Flange type steel-plastic adapter

Abstract

The utility model belongs to the technical field of pipeline joints, and particularly relates to a flange type steel-plastic conversion joint, which comprises a metal end flange plate, a plastic end flange plate, an annular elastic rubber sealing ring, a plurality of groups of double-end bolts and a split groove clamp, and the split groove clamp comprises two semi-annular clamp bodies which are spliced in a split mode. A limiting clamping groove and a clamping convex rib are arranged on the inner side wall of each semicircular hoop; an annular limiting protruding ring protruding upwards is integrally arranged on the upper end face of the metal end flange plate, and the annular limiting protruding ring is embedded in the limiting clamping groove. A clamping groove is formed in the end part of the metal steel pipe; and the clamping convex rib is embedded in the clamping groove. According to the device, the problem that fire construction is limited when the steel flange plate is connected with the metal steel pipe can be solved, and the water hammer impact resistance, construction convenience and use stability of the adapter are improved.

Description

Technical Field

[0001] This utility model belongs to the field of pipe joint technology, specifically relating to a flange-type steel-plastic conversion joint. Background Technology

[0002] Steel-plastic transition joints are key fittings for connecting metal steel pipes and plastic pipes. The rigidity of their connection structure, the safety of construction operations, and the long-term reliability of their sealing surfaces directly determine the operational stability and service life of the steel-plastic hybrid pipeline system, making them an indispensable core component. Existing flange-type steel-plastic transition joints have two major technical drawbacks: First, the connection between the steel flange and the metal pipe is mostly achieved through welding or integral casting. Welding operations require open flames, making them unsuitable for fire-prohibited work environments, and can easily cause warping and deformation of the flange sealing surface, leading to corrosion and leakage at the weld joint after long-term use. Second, the sealing between the metal and plastic ends often uses radial sealing rings. This structure has a small sealing contact area, uneven sealing pressure, poor resistance to high pressure and water hammer impact, and the metal-plastic interface is prone to delamination and cracking due to stress concentration, leading to leakage and posing a safety hazard to the pipeline system.

[0003] Chinese patent CN219933260U discloses a grooved flange conversion joint, including a flange and a connector sleeve. The connector sleeve is fixedly connected to the top of the flange, and several bolt holes are provided on the flange. A groove is formed on the outer surface of the connector sleeve, and a positioning ring is fixedly connected to the bottom edge of the flange. Two first protrusions are also fixedly connected to the bottom surface of the flange. This patent can pre-position the gasket, making it initially aligned with the flange. Subsequently, only the gasket needs to be rotated to align the bolt holes, reducing the trouble of alignment adjustment. The first protrusion abuts against the gasket and interlocks with the second protrusion on the gasket. The second protrusion also abuts against the bottom surface of the flange, forming four seals, which effectively improves the sealing performance between the gasket and the flange. However, the flange and connector sleeve of this patent are integrally cast, which poses a structural risk of long-term leakage. At the same time, the overall rigidity of the cast structure is much lower than that of the rigid connection structure with mechanical interlocking, and its resistance to water hammer impact is weak, making it unsuitable for working conditions with high requirements for structural rigidity, such as high-pressure fire fighting and water supply. Utility Model Content

[0004] The purpose of this utility model is to provide a flange-type steel-plastic conversion joint that can solve the problems of restricted hot work construction, structural leakage and insufficient rigidity when connecting steel flanges and metal pipes, improve the conversion joint's resistance to water hammer impact, and at the same time improve construction convenience and usage stability.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A flanged steel-plastic transition joint includes a metal end flange for connecting to a metal steel pipe, a plastic end flange for connecting to a polyethylene pipe fitting, an annular elastic rubber sealing ring, and several sets of double-ended bolts. It also includes split-type grooved clamps, each consisting of two interlocking semi-annular clamps. Each semi-annular clamp has a limiting groove and a snap-fit ​​rib on its inner wall. When the two semi-annular clamps are joined, the two limiting grooves form a complete circular limiting groove, and the two snap-fit ​​ribs form a complete circular snap-fit ​​rib. An outwardly protruding annular limiting rib is integrally provided at the upper end of the metal end flange, and the annular limiting rib is embedded in the limiting groove. A snap-fit ​​groove is provided at the end of the metal steel pipe, and the snap-fit ​​rib is embedded in the snap-fit ​​groove. The metal end flange and the plastic end flange are coaxially arranged opposite each other, and the annular elastic rubber sealing ring is clamped between the metal end flange and the plastic end flange.

[0007] Furthermore, the end face of the metal end flange facing the plastic end flange is arranged parallel to the end face of the plastic end flange facing the metal end flange.

[0008] Furthermore, both the metal end flange and the plastic end flange are provided with coaxial corresponding mounting through holes, and the two ends of the double-ended bolts are respectively inserted into the corresponding coaxial mounting through holes, and both ends of the double-ended bolts are threaded with lock nuts.

