Cabin penetrating structure for glass reinforced plastic pipe in ballast tank and ballast tank construction method

Abstract

A watertight bulkhead is arranged in the ballast tank, the glass reinforced plastic pipe penetrates through the watertight bulkhead through the tank penetrating structure to form a watertight structure, and the tank penetrating structure comprises a tank penetrating steel pipe, a compound plate and two flange assemblies; the cabin-penetrating steel pipe is the same as the glass steel pipe in diameter; a cabin penetrating hole is formed in the watertight cabin wall, and the diameter of the cabin penetrating hole is smaller than that of the compound plate and larger than that of the cabin penetrating steel pipe; the compound plate is arranged at the cabin penetrating hole and is in watertight connection with the watertight cabin wall; a first through hole matched with the diameter of the cabin-penetrating steel pipe is formed in the compound plate, and the cabin-penetrating steel pipe penetrates through the first through hole and is connected with the compound plate; the cabin penetrating steel pipe is connected with the glass steel pipe through a flange assembly; the invention further relates to a ballast tank construction method. The cabin penetrating structure is arranged at the position, penetrating the watertight bulkhead, of the glass steel pipe, the steel compound plate is welded to the watertight bulkhead, the glass steel pipe and the cabin penetrating steel pipe are in butt joint through the flange assembly, the problem that the position, penetrating the watertight bulkhead, of the glass steel pipe cannot be directly welded is solved, sealing is reliable, the structure is simple, and applicability is high.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, specifically to a ballast tank through-tank structure for fiberglass pipes and a ballast tank construction method. Background Technology

[0002] The ship's ballast system is one of the key systems for ensuring ship stability and navigational safety, and its ballast piping is usually located within the ballast tanks. Ballast piping is generally made of seamless steel pipes or fiberglass pipes. Seamless steel pipes have advantages such as high strength and impact resistance, but they also have problems such as heavy weight and susceptibility to corrosion. Fiberglass pipes, as a type of plastic pipe, have advantages such as light weight and corrosion resistance, and have a significant advantage in reducing the ship's weight.

[0003] When fiberglass pipes are placed in ballast tanks, they can be treated with open holes when passing through non-watertight bulkheads. However, when fiberglass pipes pass through watertight bulkheads, reliable sealing is required, which presents installation challenges. Since fiberglass pipes cannot be directly welded to steel bulkheads, existing technologies usually require custom-made penetration fittings from manufacturers. These fittings are then passed through and connected to the watertight bulkhead, with their ends connected to the fiberglass pipes on both sides of the watertight bulkhead via flanges.

[0004] This specially designed transom component comprises a steel cladding plate, a steel sleeve, a steel outer tube, a fiberglass inner tube, and specific flanges. The transom component houses the fiberglass inner tube, which is tightly fitted with the steel outer tube. A steel sleeve is then fitted tightly over the outer steel tube. The steel cladding plate connects to the outer steel sleeve and further to the watertight bulkhead. The steel outer tube and the fiberglass inner tube are of the same length and are connected at both ends to specific flanges. These flanges include a flange sealing surface; the outer ring of the flange sealing surface is made of steel pipe, and the inner ring is made of fiberglass.

[0005] However, the flange of this transom is not a standard flange and needs to be customized, resulting in a complex structure. Moreover, custom-made transoms from manufacturers have problems such as complex manufacturing processes, high procurement costs, long procurement and delivery cycles, poor compatibility, inconvenient installation, increased construction complexity, difficult maintenance, and difficulty in guaranteeing sealing performance.

[0006] Therefore, it is necessary to provide a fiberglass tube through-tank structure that is simple in structure, highly versatile, easy to install and maintain, reliable in sealing, and low in cost, to meet the requirements of large ships, especially container ships, for lightweight and high reliability of ballast systems, in order to solve the problems existing in the prior art. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a ballast tank construction method and a ballast tank construction method for fiberglass pipes penetrating the watertight bulkhead. By replacing the fiberglass pipe penetration point with a flange-type penetration structure, the steel cladding plate is directly welded to the watertight bulkhead. The fiberglass pipe and the penetration structure are connected by flanges, solving the technical problem that the fiberglass pipe cannot be directly welded to the watertight bulkhead at the point where it passes through. This achieves significant improvements in sealing reliability, structural simplification, cost reduction, ease of installation and maintenance, and increased installation efficiency at the point where the fiberglass pipe penetrates the watertight bulkhead.

