KR200408895Y1 - multi-layer pipe - Google Patents

multi-layer pipe Download PDF

Info

Publication number
KR200408895Y1
KR200408895Y1 KR2020050034153U KR20050034153U KR200408895Y1 KR 200408895 Y1 KR200408895 Y1 KR 200408895Y1 KR 2020050034153 U KR2020050034153 U KR 2020050034153U KR 20050034153 U KR20050034153 U KR 20050034153U KR 200408895 Y1 KR200408895 Y1 KR 200408895Y1
Authority
KR
South Korea
Prior art keywords
inner member
outer member
hollow tube
welded
bent
Prior art date
Application number
KR2020050034153U
Other languages
Korean (ko)
Inventor
송성효
Original Assignee
송성효
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 송성효 filed Critical 송성효
Priority to KR2020050034153U priority Critical patent/KR200408895Y1/en
Application granted granted Critical
Publication of KR200408895Y1 publication Critical patent/KR200408895Y1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/08—Making tubes with welded or soldered seams
    • B21C37/0815—Making tubes with welded or soldered seams without continuous longitudinal movement of the sheet during the bending operation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/08—Making tubes with welded or soldered seams
    • B21C37/09—Making tubes with welded or soldered seams of coated strip material ; Making multi-wall tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/14—Making tubes from double flat material

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Butt Welding And Welding Of Specific Article (AREA)

Abstract

본 고안은 다층중공관에 관련되는 것으로 특히 원형으로 굽혀지고 양단부는 이격된 상태를 이루는 내측부재 및 상기 내측부재를 감싸며 이격된 내측부재의 양단부를 구속하도록 내측으로 벤딩되는 외측부재로 구성되어 상기 외측부재의 접합부에서 용접처리 되어 성형되는 다층중공관에 있어서, 상기 내측부재의 양단부를 구속하도록 벤딩되는 외측부재의 단부는 외측부재가 2겹이 되도록 접히어 상기 내측부재의 단부와 맞닿게 되며 상기 외측부재 접합부에서 용접처리 되는 것을 특징으로 함으로서, 용접처리 되는 접합부가 내측부재와 멀어져 용접시 발생될 수 있는 외측부재의 손상으로 내측부재까지 산화되어 녹이 발생되는 문제점을 해결할 수 있는 효과를 가지는 고안이다. The present invention relates to a multi-layer hollow tube, in particular, the inner member is bent in a circular shape and both ends are spaced apart and the outer member bent inward to constrain both ends of the inner member spaced around the inner member In a multi-layer hollow tube welded and molded at a joint of a member, an end of an outer member which is bent to rest both ends of the inner member is folded so that the outer member is doubled to abut on an end of the inner member. Characterized by being welded at the member joint, the welded joint is far from the inner member is devised to solve the problem that the rust is generated by oxidation to the inner member due to the damage of the outer member that may occur during welding.

다층, 중공관, 스틸, 스테인레스, 용접처리, 녹발생 Multi-layered, hollow tube, steel, stainless, welded, rusted

Description

다층중공관{multi-layer pipe}Multi-layer pipe

도1 : 종래기술에 따른 다층중공관의 단면도.1 is a cross-sectional view of a multilayer hollow tube according to the prior art.

도2 : 본 고안에 따른 다층중공관에 대한 단면도.2 is a cross-sectional view of a multi-layer hollow tube according to the present invention.

도3 : 본 고안에 따른 다층중공관의 제조과정을 보여주는 공정도.3 is a process chart showing a manufacturing process of a multilayer hollow tube according to the present invention.

<도면에 사용된 주요부호에 대한 설명><Description of Major Symbols Used in Drawings>

100 : 내측부재 200 : 외측부재100: inner member 200: outer member

250 : 접합부250: junction

본 고안은 이종의 소재로 된 판상부재로서 성형되는 내부가 빈 원형단면을 가지는 다층 중공관에 관한 것이다.The present invention relates to a multilayer hollow tube having a hollow circular section formed inside as a plate member made of a heterogeneous material.

중공관을 제조하는 방법은 공지의 기술로서 여러가지 방법들이 있고, 다층으로 된 중공관도 이미 알려져 있다. 즉, 금속관의 내부에 합성수지로 피복하는 것 등이 있다.There are various methods for producing the hollow tube as a known technique, and a hollow tube having a multilayer is already known. That is, the inside of a metal tube is coat | covered with synthetic resin.

