JP2003050000A - Pressure transmitting device for pipeline - Google Patents
Pressure transmitting device for pipelineInfo
- Publication number
- JP2003050000A JP2003050000A JP2001237932A JP2001237932A JP2003050000A JP 2003050000 A JP2003050000 A JP 2003050000A JP 2001237932 A JP2001237932 A JP 2001237932A JP 2001237932 A JP2001237932 A JP 2001237932A JP 2003050000 A JP2003050000 A JP 2003050000A
- Authority
- JP
- Japan
- Prior art keywords
- pressure transmitter
- pressure
- main pipe
- pipeline
- branch pipe
- 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.)
- Withdrawn
Links
Landscapes
- Measuring Fluid Pressure (AREA)
- Pipeline Systems (AREA)
Abstract
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明はガスパイプライン等
の流送状況を把握・制御する圧力伝送装置に関する。
【０００２】
【従来の技術】都市ガスや各種産業ガス等のパイプライ
ンには、配管内を流れるガスの流送状況を監視あるいは
制御するため、配管途中に圧力伝送装置が設置されてい
る。例えば、都市ガスのパイプラインにおいては、ガバ
ナステーション内に配管内の圧力を計測するための圧力
伝送装置が設置されている。
【０００３】従来の圧力伝送装置は、図２に示すように
ガスパイプラインの本管１０からバルブ１、絶縁継手１
２を介して分岐された分岐管２が圧力伝送器１１の設置
場所まで延長され、圧力伝送器１１の圧力検知部に接続
されて本管圧力を計測する。そして、圧力伝送器１１の
圧力検知部が検知した圧力信号は電気信号に変換され、
この電気信号は電線管７で保護されたケーブル８によっ
てケーブルピットを経由して監視室に送られる。
【０００４】ここで、本管１０と分岐管２とを絶縁継手
１２で接続しているのは本管１０の電気防食を効率よく
行なうためである。また、分岐管２および圧力伝送器１
１と導通する電線管７は接地極９に接続されて大地電位
とされている。なお、図２の３、４は分岐管の接続用ユ
ニオンであり、５はメンテナンス用のストップバルブで
あり、６はドレンプラグである。
【０００５】また、前記圧力伝送器１１を静電気や雷撃
から保護するために、図２に点線で示すように分岐管２
の途中（圧力伝送器の手前）から導線を引き出しサージ
アブソーバ、アレスタ等の保護装置１４を介して大地に
接地するようにしたものがある。この機構によれば静電
気や雷撃のサージ電流を圧力伝送器１１に進入する前に
大地に逃がすことができる。
【０００６】
【発明が解決しようとする課題】ガス等の気相流体を配
管を通じて流送する場合、配管内壁とガスまたはガスに
含まれる不純物（水分や微小粒子等）との摩擦により静
電気が発生し、この静電気が配管に蓄積される。この静
電気の壁面に対する帯電極性および電荷分布はガスの種
類、不純物の種類とパイプライン内壁の処理状態（塗
装、無塗装）等により変わる。また、電荷の蓄積レベ
ル、拡散過程もパイプライン内壁の処理（塗装、無塗
装）の状況や電気防食の形態（外部電源、流電陽極）、
外面塗覆装、流送圧、流速により変わるが、特にパイプ
ラインが内面塗装されたものでは塗料が絶縁体であるた
め、発生した電荷は壁面に滞留し時間の経過とともに蓄
積されていく。
【０００７】ここで帯電域近傍に接地極があり、電荷量
（電圧）が接地極とのギャップの破壊電圧を超えた場合
には、接地極との間で放電が起こり、接地極への電荷の
拡散が行われる。ガスパイプラインの本管１０のガバナ
ステーション等では分岐管２が実質接地されているため
接地極となる場合が多い。
【０００８】すなわち、図２に示す従来技術では、絶縁
継手１２を介して本管１０から分岐された分岐管２に圧
力伝送器１１が取り付けられており、分岐管２および圧
力伝送器１１と導通する電線管７が接地極９に接続され
て大地電位とされている。このため、本管内壁に蓄積さ
れた静電気が破壊電圧を超えて放電して接地極へ電荷の
移動が起こった場合、その経路のなかに圧力伝送器１１
が含まれるために圧力伝送器１１が異常な指示値を示し
たり、場合によっては破損するといった不具合が起こっ
ていた。
【０００９】この対策として、前記のように分岐管２の
途中（圧力伝送器の手前）から導線を引き出しサージア
ブソーバ、アレスタ等の保護装置１４を介して大地に接
地することもできる。この場合は、圧力伝送器１１の前
で放電電荷を接地極に逃がすことができるため静電気や
雷撃のサージ電流が圧力伝送器に進入することがなく、
圧力伝送器１１の異常指示値や破損を防止することがで
きる。
【００１０】しかし、前記の場合には、サージアブソー
バを有効に作用させるには接地極の接地抵抗を十分に低
くした仕様の接地極設置が必要となる。さらに、サージ
アブソーバ、アレスタ等の保護装置１４を、パイプライ
ンに多数設置されている圧力伝送装置の全てに取り付け
ることは非常にコストがかかり、また、これらの維持・
管理に手間がかかるといった課題があった。