[0008] To achieve the objectives of the invention described above, the technical solution provided by this invention is as follows: This invention first provides a through-tank structure for fiberglass pipes in ballast tanks. A watertight tank wall is set inside the ballast tank, and the fiberglass pipe passes through the watertight tank wall through the through-tank structure to form a watertight structure. The through-tank structure includes a through-tank steel pipe, a cladding plate, and two flange assemblies. The diameter of the steel pipe passing through the cabin is the same as the diameter of the fiberglass pipe; The watertight bulkhead has a through-hole, the diameter of which is smaller than the diameter of the cladding plate but larger than the diameter of the through-hole steel pipe. The cladding is located at the passage hole and is watertightly connected to the watertight bulkhead. The cladding plate has a first through hole matching the diameter of the through-hole steel pipe, and the through-hole steel pipe passes through the first through hole and is watertightly connected to the cladding plate. Both ends of the steel pipe passing through the cabin are watertightly connected to the fiberglass pipe via flange assemblies.

[0009] In the ballast tank fiberglass pipe penetration structure of the present invention, the penetration hole is a circular through hole, the cover plate is an annular plate structure, and the relationship between the outer radius of the cover plate and the radius of the penetration hole is: R2=R3+50mm, where R2 is the outer radius of the cover plate and R3 is the radius of the penetration hole.

[0010] In a ballast tank fiberglass pipe through-tank structure of the present invention, the cladding plate is made of marine grade 20 steel and has a hot-dip galvanized layer on its surface. The thickness of the cladding plate is greater than or equal to the thickness of the watertight bulkhead. The composite plate is connected to the watertight bulkhead and the through-hole steel pipe by welding.

[0011] In the ballast tank through-tank structure of the present invention, the through-tank steel pipe is a seamless marine steel pipe with a hot-dip galvanized layer on its surface. The wall thickness of the through-tank steel pipe meets the relevant specifications of the classification society to which the ship is classified and is greater than or equal to the Class B wall thickness.

[0012] In a ballast tank through-tank structure for fiberglass pipes, the flange assembly includes a first flange, a second flange, and multiple fastening structures. The first flange and the second flange correspond one-to-one and are connected by the fastening structures. The two ends of the through-tank steel pipe are respectively watertightly connected to the two first flanges, and the fiberglass pipes located on both sides of the watertight tank wall are respectively watertightly connected to the two second flanges.

[0013] In a ballast tank fiberglass pipe through-tank structure of the present invention, the fastening structure includes bolts, flat washers and two lock nuts. The first flange and the second flange are each provided with a second through hole with the same position, diameter and number as the bolt. The diameter of the second through hole is set to the diameter of the bolt plus 1-2 mm. The first flange and the second flange are connected to the corresponding second through holes and bolts are inserted inside them. One end of the bolt is provided with a flat washer, a first lock nut and a second lock nut in sequence next to the second flange. The bolt is a grade 4.8 bolt with a nominal tensile strength of 400 MPa and a yield strength of 320 MPa. The fastening structure is made of galvanized steel.

[0014] In a ballast tank fiberglass pipe penetration structure of the present invention, the flange assembly further includes a gasket, which is disposed between the first flange and the second flange, and the gasket is made of nitrile rubber.

[0015] In the ballast tank through-tank structure of the present invention, the first flange and the second flange are both marine flanges conforming to GB / T9124.1-2019 standard. The first flange is made of steel and the second flange is made of fiberglass. Both of them are provided with a hot-dip galvanized layer. The thickness of the first flange is less than that of the second flange. The outer diameter and pitch circle PCD of the first flange and the second flange are the same, and the nominal pressure rating is PN6 or PN10. The outer diameters of the first flange and the second flange are smaller than the diameter of the through-hole; The first flange is watertightly connected to the through-chamber steel pipe by welding.

