JP5309635B2

JP5309635B2 - Gas piping repair method

Info

Publication number: JP5309635B2
Application number: JP2008072659A
Authority: JP
Inventors: 恒夫永岡; 博竹生; 泰長田
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2008-03-20
Filing date: 2008-03-20
Publication date: 2013-10-09
Anticipated expiration: 2028-03-20
Also published as: JP2009228716A

Description

本発明は、各種ガス等の気体が流通する配管（以下、ガス配管という）の腐食部からガスが漏出するのを防止するための補修方法に関するものである。 The present invention relates to a repair method for preventing gas from leaking out from a corroded portion of a pipe (hereinafter referred to as a gas pipe) through which various gases and the like flow.

ガス配管内を流通するガスに含まれる腐食成分によって腐食が進行し、管壁に発生した開口部や割れ部からガスが漏出すると、環境汚染を引き起こすばかりでなく、安全に関わる問題が生じる。そのため、ガス配管の腐食した部位（以下、腐食部という）が管壁を貫通する前に、その部位を補修する技術が種々検討されている。
たとえば、ガス配管の腐食部とその周辺の外面に当て板を当接する補修方法が広く知られている。この補修技術では、ガスの流通を停止することなく補修を行なえるので、ガス配管に連設される設備の操業を継続でき、しかも短時間で補修作業を行なえるという利点がある。しかし当て板がガス配管の外面に密着するので、腐食部がガス配管の管壁を貫通した後、ガスに含まれる腐食成分がガス配管と当て板との接合部にドレン水とともに浸入する。接合部に浸入した腐食成分は次第に濃縮されるので、腐食部周辺のガス配管や当て板の腐食が進行し易くなる。そのため、この技術で補修した後、比較的短期間でしかも広範囲の補修が新たに必要となる。 When corrosion progresses due to corrosive components contained in the gas flowing in the gas pipe and the gas leaks from the opening or crack generated in the pipe wall, it not only causes environmental pollution but also causes safety problems. For this reason, various techniques for repairing a corroded portion (hereinafter referred to as a corroded portion) of the gas pipe before penetrating the tube wall have been studied.
For example, a repair method is widely known in which a contact plate is brought into contact with a corroded portion of a gas pipe and an outer surface around the corroded portion. This repair technique has the advantage that the repair can be performed without stopping the gas flow, so that the operation of the equipment connected to the gas pipe can be continued and the repair work can be performed in a short time. However, since the contact plate is in close contact with the outer surface of the gas pipe, after the corroded portion penetrates the tube wall of the gas pipe, the corrosive component contained in the gas enters the joint portion between the gas pipe and the contact plate together with the drain water. Since the corrosive components that have entered the joint are gradually concentrated, the corrosion of the gas piping and the contact plate around the corroded portion is likely to proceed. For this reason, after repairing with this technique, a wide range of repairs are required in a relatively short period of time.

また、腐食部の周辺の内面にライニング材を塗布する（あるいは吹付ける）技術も知られている。この補修技術は、当て板を用いる補修技術に比べて耐用性は改善されるが、適用するガス配管の寸法が制約を受けるばかりでなく、補修作業の際にはガス配管に連設される設備の操業を停止せざるを得ない。
特許文献１には、バンド部材を用いて補修部の外面にパッキンを密着させる技術が開示されている。この補修技術は、補修作業が短時間で終了し、しかも補修作業中にガス配管に連設される設備の操業を継続できるという利点がある。しかし、パッキンがガス配管の外面に密着するので、腐食部がガス配管の管壁を貫通すると、ガスに含まれる腐食成分がガス配管とパッキンとの接合部に浸入する。接合部に浸入した腐食成分は次第に濃縮されるので、腐食部周辺のガス配管が進行し易くなる。そのため、この技術で補修した後、比較的短期間でしかも広範囲の補修が新たに必要となる。
特開2004-324835号公報 A technique for applying (or spraying) a lining material to the inner surface around the corroded portion is also known. Although this repair technology improves the durability compared to the repair technology using a patch plate, the size of the gas pipe to be applied is not limited, and equipment that is connected to the gas pipe during repair work. I have to stop the operation.
Patent Document 1 discloses a technique in which a packing is brought into close contact with an outer surface of a repair portion using a band member. This repair technique has the advantage that the repair work can be completed in a short time and the operation of the equipment connected to the gas pipe can be continued during the repair work. However, since the packing is in close contact with the outer surface of the gas pipe, when the corroded portion penetrates the wall of the gas pipe, the corrosive component contained in the gas enters the joint between the gas pipe and the packing. Since the corrosive component that has entered the joint is gradually concentrated, the gas piping around the corroded portion easily proceeds. For this reason, after repairing with this technique, a wide range of repairs are required in a relatively short period of time.
JP 2004-324835 A

