Field manufacturing method of plastic pipe joint for lining repair

Abstract

The invention discloses an on-site manufacturing method of a plastic pipe joint for lining repair, and belongs to the technical field of lining repair plastic pipelines. The on-site manufacturing method comprises the following steps: lining a lining plastic pipe for repair into a to-be-repaired metal pipe; connecting an internal expansion mold and a pull rod, and then putting the internal expansion mold and the pull rod into the lining plastic pipe for repairing from the end part of the lining plastic pipe for repairing; the metal lining is sleeved with an O-shaped ring and then penetrates through the pull rod to be inserted into the end of the lining plastic pipe for repairing; the tail end of the metal lining and the tail end of the metal pipe to be repaired are welded together; an internal expansion mold and a pull rod are connected with a hydraulic system through a hydraulic system connecting device, the internal expansion mold penetrates through the metal lining to pull out a metal pipe to be repaired under the driving of the hydraulic system, the metal lining is extruded and expanded through the internal expansion mold, and the metal lining compresses a lining plastic pipe for repairing. And the effect of sealing the lining plastic pipe for repairing and the metal pipe to be repaired is achieved. The method does not need steel wrapping, and is simple, convenient, feasible, high in efficiency, low in cost, safe, stable and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of lining repair of plastic pipes, and in particular to a method for on-site fabrication of a plastic pipe joint for lining repair. Background Art

[0002] As the main carrier in the storage and transportation of oil, natural gas, water, etc., steel conveying pipelines are severely corroded under the action of the environment (atmosphere, soil, microorganisms, etc.). Especially in the case of transporting corrosive media such as crude oil with high salinity, containing hydrogen sulfide and carbon dioxide, the phenomenon of corrosion perforation is particularly prominent. Therefore, the lining repair technology is of great significance for pipeline owners to reduce pipeline construction investment and production costs and improve economic benefits.

[0003] At present, there are mainly two methods for connecting the ends of the reduced-diameter lined plastic pipes: one is to use an electrofusion sleeve to connect the plastic pipes, and the outside of the joint is wrapped with steel and filled with cement mortar; the other method is to use a flange connection after the plastic pipe is flanged on-site.

[0004] The former has disadvantages such as high construction cost and low efficiency; while the latter is too dependent on the technical level of construction personnel, and there are certain leakage risks at the joints. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for on-site fabrication of a plastic pipe joint for lining repair, which does not require steel wrapping, is simple and easy to operate, has high efficiency, low cost, and is safe, stable and reliable.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: A method for on-site fabrication of a plastic pipe joint for lining repair, comprising the following steps: Step 1, lining the lining plastic pipe for repair into the metal pipe to be repaired; Step 2, connecting the internal expansion die and the pull rod and putting them into the lining plastic pipe for repair from the end of the lining plastic pipe for repair; Step 3, sleeving an O-ring on the metal lining and inserting it into the end of the lining plastic pipe for repair through the pull rod; Step 4, welding the tail end of the metal lining to the tail end of the metal pipe to be repaired; Step 5, connecting the internal expansion die and the pull rod to the hydraulic system through a hydraulic system connection device, and driving the internal expansion die to pull out of the metal pipe to be repaired through the metal lining under the drive of the hydraulic system, and expanding the diameter of the metal lining by extruding the metal lining through the internal expansion die, so that the metal lining compresses the lining plastic pipe for repair, playing a role in sealing the lining plastic pipe for repair and the metal pipe to be repaired.

[0007] A further improvement of the technical solution of the present invention lies in that: the tail end of the inner lining plastic pipe for repair is 2-3 cm shorter than the tail end of the metal pipe to be repaired.

[0008] A further improvement of the technical solution of the present invention lies in that: the metal inner lining includes a tubular extrusion end inserted inside the end of the inner lining plastic pipe for repair and a connection end that can be welded to the end of the metal pipe to be repaired.

[0009] A further improvement of the technical solution of the present invention lies in that: the outer diameter of the extrusion end is the same as the inner diameter of the inner lining plastic pipe for repair, and the tail end of the extrusion end is flush with the tail end of the inner lining plastic pipe for repair; the wall thickness of the extrusion end is 3-5 mm; the length of the extrusion end is twice the inner diameter of the inner lining plastic pipe for repair.

[0010] A further improvement of the technical solution of the present invention lies in that: several serrated annular protrusions and two circular protrusions are provided on the outer side of the front end of the extrusion end, and the O-ring is sleeved in the groove formed by the two circular protrusions.

[0011] A further improvement of the technical solution of the present invention lies in that: the connection end is provided in a stepped shape, the outer diameter of the lower stage is the same as the inner diameter of the metal pipe to be repaired; the outer diameter of the upper stage is larger than the inner diameter of the metal pipe to be repaired, and the upper stage is arranged outside the tail end of the metal pipe to be repaired.