[0016] The present invention also provides a method for constructing a ballast tank, wherein the aforementioned penetration structure for fiberglass pipes inside the ballast tank is used to achieve a watertight connection at the point where the fiberglass pipe penetrates the watertight bulkhead of the ballast tank. The method includes the following steps: Step 1: Design and layout of the ballast tank: S11: Conduct structural design, and determine the location of watertight bulkheads, the thickness of the watertight bulkheads used, and the structural form based on the ship's design and relevant specifications. S12: Conduct detailed design, use design software to draw each skeleton, determine the shape and size of each plate, and generate manufacturing and assembly drawings; S13: Perform CNC cutting and nesting, using CNC machine tools to nest and cut steel plates; Step Two: Segmented Construction S21: On the scaffolding of the sectional construction site, according to the sectional construction drawings, steel plates are laid in sequence, the framework is erected, and the framework and steel plates are welded together. S22: Pipeline laying and cable laying are carried out. Pipelines and cables that pass through watertight bulkheads are all watertight through-hole components. Install the second flange on the fiberglass pipes that are expected to be installed on both sides of the watertight bulkhead. When laying the fiberglass pipes, transport the pre-cut fiberglass pipes one by one to the sections for laying and connection. First lay the fiberglass pipe sections other than the sections on both sides of the watertight bulkhead that have the second flange installed. The installation steps for the through-cabin structure are as follows: S221: Open a through-hole. Open a through-hole at the point where the fiberglass pipe passes through the watertight bulkhead. The through-hole should be larger than the diameter of the flange assembly but smaller than the diameter of the cladding plate. S222: Welding the through-hole steel pipe assembly, passing the through-hole steel pipe through the first through hole on the cladding plate, and welding the through-hole steel pipe to the cladding plate; perpendicularly butt-welding the two ends of the through-hole steel pipe to the first flange and welding them, and applying anti-corrosion treatment to the weld; S223: Connect the through-hole steel pipe assembly to the through-hole, insert it into the through-hole from one side of the watertight bulkhead until the cladding plate is in contact with the watertight bulkhead at the through-hole, and fix the cladding plate to the watertight bulkhead around the through-hole by spot welding. S224: Laying fiberglass pipes with second flanges on both sides of the watertight bulkhead; S225: Connect the first flange and the second flange. Place gaskets between the first flange and the corresponding second flange on both sides of the watertight bulkhead. Align the end faces of the first flange and the corresponding second flange and fit them together. Screw the bolts into the aligned second through holes from one end. Place the flat washer, the first lock nut and the second lock nut into the other end in sequence. S226: Lock and fix the first flange and the second flange, keep the axis of the fiberglass pipe and the steel pipe through the cabin aligned, and tighten all the lock nuts in a diagonal, cross-shaped and step-by-step manner to ensure that there is no gap between the first flange and the second flange, and complete the watertight connection of the fiberglass pipe through the watertight cabin wall. S227: Continuous full penetration welding is performed between the transect structure and the watertight bulkhead; Step 3: Conduct a tightness test on the completed ballast tank: The assembled ballast tanks are subjected to flushing, spraying, or filling tests until their watertightness meets the standards, thus completing the construction of the ballast tanks.

[0017] In the ballast tank construction method of the present invention, all welds in the above steps are continuous full penetration welds, and non-destructive testing is performed on the welds after welding to ensure that the welding quality meets the standards.

[0018] Based on the above technical solution, the present invention, a ballast tank construction method for fiberglass pipes inside ballast tanks, has achieved the following technical advantages after practical application, compared with the traditional method of customizing ballast tank components from manufacturers: 1. The through-tank structure of the present invention solves the welding problem of FRP pipes passing through watertight tank walls, and realizes reliable sealing connection and structural fixation at the point where FRP pipes pass through watertight tank walls. It has a simple structure, is easy to manufacture, easy to install, and is easy to arrange and install on ships. It is suitable for ballast piping systems of large ships, especially container ships.

[0019] 2. This invention solves the problem that fiberglass pipes cannot be directly welded to watertight bulkheads by connecting fiberglass pipes to the specially designed steel through-cabin structure, and welding the cladding of the through-cabin structure to the watertight bulkhead. This improves construction efficiency, makes installation convenient, and ensures high welding reliability.

[0020] 3. This invention, through an innovative technical concept combining flange connection and welding composite structure, successfully solves the sealing and fixing problem of FRP pipes when passing through watertight bulkheads. It provides technical support for the widespread application of lightweight FRP pipes on ships to reduce their weight. It is particularly suitable for various large ships that use FRP pipes as ballast pipes, such as container ships and bulk carriers. It has wide applicability and helps to achieve lightweight ship design.