일반적인 중공관의 제조의 경우에는 만네스만 압연기를 이용하는 방법이 있고, 그 외 압출로서도 제조가능하며 판상소재를 점차 원형으로 변형시키면서 양 단 부를 용접하는 방법도 사용되고 있다.In the case of manufacturing a general hollow tube, there is a method using a Mannesmann rolling mill, and can also be manufactured by extrusion, and a method of welding both ends while gradually deforming the plate material in a circular shape is also used.

특히 본 고안과 관련하여서는 이종의 금속 혹은 비철금속의 판재를 겹쳐 중공관의 형태로 성형하는 것과 관련된다.In particular, the present invention relates to forming a hollow tube by overlapping plates of different metals or nonferrous metals.

이러한 중공관과 관련되는 종래기술로서 대한민국 특허출원번호 10-2001-0007750호의 복합이중파이프 및 복합이중파이프의 가압성형장치가 공지된 바 있다.As a related art related to such a hollow tube, a press forming apparatus for a composite double pipe and a composite double pipe of Korean Patent Application No. 10-2001-0007750 has been known.

이것은 철봉의 외면에 스테인레스판을 원형으로 성형하여 이중으로 된 파이 프로 제조한 것이다. 하지만 상기 인용고안에 의한 이중파이프는 미리 철봉을 준비하고 이것에 스테인레스판을 성형하여 감싸므로서 이중파이프를 완성하게 되므로서 제조비용이 비싸게 되고 성형과정 중에 스테인레스판이 제 위치를 잡지 못하고 뒤틀릴 수 있다는 문제점이 있었다.This is a double pipe made by molding a stainless steel plate on the outer surface of the iron bar. However, the double pipe according to the above-mentioned proposal is to prepare the iron rod in advance and to form a stainless steel plate wrapped around it to complete the double pipe, manufacturing costs are expensive and the stainless steel plate can be twisted in place during the molding process There was a problem.

또 다른 종래기술로서 본 고안자에 의해 선출원된 실용신안출원번호 20-2004-0025330호의 다층중공관 및 굽힘장치와 성형장치가 공지된 바 있다.As another conventional technology, a multilayer hollow tube, a bending device, and a molding device of Utility Model Application No. 20-2004-0025330, filed by the present inventor, have been known.

첨부되는 도1은 본 고안자에 출원된 다층중공관의 단면도를 보여주며, 도면을 참조하면 내측부재(10)와 상기 내측부재를 감싸는 외측부재(20)가 내측부재의 양단부를 구속하도록 벤딩되어 용접되는 구성을 가진다.1 is a cross-sectional view of a multi-layer hollow tube filed in the present inventors, and referring to the drawing, the inner member 10 and the outer member 20 surrounding the inner member are bent to rest both ends of the inner member to be welded. Has a configuration.

외측부재의 접합부에서 용접처리 되는데 도1의 경우 내측부재의 양단부간 이격거리는 외측부재의 두께(t)의 2배인 2t 정도의 이격거리를 갖게된다. 그리고 이러한 다층중공관의 목적은 녹이 발생치 않는 중공관을 저렴하게 생산하고자 하는 것이며 이를 위해 외측부재(주로 스테인레스)는 내측부재(스틸)에 비해 그 두께가 얇은 것을 사용한다. 스테인레스는 일반 스틸에 비하여 고가이기 때문이다.The welding process is performed at the joint of the outer member. In FIG. 1, the separation distance between both ends of the inner member has a separation distance of about 2t, which is twice the thickness t of the outer member. And the purpose of the multi-layer hollow tube is to produce a hollow tube that does not occur rust cheaply for this purpose, the outer member (mainly stainless steel) is used that is thinner than the inner member (steel). This is because stainless steel is more expensive than ordinary steel.

이러한 관계로 외측부재의 접합부를 용접하게 되면 용접으로 인한 손상이 발생되고 시간이 경과됨에 따라 내측부재의 산화로 인한 녹이 표면까지 발생하게 되는 문제점이 있었다. 이러한 문제는 외측부재가 얇음에 따라 용접시 외측부재와 내측부재가 일부 함께 용융되기 때문인 것으로 파악된다.In this relationship, when the joint of the outer member is welded, there is a problem that damage occurs due to welding and rust due to oxidation of the inner member occurs to the surface as time passes. This problem is understood to be due to the fact that as the outer member is thin, the outer member and the inner member are partially melted together during welding.

따라서 상기와 같은 문제점을 해결하기 위한 본 고안은, 이종 재질을 갖는 두개의 소재를 이용하여 다층중공관을 형성함에 있어 용접이 이루어지는 외측부재의 접합부를 넓게 형성시켜 내측부재가 용접의 영향을 받지 않는 다층중공관을 제작할 수 있도록 하는 것을 목적으로 한다 .Therefore, the present invention for solving the above problems, in forming a multi-layer hollow tube using two materials having different materials to form a wide junction of the outer member to be welded so that the inner member is not affected by welding Its purpose is to be able to manufacture multi-layer hollow pipes.