本発明は、ガス配管の腐食部が管壁を貫通する前に、その腐食部を補修するにあたって、補修作業が短時間で終了し、しかも補修作業中にガス配管に連設される設備の操業を継続できる補修方法を提供することを目的とする。 In the present invention, before repairing the corroded portion of the gas pipe through the pipe wall, the repair work is completed in a short time, and the operation of the equipment connected to the gas pipe during the repair work is performed. The purpose is to provide a repair method that can continue.

本発明は、ガス配管の腐食部を補修する補修方法において、腐食部が管壁を貫通する前に、腐食部を覆うようにガス配管の外側に外殻部材を配置し、ガス配管の外面と外殻部材の内面との間に隙間を設け、かつ外殻部材の端部における内面と前記ガス配管の外面との間に閉塞部材を配設して外殻部材の周縁部を全周にわたって閉塞し、隙間に滞留するドレン水を排出するドレン抜きを外殻部材の下部に配設するガス配管の補修方法である。 The present invention relates to a repair method for repairing a corroded part of a gas pipe, before the corroded part penetrates the pipe wall, an outer shell member is arranged outside the gas pipe so as to cover the corroded part, A gap is provided between the inner surface of the outer shell member and a closing member is disposed between the inner surface of the end portion of the outer shell member and the outer surface of the gas pipe to block the peripheral edge of the outer shell member over the entire circumference. And it is the repair method of the gas piping which arrange | positions the drain removal which discharges the drain water which retains in a clearance gap in the lower part of an outer shell member.

本発明によれば、ガス配管の腐食部が管壁を貫通する前に、その腐食部を補修するにあたって、補修作業が短時間で終了し、しかも補修作業中にガス配管に連設される設備の操業を継続できる。
また、ガス配管と外殻部材との隙間からドレン水を抜くことによって、腐食成分の濃縮を防止し、外殻部材の耐用性を向上できる。 According to the present invention, before repairing a corroded portion of a gas pipe through the pipe wall, the repair work is completed in a short time, and the equipment is continuously connected to the gas pipe during the repair work. Can be continued.
Further, by draining water from the gap between the gas pipe and the outer shell member, it is possible to prevent the concentration of corrosive components and improve the durability of the outer shell member.

図１は、本発明を適用して腐食部を補修したガス配管の例を模式的に示す断面図である。ガス配管１は、その内部をガスが流通する配管である。腐食部２は、ガスに含まれる腐食成分によってガス配管１が腐食した部位である。
本発明では、ガスが漏出するのを防止するために、腐食部２がガス配管１の管壁を貫通する前に補修を行なう。ガス配管１の管壁が腐食によって開口する前であれば、ガスの漏出を防止するばかりでなく、連設される設備を操業しながら補修を行なうことが可能である。
FIG. 1 is a cross-sectional view schematically showing an example of a gas pipe in which a corroded portion is repaired by applying the present invention. The gas pipe 1 is a pipe through which gas flows. The corroded portion 2 is a portion where the gas pipe 1 is corroded by a corrosive component contained in the gas.
In the present invention, in order to prevent the gas from escaping, corroded portions 2 row repair before penetrating the wall of the gas pipe 1. If the pipe wall of the gas pipe 1 is not opened due to corrosion, it is possible not only to prevent gas leakage but also to perform repairs while operating the connected equipment .