[0021] 4. This invention uses standardized marine components, such as standard flanges and steel pipes with hot-dip galvanized coatings, which have a simple structure, strong versatility, and do not require customized non-standard parts, thus reducing procurement costs and time, and bringing convenience to shipyard construction.

[0022] 5. The present invention uses a combination of nitrile rubber gaskets and double nut locking structure with welding connection method to ensure that the fiberglass pipe maintains long-term watertightness at the watertight chamber wall.

[0023] 6. The galvanized steel pipes, hot-dip galvanized cladding plates, and flanges selected in this invention all have good resistance to seawater corrosion, long service life, and high durability.

[0024] 7. The flange connection structure of the present invention facilitates disassembly, inspection or replacement in the later stage, making maintenance convenient and reducing maintenance costs.

[0025] 8. The present invention also has the advantages of stable structure, reliable sealing and flexible installation, and is suitable for various ship ballast systems. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a fiberglass pipe penetration structure for ballast tanks according to the present invention.

[0027] Figure 2 This is a schematic diagram illustrating the installation process of a ballast tank-through structure for fiberglass pipes.

[0028] Figure 3 This is a schematic diagram of the installation of a ballast tank-penetrating structure for fiberglass pipes.

[0029] Figure 4 This is a schematic diagram of the structure of a composite plate for a ballast tank fiberglass pipe through-tank structure according to the present invention.

[0030] Reference numerals: 1. Fiberglass pipe; 2. Through-tank steel pipe; 3. Cover plate; 4. Flange assembly; 41. First flange; 42. Second flange; 5. Fastener; 51. Bolt; 52. Flat washer; 53. First lock nut; 54. Second lock nut; 6. Gasket; 7. Watertight bulkhead; 8. Through-tank hole. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific examples shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0032] The technical solution of the present invention will be further described below with reference to specific embodiments: Example 1, such as Figure 1 As shown, this embodiment is a through-tank structure for fiberglass pipes in ballast tanks. The watertight bulkhead 7 is set inside the ballast tank, and the fiberglass pipe 1 is installed inside the ballast tank as a ballast pipe. The fiberglass pipe 1 is a marine-grade fiberglass pipe, and its wall thickness meets the relevant specifications of the classification society to which the ship is classified. Its thermal, pressure and stress meet the ship's requirements. The fiberglass pipe 1 passes through the watertight bulkhead 7 through the through-tank structure for fiberglass pipes in ballast tanks in this embodiment and forms a watertight structure.

[0033] The through-tank structure includes a through-tank steel pipe 2, a cladding plate 3, and two flange assemblies 4. The diameter of the through-tank steel pipe 2 is the same as that of the fiberglass pipe 1. A through-tank hole 8 is provided on the watertight bulkhead 7. The diameter of the through-tank hole 8 is smaller than the diameter of the cladding plate 3 but larger than the diameter of the through-tank steel pipe 2, so that the outer edge contour of the cladding plate 3 matches the welding area of ​​the watertight bulkhead 7, ensuring the overall structural strength and watertightness. The cladding plate 3 is located at the through-tank hole 8 and is watertightly connected to the watertight bulkhead 7 by welding; this improves construction efficiency, facilitates installation, and ensures high welding reliability. A first through hole 9, matching the diameter of the through-tank steel pipe 2, is provided on the cladding plate 3. The radius of the first through hole 9 is R1. The through-tank steel pipe 2 passes through the first through hole 9 and is watertightly connected to the cladding plate 3 by welding. Both ends of the through-tank steel pipe 2 are watertightly connected to the fiberglass pipe 1 through flange assemblies 4.

[0034] The through hole 8 is a circular through hole, and the cover plate is an annular plate structure. The relationship between the outer radius of the cover plate and the radius of the through hole is: R2=R3+50mm, where R2 is the outer radius of the cover plate and R3 is the radius of the through hole.

[0035] The cladding plate 3 is made of marine grade 20 steel and has a hot-dip galvanized layer on its surface. It has good resistance to seawater corrosion, long service life, and high durability. The thickness of the cladding plate 3 is greater than or equal to the thickness of the watertight bulkhead 7.

