JP4080685B2

JP4080685B2 - Piping sealing method and apparatus, and stainless steel piping welding method and apparatus

Info

Publication number: JP4080685B2
Application number: JP2000335741A
Authority: JP
Inventors: 忠小松崎; 政吉安嶋
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2000-11-02
Filing date: 2000-11-02
Publication date: 2008-04-23
Anticipated expiration: 2020-11-02
Also published as: JP2002144039A

Description

【０００１】
【発明の属する分野】
本発明は、新規な配管の密封方法とその装置及びステンレス鋼配管の溶接方法とその装置に係り、特に溶接作業に際し、ステンレス鋼配管内に漏洩水が発生した際の隔離と不活性ガスの充填とを行う密封方法とその装置及び溶接方法とその装置に関する。
【０００２】
【従来の技術】
既存の発電プラントのステンレス配管取替を実施する場合、既設側の配管と新設配管の取り合い部が発生する。新設側の配管には水等の異物発生の可能性はないが、既設側の配管は既存発電プラントであるため炉、各種熱交換器ないしはポンプ類と弁ないしは封水プラグ等により配管内流体を隔離している。配管の取替作業は配管内の流体の隔離後配管を切断し、開先加工、新管溶接を行い取替を実施する。配管内流体は既設弁ないしは封水プラグで隔離されるため往々にして流体の漏洩が発生する。
【０００３】
一方、ステンレス配管の溶接は配管内面に酸素がある状態で溶接を実施すると溶接部内面の裏波が酸化し溶接欠陥が発生する。そのため、特開平８―２６７２８５号公報には配管の水中での溶接法として水溶性シート材を用いる方法が示されている。又、従来は、溶接前に配管内面に対し既設側配管内面に水溶性薄膜を貼り付けその領域に不活性ガスを充填し酸素と不活性ガスを置換し酸素濃度が１％未満になったのを確認後溶接を実施することとしている。配管内面流体の漏洩が発生するとその流体により水溶性薄膜が溶解し不活性ガスが既設側配管取り合い部のさらに奥に拡散し不活性ガス充填濃度が低下する。そのため溶接部内面の酸素濃度が増加し溶接欠陥発生の原因となる。従来の技術では既設配管内から内面流体の漏洩が発生した場合には溶接の実施が困難となりそれを防止する技術が確立されていなかった。
特開平５―１４６８９３号公報及び特開平７―５１８９３号公報には配管の突合わせ溶接のバックシールド装置が開示されているが、配管内に漏洩水が発生する場合については全く示されていない。
【０００４】
【発明が解決しようとする課題】
本発明の目的は、ステンレス鋼配管内に漏洩水が発生しても単純な構造と簡単な操作で容易に装着と着脱が出来、確実に漏洩水を遮断すると共に、配管内を不活性ガスで満たし、容易に溶接することのできる配管の密封方法とその装置、並びにステンレス鋼配管の溶接方法及びその装置を提供することにある。
【０００５】
【課題を解決するための手段】
本発明は、溶接を実施しようとするステンレス鋼配管の内面に漏洩水が発生した場合、その漏洩水を溶接部から隔離し、かつ不活性ガス充填の隔壁となり、溶接作業を行うことが可能な配管の密封方法とその装置及びステンレス鋼配管の溶接方法とその装置にある。
【０００６】
本発明は、ステンレス鋼配管内に柔軟性のある中空構造のチューブを漏洩水が発生する場所と溶接部の中間に取付け、チューブ内側に外部から気体を注入し漏洩部から溶接部を隔離する工法にある。
【０００７】
更に、不活性ガス充填のための隔壁を兼ねる工法、チューブを２段構造とする工法、チューブの内側に内部気体の圧力が拡散しないように圧力保持用の内輪を持つ工法を有する。
【０００８】
漏洩があるステンレス配管内に上述の本装置を挿入し、溶接開先部に対し、漏洩のある配管側に設定する。次に、第一段チューブ及び第二段チューブに気体を封入する。これにより漏洩水が溶接開先部から隔離される。中空硬質ポールの先端にはドレンホースを取付け漏洩水をドレンホースから回収する。次に配管開放端を目張りしそこから不活性ガスを充填する。酸素濃度を確認しながら充填を実施し、不活性ガスと空気の置換が完了したなら溶接作業が可能となる。
【００１０】
本発明は、配管内に柔軟性のある中空構造の２個のチューブを各々前記配管内周面に接して取付けると共に、前記チューブの各々を該チューブ内部に充填される気体の圧力によって前記チューブが内周側に広がらないように前記配管の長さ方向に所定の間隔で設けられ前記チューブの各々に対応する２個の圧力保持用内輪によって保持し、前記圧力保持用内輪の少なくとも一方の内周側に一体に形成された漏洩水受けにより前記配管内に漏洩した漏洩水を受け、該漏洩水を前記漏洩水受けに接続された排水手段を通して前記配管外に排水すると共に、前記チューブ内に気体を注入することにより前記配管内の一方側を大気より隔離することを特徴とする配管の密封方法にある。
【００１２】
又、本発明は、配管内の内周面に接するように設けられる柔軟性のある中空構造の２個のチューブと、前記チューブ内部に充填される気体の圧力によって前記チューブが前記配管内周面全周に接すると共に内周側に広がらないように前記チューブの各々を保持する２個の圧力保持用内輪と、前記チューブの各々に設けられ該各々のチューブ内に気体を注入する注入手段と、前記各々の圧力保持用内輪間を前記配管の長さ方向に所定の間隔で連結する連結手段と、前記圧力保持用内輪の少なくとも一方の内周側に設けられた前記配管内の漏洩水を受ける漏洩水受けと、該漏洩水受けに接続され前記配管内に漏洩した漏洩水を前記配管外に排水する排水手段とを備え、前記各々のチューブ内に気体を注入することにより前記配管内の一方側を大気より隔離することを特徴とする配管の密封装置みある。
