阅读说明：本技术 空心壁不锈钢大口径管道及制造方法 (Hollow wall stainless steel large diameter pipeline and manufacturing method thereof ) 是由 廖忠烈 何维华 汪富忠 高亮娟 李佩雯 于 2020-07-10 设计创作，主要内容包括：空心壁不锈钢大口径管道及制造方法。设薄壁内圆管,外表面周向均布固定N个一边开口的空心折板。相邻两折板间留有间隙,其内固定弧形封口面板。且在内圆管两端口各固定一个轴向封口环。折板焊接后,焊接轴向封口环,最后焊接弧形封口面板。折板用折板机或模具加工成型。经试验和计算比较,本发明利用内衬空心壁的方法可代替实心壁管道,满足金属管道所需要的曲挠度和环刚力,可取代现有的大口径塑料管道和球墨铸铁管。还可用本方法制造出更大口径的管道,而这些大口径管道是用其他方法无法制造的。本发明充分利用了不锈钢管道具有较大的许用强度和耐腐蚀性能。可用于排水管道、供水管道,或燃气管道。(A hollow wall stainless steel large-caliber pipeline and a manufacturing method thereof. The thin-wall inner circular tube is arranged, and N hollow folded plates with openings on one side are uniformly distributed and fixed on the outer surface in the circumferential direction. A gap is left between two adjacent folding plates, and an arc-shaped sealing panel is fixed in the gap. And two axial sealing rings are respectively fixed at two ports of the inner circular tube. And after the folded plate is welded, welding an axial sealing ring, and finally welding an arc sealing panel. The folded plate is formed by a plate folding machine or a mould. Through test and calculation comparison, the method of the invention utilizes the inner lining hollow wall to replace a solid wall pipeline, meets the bending deflection and the annular rigidity required by a metal pipeline, and can replace the existing large-caliber plastic pipeline and the nodular cast iron pipe. Larger bore pipes can also be made by this method, which cannot be made by other methods. The invention makes full use of the larger allowable strength and corrosion resistance of the stainless steel pipeline. Can be used for water discharge pipelines, water supply pipelines or gas pipelines.)

1. Hollow wall stainless steel heavy-calibre pipeline, characterized by:

1) the inner ring of the hollow-wall stainless steel large-caliber pipeline is a stainless steel thin-wall inner circular pipe (1);

2) n hollow folded plates with an opening edge and stainless steel sections are uniformly and fixedly distributed on the outer surface of the thin-wall inner circular tube along the circumferential direction; the opening edge is reversely buckled and welded on the outer surface of the thin-wall inner circular tube;

3) a circumferential gap (3X) is formed between two circumferentially adjacent hollow folding plates on the outer surface of the thin-wall inner circular tube 1;

4) and stainless steel arc-shaped sealing panels are fixed in the N circumferential gaps.

2. The hollow-wall stainless steel large-caliber pipeline as claimed in claim 1, wherein the hollow folded plate on the outer surface of the thin-wall inner circular pipe adopts a triangular folded plate (2), and the triangular angle α is selected to be 20-100 degrees; an annular arc-shaped sealing panel (3) is fixed at the outer circumference of the circumferential gap.

3. The hollow-wall stainless steel large-diameter pipeline according to claim 2, wherein each hollow-wall stainless steel large-diameter pipeline has a length of 1-12 m, and two axial sealing rings (4) are welded to two end ports of the length; or more than 1 axial sealing ring is additionally arranged in the middle; the ring width of the axial sealing ring is equal to the radial height of the triangular folded plate.

4. The hollow-wall stainless steel large-caliber pipeline as claimed in claim 1, wherein the wall thickness Δ 1 of the thin-wall inner circular tube is 1-10 mm.