[0009] Furthermore, the double-ended bolts are evenly distributed circumferentially along the metal end flange.

[0010] Furthermore, the number of double-ended bolts is 6-12 sets.

[0011] Furthermore, the plastic end flange is integrally molded with the polyethylene pipe fitting.

[0012] Furthermore, the split groove clamp is composed of two symmetrical semi-circular clamps joined together. The joining ends of the two semi-circular clamps are provided with connecting ears, and adjacent connecting ears are locked and fixed by locking bolts.

[0013] Furthermore, the inner wall of the semi-circular clamp, the inner wall of the limiting groove, and the surface of the snap-fit ​​rib are all provided with an anti-corrosion galvanized layer.

[0014] Furthermore, between the snap-fit ​​groove of the metal steel pipe and the snap-fit ​​protrusion of the split groove clamp, a matching annular sealing gasket is sandwiched, with the annular sealing gasket fitting between the groove wall of the snap-fit ​​groove and the outer wall of the snap-fit ​​protrusion.

[0015] Furthermore, between the annular limiting protrusion of the metal end flange and the limiting groove of the split groove clamp, a mutually compatible annular sealing element is sandwiched; the annular sealing gasket and the annular sealing element are integrally formed as a sealing structure.

[0016] The beneficial effects of this utility model are as follows:

[0017] This invention utilizes a split-type grooved clamp to synchronously and mechanically connect the metal end flange and the metal pipe, eliminating the need for welding or open flame operations. It is suitable for high-risk construction scenarios where open flames are prohibited, such as gas stations, chemical explosion-proof areas, and renovations of old pipeline networks, reducing operational safety risks and construction costs, and increasing on-site assembly efficiency. The installation process eliminates welding heat input, fundamentally preventing the warping and deformation of the flange sealing surface caused by welding. Furthermore, the metal and plastic end flanges are coaxially arranged, with an annular elastic rubber sealing ring clamped between the parallel end faces of the two flanges, resulting in a larger and more comprehensive end-face sealing contact area. The sealing pressure is more uniform, and the sealing performance is more stable. Through the rigid engagement of the semi-circular clamp's snap-fit ​​ribs and snap-fit ​​grooves, and the limiting grooves and annular limiting convex rings, a rigid connection system with full axial and radial limiting is formed. The tensile, torsional, and water hammer impact resistance is significantly improved. It can stably adapt to working conditions with high requirements for structural rigidity and impact resistance, such as high-pressure fire fighting, municipal water supply, and chemical media transportation, thereby improving the operational stability and service life of the pipeline system. The split groove clamp is a split splicing structure, which is convenient for assembly and disassembly. The joint can be inspected and replaced without cutting or damaging the pipeline, reducing the difficulty of later operation and maintenance of the pipeline system. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a partial structural diagram of the present invention, excluding the polyethylene pipe fitting, plastic end flange, and double-headed bolts.

[0020] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0021] Figure 4 This is a schematic diagram of the semi-annular clamp in this utility model;

[0022] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0023] In the picture:

[0024] 1. Metal steel pipe; 2. Metal end flange; 3. Polyethylene pipe fitting; 4. Plastic end flange; 5. Double-ended bolt; 6. Semi-circular clamp; 7. Limiting groove; 8. Snap-fit ​​rib; 9. Circular limiting rib; 10. Snap-fit ​​groove. Detailed Implementation

[0025] The present invention will now be described and illustrated in detail with reference to the embodiments.

[0026] Example 1

[0027] like Figure 1-5 As shown, the flanged steel-plastic conversion joint includes a metal end flange 2 connected to the metal steel pipe 1, a plastic end flange 4 connected to the polyethylene pipe fitting 3, an annular elastic rubber sealing ring, and several sets of double-ended bolts 5. It also includes split-type grooved clamps, each consisting of two interlocking semi-annular clamps 6. Each semi-annular clamp 6 has a limiting groove 7 and a locking rib 8 on its inner sidewall. After the two semi-annular clamps 6 are joined, the two sets of limiting grooves 7 interlock to form a complete circle. The annular limiting groove 7 and two sets of snap-fit ​​ribs 8 are spliced ​​together to form a complete circular snap-fit ​​rib 8; the upper end of the metal end flange 2 is integrally provided with an outwardly protruding annular limiting rib 9, which is embedded in the limiting groove 7; the end of the metal steel pipe 1 is provided with a snap-fit ​​groove 10, and the snap-fit ​​rib 8 is embedded in the snap-fit ​​groove 10; the metal end flange 2 and the plastic end flange 4 are coaxially arranged opposite each other, and an annular elastic rubber sealing ring is clamped between the metal end flange 2 and the plastic end flange 4.