【００１１】本発明は前記した従来技術の課題を解消し
て、簡易な手段で且つ、経済的に静電気等の電撃に対し
て圧力伝送器に異常指示値や破損を生じることがないガ
スパイプラインに設置される圧力伝送装置を提供するも
のである。
【００１２】
【課題を解決するための手段】本発明のガスパイプライ
ンに設置される圧力伝送装置は、図１に示すように、ガ
スパイプラインの本管１０から分岐して設けられる圧力
伝送装置において、金属製の内面を無塗装または導電性
物質を被覆した分岐管２が本管１０の分岐部と圧力伝送
器１１の取り付け部にそれぞれ絶縁継手１２、１３を介
して接続され、該分岐管２に導通する接地線１５が圧力
伝送器の接地極９と共通して接地されていることを特徴
とする。
【００１３】＜作用＞すなわち、本発明の構成において
は、以下の点を特徴とする。
【００１４】（１）本管１０に流れるガスを圧力伝送器
１１へ導く分岐管２を、内面無塗装の金属管または導電
性の物質で被覆して管内面を導電状態とした金属製の分
岐管とした。この理由は、もし、分岐管内面が塗装等で
絶縁されていると電荷は沿面放電により分岐管２の接地
に吸収されないで接地極である圧力伝送器に届くことに
なる。これを避けるために接地線１５を通じて接地極９
に電荷を拡散しやすくするため、内面を無塗装または導
電性の物質で被覆して導電状態とした金属製の分岐管２
とした。
【００１５】（２）本管１０との分岐管２および分岐管
２と圧力伝送器１１の取り付け部を絶縁継手１２、１３
で接続した。この理由は、本管１０と分岐管２は従来技
術と同様に本管の電気防食用の電流を効率よく流すため
に絶縁継手１２を設けたものであるが、圧力伝送器１１
と分岐管２の取付け部との絶縁継手部１３は、本管から
の電撃を阻止するために設けた。
【００１６】（３）分岐管２と圧力伝送器１１を共通す
る接地極９で接地した。この理由は、圧力伝送器１１の
取り付け部の絶縁継手１３間にも電圧がかからないよう
にして、この部分での放電を防ぐためである。そこで、
分岐管２と圧力伝送器１１を共通する接地極９で接地
し、接地極の上昇電位が絶縁継手１３をはさんだ分岐管
２と圧力伝送器１１とで等しくなるようにした。
【００１７】上記の構成により、ガスパイプラインの本
管１０の内壁に蓄積された電荷が破壊電圧を超えて絶縁
継手部１２で発生した放電電荷は、分岐管２から接地線
１５側に流れ、絶縁継手１３で接続された圧力伝送器１
１に流れることはない。接地線１５を通じて流れた放電
電荷は圧力伝送器１１の接地と共通して接地された接地
極９に流れ大地に拡散する。この結果、圧力伝送器１１
には異常電流が生じないため装置が損傷することがな
く、正常な計測値が保たれる。
【００１８】
【発明の実施の形態】図１は本発明をガスパイプライン
のガバナステーション内に設置される圧力伝送装置に適
用した実施形態の例を示すものである。ガスパイプライ
ンの本管１０からバルブ１、絶縁継手１２を介して分岐
された本管１０の流送圧力を計測するステンレス製の分
岐管２が圧力伝送器１１の設置場所まで延長され、圧力
伝送器１１の圧力検知部に絶縁継手１３を介して接続さ
れている。
【００１９】分岐管２は通常の金属管を用い、防食のた
め内面に導電性の塗料を被覆したものとしてもよい。ま
た、絶縁継手１２、１３は樹脂（プロチン）等の絶縁フ
ランジ等、公知のものを使用できる。圧力伝送器１１に
は圧力検知部で検知した圧力信号を電気信号に変換する
変換器を内蔵しており、この電気信号は電線管７で保護
されたケーブル８によってケーブルピットを経由して監
視室に送られる。
【００２０】分岐管２の途中でかつ圧力伝送器１１の手
前には、接地線１５が接続されている。この接地線１５
は圧力伝送器１１と導通する電線管７の接地極９に共通
して接続され大地電位としている。
【００２１】なお、図１中の３、４は分岐管の接続用ユ
ニオンであり、５はメンテナンス用のストップバルブで
あり、６はドレンプラグである。
【００２２】
【発明の効果】本発明によれば、従来課題であったパイ
プライン本管からの静電気等の放電（電撃）による圧力
伝送器の異常指示値や破損といった不具合をサージアブ
ソーバ等の高価な保護装置を使用することなく極めて簡
易に解消し、経済的な圧力伝送装置を提供することがで
きる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure transmission device for grasping and controlling a flow state of a gas pipeline or the like. 2. Description of the Related Art In a pipeline of city gas, various industrial gases, or the like, a pressure transmission device is installed in the middle of the pipe in order to monitor or control the flow of gas flowing in the pipe. For example, in a city gas pipeline, a pressure transmission device for measuring the pressure in the piping is installed in a governor station. As shown in FIG. 2, a conventional pressure transmission device includes a main pipe 10 of a gas pipeline, a valve 1 and an insulating joint 1.
