【０００１】
【発明の属する技術分野】
本発明は、継手を介して一方の管体と他方の管体とを接続する絶縁継手構造および絶縁継手構造を備えた弁に関する。
【０００２】
【従来の技術】
従来、絶縁継手構造としては、例えば図１４に示すように、一方の管体５１の端部に、複数のねじ孔５２を有する一方のフランジ５３が一体に形成され、他方の管体５４の端部に、複数のボルト孔５５を有する他方のフランジ５６が一体に形成され、これら両フランジ５３，５６同士が複数のボルト５７，ナット５８によって接合されたものがある。
【０００３】
上記各ボルト５７は、ボルト孔５５に挿通されてねじ孔５２に螺合されている。また、両フランジ５３，５６間には、電気絶縁性およびシール性を有する絶縁シート５９が介装され、上記各ボルト孔５５の内周面には、円筒状の絶縁スリーブ６０が挿入され、各ナット５８と他方のフランジ５６との間には、絶縁ワッシャ６１が介装されている。
【０００４】
これによると、ボルト５７，ナット５８を用いて一方の管体５１と他方の管体５４とを接合した場合、両フランジ５３，５６間は絶縁シート５９で絶縁され、ボルト５７と他方のフランジ５６との間は絶縁スリーブ６０で絶縁され、ナット５８と他方のフランジ５６との間は絶縁ワッシャ６１で絶縁される。
【０００５】
また、上記のような絶縁継手構造６２を備えた弁としては、例えば図１５，図１６に示すように、ボール弁子６５を内蔵した弁本体６６が一方の本体部６６ａと他方の本体部６６ｂとに分割され、一方のフランジ５３が一方の本体部６６ａに一体に形成され、他方のフランジ５６が他方の本体部６６ｂに一体に形成され、これら両フランジ５３，５６同士が複数のボルト５７，ナット５８で接合されているものがある（例えば、特許文献１参照。）。
【０００６】
【特許文献１】
実開昭６２−１４９６７７号公報
【０００７】
【発明が解決しようとする課題】
しかしながら上記の従来形式では、例えば、地中に埋設されている配管を図１４に示した絶縁継手構造６２を用いて接合した場合、ボルト５７，ナット５８で両フランジ５３，５６同士を接合しているため、外力に対して接合強度が弱く、耐震性が劣るといった問題がある。
【０００８】
また、図１５，図１６に示したように地中に埋設されている弁６７に上記のような絶縁継手構造６２を備えた場合も同様に、ボルト５７，ナット５８で両フランジ５３，５６同士を接合しているため、外力に対して接合強度が弱く、耐震性が劣るといった問題がある。
【０００９】
本発明は、外力に対する接合強度を増大させて、耐震性を向上させることができる絶縁継手構造および絶縁継手構造を備えた弁を提供することを目的とする。
【００１０】
【課題を解決するための手段】
上記目的を達成するために本第１発明は、一方の管体と他方の管体とを継手を介して接続する絶縁継手構造であって、上記継手は、挿入孔を有する環状の第１の継手本体と、一端部が上記挿入孔に挿入される筒状の第２の継手本体とで構成され、上記第２の継手本体は、その一端部の外周面に、全周にわたって外側へ突出した鍔部を有し、上記第１の継手本体に、上記鍔部の外径よりも小さな内径を有し且つ挿入孔の手前部に位置して上記鍔部の引抜方向への移動を規制する段付部が全周にわたり一体に形成され、上記第１の継手本体に一方の管体が溶接され、上記段付部に対して鍔部とは反対側から対向するように配置された環状の固定部材が第２の継手本体に外嵌され、上記第２の継手本体に固定部材と他方の管体とが溶接され、上記第１の継手本体と第２の継手本体との間および第１の継手本体と固定部材との間に、絶縁材が全周にわたり設けられているものである。
【００１１】