[0028] The end face of the metal end flange 2 facing the plastic end flange 4 is arranged parallel to the end face of the plastic end flange 4 facing the metal end flange 2.

[0029] Both the metal end flange 2 and the plastic end flange 4 are provided with coaxial corresponding mounting through holes. The two ends of the double-ended bolt 5 are respectively inserted into the corresponding coaxial mounting through holes, and both ends of the double-ended bolt 5 are threaded with lock nuts.

[0030] The double-ended bolts 5 are evenly distributed around the circumference of the metal end flange 2.

[0031] The number of double-ended bolts 5 is 6-12 sets.

[0032] The plastic end flange 4 and the polyethylene pipe fitting 3 are integrally molded.

[0033] The split groove clamp is composed of two symmetrical semi-circular clamps 6. The two semi-circular clamps 6 are provided with connecting ears at their joint ends, and adjacent connecting ears are locked and fixed by locking bolts.

[0034] The inner wall of the semi-circular clamp 6, the inner wall of the limiting groove 7, and the surface of the snap-fit ​​rib 8 are all provided with an anti-corrosion galvanized layer.

[0035] Between the snap-fit ​​groove 10 of the metal steel pipe 1 and the snap-fit ​​protrusion 8 of the split groove clamp, a matching annular sealing gasket is provided. The annular sealing gasket is attached to the groove wall of the snap-fit ​​groove 10 and the outer wall of the snap-fit ​​protrusion 8.

[0036] Between the annular limiting protrusion 9 of the metal end flange 2 and the limiting groove 7 of the split groove clamp, a mutually compatible annular sealing element is sandwiched; the annular sealing gasket and the annular sealing element are integrally formed sealing structures.

[0037] Working process and principle:

[0038] I. Alignment and Assembly

[0039] First, the metal end flange 2 is coaxially fitted onto the end of the metal steel pipe 1, so that the end face of the metal end flange 2 with the annular limiting protrusion 9 faces the outside of the end of the metal steel pipe 1; then, the two semi-annular clamps 6 are symmetrically fastened to the end of the metal steel pipe 1, so that the limiting groove 7 on the inner side of the semi-annular clamp 6 is aligned with and fitted into the annular limiting protrusion 9 of the metal end flange 2, and at the same time, the snap-fit ​​protrusion 8 on the inner side of the semi-annular clamp 6 is aligned with and fitted into the snap-fit ​​groove 10 of the metal steel pipe 1.

[0040] After the two semi-circular clamps 6 are engaged, the two sets of limiting grooves 7 are spliced ​​together to form a complete circular limiting groove, and the two sets of interlocking ribs 8 are spliced ​​together to form a complete circular interlocking rib. Through axial bidirectional embedding and interlocking, the coaxial positioning of the metal end flange 2 and the metal steel pipe 1 is completed simultaneously. The radial and axial full limiting of the two can be achieved without welding, avoiding the problem of flange sealing surface warping and deformation caused by welding heat input. At the same time, compared with the one-piece casting structure, the mechanical interlocking connection method has stronger overall rigidity and better resistance to torsion and displacement.

[0041] II. Locking and sealing

[0042] The plastic end flange 4 and the metal end flange 2 are arranged coaxially relative to each other. The plastic end flange 4 and the polyethylene pipe fitting 3 are integrally formed structures, without the need for secondary splicing and welding. The annular elastic rubber sealing ring is placed between the relatively parallel end faces of the metal end flange 2 and the plastic end flange 4, so that the annular elastic rubber sealing ring is coaxially aligned with the two flanges. At the same time, the double-ended bolts 5 are evenly inserted into the corresponding mounting through holes of the two flanges along the circumference to complete the pre-positioning of the flange connection.

[0043] First, tighten the locking bolts of the split groove clamp. Then, lock the connecting ears at the joint ends of the two semi-annular clamps 6 with the locking bolts. During the tightening process, the annular sealing gasket between the snap-fit ​​rib 8 and the snap-fit ​​groove 10, and the annular sealing element between the limiting groove 7 and the annular limiting rib 9 are simultaneously compressed to form a sealing interlocking surface. This not only prevents the leakage of the medium inside the pipe from the interlocking gap, but also avoids the problem of steel pipe corrosion and clamp corrosion caused by the infiltration of external moisture. In conjunction with the anti-corrosion galvanized layer set on the inner wall of the semi-annular clamp 6, the inner wall of the limiting groove 7, and the surface of the snap-fit ​​rib 8, the service life of the joint can be greatly improved.

[0044] After the split grooved clamps are tightened, the lock nuts at both ends of the double-ended bolts 5 are tightened evenly in sequence, so that the parallel end faces of the metal end flange 2 and the plastic end flange 4 are evenly pressed against the annular elastic rubber sealing ring. With the double-ended bolts 5 evenly distributed around the circumference, the circumferential force on the sealing surface can be ensured, avoiding sealing ring failure caused by uneven pressure, and the sealing performance is more stable.