[0012] A further improvement of the technical solution of the present invention lies in that: the O-ring is a rubber ring.

[0013] A further improvement of the technical solution of the present invention lies in that: the internal expansion mold is a conical frustum with a smaller front end diameter than the rear end diameter; the maximum outer diameter dimension of the internal expansion mold is equal to the outer diameter dimension of the metal inner lining, and the outer diameter dimension of the metal inner lining is equal to the inner diameter dimension of the inner lining plastic pipe for repair.

[0014] A further improvement of the technical solution of the present invention lies in that: the material hardness of the internal expansion mold is greater than the material hardness of the metal inner lining.

[0015] A further improvement of the technical solution of the present invention lies in that: the specification of the inner lining plastic pipe for repair is DN50-DN600; the inner lining plastic pipe for repair is any one of polyethylene, heat-resistant polyethylene, high-temperature resistant polyolefin and cross-linked polyethylene.

[0016] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is: 1. In the present invention, a metal inner lining including an extrusion end and a connection end is inserted inside the end of a lining plastic pipe for repair. The connection end is welded to the tail end of the metal pipe to be repaired. An internal expansion die with a maximum outer diameter larger than the inner diameter of the extrusion end is pulled through the metal inner lining by a hydraulic system to draw out the metal pipe to be repaired. The extrusion end of the metal inner lining is expanded by the internal expansion die, so that the extrusion end of the metal inner lining compresses the lining plastic pipe for repair, playing a role in sealing the lining plastic pipe for repair and the metal pipe to be repaired; there is no need for steel wrapping, with high efficiency, low cost, safety and reliability.

[0017] 2. In the present invention, the tail end of the lining plastic pipe for repair is 2 - 3 cm shorter than the tail end of the metal pipe to be repaired, avoiding heat damage to the lining plastic pipe for repair caused by welding the connection end to the metal pipe to be repaired.

[0018] 3. In the present invention, the outer diameter of the extrusion end of the metal inner lining is set to be the same as the inner diameter of the lining plastic pipe for repair, the wall thickness of the extrusion end is set to be 3 - 5 mm, and the length of the extrusion end is 2 times the inner diameter of the lining plastic pipe for repair, ensuring the sealing effect of the metal inner lining.

[0019] 4. In the present invention, the metal pipe to be repaired is used as the outer sleeve for the internal expansion process, facilitating construction.

[0020] 5. For the on-site joint manufacturing method provided by the present invention, when the internal expansion die is used for lining pipes of the same specification, the internal expansion die can be reused, saving construction costs.

[0021] 6. In the present invention, several serrated annular protrusions and two circular protrusions are provided at the front end of the extrusion end of the metal inner lining, and an O-ring is sleeved in the groove formed by the two circular protrusions. The O-ring is made of a rubber ring, further ensuring the sealing effect between the lining plastic pipe for repair and the metal pipe to be repaired, without leakage risk.

[0022] 7. In the present invention, a stepped connection end is provided at the tail end of the metal inner lining for welded connection with the metal pipe to be repaired, ensuring the connection between the metal pipe to be repaired and other pipes.

[0023] 8. In the present invention, a hydraulic system is used to connect with the internal expansion die, with convenient and fast construction and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings; Figure 1It is a structural schematic diagram of a method for on-site fabrication of a plastic pipe joint for lining repair provided in an embodiment of the present invention; Figure 2 It is a structural schematic diagram of a metal lining in an embodiment of the present invention; Among them, 1 is the metal pipe to be repaired; 2 is the lining plastic pipe for repair; 3 is the metal lining; 3-1 is the extrusion end; 3-1-1 is the serrated annular protrusion; 3-1-2 is the circular annular protrusion; 3-2 is the connection end; 4 is the internal expansion mold; 5 is the O-ring; 6 is the pull rod; 7 is the device connected to the hydraulic system. Detailed implementation manners

[0025] It should be noted that the terms "including" and "having" in the description and claims of the present invention and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0026] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0027] The present invention will be further described in detail below with reference to the drawings and embodiments: As Figure 1 , Figure 2 shown, a method for on-site fabrication of a plastic pipe joint for lining repair includes the following steps: Step 1, lining the lining plastic pipe 2 for repair into the metal pipe 1 to be repaired; the outer diameter dimension of the lining plastic pipe 2 for repair is equal to the inner diameter dimension of the metal pipe 1 to be repaired; Step 2, connecting the internal expansion mold 4 and the pull rod 6 and putting them into the lining plastic pipe 2 for repair from the end of the lining plastic pipe 2 for repair; Step 3, sleeving the metal lining 3 with the O-ring 5 and inserting it through the pull rod 6 into the end part inside the lining plastic pipe 2 for repair; Step 4, welding the tail end of the metal lining 3 to the tail end of the metal pipe 1 to be repaired; Step 5: Connect the internal expansion die 4 and the pull rod 6 to the hydraulic system through the hydraulic system device 7. Driven by the hydraulic system, pull the internal expansion die 4 through the metal lining 3 out of the metal pipe 1 to be repaired, and expand the diameter of the metal lining 3 by extruding it with the internal expansion die 4, so that the metal lining 3 compresses the lining plastic pipe 2 for repair, playing a role in sealing the lining plastic pipe 2 for repair and the metal pipe 1 to be repaired.