【００１３】
又、本発明は、ステンレス鋼配管内に柔軟性のある中空構造の２個のチューブを溶接部近傍に各々前記配管内周面に接して取付けると共に、前記チューブの各々を該チューブ内部に充填される気体の圧力によって前記チューブが内周側に広がらないように前記配管の長さ方向に所定の間隔で設けられた２個の圧力保持用内輪によって保持し、前記圧力保持用内輪の少なくとも一方の内周側に一体に形成された漏洩水受けにより前記配管内に漏洩した漏洩水を受け、該漏洩水を前記漏洩水受けに接続された排水手段を通して前記配管外に排水すると共に、前記チューブ内に気体を注入することにより前記配管内の一方側を大気より隔離し、前記配管の他方側に溶接される他の配管の開放側を大気より隔離する隔壁を設け、前記他方側の前記配管内の溶接部に不活性ガスで充填した後、前記漏洩水を前記配管外に排水しながら前記ステンレス鋼配管と他の配管とを突合せ溶接することを特徴とするステンレス鋼配管の溶接方法にある。
【００１５】
又、本発明は、ステンレス鋼配管内の内周面に接するように設けられた柔軟性のある中空構造の２個のチューブと、前記チューブ内部に充填される気体の圧力によって前記チューブが前記配管内周面全周に接すると共に内周側に広がらないように前記チューブの各々を保持する２個の圧力保持用内輪と、前記各々のチューブに設けられ該各々のチューブ内に気体を注入する注入手段と、前記各々の圧力保持用内輪間を前記配管の長さ方向に所定の間隔で連結する連結手段と、前記圧力保持用内輪の少なくとも一方の内周側に一体に設けられた前記配管内の漏洩水を受ける漏洩水受けと、該漏洩水受けに接続され前記配管内に漏洩した漏洩水を前記配管外に排水する排水手段とを備え、前記各々のチューブ内に気体を注入する注入手段により前記配管内の一方側を大気より隔離し、前記配管の他方側に溶接される他の配管の開放側に設けられ大気より隔離する隔壁と、前記他方側の前記配管内に不活性ガスを充填する充填手段と、前記ステンレス鋼配管と他の配管とを突合せ溶接する溶接装置とを有することを特徴とするステンレス鋼配管の溶接装置にある。
【００１６】
【発明の実施の形態】
図１（ａ）は本発明のステンレス鋼配管の溶接方法の手順を示す作業工程のフローシートである。図１（ａ）は最初に既設側配管の内面を確認し配管内部流体の漏洩有の場合の作業工程のフローシート、図１（ｂ）は漏洩無の場合の作業工程のフローシートである。
【００１７】
本発明は既設配管内に内部流体の漏洩があった場合であり左側の手順となる。ステップ１からステップ１１までが漏洩止水装置の設定、ステップ１２からステップ１７までが配管溶接作業、ステップ１８からステップ２６までが装置の撤去、片付けである。
【００１８】
図２及び図５はステンレス鋼配管内の密封装置の断面図及びその取付け状態を示す全体図である。以下、図１、図２及び図５を使用し、具体的な実施例を説明する。ステンレス鋼配管既設側内面を確認し内部流体の漏洩が確認されたら装置取付け部の配管内面の清掃を実施する。図６は本発明のステンレス鋼配管の溶接装置の全体図である。本装置は、装置本体２７、溶接機ヘッド２８、溶接ケーブル２９、溶接機本体３０、気体ボンベ３１、不活性ガスボンベ３２、ドレンホース３３、排水系３４、他のステンレス配管３５、シート養生部３６、接続部３７を有する。
【００１９】
ステップ１では、本発明の装置及び付帯品準備として当該エリアに装置及びその付帯のホース、気体封入ボンベ等を搬入する。ステップ２では装置上部配管内挿入で図２の第一段チューブ１、第二段チューブ２、漏洩水受け３、第二段気体封入ホース４、第一段気体封入ホース５、第一段圧力保持用内輪７、第二段圧力保持用内輪８、第一段、第二段連結用ロッド９で構成された装置上部をステンレス鋼配管内面に挿入する。挿入は分割された遠隔保持兼漏洩水排水用中空硬質ポールをつかみ配管内へ挿入する。挿入位置はあらかじめマーキングを実施しその位置にあわせる。
【００２０】
ステップ３では、取付け位置確認でマーキングと装置の位置があっていることを確認する。ステップ４では、気体ボンベより第一段チューブに気体を封入で最初に準備した気体封入ボンベに第一段気体封入ホース５を接続する。次にホースに接続している弁を開操作し第一段チューブ１に気体を封入する。手順として必ず上側の第一段チューブ１から気体封入操作を実施する。
【００２１】
ステップ５では、チューブ接触状態確認で第一段チューブ１とステンレス鋼配管１２内面の接触状態を目視および遠隔保持兼漏洩水排水用中空ポール６を手動により軽く動かし確認する。ステップ６、スッテプ７では、ステップ４，５と同作業を第二段チューブ２に対し実施する。ステップ８では、遠隔保持兼漏洩水排水用中空ポール接続、分割構造となっている遠隔保持兼漏洩水排水用中空硬質ポール６を新ステンレス配管外部まで接続し延長する。
【００２２】
ステップ９では、漏洩水排水ホース接続で遠隔保持兼漏洩水排水用中空硬質ポール６の先端に取付けられているドレンノズルに漏洩水排水ホース１０を接続する。漏洩水排水ホース１０の反対側は漏洩水を排水可能な発電プラントの配水系ないしは仮設集水設備に接続する。ステップ１０では、漏洩水が通水したこと確認し、スッテプ１１では、チューブ・配管内面接触部より漏洩のないこと確認し、ステップ９までで装置の取付けは完了したのでチューブとステンレス配管１２内面の接触部より漏洩がないことを確認すると共に漏洩水排水ホース１０先端より漏洩水が排水されていることを確認する。
【００２３】