[0045] III. Operational Pressure

[0046] After the pipeline system is put into operation, when the pressure of the medium inside the pipe increases, the medium pressure will further push the metal end flange 2 and the plastic end flange 4 to press against each other. The higher the medium pressure, the stronger the clamping force of the end face seal. When the pipeline system experiences water hammer impact or vibration load, the rigid interlocking structure of the semi-circular clamp 6 can evenly distribute the impact load to the entire ring of the metal steel pipe 1's interlocking groove 10 and the annular limiting protrusion 9 of the metal end flange 2. The tensile, torsional, and water hammer impact resistance is significantly improved, and it can stably adapt to working conditions with extremely high requirements for structural rigidity, such as high-pressure fire fighting, municipal water supply, and chemical medium transportation, avoiding joint loosening and leakage problems.

[0047] IV. Maintenance and Disassembly

[0048] When the pipeline system needs maintenance or replacement of joint components, simply loosen the double-ended bolt 5 and the locking bolt in sequence to quickly disassemble the metal end flange 2, the plastic end flange 4 and the split grooved clamp, without cutting or damaging the metal steel pipe 1 and the polyethylene pipe fitting 3, making assembly and disassembly convenient.

Claims

1. A flanged steel-plastic conversion joint, comprising a metal end flange (2) connected to a metal steel pipe (1), a plastic end flange (4) connected to a polyethylene pipe fitting (3), an annular elastic rubber sealing ring, and several sets of double-ended bolts (5), characterized in that, It also includes split groove clamps, which consist of two semi-circular clamps (6) that are joined together; each semi-circular clamp (6) has a limiting groove (7) and a snap-fit ​​rib (8) on its inner sidewall. After the two semi-circular clamps (6) are joined together, the two sets of limiting grooves (7) are joined together to form a complete circular limiting groove (7), and the two sets of snap-fit ​​ribs (8) are joined together to form a complete circular snap-fit ​​rib (8); metal end flange (2) The upper end is integrally provided with an outwardly protruding annular limiting protrusion (9), which is embedded in the limiting groove (7); the end of the metal steel pipe (1) is provided with a snap-fit ​​groove (10), and the snap-fit ​​rib (8) is embedded in the snap-fit ​​groove (10). The metal end flange (2) and the plastic end flange (4) are coaxially arranged relative to each other, and the annular elastic rubber sealing ring is sandwiched between the metal end flange (2) and the plastic end flange (4).

2. The flange-type steel-plastic transition joint according to claim 1, characterized in that, The end face of the metal end flange (2) facing the plastic end flange (4) is arranged parallel to the end face of the plastic end flange (4) facing the metal end flange (2).

3. The flange-type steel-plastic transition joint according to claim 1, characterized in that, Both the metal end flange (2) and the plastic end flange (4) are provided with coaxial mounting through holes. The two ends of the double-ended bolt (5) are respectively inserted into the corresponding coaxial mounting through holes. Both ends of the double-ended bolt (5) are threaded with lock nuts.

4. The flange-type steel-plastic transition joint according to claim 1, characterized in that, The double-ended bolts (5) are evenly distributed around the metal end flange (2).

5. The flange-type steel-plastic transition joint according to claim 4, characterized in that, The number of double-ended bolts (5) is 6-12 sets.

6. The flange-type steel-plastic transition joint according to claim 1, characterized in that, The plastic end flange (4) and the polyethylene pipe fitting (3) are integrally formed.

7. The flange-type steel-plastic transition joint according to claim 1, characterized in that, The split groove clamp is composed of two symmetrical semi-circular clamps (6). The two semi-circular clamps (6) are provided with connecting ears at their joint ends, and adjacent connecting ears are locked and fixed by locking bolts.

8. The flange-type steel-plastic transition joint according to claim 1, characterized in that, The inner wall of the semi-circular clamp (6), the inner wall of the limiting groove (7), and the surface of the snap-fit ​​rib (8) are all provided with an anti-corrosion galvanized layer.

9. The flange-type steel-plastic transition joint according to claim 1, characterized in that, Between the snap-fit ​​groove (10) of the metal steel pipe (1) and the snap-fit ​​protrusion (8) of the split groove clamp, there is a matching annular sealing gasket. The annular sealing gasket is attached between the groove wall of the snap-fit ​​groove (10) and the outer wall of the snap-fit ​​protrusion (8).

10. The flange-type steel-plastic transition joint according to claim 9, characterized in that, Between the annular limiting protrusion (9) of the metal end flange (2) and the limiting groove (7) of the split groove clamp, there is a mutually compatible annular sealing element; the annular sealing gasket and the annular sealing element are integrally formed sealing structures.

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