JPH0212678B2 - - Google Patents
Info
- Publication number
- JPH0212678B2 JPH0212678B2 JP56208178A JP20817881A JPH0212678B2 JP H0212678 B2 JPH0212678 B2 JP H0212678B2 JP 56208178 A JP56208178 A JP 56208178A JP 20817881 A JP20817881 A JP 20817881A JP H0212678 B2 JPH0212678 B2 JP H0212678B2
- Authority
- JP
- Japan
- Prior art keywords
- corrosion
- pipe
- resistant
- tube
- welding
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
- 230000007797 corrosion Effects 0.000 claims description 67
- 238000005260 corrosion Methods 0.000 claims description 67
- 238000003466 welding Methods 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 11
- 238000002203 pretreatment Methods 0.000 claims description 3
- 230000035882 stress Effects 0.000 description 12
- 230000000694 effects Effects 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000010935 stainless steel Substances 0.000 description 5
- 229910001220 stainless steel Inorganic materials 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 229910000975 Carbon steel Inorganic materials 0.000 description 3
- 239000010962 carbon steel Substances 0.000 description 3
- 238000005336 cracking Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 239000012530 fluid Substances 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000004021 metal welding Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K31/00—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups
- B23K31/02—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups relating to soldering or welding
- B23K31/027—Making tubes with soldering or welding
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
- Arc Welding In General (AREA)
Description
【発明の詳細な説明】
＜産業上の利用分野＞
開示技術は油井管等の耐蝕性流体用の配管に供
する耐蝕二重管のユニツト管の管端部の処理技術
の分野に属する。DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The disclosed technology belongs to the field of technology for treating the end portion of a unit pipe of a corrosion-resistant double pipe used for piping for corrosion-resistant fluids such as oil country tubular goods.
＜要旨の概要＞
而して、この発明は外管が炭素鋼管、内管がス
テンレス鋼管等一方が耐蝕性、他方が非耐蝕性の
継手結合される前のユニツト二重管であつて、内
外管が一般部で強固に嵌合され、管端部で完全に
冶金的に結合されていないユニツト二重管に対し
て管端部にステンレス鋼の如き耐蝕性金属をリン
グ状に溶接してある端部前処理溶接ユニツト二重
管構造に関する発明であり、特に、耐蝕管側の管
端と非耐蝕管側の内面とが該非耐蝕管側に引張り
力が付与された状態でリング状に耐蝕性金属で溶
接し、冶金的に両管管端部を一体接合し、その
後、耐蝕管に圧縮残留応力が生成された状態で継
手形成用に管端に機械加工を行つて内外管の内表
面を面一に形成された端部前処理ユニツト二重管
構造に係る発明である。<Summary of the gist> The present invention is a unit double pipe, such as an outer pipe made of carbon steel and an inner pipe made of stainless steel, with one side being corrosion resistant and the other non-corrosion resistant. For unit double pipes where the pipes are tightly fitted at the general part and not completely metallurgically connected at the end of the pipe, a corrosion-resistant metal such as stainless steel is welded in a ring shape to the end of the pipe. This invention relates to a double tube structure of an end pretreatment welding unit, and in particular, the tube end on the corrosion resistant tube side and the inner surface on the non-corrosion resistant tube side are formed into a ring shape with a tensile force applied to the non-corrosion resistant tube side. The ends of both tubes are metallurgically joined together by metal welding, and then the inner surfaces of the inner and outer tubes are machined to form a joint while compressive residual stress is generated in the corrosion-resistant tube. This invention relates to a double pipe structure of an end pretreatment unit formed flush with each other.
＜従来技術＞
周知の如く、油井管や原子力プラント配管等の
腐蝕性流体用管体には耐圧性、耐熱性、耐蝕性、
耐摩耗性等を具備させるべく、例えば、外管を非
耐蝕性の炭素鋼管、内管を耐蝕性のステンレス鋼
管等にして所定に接合して一体重層させた二重管
が用いられている。<Prior art> As is well known, corrosive fluid pipes such as oil country tubular goods and nuclear power plant piping have pressure resistance, heat resistance, corrosion resistance,
In order to provide wear resistance, for example, a double tube is used, in which the outer tube is made of a non-corrosion resistant carbon steel tube, the inner tube is made of a corrosion resistant stainless steel tube, etc., which are joined in a predetermined manner to form a single layer.