The branch pipe 2 branched through the pressure transmitter 2 is extended to a place where the pressure transmitter 11 is installed, and is connected to a pressure detecting unit of the pressure transmitter 11 to measure a main pipe pressure. Then, the pressure signal detected by the pressure detector of the pressure transmitter 11 is converted into an electric signal,
This electric signal is sent to the monitoring room via a cable pit by a cable 8 protected by a conduit tube 7. Here, the main pipe 10 and the branch pipe 2 are connected by the insulating joint 12 in order to efficiently protect the main pipe 10 from corrosion. Further, the branch pipe 2 and the pressure transmitter 1
The conduit 7 electrically connected to 1 is connected to the ground electrode 9 and is set to the ground potential. 2, 3 and 4 are unions for connecting branch pipes, 5 is a stop valve for maintenance, and 6 is a drain plug. [0005] In order to protect the pressure transmitter 11 from static electricity and lightning, a branch pipe 2 as shown by a dotted line in FIG.
In some cases, a conducting wire is drawn out halfway through (before the pressure transmitter) and grounded to the ground via a protective device 14 such as a surge absorber or an arrester. According to this mechanism, static electricity or surge current of lightning can be released to the ground before entering the pressure transmitter 11. [0006] When a gaseous fluid such as gas is fed through a pipe, static electricity is generated due to friction between the inner wall of the pipe and the gas or impurities (moisture, fine particles, etc.) contained in the gas. Then, this static electricity is accumulated in the piping. The charge polarity and charge distribution of the static electricity with respect to the wall surface vary depending on the type of gas, the type of impurities, and the processing state (painted, unpainted) of the pipeline inner wall. In addition, the charge accumulation level and the diffusion process also include the processing of the inner wall of the pipeline (painted, unpainted), the form of cathodic protection (external power supply, current-carrying anode),
Although it depends on the outer coating, the feeding pressure, and the flow velocity, particularly in the case where the pipeline is coated on the inner surface, since the coating is an insulator, the generated electric charge stays on the wall surface and accumulates over time. Here, when a ground electrode exists near the charged area and the amount of charge (voltage) exceeds the breakdown voltage of the gap between the ground electrode and the ground electrode, discharge occurs between the ground electrode and the ground electrode. Is performed. In the governor station of the main pipe 10 of the gas pipeline, the branch pipe 2 is substantially grounded, so that it often becomes a grounding electrode. That is, in the prior art shown in FIG. 2, the pressure transmitter 11 is attached to the branch pipe 2 branched from the main pipe 10 via the insulating joint 12, and the pressure transmitter 11 is electrically connected to the branch pipe 2 and the pressure transmitter 11. The electric conduit 7 is connected to the ground electrode 9 and is set to the ground potential. For this reason, when the static electricity accumulated on the inner wall of the main pipe discharges beyond the breakdown voltage and the charge moves to the ground electrode, the pressure transmitter 11
, The pressure transmitter 11 has an abnormal indication value, or may be damaged in some cases. As a countermeasure, as described above, a lead wire can be drawn out of the middle of the branch pipe 2 (in front of the pressure transmitter) and grounded to the ground via a protection device 14 such as a surge absorber or an arrester. In this case, the discharge charge can be released to the ground electrode in front of the pressure transmitter 11, so that static electricity and surge current of lightning strike do not enter the pressure transmitter.