5. The method for manufacturing a hollow-walled stainless steel large-caliber pipe according to claim 1, which comprises the steps of:

1) preparing materials:

firstly, manufacturing a stainless steel thin-wall inner circular tube (1);

manufacturing N stainless steel hollow folded plates, namely processing and forming by using a plate folding machine, or compression molding or drawing and forming;

making N stainless steel outer circumference arc-shaped sealing panels, and performing compression molding or drawing molding;

2) and (3) combined welding and forming:

firstly, welding N stainless steel hollow folded plates on the outer circumferential surface of a stainless steel thin-wall inner circular tube (1) by straight seams of two edge strips (2.1) of an opening edge;

the second step is that: respectively welding an axial sealing ring (4) on the outer surfaces of two ports of the thin-wall inner circular tube welded with the hollow folded plate; or more than 1 axial sealing ring is additionally welded at the axial middle section of the thin-wall inner circular tube;

the third step: n arc-shaped sealing panels are welded in circumferential gaps (3X) between N adjacent hollow folding plates.

The technical field is as follows: the invention discloses a hollow-wall stainless steel large-caliber pipeline and a manufacturing method thereof, and relates to a 600-6000 mm large-caliber pipeline. Belongs to the class of pipelines and pipe fittings (F16L).

(II) background technology:

the existing large-caliber pipelines for water drainage, water supply and gas have been used or developed as follows:

a large-caliber plastic pipeline with the caliber of 1-2 m is manufactured by winding a steel bracket inner tube. Namely, the plastic PE is used as a matrix material, and the PP or steel plate is used as a ribbed pipeline. About 20 years of use, the following problems exist after conclusion:

1) the pipeline ring has insufficient rigidity and is buried in the depth of 1m underground, but the ground cannot be rolled by an automobile. The use period leads to a plurality of indemnity events. 2) The pipeline plastic corrugated pipe joint adopts the mode of inserting welding, but still can not avoid the joint frequently to produce the breach, leads to frequent water leakage accident. 3) The actual aging degree of the plastic is much faster than the theoretical value in use, the high molecular chain of the plastic can be broken after the pipeline is irradiated by ultraviolet rays on the ground for one day, the service life of the plastic is more difficult to be ensured for more than 10 years after the pipeline is buried underground, and leakage accidents are frequent when the pipeline is used as a sewage pipeline. 4) The plastic forbidden directive in Europe is issued by 2008.5.16, Europe does not allow the use of plastic pipes, and then Germany 'Clar company' gradually moves the plastic pipe production line to China, and China also issues the plastic forbidden directive in many provinces and cities, so that the large-diameter plastic pipes face the situation of complete elimination.

And secondly, research and development of the glass fiber reinforced plastic pipeline, wherein the production of the glass fiber reinforced plastic is not environment-friendly, and the glass fiber has permanent damage to people, so that the American 'Corning company' is researched and developed in China for three years, and finally, the development of the project in China is stopped.

Thirdly, the feasibility of using the nodular cast iron pipe as a drainage pipeline is that the nodular cast iron pipe has a unit weight of 1068kg and the wall thickness of the nodular cast iron pipe with the diameter of 2m is about 20mm because the nodular cast iron pipe is too heavy, and the unit weight is GB/T13295-2013. The laying of the ductile iron pipes as the sewer pipes causes a lot of troubles because the pipes are too heavy, a cement mat of sufficient strength must be provided before laying the pipes, and a steel bar cement mat must be added to prevent collapse, so the ductile iron pipes are not generally used as the sewer pipes in the cities.

Problems existing in the fourth and large-caliber carbon steel pipelines as the drain pipes

Because the ductile cast iron pipe is difficult to be used as a sewer pipeline, the existing drainage pipeline can only adopt a large-caliber plastic pipeline or a large-caliber carbon steel pipeline. When the carbon steel pipeline is used, in order to prevent corrosion perforation, high-strength cement must be paved in the carbon steel pipeline, and once the high-strength cement is broken and seeps water, the service life of the pipeline is only two or three years. Remarking: the cement coating is also used as the inner coating of the heavy-calibre nodular cast iron pipe, why is the water leakage without perforation? The reason is that: the cathode potential of graphite in the nodular cast iron pipe is as high as-2.1V, so that the electrochemical corrosion phenomenon cannot occur, and the cathode potential of the carbon steel pipeline is +0.44V, so that the electrochemical corrosion is inevitably generated.