[0036] The through-hull steel pipe 2 is a seamless marine steel pipe with a hot-dip galvanized layer on its surface to improve its resistance to seawater corrosion, resulting in a long service life and high durability. The wall thickness of the through-hull steel pipe 2 meets the relevant specifications of the classification society to which the ship is classified and is greater than or equal to the Class B wall thickness.

[0037] The flange assembly includes a first flange 41, a second flange 42, and multiple fastening structures 5. The first flange 41 and the second flange 42 correspond one-to-one and are connected by the fastening structures 5. The two ends of the through-tank steel pipe 2 are respectively watertightly connected to the two first flanges 41, and the fiberglass pipes 1 located on both sides of the watertight bulkhead 7 are respectively watertightly connected to the two second flanges 42. The flange connection structure facilitates later disassembly, inspection, or replacement, making maintenance convenient and reducing maintenance costs.

[0038] The fastening structure 5 includes a bolt 51, a flat washer 52, and two lock nuts to enhance the anti-loosening effect. Both the first flange 41 and the second flange 42 are provided with second through holes of the same position, diameter, and number as the bolt 51. The diameter of the second through hole is set to the diameter of the bolt 51 plus 1-2 mm. The corresponding second through holes on the first flange 41 and the second flange 42 are connected and the bolt 51 is inserted inside. One end of the bolt 51 is close to the second flange 42 and is provided with a flat washer 52, a first lock nut 53, and a second lock nut 54 in sequence. The bolt 51 is a 4.8 grade bolt with a nominal tensile strength of 400 MPa and a yield strength of 320 MPa. The bolt 51, the first lock nut 53, the second lock nut 54, and the flat washer 52 of the fastening structure 5 are all made of galvanized steel.

[0039] The flange assembly 4 also includes a gasket 6, which is disposed between the first flange 41 and the second flange 42. The gasket 6 is made of nitrile rubber, giving it good seawater resistance and sealing performance. Furthermore, the use of a nitrile rubber gasket and the aforementioned double-nut locking fastening structure 5, combined with the welded connection method, ensures that the fiberglass pipe 1 maintains long-term watertightness at the point where it penetrates the watertight bulkhead 7.

[0040] Both the first flange 41 and the second flange 42 are marine flanges conforming to the GB / T9124.1-2019 standard. The first flange 41 is made of steel, and the second flange 42 is made of fiberglass. Both have a hot-dip galvanized layer on their surface, giving them good resistance to seawater corrosion, long service life, and high durability. The thickness of the first flange 41 is less than that of the second flange 42. The outer diameter and pitch circle (PCD) of the first flange 41 and the second flange 42 are the same, and the nominal pressure rating is either PN6 or PN10. The flanges are matched with standard flanges and through-tank steel pipes 2, etc. The flange structure is simple, and the overall structure of the through-tank structure is simple and versatile. It does not require the customization of non-standard parts, which reduces procurement costs and time, and brings convenience to shipyard construction.

[0041] The outer diameters of the first flange 41 and the second flange 42 are smaller than the diameter of the through hole 8. The first flange 41 and the through steel pipe 2 are connected by welding to form a watertight connection, and the weld is treated with anti-corrosion treatment. Because welding will damage the galvanized layer, anti-corrosion treatment is carried out to improve the resistance to seawater corrosion and extend the service life.

[0042] By combining innovative flange connection with welding composite structure, the sealing and fixing problem of FRP pipe 1 through 7 watertight bulkheads was successfully solved. This provides technical support for the widespread application of lightweight FRP pipes in ships to reduce their weight. It is especially suitable for various large ships that use FRP pipes as ballast pipes, such as container ships and bulk carriers. It has wide applicability and helps to achieve lightweight ship design.

[0043] The flange assembly may also include an alignment structure, which is a concentric positioning step provided on the steel first flange 41, which mates with the inner hole or back of the fiberglass second flange 42 to achieve automatic concentricity between the first flange 41 and the second flange 42, share part of the shear force of the bolts, prevent the bolt holes on the fiberglass second flange 42 from bearing excessive lateral loads, help the two flange faces to align and parallel, reduce bending moment, and increase the overall structural stability after the through-cabin structure is installed.