ステップ１２では、開先合せで既設管開先部と新管開先部の仮付け溶接を実施する。ステップ１３では、不活性ガス注入段取で新管端面にシート等で養生を実施する。養生が完了したらシートに不活性ガス注入用ノズル１１を挿入する。次にステップ１４では、不活性ガス注入で不活性ガスボンベより不活性ガスをステンレス配管１２内面に充填する。ステップ１５では、酸素濃度確認はテープ等で養生してある溶接当該部１４に酸素濃度計を接近させテープを一部はがしその位置で測定する。酸素濃度が１％未満になるまで不活性ガスの充填を実施する。酸素濃度が１％未満に達したら溶接を開始する。
【００２４】
ステップ１６では、溶接機を溶接当該部１４に取付けステップ１７で溶接を実施する。ステップ１７では、溶接が完了し次からの手順で装置の撤去を実施する。最初にステップ１８では、漏洩水排水ホース１０を遠隔保持兼漏洩水排水用中空硬質ポール６から取り外す。取外し時は残留水に注意する。
【００２５】
ステップ１９では、第二段チューブ気体抜きは第二段チューブ２から第二段気体封入ホース４をとうし気体を抜き取る。気体はチューブの内圧により放出されるが放出は影響のないエリアに向かって放出する。気体を放出することにより第二段チューブ２は収縮しステンレス配管１２内面からはがれるため両者の接触部にたまっていた漏洩水が流出する可能性があるため水処理用水受けを準備する。ステップ２０では、遠隔保持兼漏洩水排水用中空ポール固定、第一弾チューブ１の封入気体を放出する前に遠隔保持兼漏洩水排水用中空硬質ポール６を作業員ないしは固定治具を用いて仮固定する。ステップ２１では、第一弾チューブ気体抜きはステップ１９と同手順で実施する。
【００２６】
ステップ２２では、装置引き抜き及びステップ２３では、遠隔保持兼漏洩水排水用中空ポール延長部解体で装置をステンレス配管１２の新管がわにゆっくりした速度で引き抜きを行い管端部に遠隔保持兼漏洩水排水用中空硬質ポール６の接続部が出てきた段階で順次解体しながら装置の引き抜きを実施する。
【００２７】
ステップ２４では、気体封入ホース解体で装置より気体封入ホースを取り外す。ステップ２５では、装置上部引き抜きでステンレス配管１２内部より装置上部を引抜き、ステップ２６では、装置等の片づけを実施する。
次に図２及び図３はにより装置の構成を説明する。図３は図２の第一段チューブ１及び第二段チューブ２を除いた本発明の密封装置の斜視図である。本装置は、縦に設置されされた配管に対して配管内を密封し、溶接機１３により溶接する状況を示すものである。本装置は、ゴムチューブからなる第一段チューブ１、第二段チューブ２、この２つのチューブがステンレス配管内面１２に接触し、漏洩水及び不活性ガスを隔離する機能を有している。隔離された漏洩水は、漏洩水受け３にたまり、遠隔保持兼漏洩水排水用中空硬質ポール６の内側を通って漏洩水が排水ホース１０から回収される。第一段チューブ１及び第二段チューブ２は遠隔で第一段気体封入ホース５より第一段チューブ１に気体を封入する。
【００２８】
本実施例では、密封を２段のチューブを用いて固定するもので、第二段チューブ２の一方に漏洩水受け３を設け、密封を行う。第一段チューブ１は、第二段チューブ２の漏洩水による重さを支えると共に、２個のチューブの長さ方向での配置により各々の配管内での中心位置に設置される適切な設置が得られるものである。図に示すように、本発明の密封装置は、チューブと、内輪と、漏洩水受けと、チューブへのガス供給手段と、漏洩水の排水手段とを有する極めて単純な構造からなるもので、そのため操作もきわめて簡単である。
【００２９】
第一段チューブ１に気体封入が完了後、第二段チューブ２に第二段気体封入ホース４より気体を封入する。第一段チューブ１及び第二段チューブ２ステンレス配管内面１２との接触面圧力確保のため、それぞれ内側に第一段圧力保持用内輪７と第二段圧力保持用内輪８を有する構造としている。この第一段圧力保持用内輪７と第二段圧力保持用内輪８とは図３に示すように円錐台形状のリングを２個重ね合わせ、チューブが密着するように形成され、図３に示す８〜１０本のロッドからなる第一段・第二段圧力保持用内輪連結用支持部材９に溶接により固定される。チューブ以外の材料は、いずれも炭素鋼からなる。
【００３０】
ステンレス鋼よりなる漏洩水受け３に接続されるエンビ管よりなる遠隔保持兼漏洩水排水用硬質ポール６はステンレス配管１２の内面奥に設定されることから、中間に接続部を有する構造とし延長を可能としている。これで溶接当該部１４には漏洩水が接触しなくなったため溶接開始のひとつの条件が確保できたことになる。漏洩水受け３は第二段圧力保持用内輪８にネジ止めされる。
【００３１】
次に、ステンレス配管１２の開放端に目張りとなるシート養生部３６をテープ３８でテーピングによって密封し、そこに不活性ガス注入用ノズル１１を設定して不活性ガスの注入を行う。不活性ガスは第一段チューブ１及び第二段チューブ２が隔壁となりそれより上部には侵入しないため不活性ガス領域が形成される。不活性ガスと空気の置換が完了したら溶接機１３により溶接作業が開始可能となる。シート養生部３６には、各種ホース、遠隔保持兼漏洩水排水用硬質ポール６が密閉した状態で外に延長される。
【００３２】
次に図４によりチューブによるステンレス配管内面の接触面圧力について説明する。図４（ａ）に示す様に、チューブのみステンレス配管内面に設定した場合ステンレス配管１８とチューブ１５の接触面圧力を上昇させようとしチューブ１５に封入する気体の圧力を上昇させてもチューブ１５は膨張方向１７に示すようにステンレス配管１８とは反対側の内面に膨張し、加圧後のチューブ１６に示すように内側に膨張する。そのため、チューブ１５とステンレス配管１８の接触面圧力は一向に上昇せず漏洩水の隔離機能が低いものとなっている。
【００３３】