이와 같은 목적달성을 위한 본 고안은, 원형으로 굽혀지고 양단부는 이격된 상태를 이루는 내측부재 및 상기 내측부재를 감싸며 이격된 내측부재의 양단부를 구속하도록 내측으로 벤딩되는 외측부재로 구성되어 상기 외측부재의 접합부에서 용접처리되어 성형되는 다층중공관에 있어서, 상기 내측부재의 양단부를 구속하도록 벤딩되는 외측부재의 단부는 외측부재가 2겹이 되도록 접히어 상기 내측부재의 단부와 맞닿게 되며 상기 외측부재 접합부에서 용접처리 되도록 하며, 또한 상기 외측부재는 그 단부가 일차적으로 2겹이 되도록 접히고, 이어서 상기 내측부재의 내면과 접촉되도록 재차 벤딩되는 것을 특징으로 하는 다층중공관에 관한 것이다. The present invention for achieving the object, the outer member is formed of an inner member bent in a circular shape and both ends are spaced apart and the outer member bent inward to constrain both ends of the inner member spaced around the inner member In a multi-layer hollow tube welded and molded at a joint portion of an inner side of the inner member, the end of the outer member bent to rest both ends of the inner member is folded so that the outer member is doubled so as to contact the end of the inner member and the outer member. It is to be welded at the joint portion, and the outer member is folded to the first two ends of the first, and then bent again to contact with the inner surface of the inner member is a multi-layer hollow tube.

첨부되는 도2는 본 고안에 따른 다층중공관의 하나의 실시예를 보여주는 단면도를 나타내며, 크게 내측부재(100)와 외측부재(200)로 이루어져 내부가 빈 중공 관을 형성하게 된다.2 is a cross-sectional view showing one embodiment of a multi-layer hollow tube according to the present invention, and is formed of an inner member 100 and an outer member 200 to form a hollow hollow tube.

본 실시예에서 내측부재(100)는 일반스틸로 하며 외측부재(200)는 스테인레스 재질판을 사용하며 외측부재는 내측부재에 비하여 그 두께가 상대적으로 얇은 것을 사용한다. 물론 내측부재와 외측부재의 두께는 적절히 변경 가능하며, 재질의 면에서도 사용목적 등에 따라 변화를 줄 수 있다.In this embodiment, the inner member 100 is made of general steel, the outer member 200 is made of stainless steel plate and the outer member is used that is relatively thin in thickness than the inner member. Of course, the thickness of the inner member and the outer member can be appropriately changed, and in terms of material can also be changed depending on the purpose of use.

내측부재(100)는 둥글게 성형되며 그 양단부는 이격되어 있고, 이러한 내측부재의 외측을 외측부재(200)가 감싸게 되며 상기 외측부재의 단부가 내측으로 벤딩되어 내측부재를 구속하도록 한다.The inner member 100 is roundly formed, and both ends thereof are spaced apart, and the outer member 200 is wrapped around the outer side of the inner member, and the end of the outer member is bent inward to restrain the inner member.

보다 구체적으로는 도2와 같이 외측부재(200)의 각 단부는 외측부재가 2겹이 되도록 굽혀지며 이러한 2겹겹침부에 의해 내측부재의 단부가 접촉되어 지지하는 역할을 하게 된다.More specifically, as shown in FIG. 2, each end of the outer member 200 is bent so that the outer member has two layers, and the two ends of the inner member come into contact with and support the two ends.

외측부재(200)의 단부를 2겹이 되도록 함으로서 용접이 이루어지는 접합부(25)는 넓게 형성되며 이와 같은 구조로 다층중공관을 형성함으로서 최종적인 용접이 행하여지더라도 내측부재에는 용접의 영향이 미치지 않게 할 수 있는 것이다.By joining the ends of the outer member 200 in two layers, the joint part 25 where welding is made is widely formed, and by forming a multilayer hollow tube in such a structure, even if the final welding is performed, the inner member is not affected by welding. You can do it.

그리고 도2에 도시된 바와 같이, 외측부재(200)의 단부를 2겹으로 겹치게 한 후, 외측부재의 나머지 부분을 점선과 같이 직선으로 둘 수 있으며, 또는 비스듬히 경사지게 처리할 수도 있다.And, as shown in Figure 2, after overlapping the end of the outer member 200 in two layers, the remaining portion of the outer member can be placed in a straight line, such as a dashed line, or may be inclined obliquely.