以下では、図１を参照して、腐食部２がガス配管１の管壁を貫通する前に補修を行なう例について説明する。
図１に示すように、腐食部２を覆うようにガス配管１の外側に外殻部材３を配置し、ガス配管１の外面と外殻部材３の内面との間に隙間５を設ける。さらに外殻部材３の端部の内面とガス配管１の外面との間に閉塞部材４を取付ける。図１には外殻部材３の円周方向の端部に取付けた閉塞部材４を示すが、外殻部材３の長手方向の端部にも閉塞部材４を取付ける。したがって、外殻部材３の周縁部は全周にわたって閉塞部材４が取付けられ、隙間５は密閉される。 Below, with reference to FIG. 1, the example which repairs before the corrosion part 2 penetrates the pipe wall of the gas piping 1 is demonstrated.
As shown in FIG. 1, an outer shell member 3 is disposed outside the gas pipe 1 so as to cover the corroded portion 2, and a gap 5 is provided between the outer surface of the gas pipe 1 and the inner surface of the outer shell member 3. Further, the closing member 4 is attached between the inner surface of the end portion of the outer shell member 3 and the outer surface of the gas pipe 1. Although FIG. 1 shows the closing member 4 attached to the circumferential end of the outer shell member 3, the closing member 4 is also attached to the longitudinal end of the outer shell member 3. Therefore, the closing member 4 is attached to the peripheral edge of the outer shell member 3 over the entire periphery, and the gap 5 is sealed.

このようにして腐食部２が管壁を貫通する前に外殻部材３と閉塞部材４を配設することによって、ガス配管１に連設される設備を操業しながら補修を行なうことが可能となり、かつ補修が終了した後も操業を継続できる。
その後、腐食が進行して、腐食部２が管壁を貫通しても、ガス配管１内を流通するガスは隙間５内に充満するのみで、大気中に漏出する惧れはない。ただし時間の経過に伴って、ガスに含まれる腐食成分がドレン水ととともに隙間５内に滞留する。そのため、外殻部材３の下部にドレン抜き７を配設する。ドレン抜きからドレン水を定期的に排出することによって、腐食成分が濃縮するのを防止し、外殻部材３の耐用性を向上できる。 By arranging the outer shell member 3 and the closing member 4 before the corroded portion 2 penetrates the pipe wall in this way, it becomes possible to perform repairs while operating the equipment connected to the gas pipe 1. And the operation can be continued after the repair is completed.
Then, even if corrosion progresses and the corroded part 2 penetrates the pipe wall, the gas flowing through the gas pipe 1 only fills the gap 5 and there is no possibility of leaking into the atmosphere. However, as time passes, the corrosive component contained in the gas stays in the gap 5 together with the drain water. Therefore, a drain remover 7 is disposed at the lower part of the outer shell member 3. By draining the drain water periodically from the drain, it is possible to prevent the corrosion components from concentrating and to improve the durability of the outer shell member 3.

コークス炉から排出されるコークス炉ガス（いわゆるＣガス）のガス配管の補修を行なうにあたって、腐食部がガス配管の管壁を貫通する前に、本発明を適用して補修を行なった。これを発明例とする。
すなわち発明例では、図１に示すように、腐食部２を覆うようにガス配管１の外側に外殻部材３を配置して、ガス配管１の外面と外殻部材３の内面との間に隙間５を設け、さらに外殻部材３の周縁部全周にわたって閉塞部材４を取付けた。このようにして隙間５を密閉した。また外殻部材３の下部にドレン抜き７を配設しておき、腐食部２が管壁を貫通した後、腐食成分が混入したドレン水を定期的に排出した。 In repairing the gas piping of the coke oven gas (so-called C gas) discharged from the coke oven, the repair was performed by applying the present invention before the corroded portion penetrated the wall of the gas piping. This is an invention example.
That is, in the invention example, as shown in FIG. 1, an outer shell member 3 is disposed outside the gas pipe 1 so as to cover the corroded portion 2, and between the outer surface of the gas pipe 1 and the inner surface of the outer shell member 3. A gap 5 was provided, and a closing member 4 was attached over the entire periphery of the outer periphery of the outer shell member 3. In this way, the gap 5 was sealed. In addition, a drain remover 7 was disposed at the lower part of the outer shell member 3, and after the corroded portion 2 penetrated the tube wall, drain water mixed with corrosive components was periodically discharged.