Fifth, the condition and prospect of the stainless steel pipeline as the large-caliber drain pipe

In conclusion, the large-caliber drainage pipeline has fatal defects no matter a plastic pipeline, a nodular cast iron pipe or a carbon steel pipeline is adopted. The market calls for designing a stainless steel pipeline with low cost and long service life. The stainless steel pipeline has the advantages that: the environment-friendly type steel pipe joint is environment-friendly, has high ring rigidity and strong corrosion resistance, can be welded and connected, and has almost semi-permanent service life when the materials are selected properly. Stainless steel pipelines are already mandatory in europe as sewer pipelines, see EN1124, but the biggest disadvantage of this set of standards is that the maximum caliber is only 315mm, what is the small-caliber stainless steel pipelines do not meet the use requirements? Therefore, in Europe, a large-diameter pipeline is formed by connecting a plurality of pipelines in parallel. Due to engineering requirements, large-scale domestic sewage treatment plants also use stainless steel pipes with large calibers, such as DN800x30mm, DN1000x40mm and DN1600x60mm, the pipe walls of the three stainless steel pipes are respectively 30mm, 40mm and 60mm, the cost of the pipes is very high, how do it? Because the method is a key project of the country, the method can be used at high cost. However, for many small-sized sewage treatment plants, due to insufficient investment, only large-diameter plastic pipes or (cement or resin) coated carbon steel pipes with poor service performance and short service life can be used.

(III) the invention content:

the invention provides a hollow-wall stainless steel large-caliber pipeline and a manufacturing method thereof, and aims to solve the problems of poor rigidity, easiness in cracking and fragile interface of the conventional large-caliber plastic pipeline. The second purpose is to solve the problem that the existing heavy-caliber nodular cast iron pipe is difficult to install, high in cost and incapable of meeting the mandatory requirement of GB5749 on the sanitation performance of the drinking water pipeline when being used for the drinking water pipeline.

The technical scheme is as follows:

hollow wall stainless steel heavy caliber pipeline, characterized by:

1) the inner ring of the hollow-wall stainless steel large-caliber pipeline is a stainless steel thin-wall inner circular tube 1. 2) N hollow folded plates with an opening edge and stainless steel sections are uniformly and fixedly distributed on the outer surface of the thin-wall inner circular tube along the circumferential direction; the opening edge is reversed and welded on the outer surface of the thin-wall inner circular tube. 3) And a circumferential gap of 3X is formed between two circumferentially adjacent hollow folding plates on the outer surface of the thin-wall inner circular tube. 4) The arc-shaped sealing panels of stainless steel are fixed in the N circumferential gaps, and the arc length of each panel is pi D_w/N。

The hollow folded plate on the outer surface of the thin-wall inner circular tube can adopt a triangular folded plate 2, and the angle alpha of the triangle is selected to be 20-100 degrees; an annular arc-shaped sealing panel 3 is fixed at the outer circumference of the circumferential gap. The length of each hollow-wall stainless steel large-caliber pipeline is 1-12 m, and two axial sealing rings 4 can be welded at two end openings of the length of each hollow-wall stainless steel large-caliber pipeline respectively; or more than 1 axial sealing ring is additionally arranged in the middle; the ring width of the axial sealing ring is equal to the radial height of the triangular folded plate. The wall thickness delta 1 of the thin-wall inner circular tube 1 can be 1-10 mm.

The manufacturing method of the hollow wall stainless steel large-caliber pipeline is characterized by comprising the following steps:

1) preparing materials, namely manufacturing a stainless steel thin-wall inner circular tube 1. And manufacturing N stainless steel hollow folded plates, namely processing and forming by using a plate folding machine, or compression molding or drawing and forming. And thirdly, manufacturing N stainless steel outer circumference arc-shaped sealing panels, wherein the N stainless steel outer circumference arc-shaped sealing panels are molded by compression molding or drawing. 2) The first step of combined welding forming is that N stainless steel hollow folded plates are welded on the outer circumferential surface of the stainless steel thin-wall inner circular tube 1 through straight seams by using two edge strips 2.1 of an opening edge. The second step is that: respectively welding an axial sealing ring 4 on the outer surface of two ports of the thin-wall inner circular tube welded with the hollow folded plate; or an axial sealing ring is additionally welded at the axial middle section of the thin-wall inner circular pipe. The third step: and N arc-shaped sealing panels are welded in the circumferential gaps 3X between the N adjacent hollow folding plates.