더욱 바람직하게는 외측부재(200)의 단부를 일차적으로 2겹이 되도록 성형한 후 연이어 나머지 부분에 대해서는 내측부재의 내면과 접촉되도록 벤딩시킨 구조를 갖도록 한다. 이처럼 외측부재의 단부를 연속적으로 2단으로 벤딩함으로서 내측부 재를 보다 확고히 구속할 수 있게된다.More preferably, the ends of the outer member 200 are formed to be primarily doubled, and then have a structure in which the ends of the outer member 200 are bent to contact the inner surface of the inner member. By bending the end of the outer member in two stages in this way it is possible to more firmly restrain the inner member.

종래기술과의 보다 구체적인 비교를 하면, 도1과 같이 내측부재의 양단부의 이격거리는 외측부재의 두께(t)의 2배인 2t 정도이나, 본 고안의 경우에는 2t+2x 이므로 용접에 의한 내측부재의 손상을 현저히 줄일 수 있는 것이다.In a more specific comparison with the prior art, as shown in FIG. 1, the separation distance between both ends of the inner member is about 2t, which is twice the thickness t of the outer member, but in the present invention, since it is 2t + 2x, Damage can be significantly reduced.

이하, 상술한 바와 같은 구성을 가지는 다층중공관을 성형하는 과정에 대해 개략적으로 설명하도록 하며, 도3은 본 고안에 따른 다층중공관을 성형하는 과정을 보여주는 공정도이다.Hereinafter, a process of forming a multilayer hollow tube having the configuration as described above will be described schematically, and FIG. 3 is a process diagram showing a process of forming a multilayer hollow tube according to the present invention.

스틸판과 스테인레스판을 준비하며 외측부재(200)가 되는 스테인레스판의 폭이 내측부재(100)인 스틸판 보다 넓도록 하며, 다수의 롤이 연속적으로 구비되는 성형장치를 이용하여 외측부재의 양단부를 상측으로 벤딩시키고, 이어서 일차 벤딩된 단부를 2겹으로 겹치도록 한다. 그리고 내측부재보다 돌출된 외측부재의 나머지 부위는 내측부재의 상면과 접촉되도록 다시 한번 벤딩 처리 한다. 이와 같이 두개의 판을 성형한 후에는 포밍기를 이용하여 판상인 것을 점차 원형단면을 가지는 중공관을 이루도록 변화시키게 된다. 포밍기는 널리 사용되는 것이므로 구체적인 설명을 생략한다.A steel plate and a stainless plate are prepared, and the width of the stainless plate to be the outer member 200 is wider than that of the inner plate 100, and both ends of the outer member are formed by using a molding apparatus in which a plurality of rolls are continuously provided. Is bent upwards, and then the primary bent ends are overlapped in two layers. The remaining portion of the outer member protruding from the inner member is bent again to be in contact with the upper surface of the inner member. After forming the two plates as described above, the plate-shaped is gradually changed to form a hollow tube having a circular cross section by using a forming machine. The forming machine is widely used, so a detailed description thereof will be omitted.

상기 포밍기를 이용하여 도2와 같은 원형으로 성형한 후에는 외측부재의 접촉에 의해 형성되는 접합부 외면에서 용접하여 일체화된 다층중공관을 제조하게 된다.After forming in a circular shape as shown in Figure 2 by using the forming machine is welded on the outer surface of the joint formed by the contact of the outer member to produce an integrated multi-layer hollow tube.

본 고안에 따른 다층중공관은 용접이 이루어지는 외측부재의 접합부가 넓 기 때문에 용접이 행하여지더라도 용접에 의해 내측부재가 함께 용융되어 용접부위에 녹이 발생되는 문제점을 해결할 수 있다는 효과가 있다.  The multi-layer hollow tube according to the present invention has an effect of solving the problem that the inner part is melted together by welding and rust is generated even though welding is performed because the joint of the outer member to be welded is wide.

즉, 본 고안은 기본적으로 저렴한 비용으로 외관이 미려한 중공관을 제공할 수 있음에 더하여 용접으로 인해 수반될 수 있는 녹 발생과 같은 문제점을 완전히 해결할 수 있으므로 보다 우수한 품질을 가지는 다층중공관을 제공할 수 있어 제품경쟁력을 확보할 수 있게되는 효과도 있다.     That is, the present invention can provide a hollow tube with a beautiful appearance at a low cost, and can completely solve problems such as rust caused by welding, thereby providing a multilayer hollow tube having better quality. It also has the effect of securing product competitiveness.