而して、現場配管に際しては、例えば、第１図
に示す様に、非耐蝕性外管１に耐蝕性内管２を接
合させたユニツト二重管３，３の相互を溶接継手
４を介して連結させている態様がある。 For on-site piping, for example, as shown in FIG. There is a mode in which they are connected together.
勿論、溶接継手の他にカツプリング継手、フラ
ンジ継手を介する場合もある。 Of course, in addition to welded joints, coupling joints and flange joints may also be used.
ところで、ユニツト二重管３は製造時の設備の
条件等から、又、現場までの輸送の制約等からそ
の長さには制限があり、したがつて、製造後、野
積等されて現場据付までの時間の長さにより第２
図に示す様に、管端部５の内外両管１，２の境界
面６に腐蝕７が侵入してくる虞がある。 By the way, the length of the unit double pipe 3 is limited due to the conditions of the equipment at the time of manufacture and restrictions on transportation to the site. the second depending on the length of time
As shown in the figure, there is a possibility that corrosion 7 may invade the interface 6 between the inner and outer tubes 1 and 2 at the tube end 5.
蓋し、一般に管端部５に於いては工場での製造
段階で継手加工面８を成形する等により機械的、
冶金的に内外両管１，２が結合されておらず、し
たがつて、野積や海上輸送で腐蝕が進行するのが
実情であるからである。 Generally, the pipe end 5 is mechanically processed by forming a joint surface 8 during manufacturing at a factory.
This is because the inner and outer pipes 1 and 2 are not metallurgically connected, and therefore corrosion progresses during open storage and sea transportation.
＜発明が解決しようとする課題＞
これに対処するに、管端部にキヤツプ等を嵌着
する等の手段が試みられているが、効果は程度の
差であつて完全に腐蝕の進行を阻止出来ないとい
う欠点があつた。<Problem to be solved by the invention> To deal with this, measures such as fitting a cap or the like to the end of the pipe have been attempted, but the effectiveness varies in degree and it has not been possible to completely prevent the progress of corrosion. The drawback was that I couldn't do it.
そして、ユニツト管３の管端部５に於いては上
述した如く、内外両管１，２が完全に機械的、冶
金的に結合されておらず、一体化されていないた
めに、所謂切欠き効果が現われ、又、溶接時の熱
応力の差や溶着金属との結合等の複雑な条件が競
合して第３図に示す様に、溶接部４に内外両管
１，２の境界部６からクラツク９が発生するとい
う不具合もあつた。 As mentioned above, at the tube end 5 of the unit tube 3, the inner and outer tubes 1 and 2 are not completely mechanically and metallurgically connected and are not integrated, so there is a so-called notch. This effect appears, and due to competing complex conditions such as the difference in thermal stress during welding and bonding with the weld metal, a boundary 6 between the inner and outer pipes 1 and 2 is formed at the welded part 4, as shown in FIG. There was also a problem where crack 9 occurred.
これに対し、例えば、特公昭44−5289号公報発
明や特開昭54−78340号公報発明等があるが、こ
れらの公知発明は複数のユニツト二重管の継手部
分の据付現物での溶接技術に係わるものであつ
て、継手以前の、即ち、工場にて設定長さのユニ
ツト二重管の製造から現場据付までの野積等の期
間の放置状態における管端部の内外管に対する腐
蝕の侵入に対処する技術ではなく腐食進行の防止
には役立たない都合さを有していた。 On the other hand, for example, there are the inventions disclosed in Japanese Patent Publication No. 44-5289 and the inventions disclosed in Japanese Patent Application Laid-open No. 54-78340, but these known inventions are based on welding techniques for actual installation of joints of multiple unit double pipes. This is related to corrosion intrusion into the inner and outer pipes at the end of the pipe when it is left unused for a period of time, such as during the period from manufacturing the unit double pipe of the set length at the factory to installation on site, before fitting. This technique is not a countermeasure, and is inconvenient in preventing the progress of corrosion.