[0044] Through the above design, the present invention provides a flange-type steel penetration structure at the location where the fiberglass pipe needs to pass through the watertight bulkhead. The cladding of the penetration structure can be directly welded to the watertight bulkhead, while the fiberglass pipe is connected to the penetration structure via the flange. This effectively solves the technical problem that the fiberglass pipe cannot be directly welded to the watertight bulkhead, making installation convenient, improving construction efficiency, and reducing costs.

[0045] Example 2: This example describes a ballast tank construction method. In this example, the fiberglass pipe 1 uses the ballast tank penetration structure from Example 1 at the point where it penetrates the watertight bulkhead 7 of the ballast tank to achieve a watertight connection at the point where the fiberglass pipe penetrates the watertight bulkhead. The implementation steps include the following: Step 1: Design and layout of the ballast tank: S11: Conduct structural design, and determine the location of the watertight bulkhead 7, the plate thickness of the watertight bulkhead 7 used, and the structural form based on the ship's design and relevant specifications. S12: Conduct detailed design, use design software to draw each skeleton, determine the shape and size of each plate, and generate manufacturing and assembly drawings; S13: Perform CNC cutting and nesting, using CNC machine tools to nest and cut steel plates; Step Two: Segmented Construction S21: On the scaffolding of the sectional construction site, according to the sectional construction drawings, steel plates are laid in sequence, the framework is erected, and the framework and steel plates are welded together. S22: Pipeline laying and cable laying are carried out. Pipelines and cables passing through the watertight bulkhead 7 are all watertight through-hole components. Install the second flange 42 on the fiberglass pipe 1 that is expected to be installed on both sides of the watertight bulkhead 7. When laying the fiberglass pipe 1, transport the pre-cut fiberglass pipe 1 to the section for laying and connection. First lay the fiberglass pipe sections other than the fiberglass pipe sections on both sides of the watertight bulkhead 7 that are equipped with the second flange 42. The installation steps for the through-cabin structure are as follows: S221: Open a through hole 8. Open a through hole 8 at the point where the fiberglass pipe 1 passes through the watertight bulkhead 7. The through hole 8 is larger than the diameter of the flange assembly and smaller than the diameter of the cladding plate 3. S222: Weld the through-hole steel pipe assembly, pass the through-hole steel pipe 2 through the first through hole on the cladding plate 3, and weld the through-hole steel pipe 2 onto the cladding plate 3; weld the two ends of the through-hole steel pipe 2 perpendicularly to the first flange 41 and weld them respectively; S223: Connect the through-hole steel pipe assembly to the through-hole 8, insert it into the through-hole 8 from one side of the watertight bulkhead 7 until the cladding plate 3 is attached to the watertight bulkhead 7 at the through-hole 8, and fix the cladding plate 3 to the watertight bulkhead 7 around the through-hole 8 by spot welding. S224: Fiberglass pipes 1 with second flanges 42 are laid on both sides of the watertight bulkhead 7; S225: Connect the first flange 41 and the second flange 42. Place gaskets between the first flange 41 and the corresponding second flange 42 on both sides of the watertight bulkhead 7. Align the end faces of the first flange 41 and the corresponding second flange 42 and fit them together. Screw the bolt 51 into the aligned second through hole from one end. Place the flat washer 52, the first lock nut 53 and the second lock nut 54 into the other end in sequence. S226: Lock and fix the first flange 41 and the second flange 42, keep the axes of the fiberglass pipe 1 and the through-hole steel pipe 2 aligned, and tighten all the locking nuts evenly in a diagonal, cross-shaped and step-by-step manner. Usually, tightening is done in at least 3 steps. The method of tightening in multiple rounds ensures that the gasket is subjected to uniform force and that the flange faces are parallel and fit together. Then check whether the flange faces are completely fitted and whether there are any abnormal deformations or cracks. Ensure that there are no gaps between the first flange 41 and the second flange 42, and complete the watertight connection of the fiberglass pipe 1 through the watertight bulkhead 7. S227: The through-tank structure is continuously and fully penetrated welded to the watertight bulkhead 7; the through-tank structure has a simple overall structure, is easy to install, and is easy to arrange and install on ships, making it suitable for ballast piping systems of large ships, especially container ships. It has advantages such as structural stability, reliable sealing, and flexible installation, and is suitable for ballast systems of various types of ships.