[0028] Further, as Figure 1 shown, the tail end of the lining plastic pipe 2 for repair is 2 - 3 cm shorter than the tail end of the metal pipe 1 to be repaired. This distance is set to prevent the heat generated during the welding of the tail end of the metal lining 3 and the tail end of the metal pipe 1 to be repaired from damaging the lining plastic pipe 2 for repair.

[0029] Further, as Figure 2 shown, the metal lining 3 includes a tubular extrusion end 3 - 1 inserted inside the end of the lining plastic pipe 2 for repair and a connection end 3 - 2 that can be welded to the end of the metal pipe 1 to be repaired.

[0030] Further, as Figure 2 shown, the outer diameter of the extrusion end 3 - 1 is the same as the inner diameter of the lining plastic pipe 2 for repair, and the tail end of the extrusion end 3 - 1 is flush with the tail end of the lining plastic pipe 2 for repair; the wall thickness of the extrusion end 3 - 1 is 3 - 5 mm; the length of the extrusion end 3 - 1 is twice the inner diameter of the lining plastic pipe 2 for repair.

[0031] Further, as Figure 2 shown, several serrated annular protrusions 3 - 1 - 1 and two circular protrusions 3 - 1 - 2 are provided on the outer side of the front end of the extrusion end 3 - 1. The O - ring 5 is sleeved in the groove formed by the two circular protrusions 3 - 1 - 2. The setting of several serrated annular protrusions 3 - 1 - 1 is to ensure the sealing effect between the lining plastic pipe 2 for repair and the metal pipe 1 to be repaired; the depth of the groove formed between the two circular protrusions 3 - 1 - 2 is greater than the depth of the groove formed between the several serrated annular protrusions 3 - 1 - 1, so as to facilitate the installation of the O - ring 5 and further ensure the sealing effect. The two circular protrusions 3 - 1 - 2 are arranged between the several serrated annular protrusions 3 - 1 - 1. Specifically, seven serrated annular protrusions 3 - 1 - 1 can be set, and two circular protrusions are set between the second serrated annular protrusion and the third serrated annular protrusion. The heights of the serrated annular protrusions 3 - 1 - 1 and the circular protrusions 3 - 1 - 2 are the same, generally 2 mm. The wall thickness of the rear end of the extrusion end 3 - 1 (the part without serrated annular protrusions 3 - 1 - 1 and circular protrusions 3 - 1 - 2) is 1 - 3 mm, so the wall thickness of the extrusion end 3 - 1 is 3 - 5 mm.

[0032] Further, as Figure 2As shown, the connecting end 3-2 is set in a stepped shape. The outer diameter of the lower stage is the same as the inner diameter of the metal pipe 1 to be repaired; the outer diameter of the upper stage is larger than the inner diameter of the metal pipe 1 to be repaired, and the upper stage is arranged outside the tail end of the metal pipe 1 to be repaired. The setting of the connecting end 3-2 is to ensure convenient welding when the metal lining 3 is welded to the metal pipe 1 to be repaired.

[0033] Furthermore, the O-ring 5 is a rubber ring, which further ensures the risk of no leakage.

[0034] Furthermore, the internal expansion die 4 is a conical frustum with a smaller front end diameter than the rear end diameter (that is, a conical frustum with a small front end and a large rear end); the maximum outer diameter dimension of the internal expansion die 4 is equal to the outer diameter dimension of the metal lining 3, and the outer diameter dimension of the metal lining 3 is equal to the inner diameter dimension of the lining plastic pipe 2 for repair. When the internal expansion die 4 is pulled by the hydraulic system, the front end with a smaller outer diameter (the outer diameter dimension is smaller than the inner diameter dimension of the extrusion end) first enters the extrusion end 3-1 of the metal lining 3, and finally the rear end with the largest outer diameter (the outer diameter dimension is the same as the outer diameter of the metal lining 3) enters the extrusion end 3-1. Under the traction force of the hydraulic system, the internal expansion die 4 expands the diameter of the extrusion end 3-1 of the metal lining 3, so that the inner diameter dimension of the metal lining 3 reaches the inner diameter dimension of the lining plastic pipe 2 for repair, and the extrusion end 3-1 of the metal lining 3 tightly presses the lining plastic pipe 2 for repair on the inner wall of the metal pipe 1 to be repaired, so as to achieve a sealing effect.