An abnormal indication value or breakage of the pressure transmitter 11 can be prevented. However, in the above case, it is necessary to provide a ground electrode having a sufficiently low ground resistance so that the surge absorber works effectively. Furthermore, it is very costly to attach the protection devices 14 such as surge absorbers and arresters to all the pressure transmission devices installed in the pipeline, and it is very costly.
There was a problem that management took time. The present invention solves the above-mentioned problems of the prior art, and provides a simple and economical gas pipeline that does not cause an abnormal indication value or breakage in a pressure transmitter against an electric shock such as static electricity. It is to provide a pressure transmission device to be installed. A pressure transmission device installed in a gas pipeline according to the present invention is, as shown in FIG. 1, a pressure transmission device branched from a main pipe 10 of the gas pipeline. A branch pipe 2 whose inner surface is made of unpainted metal or coated with a conductive substance is connected to a branch part of a main pipe 10 and a mounting part of a pressure transmitter 11 via insulating joints 12 and 13, respectively. The conductive ground wire 15 is grounded in common with the ground pole 9 of the pressure transmitter. <Operation> That is, the configuration of the present invention has the following features. (1) The branch pipe 2 for guiding the gas flowing through the main pipe 10 to the pressure transmitter 11 is coated with an unpainted metal pipe on the inner surface or a conductive material to cover the inner surface of the pipe with a metal branch. Tube. The reason for this is that if the inner surface of the branch pipe is insulated by painting or the like, the electric charge will not be absorbed by the ground of the branch pipe 2 by creeping discharge but will reach the pressure transmitter which is the ground electrode. In order to avoid this, ground electrode 9
In order to spread the electric charge easily, the inner surface of the metal branch pipe 2 is made uncoated or coated with a conductive substance to make it conductive.
And (2) The branch pipe 2 with the main pipe 10 and the mounting part of the branch pipe 2 with the pressure transmitter 11 are insulated joints 12 and 13.
Connected with. The reason for this is that the main pipe 10 and the branch pipe 2 are provided with the insulating joint 12 in order to efficiently flow the current for cathodic protection of the main pipe as in the prior art.
The insulating joint 13 between the main pipe and the mounting part of the branch pipe 2 is provided to prevent electric shock from the main pipe. (3) The branch pipe 2 and the pressure transmitter 11 are grounded by a common ground electrode 9. The reason for this is to prevent a voltage from being applied between the insulating joints 13 at the mounting portion of the pressure transmitter 11 and to prevent discharge at this portion. Therefore,
The branch pipe 2 and the pressure transmitter 11 are grounded by a common ground electrode 9 so that the rising potential of the ground electrode is equal between the branch pipe 2 and the pressure transmitter 11 across the insulating joint 13. With the above structure, the electric charge accumulated on the inner wall of the main pipe 10 of the gas pipeline exceeds the breakdown voltage, and the discharge electric charge generated in the insulating joint portion 12 flows from the branch pipe 2 to the ground line 15 side, and Pressure transmitter 1 connected by joint 13
It does not flow to 1. The discharge charge flowing through the ground line 15 flows to the ground electrode 9 which is grounded in common with the ground of the pressure transmitter 11, and diffuses to the ground. As a result, the pressure transmitter 11
Since no abnormal current is generated in the device, the device is not damaged and a normal measured value is maintained. FIG. 1 shows an example of an embodiment in which the present invention is applied to a pressure transmission device installed in a governor station of a gas pipeline. A branch pipe 2 made of stainless steel for measuring the flow pressure of the main pipe 10 branched from the main pipe 10 of the gas pipeline via the valve 1 and the insulating joint 12 is extended to a place where the pressure transmitter 11 is installed. 11 is connected via an insulating joint 13 to the pressure detecting section. The branch pipe 2 may be an ordinary metal pipe having an inner surface coated with a conductive paint for corrosion protection. Further, as the insulating joints 12 and 13, known members such as an insulating flange made of resin (protin) or the like can be used. The pressure transmitter 11 has a built-in converter for converting a pressure signal detected by the pressure detection unit into an electric signal. The electric signal is transmitted to the monitoring room via the cable pit by the cable 8 protected by the conduit tube 7. Sent to In the middle of the branch pipe 2 and in front of the pressure transmitter 11, a ground wire 15 is connected. This ground line 15
Are connected in common to the ground electrode 9 of the conduit tube 7 that is in communication with the pressure transmitter 11, and have a ground potential. In FIG. 1, reference numerals 3 and 4 denote unions for connecting branch pipes, reference numeral 5 denotes a stop valve for maintenance, and reference numeral 6 denotes a drain plug. According to the present invention, problems such as an abnormal indication value or breakage of a pressure transmitter due to discharge (electric shock) of static electricity or the like from a pipeline main pipe, which has been a problem to be solved by the prior art, can be avoided by using a high cost such as a surge absorber. It is possible to provide a pressure transmission device which can be solved very easily without using a simple protection device and which is economical.