これによると、第１の継手本体の挿入孔に第２の継手本体の一端部を挿入し、第２の継手本体の他端側から固定部材を外嵌し、この固定部材を第２の継手本体に溶接する。これにより、段付部が鍔部に対して引抜方向側に対向するため、第２の継手本体の引抜方向への移動は上記段付部と鍔部とによって規制される。また、段付部が固定部材に対して押込方向側に対向するため、第２の継手本体の押込方向への移動は上記段付部と固定部材とによって規制される。これにより、第２の継手本体が第１の継手本体に固定され、第１の継手本体と第２の継手本体との間および第１の継手本体と固定部材との間は絶縁材で絶縁される。
【００１２】
また、上記第１の継手本体に一方の管体が溶接され、第２の継手本体に他方の管体と固定部材とが溶接されて一体に取付けられているとともに、段付部が第１の継手本体に一体に形成されているため、ボルト，ナットで両フランジ同士を接合する従来形式の絶縁継手構造に比べて、外力に対する接合強度が増大し、耐震性が向上する。
【００１３】
また、本第２発明は、絶縁材は、相対向する鍔部の引抜方向側の端面と段付部の押込方向側の端面との間に装填される一方の絶縁パッキンと、相対向する段付部の引抜方向側の端面と固定部材の押込方向側の端面との間に装填される他方の絶縁パッキンと、鍔部の外周面と挿入孔の内周面との間に装填される第１の絶縁樹脂部材と、第２の継手本体の外周面と段付部の内周面との間に装填される第２の絶縁樹脂部材とで構成され、上記一方の絶縁パッキンの径方向の幅が他方の絶縁パッキンの径方向の幅よりも小さく形成されているものである。
【００１４】
これによると、一方の絶縁パッキンの接触面積が他方の絶縁パッキンの接触面積よりも小さくなるため、一方の絶縁パッキンの圧縮量が他方の絶縁パッキンの圧縮量よりも大きくなり、一方の絶縁パッキンの面圧が他方の絶縁パッキンの面圧よりも高くなる。これによって、上記一方の絶縁パッキンはシールに要する十分大きな面圧を確保することができ、したがって、鍔部の引抜方向側の端面と段付部の押込方向側の端面との間が上記一方の絶縁パッキンによって確実にシールされ、内部の流体が上記鍔部の引抜方向側の端面と段付部の押込方向側の端面との間を通って外部へ漏れ出すのを確実に防止することができる。
【００１５】
さらに、本第３発明は、上記第１発明又は第２発明の絶縁継手構造を備えた弁であって、第１の継手本体が弁箱の一部を形成し、この弁箱に一方の管体が一体に設けられ、第２の継手本体の他端部に他方の管体が溶接され、弁箱内の弁体を開くことによって、流体が一方の管体と他方の管体との間を流れるものである。
【００１６】
これによると、継手を介して他方の管体が弁箱に接続されるため、ボルト，ナットで両フランジ同士を接合する従来形式の絶縁継手構造を備えた弁に比べて、外力に対する接合強度が増大し、耐震性が向上する。
【００１７】
【発明の実施の形態】
以下、本発明における第１の実施の形態を図１〜図１０に基づいて説明する。図１に示すように、１は一方の管体２と他方の管体３とを継手４を介して接続する絶縁継手構造である。
【００１８】
図１〜図５に示すように、上記継手４は、挿入孔５を有する円環状の第１の継手本体６と、一端部が上記挿入孔５に挿入される円筒状の第２の継手本体７とで構成されている。尚、図３に示すように、上記挿入孔５は第１の継手本体６の他端側に形成され、第１の継手本体６の一端側には、挿入孔５よりも外側に拡径した内周面６ａが形成されている。また、図４に示すように、第２の継手本体７は、その一端部の外周面に、全周にわたって外側へ突出した鍔部８を有している。尚、上記鍔部８の外周面８ａには、径方向の内側に落ち込んだ被係合部８ｂが形成されている。
【００１９】