Claims (2)

원형으로 굽혀지고 양단부는 이격된 상태를 이루는 내측부재(100) 및 상기 내측부재를 감싸며 이격된 내측부재의 양단부를 구속하도록 내측으로 벤딩되는 외측부재(200)로 구성되어 상기 외측부재의 접합부에서 용접처리되어 성형되는 다층중공관에 있어서,  The inner member 100 which is bent in a circular shape and both ends are spaced apart and the outer member 200 which wraps the inner member and bends inward to restrain both ends of the spaced inner member are welded at the joint of the outer member. In the multilayer hollow tube to be processed and molded, 상기 내측부재(100)의 양단부를 구속하도록 벤딩되는 외측부재(200)의 단부는 외측부재가 2겹이 되도록 접히어 상기 내측부재의 단부와 맞닿게 되며 상기 외측부재 접합부(250)에서 용접처리 되는 것을 특징으로 하는 다층중공관.       An end of the outer member 200 which is bent to constrain both ends of the inner member 100 is folded so that the outer member is two-ply and abuts the end of the inner member and welded at the outer member junction 250 Multi-layer hollow tube, characterized in that. 제1항에 있어서, 상기 외측부재(200)는,The method of claim 1, wherein the outer member 200, 그 단부가 일차적으로 2겹이 되도록 접히고, 이어서 상기 내측부재의 내면과 접촉되도록 재차 벤딩되는 것을 특징으로 하는 다층중공관.The end of the multi-layer hollow tube, characterized in that the first folded in two layers, and then bent again to contact the inner surface of the inner member.
KR2020050034153U 2005-12-05 2005-12-05 multi-layer pipe KR200408895Y1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR2020050034153U KR200408895Y1 (en) 2005-12-05 2005-12-05 multi-layer pipe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR2020050034153U KR200408895Y1 (en) 2005-12-05 2005-12-05 multi-layer pipe

Related Child Applications (1)

Application Number Title Priority Date Filing Date
KR1020060061730A Division KR100621403B1 (en) 2006-07-03 2006-07-03 Multi-layer pipe

Publications (1)

Publication Number Publication Date
KR200408895Y1 true KR200408895Y1 (en) 2006-02-14

Family

ID=41759275

Family Applications (1)

Application Number Title Priority Date Filing Date
KR2020050034153U KR200408895Y1 (en) 2005-12-05 2005-12-05 multi-layer pipe

Country Status (1)

Country Link
KR (1) KR200408895Y1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109153055A (en) * 2017-01-19 2019-01-04 株式会社哈斯科 The manufacturing method of dual pipe

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109153055A (en) * 2017-01-19 2019-01-04 株式会社哈斯科 The manufacturing method of dual pipe

Similar Documents

Publication Publication Date Title
JP4546543B2 (en) Multi-layer pipe manufacturing method
WO2009146838A8 (en) Method for producing a large steel tube
JP2008523996A5 (en)
WO2008111200A1 (en) Seamless steel pipe, hollow spring utilizing seamless steel pipe, and process for manufacturing the same
JPWO2016043280A1 (en) Method for manufacturing molded product, mold, and tubular molded product
US4796797A (en) Method for making thin-walled metal pipes
WO2007058157A1 (en) Hot-rolled t-bar for hull reinforcing member and process for producing hot-rolled t-bar
CA2474290A1 (en) Method of manufacturing seamless steel pipe
CN105333241A (en) Steel-clamping rib-stiffened hollow plastic outer corrugated pipe and manufacturing method thereof
KR200408895Y1 (en) multi-layer pipe
CA2706347A1 (en) Production-optimized process for producing a multilayer pipe
KR100621403B1 (en) Multi-layer pipe
KR101049632B1 (en) Metal tube manufacturing method with excellent formability
KR101039262B1 (en) Continueously manufacturing apparatus for metal pipe using residual stress
US20090242067A1 (en) Processes for textured pipe manufacturer
CN104853859A (en) Method for the high-speed production of a multi-layered tube
KR200370488Y1 (en) multi-layer pipe, bending equipment and manufacturing equiement for the same
JPH06114571A (en) Production of clad pipe
JP2008184686A (en) Method for manufacturing low yr square steel tube for building
CN1299715A (en) Manufacture of bimetallic compisite pipe
KR200403925Y1 (en) multi-layer pipe
KR100621400B1 (en) multi-layer pipe and bending machine
JP5867071B2 (en) Manufacturing method for thick ERW steel pipe
JP2002192223A (en) Manufacturing method for welded metal pipe
JPH11342418A (en) Multiplex wind tube forming device

Legal Events

Date Code Title Description
REGI Registration of establishment
FPAY Annual fee payment

Payment date: 20060217

Year of fee payment: 3

EXTG Extinguishment