＜発明の目的＞
この発明の目的は上述従来技術に基づく耐蝕ユ
ニツト二重管の管端部に於ける腐蝕侵入等の問題
点を解決すべき技術的課題とし、継手加工に先立
ち、予め管端部の少なくとも耐蝕管側にリング状
金属を前処理溶接して両管を冶金的に一体結合し
ておき、腐蝕侵入、クラツク発生等を防止するこ
とが出来るようにして各種産業における配管技術
利用分野に益する優れた端部前処理溶接ユニツト
二重管構造を提供せんとするものである。<Objective of the Invention> The object of the present invention is to solve problems such as corrosion intrusion at the pipe end of the corrosion-resistant unit double pipe based on the above-mentioned prior art, and to A ring-shaped metal is preprocessed and welded to at least the corrosion-resistant pipe side of the part to metallurgically connect the two pipes together to prevent corrosion penetration, cracks, etc., and the field of use of piping technology in various industries. It is an object of the present invention to provide a double pipe structure of an excellent end pretreatment welding unit that is beneficial for the following purposes.
＜問題点を解決するための手段・作用＞
上述目的に沿い先述特許請求の範囲を要旨とす
るこの発明の構成は前述課題を解決するために、
耐蝕ユニツト二重管の管端の内外管の接合部に於
いて非耐蝕管側の管端に該非耐蝕管側に引張り力
を付与し、引張応力を形成させた状態でリング状
の耐蝕金属を内外両管を溶接させて両管を冶金的
に一体結合し、非耐蝕管に対する引張り力を解放
すると、耐蝕管には圧縮残留応力が生じ、そこ
で、後段の継手加工に備えて機械加工により管端
面を面一にするように加工を行うようにし、而し
て、上述前処理溶接により両管管端は冶金的に一
体結合されているため、現場継手連結前に管端部
両管境界部に腐蝕が侵入せず、溶接に際してはク
ラツクも発生させず、配管稼動に際しては耐蝕管
には圧縮残留応力により応力腐蝕割れが生じない
ようにした技術的手段を講じたものである。<Means/actions for solving the problems> In order to solve the above-mentioned problems, the structure of the present invention, which is based on the scope of the above-mentioned claims in accordance with the above-mentioned object,
Corrosion-resistant unit: At the junction of the inner and outer tubes at the pipe end of a double pipe, a tensile force is applied to the non-corrosion-resistant pipe end on the non-corrosion-resistant pipe side, and a ring-shaped corrosion-resistant metal is placed in a state where tensile stress is formed. When the inner and outer tubes are welded to metallurgically join them together and release the tensile force on the non-corrosion-resistant tube, compressive residual stress is generated in the corrosion-resistant tube, so the tube is machined in preparation for the subsequent joint processing. Processing is done so that the end faces are flush, and since both pipe ends are metallurgically joined together by the pre-treatment welding described above, the boundary between the pipe ends and both pipes is Technical measures have been taken to prevent corrosion from penetrating into the piping, to prevent cracks from occurring during welding, and to prevent stress corrosion cracking from occurring in the corrosion-resistant pipes due to compressive residual stress during pipe operation.
＜実施例＞
次に、この発明の実施例を第４図以下の図面に
基づいて説明すれば以下の通りである。尚、第
１，２，３図と同一態様部分については同一符号
を付して説明するものとする。<Example> Next, an example of the present invention will be described below based on the drawings from FIG. 4 onwards. It should be noted that portions having the same features as those in FIGS. 1, 2, and 3 will be described with the same reference numerals.
第４〜７図に示す実施例において、所定長さの
ユニツト耐蝕二重管３は非耐蝕性の炭素鋼製の外
管１に対して耐蝕性のステンレス鋼製の内管２
が、例えば、出願人の先願発明である熱拡管法等
により重層緊結され、一体化されて造られてお
り、内管２は管端部に於いて第４図に示す様に、
設定長さ外管１より短くされ、段差部１０を形成
されている。 In the embodiment shown in FIGS. 4 to 7, a unit corrosion-resistant double tube 3 of a predetermined length has an outer tube 1 made of non-corrosion resistant carbon steel and an inner tube 2 made of corrosion resistant stainless steel.
However, for example, the inner tube 2 is made in a multi-layered and integrated manner using the heat expansion method, which is an earlier invention of the applicant, and the inner tube 2 has the inner tube 2 at the tube end as shown in FIG.