しかし、図４（ｂ）に示すように、本発明は圧力保持用内輪１９をチューブ１５の内側に設定することによりチューブ１５とステンレス配管１８の接触面圧力を上昇させることにより漏洩水の隔離機能を向上させることが可能となっている。内側に逃げていた圧力は圧力保持用内輪１９により拘束され膨張方向１７が上下及び配管内面側となり加圧前のチューブ接触範囲２０が加圧後のチューブ接触範囲２１へと大きくなり、それにより漏洩水の隔離機能向上が図られる。
【００３４】
図５は、不活性ガス領域２５を形成するための隔壁としての機能について説明する断面図である。ステンレス鋼配管２６を溶接する場合、配管内面の溶接部酸化防止として空気から不活性ガスに内面を置換する必要がある。従来の技術では、その隔壁として水溶性の薄膜を貼り付け不活性ガスの隔壁を設定し不活性ガス領域を形成している。しかし、配管内面に漏洩水が発生した場合その漏洩水により水溶性の薄膜は融解し不活性ガス隔壁としての機能を喪失し溶接が困難となる。
【００３５】
本発明では漏洩水を隔離するチューブ２２が不活性ガスの隔壁を兼ねることにより不活性ガス領域２５を形成可能としている。チューブ２２とステンレス鋼配管２６の接触部及び圧力保持用内輪２３により不活性ガス隔壁２５を構成し、それより上部には不活性ガスは侵入せず不活性ガス領域２５を形成することが可能である。また、チューブ２２及び圧力保持用内輪２３は非水溶性であるため漏洩水に影響を受けない。構成された不活性ガス領域内に不活性ガス注入ノズル２４から不活性ガスを注入し不活性ガス密封領域２５を形成する。これによりステンレス鋼配管の既設配管と新規配管との突合せ溶接が配管の外周側から可能となる。
【００３６】
【発明の効果】
本発明によれば、ステンレス鋼配管内に漏洩水が発生しても単純な構造と簡単な操作で容易に装着と着脱が出来、確実に漏洩水を遮断すると共に、配管内を不活性ガスで満たし、容易に配管内を密封することのできる密封方法とその装置により既設のステンレス鋼配管の溶接が容易に行うことができるものである。
【図面の簡単な説明】
【図１（ａ）】漏洩水がある場合の本発明の溶接作業工程を示すフロー図。
【図１（ｂ）】漏洩水がない場合の溶接作業工程を示すフロー図。
【図２】密封断面図装置の取付け状態を示す断面図。
【図３】密封断面図装置の斜視図。
【図４】圧力保持用内輪の有無による配管内の状態を示す図。
【図５】配管内を不活性ガスで充満した状態を示す図。
【図６】密封断面図装置の全体構成図。
【符号の説明】
１…第一段チューブ、２…第二段チューブ、３…漏洩水受け、４…第二段気体封入ホース、５…第一段気体封入ホース、６…遠隔保持兼漏洩水排水用中空硬質ポール、７…第一段圧力保持用内輪、８…第二段圧力保持用内輪、９…第一段・第二段圧力保持用内輪連結用ロッド、１０…排水ホース、１１…不活性ガス注入用ノズル、１２…ステンレス配管、１３…溶接機、１４…溶接当該部、１５…チューブ、１６…加圧後のチューブ、１７…膨張方向、１８…ステンレス配管、１９…圧力保持用内輪、２０…チューブ接触範囲、２１…加圧後チューブ接触範囲、２２…チューブ、２３…圧力保持用内輪、２４…不活性ガス注入ノズル、２５…不活性ガス密封領域、２６…ステンレス配管、２７…装置本体、２８…溶接機ヘッド、２９…溶接ケーブル、３０…溶接機本体、３１…気体ボンベ、３２…不活性ガスボンベ、３３…ドレンホース、３４…排水系、３５…ステンレス配管、３６…シート養生部、３７…接続部。[0001]
[Field of the Invention]
The present invention relates to a novel pipe sealing method and apparatus, and a stainless steel pipe welding method and apparatus, and in particular, isolation and filling with inert gas when leakage water occurs in stainless steel pipe during welding work. The present invention relates to a sealing method and an apparatus thereof, and a welding method and an apparatus thereof.
[0002]
[Prior art]
When exchanging stainless steel pipes in an existing power plant, a joint between the existing pipe and the new pipe is generated. There is no possibility of foreign matter such as water in the new piping, but the existing piping is an existing power plant, so the fluid in the piping is supplied by a furnace, various heat exchangers or pumps and valves or sealing plugs, etc. Isolated. In the pipe replacement work, after the fluid in the pipe is isolated, the pipe is cut, and groove replacement and new pipe welding are performed. Since the fluid in the pipe is isolated by an existing valve or a sealing plug, fluid leakage often occurs.