図１，図３に示すように、第１の継手本体６には、挿入孔５の手前部に位置して上記鍔部８の引抜方向Ａへの移動を規制する段付部９が全周にわたり一体に形成されている。尚、上記段付部９の内径Ｄｉは、鍔部８の外径Ｄｏよりも小さく且つ第２の継手本体７の外径Ｄよりも僅かに大きく形成されている。
【００２０】
また、上記第１の継手本体６の一端には、両端部の口径が異なる異径短管１１（レジューサ等）を介して、上記一方の管体２が全周溶接Ｗ１により一体に接合されている。尚、上記異径短管１１は全周溶接Ｗ２により第１の継手本体６に一体に接合されている。
【００２１】
また、上記段付部９に対して鍔部８とは反対側（手前外側）から対向するように配置された円環状の固定部材１３が第２の継手本体７に外嵌されている。尚、上記固定部材１３の他端部は全周溶接Ｗ３によって第２の継手本体７の外周面に一体に接合されている。また、上記第２の継手本体７の他端部には、他方の管体３が全周溶接Ｗ４によって一体に接合されている。
【００２２】
また、上記第１の継手本体６と第２の継手本体７との間および第１の継手本体６と固定部材１３との間は絶縁材１４によって絶縁されている。すなわち、図２，図６に示すように、絶縁材１４は、相対向する鍔部８の引抜方向Ａ側の端面８ｃと段付部９の押込方向Ｂ側の端面９ａとの間に装填される円環状の一方の絶縁パッキン１４ａと、相対向する段付部９の引抜方向Ａ側の端面９ｂと固定部材１３の押込方向Ｂ側の端面１３ａとの間に装填される円環状の他方の絶縁パッキン１４ｂと、鍔部８の外周面８ａと挿入孔５の内周面との間に装填される円筒状の第１の絶縁樹脂部材１４ｃと、第２の継手本体７の外周面と段付部９の内周面９ｃとの間に装填される円筒状の第２の絶縁樹脂部材１４ｄとで構成されている。
【００２３】
尚、上記絶縁パッキン１４ａ，１４ｂの材質は例えば四ふっ化エチレン（ＰＴＦＥ）等である。また、上記各絶縁樹脂部材１４ｃ，１４ｄも絶縁パッキン１４ａ，１４ｂと同程度以上の硬度を有する絶縁樹脂を材質としている。
【００２４】
また、上記両絶縁パッキン１４ａ，１４ｂの内径は同一であり、一方の絶縁パッキン１４ａの外径が他方の絶縁パッキン１４ｂの外径よりも小さく形成され、これにより、一方の絶縁パッキン１４ａの径方向の幅Ｄａは他方の絶縁パッキン１４ｂの径方向の幅Ｄｂよりも小さく形成されている。
【００２５】
また、上記第１の絶縁樹脂部材１４ｃは、鍔部８の被係合部８ｂ（図４参照）に係合して押込方向Ｂへの位置ずれを防止する位置決め用突片１４ｃｉを有している。尚、図２に示すように、上記位置決め用突片１４ｃｉは一方の絶縁パッキン１４ａの外周側に位置し、また、第２の絶縁樹脂部材１４ｄは両絶縁パッキン１４ａ，１４ｂの内周側に位置している。
【００２６】
また、鍔部８の外周面８ａに全周にわたり形成された溝１６には、第１の絶縁樹脂部材１４ｃの内周面と鍔部８の外周面８ａとの間をシールする内側Ｏ−リング１７（シール部材の一例）が嵌め込まれている。さらに、挿入孔５の内周面に全周にわたり形成された溝１８には、第１の絶縁樹脂部材１４ｃの外周面と挿入孔５の内周面との間をシールする外側Ｏ−リング１９（シール部材の一例）が嵌め込まれている。
【００２７】
以下、上記構成における作用を説明する。
先ず、図７，図８に示すように、両Ｏ−リング１７，１９をそれぞれ溝１６，１８に嵌め込んだ後、第１の継手本体６の一端側から一方の絶縁パッキン１４ａと第１の絶縁樹脂部材１４ｃとを挿入し、上記第１の絶縁樹脂部材１４ｃを挿入孔５の内周面に嵌め込み、上記一方の絶縁パッキン１４ａを第１の絶縁樹脂部材１４ｃ内に嵌め込んで段付部９の端面９ａに当て付ける。
【００２８】