発明例について、使用した外殻部材３（鋼種：ＪＩＳ規格STPY400相当）の腐食の進行状況を調査した。そして、その調査結果に基づいて、腐食が厚み９mmの外殻部材３を貫通するに要する時間（以下、耐用期間という）を算出した。
一方、従来はガス配管１の腐食部２とその周辺の外面に当て板６を当接して補修を行なっていた。これを従来例とする。 Regarding the inventive examples, the progress of corrosion of the outer shell member 3 (steel type: JIS standard STPY400 equivalent) used was investigated. Based on the result of the investigation, the time required for corrosion to penetrate the outer shell member 3 having a thickness of 9 mm (hereinafter referred to as the service life) was calculated.
On the other hand, conventionally, repair has been performed by contacting the contact plate 6 against the corroded portion 2 of the gas pipe 1 and the outer surface in the vicinity thereof. This is a conventional example.

すなわち従来例では、図２に示すように、当て板６の周縁部をガス配管１に溶接して、当て板６とガス配管１を密着させた。そのため、腐食が進行して、腐食部２が管壁を貫通した後、ガスに含まれる腐食成分が当て板６とガス配管１との接合部にドレン水とともに毛細管現象によって浸入した。このドレン水を排出することは困難であるから、従来例ではドレン抜きを配設しなかった。 That is, in the conventional example, as shown in FIG. 2, the peripheral portion of the contact plate 6 is welded to the gas pipe 1, and the contact plate 6 and the gas pipe 1 are brought into close contact with each other. Therefore, after the corrosion progressed and the corroded portion 2 penetrated the tube wall, the corrosive component contained in the gas infiltrated into the junction between the contact plate 6 and the gas pipe 1 together with drain water by a capillary phenomenon. Since it is difficult to discharge this drain water, drainage was not provided in the conventional example.

従来例について、使用した当て板６（鋼種：ＪＩＳ規格STPY400相当）の腐食の進行状況を調査し、その調査結果に基づいて発明例と同様に当て板６の耐用期間を算出した。
発明例では外殻部材３の耐用期間が30年程度であったのに対して、比較例では当て板６の耐用期間は15〜20年程度であった。 About the conventional example, the progress of the corrosion of the used plate 6 (steel type: JIS standard STPY400 equivalent) was investigated, and the lifetime of the plate 6 was calculated in the same manner as the invention example based on the investigation result.
In the example of the invention, the lifetime of the outer shell member 3 was about 30 years, whereas in the comparative example, the lifetime of the backing plate 6 was about 15 to 20 years.

本発明を適用して腐食部を補修したガス配管の例を模式的に示す断面図である。It is sectional drawing which shows typically the example of the gas piping which repaired the corrosion part by applying this invention. 当て板を用いて腐食部を補修したガス配管の例を模式的に示す断面図である。It is sectional drawing which shows typically the example of the gas piping which repaired the corrosion part using the contact plate.

符号の説明Explanation of symbols

１ガス配管
２腐食部
３外殻部材
４閉塞部材
５隙間
６当て板
７ドレン抜き
８バルブ
９溶接部
DESCRIPTION OF SYMBOLS 1 Gas piping 2 Corrosion part 3 Outer shell member 4 Closure member 5 Crevice 6 Catch plate 7 Drain removal 8 Valve 9 Welding part

Claims

ガス配管の腐食部を補修する補修方法において、前記腐食部が管壁を貫通する前に、前記腐食部を覆うように前記ガス配管の外側に外殻部材を配置し、前記ガス配管の外面と前記外殻部材の内面との間に隙間を設け、かつ前記外殻部材の端部における内面と前記ガス配管の外面との間に閉塞部材を配設して前記外殻部材の周縁部を全周にわたって閉塞し、前記隙間に滞留するドレン水を排出するドレン抜きを前記外殻部材の下部に配設することを特徴とするガス配管の補修方法。 In the repairing method for repairing the corroded portion of the gas pipe, before the corroded portion penetrates the pipe wall, an outer shell member is disposed outside the gas pipe so as to cover the corroded portion, and the outer surface of the gas pipe A gap is provided between the inner surface of the outer shell member, and a closing member is disposed between the inner surface of the end portion of the outer shell member and the outer surface of the gas pipe so that the peripheral edge portion of the outer shell member is entirely disposed. A method for repairing a gas pipe, characterized in that a drain outlet that closes around the circumference and discharges drain water that stays in the gap is disposed below the outer shell member.