【図面の簡単な説明】
【図１】本発明の実施例で、ガスパイプラインのガバナ
ステーションに設置される圧力伝送装置を示した図であ
る。
【図２】従来の圧力伝送装置を示した図である。
【符号の説明】
１ バルブ
２ 分岐管
３ ハーフユニオン
４ ティーユニオン
５ ストップバルブ
６ ドレンプラグ
７ 電線管
８ ケーブル
９ 接地極
１０ ガスパイプライン（本管）
１１ 圧力伝送器
１２ 絶縁継手
１３ 絶縁継手
１４ サージアブソーバ
１５ 接地線BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a pressure transmission device installed in a governor station of a gas pipeline in an embodiment of the present invention. FIG. 2 is a diagram showing a conventional pressure transmission device. [Description of Signs] 1 Valve 2 Branch pipe 3 Half union 4 T union 5 Stop valve 6 Drain plug 7 Conduit 8 Cable 9 Ground pole 10 Gas pipeline (main pipe) 11 Pressure transmitter 12 Insulation joint 13 Insulation joint 14 Surge absorber 15 Ground wire
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2F055 AA39 BB20 CC60 DD20 EE40 FF38 GG44 HH05 3J071 AA02 BB12 BB14 CC11 DD36 EE05 FF03 ────────────────────────────────────────────────── ─── Continuation of front page F term (reference) 2F055 AA39 BB20 CC60 DD20 EE40 FF38 GG44 HH05 3J071 AA02 BB12 BB14 CC11 DD36 EE05 FF03
Claims (1)
けられる圧力伝送装置において、管内面を導電状態とし
た金属製の分岐管が本管の分岐部と圧力伝送器の取り付
け部にそれぞれ絶縁継手を介して接続され、該分岐管に
導通する接地線が圧力伝送器の接地極と共通して接地さ
れていることを特徴とするパイプラインの圧力伝送装
置。Claims: 1. In a pressure transmission device provided by branching from a main pipe of a gas pipeline, a metal branch pipe whose inside surface is in a conductive state is connected to a branch portion of the main pipe and a pressure transmitter. A pressure transmission device for pipelines, wherein each of the pressure transmission devices is connected to a mounting portion via an insulating joint, and a ground wire that is connected to the branch pipe is grounded in common with a ground electrode of the pressure transmitter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001237932A JP2003050000A (en) | 2001-08-06 | 2001-08-06 | Pressure transmitting device for pipeline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001237932A JP2003050000A (en) | 2001-08-06 | 2001-08-06 | Pressure transmitting device for pipeline |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003050000A true JP2003050000A (en) | 2003-02-21 |
Family
ID=19068935
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001237932A Withdrawn JP2003050000A (en) | 2001-08-06 | 2001-08-06 | Pressure transmitting device for pipeline |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003050000A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102315521A (en) * | 2010-07-06 | 2012-01-11 | 中国石油天然气集团公司 | Pipeline station instrument equipment grounding device |
| CN102315523A (en) * | 2010-07-06 | 2012-01-11 | 中国石油天然气集团公司 | Earthing method and device of pipeline station instrument equipment |
| CN102315522A (en) * | 2010-07-06 | 2012-01-11 | 中国石油天然气集团公司 | Earthing device of pipeline station instrument equipment and construction method of earthing device |
| CN102623809A (en) * | 2012-04-01 | 2012-08-01 | 无锡辉腾科技有限公司 | Lightning protection device for vaporizer |
-
2001
- 2001-08-06 JP JP2001237932A patent/JP2003050000A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102315521A (en) * | 2010-07-06 | 2012-01-11 | 中国石油天然气集团公司 | Pipeline station instrument equipment grounding device |
| CN102315523A (en) * | 2010-07-06 | 2012-01-11 | 中国石油天然气集团公司 | Earthing method and device of pipeline station instrument equipment |
| CN102315522A (en) * | 2010-07-06 | 2012-01-11 | 中国石油天然气集团公司 | Earthing device of pipeline station instrument equipment and construction method of earthing device |
| CN102623809A (en) * | 2012-04-01 | 2012-08-01 | 无锡辉腾科技有限公司 | Lightning protection device for vaporizer |
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