Groove structure for pressure steel pipe welding and welding method

Abstract

According to the structural scheme, the pressure steel pipe welding groove structure comprises pressure steel pipes, the welding position of the two pressure steel pipes is composed of an upper groove, a transition groove area and a lower groove, the depth of an upper outer groove of the upper groove is larger than that of an upper inner groove, and the depth of a lower groove of the upper groove is larger than that of a lower outer groove of the transition groove area. The depth of the lower inner groove of the lower groove is larger than that of the lower outer groove. The method has the beneficial effects that the segmented non-uniform groove structure is adopted, overhead welding can be reduced, flat welding can be increased, and vertical welding can be properly adjusted, so that the welding operation efficiency of a pressure steel pipe mounting welding seam is effectively improved, the labor intensity of welding operation is effectively reduced, and effective control over the welding cost and the welding quality is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a groove structure for welding a pressure steel pipe and a welding method. Background Art

[0002] At present, after the excavation and support of the pressure pipeline of the hydropower station is completed, the pressure steel pipe is installed in sections and the concrete is backfilled in sections. Generally, the pressure steel pipe is manufactured in sections in the workshop and transported to the pressure pipeline site for installation. The circumferential weld groove usually adopts an X-shaped unequal-sided uniform groove. As a result, the annular weld has different welding conditions such as flat welding, overhead welding, and vertical welding. That is, the top and bottom of the steel pipe are mainly flat welding and overhead welding, and the two sides are mainly vertical welding. As we all know, overhead welding is the most difficult in welding operations, followed by vertical welding, and flat welding is relatively easy. Therefore, this traditional full-ring unequal-sided uniform groove type has the following shortcomings in terms of resource investment, quality control, working environment, welding efficiency, and engineering cost during on-site installation and welding: 1. The welder’s operation skills are high, the amount of upturned seam welding is large, and quality control is difficult; Second, due to the limitations of the working environment and working conditions, the resource input is large and the labor intensity is high; 3. The welding efficiency is relatively low, the weld reliability is poor, and the engineering cost is relatively high.

[0003] To sum up, designing a groove structure for circumferential welding of hydropower station pressure steel pipe installation that is simple in structure and convenient for welding, which can adapt to the working environment conditions, effectively reduce labor intensity, improve welding efficiency, and is beneficial to project cost and quality control, has become an issue that needs to be urgently studied and solved by engineering and technical personnel in this field. Summary of the invention

[0004] In view of the above-mentioned problems in the prior art, the present invention provides a groove structure for penstock welding in order to effectively solve some problems and shortcomings brought about by the groove structure (full-ring uniform groove) commonly used in the installation process of penstocks in hydropower stations to the welding process. The technical scheme is as follows: comprising a penstock, the welding point of two penstocks consists of an upper groove, a transition groove area and a lower groove, the depth of the upper outer groove of the upper groove is deeper than the depth of the upper inner groove, the depth of the lower inner groove of the lower groove is deeper than the depth of the lower outer groove, forming a segmented uneven groove structure, wherein the wall thickness of the penstock is δ, the welding root gap between the penstocks is c, and the welding root width of the penstock is d.

[0005] As a preferred solution, the opening angle between the upper outer groove and the lower inner groove is α1, wherein the value range of α1 is 40°≤α1≤60°.

[0006] As a preferred solution, the opening angle between the upper inner bevel and the lower outer bevel is α2, wherein the value range of α2 is 50°≤α2≤70°.

[0007] As a preferred solution, the value range of the pipe wall thickness δ of the pressure steel pipe is 25.0≤δ≤120.0mm.

[0008] As a preferred solution, the value range of the welding root gap c between the pressure steel pipes is c≤2mm.

[0009] As a preferred embodiment, the welding root width d of the pressure steel pipe has a value range of 1.0≤d≤3.0mm.

[0010] As a preferred solution, the depth of the upper inner groove and the lower outer groove is h, and the value range of h is δ / 3≤h≤(δ / 2-d).

[0011] As a preferred solution, the outer structure of the transition groove area gradually becomes shallower from the upper outer groove connection to the lower outer groove connection, and the inner structure gradually becomes deeper from the upper inner groove connection to the lower inner groove connection.

[0012] The present invention also provides a welding method for the groove structure: S1: Butt the upslope, transition groove area and downslope of the two penstocks, and perform air planing and trimming when the seam width is ≤3mm; S2: After the butt joint is completed, the upper outer groove is welded flat, the upper inner groove is welded overhead, the transition groove area on both sides is welded vertically inside and outside, the lower outer groove is welded overhead, and the lower inner groove is welded flat.

[0013] As a preferred solution, the welding is manual arc welding or automatic welding.

[0014] Beneficial effects of the present invention: The present invention adopts a segmented uneven groove structure, which can reduce overhead welding, increase flat welding and appropriately adjust vertical welding, thereby effectively improving the welding efficiency of the pressure steel pipe installation weld, effectively reducing the labor intensity of the welding operation, and is conducive to the effective control of welding cost and welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the pipe orifice structure of the pressure steel pipe in the present invention.

[0016] Figure 2 for Figure 1 Cross-sectional view from the middle AA perspective (upper cut of the pressure steel pipe).

[0017] Figure 3 for Figure 1Cross-sectional view from the middle BB perspective (lower section of the penstock).

[0018] Figure 4 for Figure 2 Schematic diagram of the detailed structure of the upslope of the medium pressure steel pipe.

[0019] Figure 5 for Figure 3 Schematic diagram of the detailed structure of the downslope of the medium pressure steel pipe.