The invention has the beneficial effects that:

1) as can be seen from a comparison of the latter two tables (table 1, table 2); compared with the cost of products with the same wall thickness or 1.5 times of the wall thickness, the hollow-wall large-caliber drainage pipeline formed by splicing and welding the stainless steel folded plates is basically in the same state, but the hollow-wall large-caliber pipeline formed by splicing and welding the stainless steel triangular folded plates has the unparalleled excellent performance.

2) The dynamic curve of the stainless steel pipeline is very good in a low-speed (<3m/s) flowing state, the stainless steel pipeline can show excellent wear resistance, the stainless steel pipeline with the thickness of 2mm can be worn by 0.03mm in each decade on average, and the stainless steel pipeline with the inner thin wall can still be used safely after two hundred years (see the average wear curve chart of the stainless steel in China edition in the stainless steel journal in the world), so that the service life of the thin-wall stainless steel water supply and drainage pipeline is almost semipermanent. The mechanical parameters of the hollow-wall large-caliber pipeline completely meet the requirements of the nodular cast iron pipe, so that the hollow-wall large-caliber pipeline formed by splicing and welding the stainless steel triangular sections has all the conditions for replacing a large-caliber plastic pipeline and a large-caliber nodular cast iron pipeline.

3) The triangular folded plate used as the inner wall is not the only choice, and the hollow folded plate can also be made of profiles with other section shapes; when the wall thickness or the height of the hollow folded plate is increased, the annular rigidity of the large-caliber pipeline with the hollow wall can be increased, and particularly when the height of the hollow folded plate is increased, the annular rigidity of the pipeline is increased in proportion.

4) The weight comparison table of hollow wall stainless steel large caliber pipe is provided, the hollow wall pipe composed of short hollow folded plates can be used as a water discharge pipe (in the embodiment 1, the width B2X is high, the height H2X is 47.7x41x2.25mm, and the thickness delta 2 is 47.7x41x2.25mm), and the hollow wall pipe composed of high hollow folded plates can be used as a water supply pipe or a gas pipe instead of a nodular cast iron pipe (in the embodiment 2, the width B2 is multiplied by the height H2 is multiplied by the thickness delta 2 is 70.9 x 61 x 2.25).

5) Through test and calculation comparison, the method of the invention utilizes the inner lining hollow wall to replace a solid wall pipeline, meets the bending deflection and the annular rigidity required by a metal pipeline, and can replace the existing large-caliber plastic pipeline and the nodular cast iron pipe. Larger bore (e.g., over 4000 mm) pipes can also be made by this method, which cannot be made by other methods. The invention fully utilizes the high strength and corrosion resistance of the stainless steel pipeline and the principle that the deflection of the pipeline manufactured by the hollow wall is basically equal to the deflection of the pipeline manufactured by the solid wall, and the pipeline manufactured by the method has the characteristics of low cost, long service life and easy popularization and use.

6) The axial sealing rings 4 arranged at the two axial ends can increase the annular rigidity of the large-caliber pipeline with the hollow wall and the twisting force of the pipeline.

7) The hollow folded plate is a triangular folded plate, so that the arc-shaped sealing panel is conveniently manufactured on the outer surface, the outer surface of the hollow-wall stainless steel large-caliber pipeline is arc-shaped, and the ovality of the pipeline is kept to be the same as that of the solid steel pipe.

(IV) description of the drawings

FIG. 1 is a perspective view of a hollow wall stainless steel large diameter pipeline in example 1. (triangular flaps 2 are used).

Figure 2 cross-sectional view of embodiment 1. I.e., the cross-sectional view B-B in fig. 1.

Fig. 3 is a perspective view showing the structure between two circumferentially adjacent triangular flaps 2 in fig. 2 according to embodiment 1.

Fig. 4 is a perspective view of the annular arc-shaped opening closure panel 3 of fig. 3 according to embodiment 1.

(V) detailed description of the preferred embodiments