[0003]
On the other hand, when welding of stainless steel pipes is carried out in a state where oxygen is present on the inner surface of the pipe, the back surface of the inner surface of the welded portion is oxidized and a welding defect occurs. For this reason, JP-A-8-267285 discloses a method of using a water-soluble sheet material as a welding method for piping in water. Also, conventionally, before welding, a water-soluble thin film was attached to the inner surface of the existing pipe with respect to the inner surface of the pipe, and the region was filled with inert gas to replace oxygen and inert gas, resulting in an oxygen concentration of less than 1%. After confirming this, welding will be carried out. When leakage of the pipe inner surface fluid occurs, the water-soluble thin film is dissolved by the fluid, and the inert gas diffuses further into the existing side pipe joint portion, and the inert gas filling concentration is lowered. For this reason, the oxygen concentration on the inner surface of the welded portion increases, causing welding defects. In the conventional technology, when leakage of the internal fluid from the existing piping occurs, it is difficult to perform welding, and a technology for preventing the leakage has not been established.
Japanese Laid-Open Patent Publication Nos. 5-146893 and 7-51893 disclose back-butting devices for butt welding of pipes, but they do not show any case where leakage water is generated in the pipes.
[0004]
[Problems to be solved by the invention]
The object of the present invention is that even if leaked water is generated in the stainless steel pipe, it can be easily attached and detached with a simple structure and simple operation, and the leaked water is reliably shut off and the inside of the pipe is filled with an inert gas. An object of the present invention is to provide a pipe sealing method and apparatus which can be filled and welded easily, and a stainless steel pipe welding method and apparatus.
[0005]
[Means for Solving the Problems]
In the present invention, when leakage water is generated on the inner surface of a stainless steel pipe to be welded, the leakage water is isolated from the welded portion and becomes a partition wall filled with an inert gas, so that welding work can be performed. There are a pipe sealing method and apparatus and a stainless steel pipe welding method and apparatus.
[0006]
The present invention is a method of attaching a flexible hollow structure tube in a stainless steel pipe between a place where leakage water is generated and a welded portion, and injecting gas from outside into the tube to isolate the welded portion from the leaked portion. It is in.
[0007]
Furthermore, there are a construction method that also serves as a partition for filling with an inert gas, a construction method having a two-stage tube, and a construction method having an inner ring for holding pressure so that the pressure of the internal gas does not diffuse inside the tube.
[0008]
The above-mentioned apparatus is inserted into a stainless steel pipe having a leak, and set on the pipe side having a leak with respect to the weld groove. Next, gas is sealed in the first stage tube and the second stage tube. This isolates the leaked water from the weld groove. A drain hose is attached to the tip of the hollow rigid pole to collect leaked water from the drain hose. Next, the open end of the pipe is marked and filled with an inert gas. Filling is performed while checking the oxygen concentration, and welding can be performed if the replacement of the inert gas and air is completed.
[0010]
The invention, together with each attached in contact with the pipe inner peripheral surface two tubes having a hollow structure having flexibility in the pipe, the tube each of the tubes by the pressure of the gas charged inside the tube held by two pressure retaining inner ring inner periphery length direction of the pipe so as not spread side provided at a predetermined interval corresponding to each of the tubes, at least one of the inner periphery of the inner ring for the pressure maintenance The leaked water receiver integrally formed on the side receives leaked water leaked into the pipe, drains the leaked water out of the pipe through drainage means connected to the leaked water receiver, and gas into the tube. In the pipe sealing method, one side of the pipe is isolated from the atmosphere by injecting .
[0012]
The present invention also provides two tubes having a flexible hollow structure provided so as to be in contact with the inner peripheral surface of the pipe, and the tube inner peripheral surface by the pressure of gas filled in the tube. Two inner rings for holding pressure so as to be in contact with the entire circumference and not to spread on the inner circumference side, and an injection means provided in each of the tubes and injecting gas into each of the tubes; The connecting means for connecting the pressure holding inner rings at a predetermined interval in the length direction of the pipe and the leaked water in the pipe provided on the inner peripheral side of at least one of the pressure holding inner rings. A leakage water receiver and drainage means connected to the leakage water receiver and draining the leaked water leaking into the pipe to the outside of the pipe, and by injecting gas into each of the tubes, Side to atmosphere Ri is seen sealing device of the pipe, characterized in that to isolate.
[0013]
In the present invention, two tubes having a flexible hollow structure are attached in the vicinity of the welded portion in the stainless steel pipe in contact with the inner peripheral surface of the pipe, and each of the tubes is filled in the tube. The tube is held by two pressure holding inner rings provided at a predetermined interval in the length direction of the pipe so that the tube does not expand to the inner peripheral side due to the pressure of the gas, and at least one of the pressure holding inner rings The leaked water receiver integrally formed on the inner peripheral side receives leaked water leaked into the pipe, drains the leaked water out of the pipe through drainage means connected to the leaked water receiver, wherein one side of the pipe isolated from the atmosphere, said open side of the other pipe is welded to the other side of the distribution pipe provided with a partition wall for isolating from the atmosphere, the pipe of the other side by injecting gas into After filling with an inert gas to the weld, before the liver Momizu the welding method of a stainless steel pipe characterized by butt welding and the stainless steel piping and other piping while draining out the pipe is there.
[0015]
Further, the present invention includes a two tubes having a hollow structure with flexibility provided in contact with the inner peripheral surface of the stainless steel pipe, the tube by the pressure of the gas charged inside the tube the Two pressure retaining inner rings that hold each of the tubes so as to be in contact with the entire inner circumferential surface of the pipe and do not spread to the inner circumferential side, and gas is injected into each of the tubes provided in each of the tubes Injecting means, connecting means for connecting each of the pressure holding inner rings at a predetermined interval in the length direction of the pipe, and the pipe integrally provided on the inner peripheral side of at least one of the pressure holding inner rings An infusion for injecting gas into each of the tubes, comprising: a leaked water receiver for receiving the leaked water in the pipe; and a drainage means for draining the leaked water connected to the leaked water receiver and leaking into the pipe to the outside of the pipe Before by means One side of the pipe isolated from the atmosphere, filling a partition isolating from the atmosphere is provided on the open side of the other pipe is welded to the other side of the piping, the inert gas on the other side of the inner pipe and filling means for, in a welding apparatus of a stainless steel pipe characterized by having the stainless steel piping and other piping and welding apparatus for butt welding.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Fig.1 (a) is a flow sheet of the work process which shows the procedure of the welding method of the stainless steel piping of this invention. FIG. 1 (a) is a flow sheet for the work process when the inner surface of the existing pipe is first checked and leakage of the fluid inside the pipe is present, and FIG. 1 (b) is a flow sheet for the work process when there is no leakage.
