshop storage rack provided by the present application can automatically place and store pipe in pipe production workshop, facilitate operator to take and place pipe, effectively save human resources and improve the work efficiency of operator.

The utility model relates to a frame integrated with a motor hanging bracket seat, which comprises a hanging bracket seat, a frame lower pipe, a middle pipe and a lower fork pipe, the upper end of the middle pipe is respectively connected with the frame lower pipe and the lower fork pipe through pipe fittings, and the upper part of the hanging bracket seat is sequentially provided with an extension support column A, an extension support column B and a connecting branch at intervals. And the lower ends of the frame lower pipe, the middle pipe and the lower fork pipe are respectively welded and fixed with the extension support column A, the extension support column B and the connecting branch. The frame structure is redesigned according to the welding process, and the extending supporting column A, the extending supporting column B and the connecting branch are designed on the hanging bracket seat, so that when other pipe fittings are welded with the hanging bracket seat, the welding bead position can be expanded outwards, special-shaped welding is reduced, the welding difficulty is reduced, and the welding thermal corrosion deformation is reduced; meanwhile, the welding bead position is expanded, the welding bead of the hanging bracket seat and the pipe fitting is more regular, a mechanical arm can be connected for welding in batch production, and the labor cost is reduced.

The utility model relates to a deep geothermal heat energy exploration and production single well structure adopting a pipe-in-pipe structure, which solves the problems that the traditional geothermal heat energy exploration and production does not utilize much geothermal heat energy of an underground dry and hot rock stratum, and a multi-well heat production structure is generally adopted. The structure comprises a vertically downward exploring well, a casing pipe is arranged on the well wall of the exploring well, a central pipe is arranged in the center of the casing pipe, a heat preservation layer is arranged on the pipe wall of the central pipe, a cold water injection channel is formed between the inner wall of the casing pipe and the outer wall of the central pipe, a hot water ascending channel is formed in the central pipe, and the bottom end of the exploring well is drilled to a dry hot rock stratum. And cracks are formed in the hot dry rock stratum at the bottom end of the exploring well. According to the utility model, pipe-in-pipe single well heat collection is adopted, open type heat collection is adopted at the well bottom, and cracks are artificially manufactured at the dry-hot rock stratum at the bottom end of the exploring and producing well, so that the heat exchange efficiency is improved, the efficient development and utilization of deep geothermal resources are realized, and the stability and sustainability of the underground environment are kept at the same time.

The utility model discloses a pipe-in-pipe water return device which comprises a pipe body, a partition plate, a conversion valve and a connecting piece. The pipe body comprises an L-shaped pipe body and a straight pipe body, the L-shaped pipe body and the straight pipe body are divided into an input cavity and a backflow cavity by the partition plate, and the outer wall of the L-shaped pipe body and the outer wall of the straight pipe body are coated with thermochromic coating; the connecting piece comprises a pipe body connecting piece and an adaptive connecting piece, the L-shaped pipe body is communicated with the straight pipe body through the pipe body connecting piece, one side of the straight pipe body is connected with the adaptive connecting piece, and the other side of the L-shaped pipe body is connected with the conversion valve; the conversion valve is located at the first end, away from the straight pipe body, of the L-shaped pipe body and comprises a valve body, a valve element and a flow turning ring. The adaptive connecting piece comprises an adaptive connecting plate, an adaptive upper bottom surface and an adaptive lower bottom surface; adaptive left through holes corresponding to the input cavity and the backflow cavity respectively are formed in the adaptive lower bottom surface; and the straight pipe body middle partition plate is clamped to the adaptive connecting plate. According to the utility model, the additional laying design and construction of the water return pipeline can be reduced, and the design workload and laying workload are reduced.

An end fitting assembly for a pipe-in-pipe assembly comprises a socket portion, a connector portion extending from the socket portion, a stop located between the socket portion and the connector portion, a collar that fits around the socket portion and attaches to the stop, and a wedge that fits between the collar and an inner composite pipe. When the collar is pushed onto the wedge, a series of collar cone sections engage a series of wedge cone sections causing a compression force on the inner composite pipe. The collar and the wedge are shaped so that they fit within an outer pipe of the pipe-in-pipe assembly. The compact shape of the collar and wedge facilitate reeling the pipe-in-pipe assembly onto a reel without causing excessive stress in the pipe-in-pipe assembly.

A pipe-in-pipe (PIP) pipeline assembly for the transport of a fluid in a marine environment that includes:(a) a PIP pipeline length comprising at least metal inner and outer pipes and an annular space thereinbetween, the inner metal pipe having an internal diameter;(b) a PIP bulkhead, havinga first end connected to an end of the PIP pipeline length and comprising at least a metal inner pipe with a first internal diameter, an outer pipe, and an annular space thereinbetween, anda second end comprising an outer pipe with a second internal diameter, and being able to be joined to a second end of a second PIP bulkhead,wherein the second internal diameter of the second end is greater than the first internal diameter of the first end of the PIP bulkhead.