[0035] Furthermore, the material hardness of the internal expansion die 4 is greater than that of the metal lining 3. Generally, the material of the metal lining 3 is selected as stainless steel material, which is machined by turning a stainless steel pipe, and the internal expansion die 4 is selected as alloy steel material.

[0036] Furthermore, the specification of the lining plastic pipe 2 for repair is DN50-DN600; the lining plastic pipe 2 for repair is any one of polyethylene, heat-resistant polyethylene, high-temperature resistant polyolefin and cross-linked polyethylene.

[0037] Specifically, when the specification of the metal pipe 1 to be repaired is Φ114 (114.3) × 6, the specification of the lining plastic pipe 2 for repair is Φ98 × 5, the metal lining 3 is machined from a stainless steel pipe with a specification of Φ108 × 14.0 (14.2), and the O-ring 5 uses FKM with an inner diameter of Φ82.5 × Φ3.55 (FKM is the abbreviation of fluororubber, and fluororubber can be divided into three basic types: namely fluorocarbon rubber, fluorosilicone rubber, and fluorophosphonitrile rubber).

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A on-site manufacturing method for a plastic pipe joint used for inner lining repair, characterized in that: It includes the following steps: Step 1: Liner plastic pipe for repair (2) is lined into the metal pipe to be repaired (1). Step 2: After connecting the internal expansion die (4) and the pull rod (6), they are put into the liner plastic pipe for repair (2) from the end of the liner plastic pipe for repair (2). Step 3: After the metal liner (3) is sleeved with an O-ring (5), it passes through the pull rod (6) and is inserted into the inner part of the end of the liner plastic pipe for repair (2). Step 4: The tail end of the metal liner (3) is welded to the tail end of the metal pipe to be repaired (1). Step 5: The internal expansion die (4) and the pull rod (6) are connected to the hydraulic system through a hydraulic system device (7). Driven by the hydraulic system, the internal expansion die (4) passes through the metal liner (3) and is pulled out of the metal pipe to be repaired (1). The metal liner (3) is extruded and expanded in diameter by the internal expansion die (4), so that the metal liner (3) compresses the liner plastic pipe for repair (2), playing a role in sealing the liner plastic pipe for repair (2) and the metal pipe to be repaired (1).

2. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 1, characterized in that: The tail end of the liner plastic pipe for repair (2) is 2 - 3 cm shorter than the tail end of the metal pipe to be repaired (1).

3. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 1, characterized in that: The metal liner (3) includes a tubular extrusion end (3 - 1) inserted into the inner part of the end of the liner plastic pipe for repair (2) and a connection end (3 - 2) that can be welded to the end of the metal pipe to be repaired (1).

4. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 3, characterized in that: The outer diameter of the extrusion end (3 - 1) is the same as the inner diameter of the liner plastic pipe for repair (2), and the tail end of the extrusion end (3 - 1) is flush with the tail end of the liner plastic pipe for repair (2); the wall thickness of the extrusion end (3 - 1) is 3 - 5 mm; the length of the extrusion end (3 - 1) is twice the inner diameter of the liner plastic pipe for repair (2).

5. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 3, characterized in that: Several serrated annular protrusions (3 - 1 - 1) and two circular annular protrusions (3 - 1 - 2) are arranged on the outer side of the front end of the extrusion end (3 - 1), and the O-ring (5) is sleeved in the groove formed by the two circular annular protrusions (3 - 1 - 2).

6. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 3, characterized in that: The connection end (3 - 2) is arranged in a stepped shape. The outer diameter of the low stage is the same as the inner diameter of the metal pipe to be repaired (1); the outer diameter of the high stage is larger than the inner diameter of the metal pipe to be repaired (1), and the high stage is arranged outside the tail end of the metal pipe to be repaired (1).

7. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 1, characterized in that: The O-ring (5) is a rubber ring.

8. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 1, characterized in that: The internal expansion die (4) is a conical frustum with a smaller front end diameter than the rear end diameter; the maximum outer diameter size of the internal expansion die (4) is equal to the outer diameter size of the metal liner (3), and the outer diameter size of the metal liner (3) is equal to the inner diameter size of the liner plastic pipe for repair (2).

9. The on-site manufacturing method of a plastic pipe joint for inner lining repair according to claim 1, characterized in that: The material hardness of the internal expansion die (4) is greater than the material hardness of the metal liner (3).

10. The on-site manufacturing method of a plastic pipe joint for lining repair according to claim 1, characterized in that: The specification of the liner plastic pipe for repair (2) is DN50 - DN600; the liner plastic pipe for repair (2) is any one of polyethylene, heat-resistant polyethylene, high-temperature resistant polyolefin, and cross-linked polyethylene.

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