[0017]
The present invention is a case where there is a leakage of internal fluid in the existing piping, and the procedure on the left side. Steps 1 to 11 are the setting of the leakage water stop device, steps 12 to 17 are the pipe welding work, and steps 18 to 26 are the removal and cleaning up of the device.
[0018]
2 and 5 are a cross-sectional view of the sealing device in the stainless steel pipe and an overall view showing the mounting state thereof. Hereinafter, specific examples will be described with reference to FIGS. 1, 2, and 5. Check the existing inner surface of the stainless steel pipe and if the internal fluid is confirmed to be leaked, clean the inner surface of the pipe at the device mounting section. FIG. 6 is an overall view of a stainless steel pipe welding apparatus of the present invention. This apparatus includes an apparatus main body 27, a welder head 28, a welding cable 29, a welder main body 30, a gas cylinder 31, an inert gas cylinder 32, a drain hose 33, a drainage system 34, another stainless steel pipe 35, a sheet curing unit 36, A connection part 37 is provided.
[0019]
In step 1, as an apparatus and accessory preparation of the present invention, the apparatus and its accompanying hose, gas cylinder, etc. are carried into the area. In step 2, the first-stage tube 1, second-stage tube 2, leaked water receiver 3, second-stage gas-filled hose 4, first-stage gas-filled hose 5 and first-stage pressure hold in FIG. The upper part of the apparatus composed of the inner ring 7, the second stage pressure holding inner ring 8, the first stage, and the second stage connecting rod 9 is inserted into the inner surface of the stainless steel pipe. To insert, hold the divided hollow rigid pole for remote holding and leaking water drainage and insert it into the pipe. The insertion position is marked in advance and adjusted to that position.
[0020]
In step 3, it is confirmed that the marking and the position of the apparatus are in the attachment position confirmation. In step 4, the first-stage gas sealing hose 5 is connected to the gas-sealed cylinder prepared first by sealing the gas from the gas cylinder into the first-stage tube. Next, the valve connected to the hose is opened, and gas is sealed in the first stage tube 1. As a procedure, the gas filling operation is always performed from the upper first tube 1.
[0021]
In step 5, the contact state between the first stage tube 1 and the inner surface of the stainless steel pipe 12 is confirmed by visually checking and moving the hollow pole 6 for remotely holding and leaking water drainage lightly by manual operation. In step 6 and step 7, the same operation as in steps 4 and 5 is performed on the second-stage tube 2. In step 8, the remote holding / leakage water drainage hollow pole connection, the remote holding / leakage water drainage hollow hard pole 6 is connected to the outside of the new stainless steel pipe and extended.
[0022]
In step 9, the leakage water drainage hose 10 is connected to the drain nozzle attached to the tip of the hollow hard pole 6 for remote holding and draining water drainage by connecting the leakage water drainage hose. The other side of the leaked water drain hose 10 is connected to a water distribution system or a temporary water collecting facility of a power plant that can drain the leaked water. In step 10, it is confirmed that leaked water has passed, and in step 11, it is confirmed that there is no leakage from the tube / pipe inner surface contact portion. It is confirmed that there is no leakage from the contact portion and that the leakage water is drained from the tip of the leakage water drain hose 10.
[0023]
In step 12, the existing pipe groove part and the new pipe groove part are tack-welded by groove alignment. In step 13, curing is performed with a sheet or the like on the end face of the new pipe by an inert gas injection setup. When curing is completed, the inert gas injection nozzle 11 is inserted into the sheet. Next, in step 14, the inner surface of the stainless steel pipe 12 is filled with an inert gas from an inert gas cylinder by injecting an inert gas. In step 15, the oxygen concentration is confirmed by bringing the oxygen concentration meter closer to the welded portion 14 that has been cured with a tape or the like and peeling off the tape to measure at that position. Fill with inert gas until the oxygen concentration is less than 1%. Welding is started when the oxygen concentration reaches less than 1%.
[0024]
In step 16, the welding machine is attached to the welding portion 14 and welding is performed in step 17. In step 17, the welding is completed and the apparatus is removed by the following procedure. First, in step 18, the leaked water drain hose 10 is removed from the hollow hard pole 6 for remotely holding and draining drained water. Be careful of residual water when removing.
[0025]
In step 19, the second-stage tube gas is extracted from the second-stage tube 2 through the second-stage gas-filled hose 4. The gas is released by the internal pressure of the tube, but the discharge is released toward an area where there is no influence. By releasing the gas, the second-stage tube 2 is contracted and peeled off from the inner surface of the stainless steel pipe 12, so that leaked water that has accumulated at the contact portion between the two may flow out. In step 20, the remote holding / leakage water drainage hollow pole is fixed, and the remote holding / leakage water drainage hollow hard pole 6 is temporarily attached by using an operator or a fixing jig before releasing the gas sealed in the first tube 1. Fix it. In step 21, the first bullet tube is vented in the same procedure as in step 19.
[0026]
In step 22, the device is pulled out and in step 23, the device is pulled out at a slow speed by the new pipe of stainless steel pipe 12 by dismantling the hollow pole extension for remote holding and leaking water drainage, and remotely holding and leaking at the pipe end. The apparatus is pulled out while disassembling in sequence when the connection portion of the hollow hard pole 6 for water drainage comes out.