The set length is shorter than the outer tube 1, and a stepped portion 10 is formed.
而して、ユニツト二重管３の製造後、外管１の
管端をクランプし、油圧ジヤツキ等により軸方向
に引張り、該外管１に引張り力を与えて第５図に
示す様に、段差部１０にステンレスの肉盛溶接１
１を前処理溶接としてリング状に施し、内管２の
管端２′と外管１の管端内面（境界面）を一体的
に冶金的に結合する。 After manufacturing the unit double tube 3, the tube end of the outer tube 1 is clamped and pulled in the axial direction using a hydraulic jack or the like to apply a tensile force to the outer tube 1, as shown in FIG. Overlay welding of stainless steel on the stepped portion 10 1
1 is applied in a ring shape as a pretreatment weld, and the tube end 2' of the inner tube 2 and the tube end inner surface (boundary surface) of the outer tube 1 are integrally metallurgically joined.
したがつて、当該前処理溶接後はユニツト二重
管３の管端部ではリング状の肉盛溶接１１により
内外管１，２の境界面は確実に一体結合され、シ
ールされ、又、外管１に対する引張り力を解放す
ると、内管２、特に、その管端部には応力腐蝕割
れを防止する圧縮残留応力が生成される。 Therefore, after the pretreatment welding, the boundary surfaces of the inner and outer tubes 1 and 2 are reliably joined and sealed by ring-shaped overlay welding 11 at the tube end of the unit double tube 3, and the outer tube Upon release of the tensile force on 1, compressive residual stresses are created in the inner tube 2, particularly at its tube ends, which prevent stress corrosion cracking.
この場合、耐蝕性内管２の管端部２′に耐蝕金
属を肉盛溶接１１することは該耐蝕性内管２に対
し冶金的になじみが良く、非耐蝕性外管１に引張
り力が付与され、一方、耐蝕性内管２には圧縮応
力が生成され易く、肉盛量が少なくて済む等の
様々なメリツトがある。 In this case, overlay welding 11 of corrosion-resistant metal to the tube end 2' of the corrosion-resistant inner tube 2 is metallurgically compatible with the corrosion-resistant inner tube 2, and the tensile force is applied to the non-corrosion-resistant outer tube 1. On the other hand, the corrosion-resistant inner tube 2 has various advantages such as compressive stress is easily generated and only a small amount of overlay is required.
又、肉盛溶接１１を管端部にて内外管１，２に
施すことは先述同様の機械的、冶金的な不完全結
合の問題が基本的にはあるが、工場内にてユニツ
ト二重管３の製造後に肉盛溶接１１を行う場合、
完全に設備が整つていること、管理が充分である
こと等の有利な条件で行うことが可能であるた
め、前述のクラツク等の発生の虞は生じない。 In addition, applying overlay welding 11 to the inner and outer tubes 1 and 2 at the tube ends basically has the same mechanical and metallurgical incomplete bonding problem as mentioned above, but the unit is double-layered in the factory. When performing overlay welding 11 after manufacturing the pipe 3,
Since it can be carried out under advantageous conditions such as complete equipment and sufficient management, there is no risk of the above-mentioned cracks occurring.
そして、最後に工場内にて適宜に機械切削等に
より、第６図に示す様に、現場での継手連結に備
えて前処理溶接の肉盛溶接１１の内面を内管２の
内面と面一に機械加工すると共に管端に対し突合
せ溶接の開先加工面８を形成させる。 Finally, in the factory, the inner surface of the overlay weld 11 of the pretreatment welding is made flush with the inner surface of the inner tube 2 in preparation for joint connection in the field, as shown in FIG. At the same time, a grooved surface 8 for butt welding is formed on the tube end.
この状態で、工場内で所定に格納するか、野積
するかし、或は、海上輸送を行つて現場継手連結
に備えるようにしても、管端部５から内外管１，
２の境界面６′から腐蝕が侵入することは確実に
防止出来る。 In this state, the inner and outer pipes 1, 1,
It is possible to reliably prevent corrosion from entering through the interface 6' between the two.