[0046] All welds in the above steps are continuous full penetration welds, and non-destructive testing is performed on the welds after welding to ensure that the welding quality meets the standards.

[0047] Step 3: Conduct a tightness test on the completed ballast tank: The assembled ballast tanks are subjected to flushing, spraying, or filling tests until their watertightness meets the standards, thus completing the construction of the ballast tanks.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A through-tank structure for fiberglass pipes in ballast tanks, wherein a watertight bulkhead (7) is installed inside the ballast tank, characterized in that, The fiberglass pipe (1) passes through the watertight bulkhead (7) through the compartment structure and forms a watertight structure. The compartment structure includes a compartment steel pipe (2), a cladding plate (3), and two flange assemblies (4). The diameter of the steel pipe (2) that penetrates the cabin is the same as the diameter of the fiberglass pipe (1); The watertight bulkhead (7) has a through hole (8), the diameter of which is smaller than the diameter of the cladding plate (3) and larger than the diameter of the through steel pipe (2). The cladding plate (3) is located at the hatch (8) and is watertightly connected to the watertight bulkhead (7); The cladding plate (3) has a first through hole (9) with a diameter matching that of the through steel pipe (2), and the through steel pipe (2) passes through the first through hole (9) and is watertightly connected to the cladding plate (3). Both ends of the steel pipe (2) are watertightly connected to the fiberglass pipe (1) via flange assembly (4).

2. The through-tank structure for fiberglass pipes in ballast tanks according to claim 1, characterized in that, The through hole (8) is a circular through hole, and the cover plate is an annular plate structure. The relationship between the outer radius of the cover plate (3) and the radius of the through hole (8) is: R2 = R3 + 50 mm, where R2 is the outer radius of the cover plate (3) and R3 is the radius of the through hole (8).

3. The through-tank structure for fiberglass pipes in ballast tanks according to claim 1, characterized in that, The cladding plate (3) is made of marine 20# steel and has a hot-dip galvanized layer on its surface. The thickness of the cladding plate (3) is greater than or equal to the thickness of the watertight bulkhead (7). The composite plate (3) is connected to the watertight bulkhead (7) and the through-hole steel pipe (2) by welding.

4. A transect structure for fiberglass pipes inside a ballast tank according to claim 1, characterized in that, The through-hull steel pipe (2) is a seamless marine steel pipe with a hot-dip galvanized layer on its surface. The wall thickness of the through-hull steel pipe (2) meets the relevant specifications of the classification society to which the ship is classified and is greater than or equal to the Class B wall thickness.

5. A transect structure for fiberglass pipes in ballast tanks according to claim 1, characterized in that, The flange assembly includes a first flange (41), a second flange (42) and multiple fastening structures (5). The first flange (41) and the second flange (42) correspond one to one and are connected by the fastening structures (5). The two ends of the through-tank steel pipe (2) are respectively watertight connected to the two first flanges (41), and the fiberglass pipes (1) located on both sides of the watertight bulkhead (7) are respectively watertight connected to the two second flanges (42).

6. A transect structure for fiberglass pipes in a ballast tank according to claim 5, characterized in that, The fastening structure (5) includes a bolt (51), a flat washer (52) and two locking nuts. The first flange (41) and the second flange (42) are provided with second through holes that are the same as the bolt (51) in terms of position, diameter and number. The diameter of the second through hole is set to the diameter of the bolt (51) plus 1-2 mm. The first flange (41) is connected to the corresponding second through hole on the second flange (42) and a bolt (51) is inserted inside. One end of the bolt (51) is close to the second flange (42) and a flat washer (52), a first lock nut (53) and a second lock nut (54) are sequentially provided. The bolt (51) is a 4.8 grade bolt with a nominal tensile strength of 400 MPa and a yield strength of 320 MPa. The fastening structure (5) is made of galvanized steel.

7. A transect structure for fiberglass pipes in ballast tanks according to claim 6, characterized in that, The flange assembly (4) also includes a gasket (6), which is disposed between the first flange (41) and the second flange (42), and the gasket (6) is made of nitrile rubber.