[0027]
In step 24, the gas-filled hose is removed from the apparatus by disassembling the gas-filled hose. In step 25, the upper part of the apparatus is pulled out from the inside of the stainless steel pipe 12 by pulling out the upper part of the apparatus. In step 26, the apparatus and the like are cleaned up.
Next, FIGS. 2 and 3 explain the configuration of the apparatus. FIG. 3 is a perspective view of the sealing device of the present invention excluding the first stage tube 1 and the second stage tube 2 of FIG. This apparatus shows the situation where the inside of the pipe is sealed with respect to the pipe installed vertically and is welded by the welding machine 13. In this apparatus, a first-stage tube 1 and a second-stage tube 2 made of rubber tubes have a function of contacting the inner surface 12 of the stainless steel pipe and isolating leaked water and inert gas. The isolated leaked water accumulates in the leaked water receiver 3, and the leaked water is collected from the drainage hose 10 through the inside of the hollow rigid pole 6 for remotely holding and draining the drained water. The first-stage tube 1 and the second-stage tube 2 remotely enclose gas into the first-stage tube 1 from the first-stage gas-filled hose 5.
[0028]
In this embodiment, the sealing is fixed by using a two-stage tube, and the leakage water receiver 3 is provided on one side of the second-stage tube 2 to perform the sealing. The first stage tube 1 supports the weight of the second stage tube 2 due to the leaked water, and the proper arrangement that is installed at the center position in each pipe by the arrangement of the two tubes in the length direction is possible. It is obtained. As shown in the figure, the sealing device of the present invention has a very simple structure having a tube, an inner ring, a leaked water receiver, a gas supply means to the tube, and a drainage means for leaked water. The operation is very simple.
[0029]
After the first stage tube 1 has been filled with gas, the second stage tube 2 is filled with gas from the second stage gas sealed hose 4. The first-stage tube 1 and the second-stage tube 2 have a structure having a first-stage pressure holding inner ring 7 and a second-stage pressure holding inner ring 8 on the inner side in order to ensure the contact surface pressure with the inner surface 12 of the stainless steel pipe. As shown in FIG. 3, the first-stage pressure holding inner ring 7 and the second-stage pressure holding inner ring 8 are formed so that two frustoconical rings are stacked and the tubes are in close contact with each other, as shown in FIG. It is fixed by welding to a support member 9 for connecting an inner ring for first-stage / second-stage pressure holding composed of 8 to 10 rods. All materials other than the tube are made of carbon steel.
[0030]
Since the remote holding / leakage water draining hard pole 6 made of an enviroment pipe connected to the leaking water receiver 3 made of stainless steel is set in the inner surface of the stainless steel pipe 12, it has a structure having a connecting portion in the middle and is extended. It is possible. As a result, leaked water does not come into contact with the welded part 14, so that one condition for starting welding can be secured. The leaking water receiver 3 is screwed to the second-stage pressure holding inner ring 8.
[0031]
Next, the sheet curing part 36 that serves as a cover at the open end of the stainless steel pipe 12 is sealed with a tape 38 by taping, and the inert gas injection nozzle 11 is set therein to inject the inert gas. Since the first stage tube 1 and the second stage tube 2 form partition walls and the inert gas does not enter the upper part, an inert gas region is formed. When the replacement of the inert gas and air is completed, the welding work can be started by the welding machine 13. Various hoses and remote holding / leakage water draining hard poles 6 are extended to the sheet curing unit 36 in a sealed state.
[0032]
Next, the contact surface pressure on the inner surface of the stainless steel pipe by the tube will be described with reference to FIG. As shown in FIG. 4 (a), when only the tube is set on the inner surface of the stainless steel pipe, the tube 15 does not move even if the pressure of the gas sealed in the tube 15 is increased to increase the contact surface pressure between the stainless steel pipe 18 and the tube 15. As shown in the expansion direction 17, it expands to the inner surface opposite to the stainless steel pipe 18, and expands inward as shown by the tube 16 after pressurization. Therefore, the contact surface pressure between the tube 15 and the stainless steel pipe 18 does not increase at all, and the function of isolating leaked water is low.
[0033]
However, as shown in FIG. 4 (b), the present invention sets the pressure holding inner ring 19 inside the tube 15 to increase the contact surface pressure between the tube 15 and the stainless steel pipe 18, thereby separating the leakage water. It is possible to improve. The pressure escaping inward is restrained by the pressure-holding inner ring 19 so that the expansion direction 17 is up and down and the inner surface of the pipe, and the tube contact range 20 before pressurization increases to the tube contact range 21 after pressurization, thereby leaking. The water isolation function is improved.
[0034]
FIG. 5 is a cross-sectional view illustrating a function as a partition for forming the inert gas region 25. When the stainless steel pipe 26 is welded, it is necessary to replace the inner surface from air to an inert gas in order to prevent welding portion oxidation on the inner surface of the pipe. In the conventional technique, an inert gas partition is formed by attaching a water-soluble thin film as the partition and setting an inert gas partition. However, when leaked water is generated on the inner surface of the pipe, the water-soluble thin film is melted by the leaked water and the function as an inert gas partition is lost, and welding becomes difficult.
[0035]
In the present invention, the inert gas region 25 can be formed by the tube 22 for isolating leaked water also serving as an inert gas partition. An inert gas partition wall 25 is constituted by the contact portion between the tube 22 and the stainless steel pipe 26 and the pressure holding inner ring 23, and an inert gas region 25 can be formed above the inert gas partition without intrusion. is there. Moreover, since the tube 22 and the pressure holding inner ring 23 are insoluble in water, they are not affected by leaked water. Inert gas is injected from the inert gas injection nozzle 24 into the configured inert gas region to form an inert gas sealed region 25. This makes it possible to butt weld the existing piping of the stainless steel piping and the new piping from the outer peripheral side of the piping.