そして、現場にて継手連結するに際しては、第
７図に示す様に、現場突合せ溶接継手４を形成す
ると、内外両管１，２が前処理溶接の肉盛溶接１
１により冶金的に結合されて一体化されているた
め、第３図に示す様な切欠き効果が現われず、ク
ラツク等の発生も防止される。 When connecting the joints on-site, as shown in FIG.
1, the notch effect shown in FIG. 3 does not occur, and the occurrence of cracks and the like is also prevented.
又、第８図に示す実施例は第４図に示す段差部
１０に対して機械加工により外管１の内面にも切
削加工を与えて一体結合面１０′を形成させ、よ
り確実に内外両管１，２の境界面６に対するシー
ルを与えて冶金的結合を与える前処理溶接の肉盛
溶接１１を施すようにした態様であり、上述実施
例と実質的作用効果は同じである。 In addition, in the embodiment shown in FIG. 8, the inner surface of the outer tube 1 is also machined by machining the stepped portion 10 shown in FIG. This is an embodiment in which build-up welding 11 is performed as a pretreatment weld to provide a seal to the interface 6 of the tubes 1 and 2 to provide metallurgical bonding, and the practical effect is the same as that of the above-described embodiment.
尚、この発明の実施態様は上述各実施例に限る
ものでないことは勿論であり、例えば、リング状
耐蝕金属は予め別体成形しておき、電子ビーム溶
接、摩擦圧接等によりユニツト管の管端に前処理
溶接するようにしても良い。 It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments. For example, a ring-shaped corrosion-resistant metal is formed separately in advance, and the tube end of a unit tube is bonded by electron beam welding, friction welding, etc. Pretreatment welding may be performed.
＜発明の効果＞
以上、この発明によれば、ユニツト管の内外管
の一方が耐蝕管であるユニツト二重管の管端部に
て耐蝕管の管端面と非耐蝕管内面とが非耐蝕管に
引張り応力を付与した状態で耐蝕金属にてリング
状に一体的に前処理溶接され、非耐蝕管に対する
引張り力を解放して耐蝕管に圧縮残留応力を生じ
させて後、現場継手連結に備えての機械加工が施
され、内外両管端の内表面を面一に加工するよう
にしたことにより、ユニツト二重管の管端部の内
外管が冶金的に確実に一体結合され、したがつ
て、工場で管体製造後、野積されたり、海上輸送
される段階でユニツト管端の管境界面に腐蝕が発
生して侵入する虞が全くないという優れた効果が
奏される。<Effects of the Invention> As described above, according to the present invention, at the pipe end of the unit double pipe in which one of the inner and outer pipes of the unit pipe is a corrosion-resistant pipe, the pipe end face of the corrosion-resistant pipe and the inner surface of the non-corrosion-resistant pipe are the same as the non-corrosion-resistant pipe. A corrosion-resistant metal is integrally pre-welded in a ring shape with tensile stress applied to the pipe, and the tensile force on the non-corrosion-resistant pipe is released to create compressive residual stress in the corrosion-resistant pipe, in preparation for on-site joint connection. The inner and outer surfaces of both the inner and outer tube ends are machined to be flush with each other, so that the inner and outer tubes at the tube ends of the unit double tube are reliably joined together metallurgically. This provides an excellent effect in that there is no risk of corrosion occurring and penetrating the tube boundary surface at the end of the unit tube when the tube body is manufactured in a factory and then stored in the open or transported by sea.
又、非耐蝕管側に引張り力を与えて前処理溶接
をすることにより、ユニツト管体の耐蝕管に圧縮
残留応力が形成され、稼動中に応力腐蝕割れが発
生しないという優れた効果もある。 In addition, by applying tensile force to the non-corrosion resistant tube side and performing pretreatment welding, compressive residual stress is formed in the corrosion resistant tube of the unit tube body, which has the excellent effect of preventing stress corrosion cracking from occurring during operation.
更に、耐蝕管側の端面に耐蝕金属を前処理溶接
することにより、該耐蝕管になじみの良い耐蝕金
属の使用量も少なくて済み、重量軽減、省資源に
つながるうえに、コストダウンにつながるメリツ
トもある。 Furthermore, by pre-welding a corrosion-resistant metal to the end face of the corrosion-resistant tube, the amount of corrosion-resistant metal that is compatible with the corrosion-resistant tube can be reduced, leading to weight reduction, resource conservation, and cost reduction. There is also.