8. A transect structure for fiberglass pipes in ballast tanks according to claim 7, characterized in that, The first flange (41) and the second flange (42) are both marine flanges conforming to GB / T9124.1-2019 standard. The first flange (41) is made of steel and the second flange (42) is made of fiberglass. Both of them have a hot-dip galvanized layer on their surface. The thickness of the first flange (41) is less than the thickness of the second flange (42). The outer diameter and pitch circle PCD of the first flange (41) and the second flange (42) are the same, and the nominal pressure rating is either PN6 or PN10. The outer diameters of the first flange (41) and the second flange (42) are smaller than the diameter of the through hole (8); The first flange (41) and the through-tank steel pipe (2) are connected in a watertight manner by welding.

9. A method for constructing a ballast tank, wherein the fiberglass pipe (1) is connected to the watertight bulkhead (7) of the ballast tank using the through-tank structure of claim 8 for fiberglass pipes within the ballast tank, characterized in that, The implementation steps include the following: Step 1: Design and layout of the ballast tank: S11: Conduct structural design, and determine the location of the watertight bulkhead (7) and the plate thickness and structural form of the watertight bulkhead (7) to be used, based on the ship's design and relevant specifications. S12: Conduct detailed design, use design software to draw each skeleton, determine the shape and size of each plate, and generate manufacturing and assembly drawings; S13: Perform CNC cutting and nesting, using CNC machine tools to nest and cut steel plates; Step Two: Segmented Construction S21: On the scaffolding of the sectional construction site, according to the sectional construction drawings, steel plates are laid in sequence, the framework is erected, and the framework and steel plates are welded together. S22: Pipeline laying and cable laying are carried out. Pipelines and cables that pass through the watertight bulkhead (7) are all watertight through-hole components. Install the second flange (42) on the fiberglass pipe (1) that is expected to be installed on both sides of the watertight bulkhead (7). When laying the fiberglass pipe (1), transport the pre-cut fiberglass pipe (1) to the section for laying and connection. First lay the fiberglass pipe sections other than the fiberglass pipe sections on both sides of the watertight bulkhead (7) with the second flange (42) installed. The installation steps for the through-cabin structure are as follows: S221: Open a through hole (8). Open a through hole (8) at the point where the fiberglass pipe (1) passes through the watertight bulkhead (7). The diameter of the through hole (8) is larger than that of the flange assembly and smaller than that of the cladding plate (3). S222: Weld the through-hole steel pipe assembly, pass the through-hole steel pipe (2) through the first through hole on the cladding plate (3), and weld the through-hole steel pipe (2) onto the cladding plate (3); weld the two ends of the through-hole steel pipe (2) perpendicularly to the first flange (41) and perform anti-corrosion treatment on the weld; S223: Connect the through-hole steel pipe assembly to the through-hole (8), insert it from one side of the watertight bulkhead (7) into the through-hole (8) until the cladding plate (3) is attached to the watertight bulkhead (7) at the through-hole (8), and fix the cladding plate (3) to the watertight bulkhead (7) around the through-hole (8) by spot welding. S224: Lay fiberglass pipes (1) with second flanges (42) on both sides of the watertight bulkhead (7); S225: Connect the first flange (41) and the second flange (42). Place gaskets between the first flange (41) and the corresponding second flange (42) on both sides of the watertight bulkhead (7). Align the end faces of the first flange (41) and the corresponding second flange (42) and fit them together. Screw the bolt (51) into the aligned second through hole from one end. Place the flat washer (52), the first lock nut (53) and the second lock nut (54) into the other end in sequence. S226: Lock the first flange (41) and the second flange (42) together, keep the axes of the fiberglass pipe (1) and the through-hole steel pipe (2) aligned, and tighten all the locking nuts in a diagonal, cross-shaped and step-by-step manner to ensure that there is no gap between the first flange (41) and the second flange (42), and complete the watertight connection of the fiberglass pipe (1) through the watertight bulkhead (7); S227: The through-tank structure is continuously and fully penetrated welded to the watertight bulkhead (7); Step 3: Conduct a tightness test on the completed ballast tank: The assembled ballast tanks are subjected to flushing, spraying, or filling tests until their watertightness meets the standards, thus completing the construction of the ballast tanks.

10. A method for constructing a ballast tank according to claim 9, characterized in that, All welds in the above steps are continuous full penetration welds, and non-destructive testing is performed on the welds after welding to ensure that the welding quality meets the standards.

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