[0036]
【The invention's effect】
According to the present invention, even if leaked water is generated in the stainless steel pipe, it can be easily attached and detached with a simple structure and simple operation, and the leaked water is reliably shut off and the pipe is filled with an inert gas. The existing stainless steel pipe can be easily welded by the sealing method and apparatus capable of satisfying and easily sealing the inside of the pipe.
[Brief description of the drawings]
FIG. 1 (a) is a flowchart showing a welding operation process of the present invention when there is leaked water.
FIG. 1B is a flowchart showing a welding operation process when there is no leakage water.
FIG. 2 is a cross-sectional view showing an attached state of the sealed cross-sectional view device.
FIG. 3 is a perspective view of a sealed sectional view device.
FIG. 4 is a view showing a state in a pipe depending on the presence / absence of a pressure holding inner ring.
FIG. 5 is a diagram showing a state where the inside of a pipe is filled with an inert gas.
FIG. 6 is an overall configuration diagram of a sealed sectional view device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... First stage tube, 2 ... Second stage tube, 3 ... Leaked water receptacle, 4 ... Second stage gas enclosure hose, 5 ... First stage gas enclosure hose, 6 ... Hollow hard pole for remote maintenance and leakage water drainage , 7 ... Inner ring for holding first-stage pressure, 8 ... Inner ring for holding second-stage pressure, 9 ... Rod for connecting inner ring for holding first-stage / second-stage pressure, 10 ... Drain hose, 11 ... For injecting inert gas Nozzle, 12 ... stainless steel pipe, 13 ... welder, 14 ... welded part, 15 ... tube, 16 ... tube after pressurization, 17 ... expansion direction, 18 ... stainless steel pipe, 19 ... inner ring for holding pressure, 20 ... tube Contact range, 21 ... Tube contact range after pressurization, 22 ... Tube, 23 ... Pressure-holding inner ring, 24 ... Inert gas injection nozzle, 25 ... Inert gas sealing area, 26 ... Stainless pipe, 27 ... Device main body, 28 ... welder head, 29 ... weld ke Bull, 30 ... welder body 31 ... gas canister 32 ... inert gas cylinder, 33 ... drain hose, 34 ... drainage system, 35 ... stainless pipe, 36 ... sheet curing unit, 37 ... connecting portion.

Claims

Two tubes having a flexible hollow structure are installed in the pipe so as to be in contact with the inner peripheral surface of the pipe, and the tubes are moved to the inner peripheral side by the pressure of gas filled in the tubes. The pipes are held by two pressure holding inner rings corresponding to each of the tubes, and are integrated with at least one inner peripheral side of the pressure holding inner ring so as not to spread. Receiving leaked water leaked into the pipe by the formed leaked water receiver, draining the leaked water out of the pipe through drainage means connected to the leaked water receiver, and injecting gas into the tube A pipe sealing method characterized in that one side of the pipe is isolated from the atmosphere by

Two tubes having a flexible hollow structure provided so as to be in contact with the inner peripheral surface in the pipe, and the tube is in contact with the entire inner peripheral surface of the pipe by the pressure of the gas filled in the tube and Two pressure holding inner rings for holding each of the tubes so as not to spread to the circumferential side, injection means provided in each of the tubes and injecting the gas into each of the tubes, and each of the pressure holdings A connecting means for connecting the inner rings for a predetermined distance in the length direction of the pipe, and a leaked water receiver for receiving the leaked water in the pipe provided on at least one inner peripheral side of the pressure holding inner ring, A drainage means connected to the leaked water receiver and draining leaked water leaking into the pipe to the outside of the pipe, and by injecting the gas into each of the tubes, one side of the pipe from the atmosphere Interval Sealing device of the pipe, characterized by.

In the stainless steel pipe, two flexible hollow tubes are attached in contact with the inner peripheral surface of the pipe in the vicinity of the welded portion, and each of the tubes is moved by the pressure of the gas filled in the tube. The tube is held by two pressure holding inner rings provided at predetermined intervals in the length direction of the pipe so that the tube does not spread to the inner circumference side, and is integrated with at least one inner circumference side of the pressure holding inner ring. Receiving leaked water leaked into the pipe by the formed leaked water receiver, draining the leaked water out of the pipe through drainage means connected to the leaked water receiver, and injecting the gas into the tube By providing a partition that isolates one side of the pipe from the atmosphere and isolates the open side of the other pipe welded to the other side of the pipe from the atmosphere, and inactive in the pipe on the other side After filling the scan, a method of welding stainless steel pipe characterized by butt welding and the stainless steel piping and other piping while draining the leakage water outside the pipe.

Two tubes having a flexible hollow structure provided so as to be in contact with the inner peripheral surface of the stainless steel pipe, and the tube is placed around the inner peripheral surface of the pipe by the pressure of the gas filled in the tube. Two pressure-holding inner rings that are in contact with each other so as not to spread toward the inner peripheral side, injection means that are provided in each of the tubes and inject the gas into each of the tubes, and A connecting means for connecting the pressure holding inner rings at a predetermined interval in the length direction of the pipe, and leaking water in the pipe integrally provided on the inner peripheral side of at least one of the pressure holding inner rings. And a drainage means for draining the leaked water connected to the leaked water receiver and leaking into the pipe to the outside of the pipe, and the pipe by the injection means for injecting the gas into each tube. A partition wall provided on an open side of another pipe welded to the other side of the pipe and isolated from the atmosphere, and a filling means for filling the other side of the pipe with an inert gas And a welding apparatus for butt welding the stainless steel pipe and another pipe.