そして、ユニツト管を溶接継手を介して連絡す
る場合にも切欠き効果等も生ぜず、したがつて、
溶接部にクラツク等の欠陥が生じないという優れ
た効果も奏される。 Also, when unit pipes are connected via welded joints, no notch effect occurs, and therefore,
Another advantageous effect is that defects such as cracks do not occur in the welded area.
第１図は二重管の継手溶接接断面図、第２図は
管端部境界腐蝕断面図、第３図は溶接継手のクラ
ツク断面図、第４図以下はこの発明の実施例の説
明図であり、第４，５，６，７図は１実施例の工
程断面図、第８図は別の実施例の断面図である。
１……外管、２……内管、６，６′……境界
（面）、５……管端部、１１……前処理溶接（耐蝕
金属）、３……二重管。
Fig. 1 is a cross-sectional view of a welded joint of a double pipe, Fig. 2 is a cross-sectional view of boundary corrosion at the pipe end, Fig. 3 is a cross-sectional view of a crack in a welded joint, and Fig. 4 and the following are explanatory diagrams of embodiments of this invention. 4, 5, 6, and 7 are process sectional views of one embodiment, and FIG. 8 is a sectional view of another embodiment. 1... Outer tube, 2... Inner tube, 6, 6'... Boundary (surface), 5... Tube end, 11... Pretreatment welding (corrosion resistant metal), 3... Double tube.
Claims (1)
合管の一方が耐蝕管で他方が非耐蝕管であつて該
内外管の境界の管端部に対して前処理溶接がなさ
れているユニツト二重管構造において、上記内外
管の管端部で非耐蝕管側に引張り力が付与された
状態で耐蝕管側の端面と非耐蝕管側の内面とが耐
蝕性金属でリング状に一体的に前処理溶接されて
非耐蝕性管と一体接合され、該耐蝕管には圧縮残
留応力が付与されて管端部内面が機械的に継手用
に加工され耐蝕管内表面継手用加工面が面一に形
成されていることを特徴とする端部前処理溶接ユ
ニツト二重管構造。1 Unit 2 where one of the joining pipes of the inner and outer pipes of the unit pipe is a corrosion-resistant pipe and the other is a non-corrosion-resistant pipe, and pre-treatment welding is performed on the pipe end at the boundary between the inner and outer pipes. In the heavy pipe structure, when a tensile force is applied to the non-corrosion-resistant pipe side at the pipe ends of the inner and outer pipes, the end face on the corrosion-resistant pipe side and the inner surface on the non-corrosion-resistant pipe side are integrally formed in a ring shape with corrosion-resistant metal. Pre-treatment welding is performed to integrally join the non-corrosion-resistant pipe, and compressive residual stress is applied to the corrosion-resistant pipe, and the inner surface of the pipe end is mechanically machined for a joint, so that the inner surface of the corrosion-resistant pipe is flush with the machined surface for the joint. The end pretreatment welding unit is characterized by a double pipe structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56208178A JPS58110191A (en) | 1981-12-24 | 1981-12-24 | Construction of welded double pipe pretreated with end part |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56208178A JPS58110191A (en) | 1981-12-24 | 1981-12-24 | Construction of welded double pipe pretreated with end part |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58110191A JPS58110191A (en) | 1983-06-30 |
| JPH0212678B2 true JPH0212678B2 (en) | 1990-03-23 |
Family
ID=16551946
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56208178A Granted JPS58110191A (en) | 1981-12-24 | 1981-12-24 | Construction of welded double pipe pretreated with end part |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58110191A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60102571U (en) * | 1983-12-20 | 1985-07-12 | 石川島播磨重工業株式会社 | Connection structure of lining pipe |
| JPH0633837B2 (en) * | 1989-03-07 | 1994-05-02 | 株式会社島津製作所 | Chromatographic separation tube |
| JP5890742B2 (en) * | 2012-04-27 | 2016-03-22 | 株式会社東芝 | Centrifugal thin film dryer |
-
1981
- 1981-12-24 JP JP56208178A patent/JPS58110191A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58110191A (en) | 1983-06-30 |
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