[0020] In the figure: 1, pressure steel pipe; 101, upper bevel; 1011, upper outer bevel; 1012, upper inner bevel; 102, transition bevel area; 103, lower bevel; 1031, lower outer bevel; 1032, lower inner bevel. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below based on the accompanying drawings and specific embodiments.

[0022] Example 1 like Figure 1-4 The structure shown includes a pressure steel pipe 1, and the welding point of two pressure steel pipes 1 consists of an upper groove 101, a transition groove area 102 and a lower groove 103. The depth of the upper outer groove 1011 of the upper groove 101 is deeper than the depth of the upper inner groove 1012, and the depth of the lower inner groove 1032 of the lower groove 103 is deeper than the depth of the lower outer groove 1031, forming a segmented uneven groove structure, wherein the wall thickness of the pressure steel pipe 1 is δ, the welding root gap between the pressure steel pipes 1 is c, and the welding root width of the pressure steel pipe 1 is d.

[0023] Furthermore, the opening angle between the upper outer groove 1011 and the lower inner groove 1032 is α1, wherein the value range of α1¬ is 40°≤α1≤60°, and further, α1 is 60°.

[0024] Furthermore, the opening angle between the upper inner groove 1012 and the lower outer groove 1031 is α2, wherein the value range of α2 is 50°≤α2≤70°, and further, α2 is 60°.

[0025] Furthermore, the value range of the tube wall thickness δ of the pressure steel tube 1 is 25.0≤δ≤120.0mm.

[0026] Furthermore, the value range of the welding root gap c between the pressure steel pipes 1 is c≤2mm, and further, c is 2mm.

[0027] Furthermore, the welding root width d of the pressure steel pipe 1 has a value range of 1.0≤d≤3.0mm, and further, d is 2mm.

[0028] Furthermore, the depths of the upper inner groove 1012 and the lower outer groove 1031 are h, and the value range of h is δ / 3≤h≤(δ / 2-d).

[0029] Furthermore, the outer structure of the transition groove area 102 gradually becomes shallower from the connection of the upper outer groove 1011 to the connection of the lower outer groove 1031, and the inner structure gradually becomes deeper from the connection of the upper inner groove 1012 to the connection of the lower inner groove 1032.

[0030] Example 2 The groove structure of the above embodiment 1 is adopted, and the welding process is as follows: S1: butt the upper bevel 101, transition bevel area 102 and lower bevel 103 of the two penstocks 1, and perform air planing and trimming when the seam width is ≤3 mm; S2: After the butt joint is completed, the upper outer groove 1011 is welded flat, the upper inner groove 1012 is welded overhead, the transition groove area 102 on both sides is welded vertically inside and outside, the lower outer groove 1031 is welded overhead, and the lower inner groove 1032 is welded flat to complete the welding of the pressure steel pipe. The above welding adopts manual arc welding, conventional welding materials and conventional welding conditions.

Claims

1. A groove structure for welding a pressure steel pipe, characterized in that: The invention comprises a penstock (1), wherein the welding part of two penstocks (1) is composed of an upper groove (101), a transition groove area (102) and a lower groove (103), wherein the depth of the upper outer groove (1011) of the upper groove (101) is deeper than the depth of the upper inner groove (1012), and the depth of the lower inner groove (1032) of the lower groove (103) is deeper than the depth of the lower outer groove (1031), thereby forming a segmented uneven groove structure, wherein the wall thickness of the penstock (1) is δ, the weld root gap between the penstocks (1) is c, and the weld root width of the penstock (1) is d.

2. A groove structure for welding a pressure steel pipe according to claim 1, characterized in that: The opening angle between the upper outer bevel (1011) and the lower inner bevel (1032) is α1, wherein the value range of α1 is 40°≤α1≤60°.

3. The groove structure of a pressure steel pipe welding according to claim 1 is characterized in that: The opening angle between the upper inner bevel (1012) and the lower outer bevel (1031) is α2, wherein the value range of α2 is 50°≤α2≤70°.

4. The groove structure of a pressure steel pipe weld according to claim 1, characterized in that: The value range of the wall thickness δ of the pressure steel pipe (1) is 25.0≤δ≤120.0 mm.

5. The groove structure of a pressure steel pipe weld according to claim 1, characterized in that: The value range of the welding root gap c between the pressure steel pipes (1) is c≤2 mm.

6. The groove structure of a pressure steel pipe weld according to claim 1, characterized in that: The value range of the welding root width d of the pressure steel pipe (1) is 1.0≤d≤3.0mm.

7. The groove structure of a pressure steel pipe weld according to claim 1, characterized in that: The depths of the upper inner groove (1012) and the lower outer groove (1031) are h, and the value range of h is δ / 3≤h≤(δ / 2-d).

8. The groove structure of a pressure steel pipe weld according to claim 1, characterized in that: The outer structure of the transition groove area (102) gradually becomes shallower from the connection of the upper outer groove (1011) to the connection of the lower outer groove (1031), and the inner structure gradually becomes deeper from the connection of the upper inner groove (1012) to the connection of the lower inner groove (1032).

9. A welding method for a groove structure of a pressure steel pipe according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: butting the upper bevel (101), transition bevel area (102) and lower bevel (103) of two penstocks (1), and performing air planing and trimming treatment when the seam width is ≤3 mm; S2: After the butt joint is completed, the upper outer groove (1011) is welded flat, the upper inner groove (1012) is welded overhead, the transition groove areas (102) on both sides are welded vertically inside and outside, the lower outer groove (1031) is welded overhead, and the lower inner groove (1032) is welded flat.

10. The welding method for the groove structure of a pressure steel pipe according to claim 9, characterized in that: The welding is manual arc welding or automatic welding.

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