次に、図８の仮想線で示すように、第２の継手本体７を第１の継手本体６の一端側から挿入孔５に挿入する。この際、図９に示すように、鍔部８が一方の絶縁パッキン１４ａを介して段付部９に当接することにより、第２の継手本体７の引抜方向Ａへの移動が規制され、上記挿入孔５に第２の継手本体７の一端部が挿入される。その後、他方の絶縁パッキン１４ｂと第２の絶縁樹脂部材１４ｄとを第２の継手本体７に外嵌し、上記第２の絶縁樹脂部材１４ｄを段付部９の内周面９ｃと第２の継手本体７の外周面との間に挿入し、上記他方の絶縁パッキン１４ｂを段付部９の端面９ｂに当て付けて第２の絶縁樹脂部材１４ｄに外嵌する。
【００２９】
そして、図１０に示すように、固定部材１３を第２の継手本体７の他端側から第２の継手本体７に外嵌して第１の継手本体６側に押し付けるとともに、上記第２の継手本体７に引抜方向Ａへの引張力Ｆを加えて引張り、第２の継手本体７を引抜方向Ａへ伸ばした状態で、固定部材１３を第２の継手本体７の外周面に溶接（全周溶接Ｗ３）する。次に、上記引張力Ｆを除くことによって、第２の継手本体７が押込方向Ｂへ縮もうとするため、固定部材１３と鍔部８とがそれぞれ段付部９に強い押圧力で押圧され、隙間が生じることはない。
【００３０】
その後、図１０の仮想線で示すように、他方の管体３を第２の継手本体７の他端に全周溶接Ｗ４（図１参照）によって一体に接合する。さらに、第１の継手本体６の一端側に全周溶接Ｗ２（図１参照）によって異径短管１１を一体に接合するとともに、この異径短管１１に全周溶接Ｗ１（図１参照）によって一方の管体２を一体に接合する。これにより、図１に示すように、継手４を介して一方の管体２と他方の管体３とが接続される。
【００３１】
上記のような絶縁継手構造１によると、段付部９は鍔部８に対して引抜方向Ａ側に対向するため、第２の継手本体７の引抜方向Ａへの移動は上記段付部９と鍔部８とによって規制される。また、段付部９は固定部材１３に対して押込方向Ｂ側に対向するため、第２の継手本体７の押込方向Ｂへの移動は上記段付部９と固定部材１３とによって規制される。これにより、第２の継手本体７が第１の継手本体６に固定される。
【００３２】
この際、図２に示すように、相対向する鍔部８の端面８ｃと段付部９の端面９ａとの間が一方の絶縁パッキン１４ａによって絶縁され、相対向する段付部９の端面９ｂと固定部材１３の端面１３ａとの間が他方の絶縁パッキン１４ｂによって絶縁され、鍔部８の外周面８ａと挿入孔５の内周面との間が第１の絶縁樹脂部材１４ｃによって絶縁され、第２の継手本体７の外周面と段付部９の内周面９ｃとの間が第２の絶縁樹脂部材１４ｄによって絶縁される。これにより、例えば、両管体２，３内に都市ガス等の可燃性の流体が流れる場合であっても、上記一方の管体２と他方の管体３との間が絶縁されるため、防爆および防食効果が得られる。
【００３３】
また、上記第１の継手本体６に異径短管１１を介して一方の管体２が溶接され、第２の継手本体７に他方の管体３と固定部材１３とが溶接されて一体に取付けられているとともに、段付部９が第１の継手本体６に一体に形成されているため、従来（図１４参照）のようにボルト５７，ナット５８で両フランジ５３，５６同士を接合する形式の絶縁継手構造６２に比べて、外力に対する接合強度が増大し、耐震性が向上する。
【００３４】
さらに、図６に示すように、一方の絶縁パッキン１４ａの径方向の幅Ｄａは他方の絶縁パッキン１４ｂの径方向の幅Ｄｂよりも小さく形成されているため、図２に示すように、一方の絶縁パッキン１４ａの接触面積は他方の絶縁パッキン１４ｂの接触面積よりも小さくなる。これにより、上記のように固定部材１３を押込方向Ｂへ押し込んだ状態で第２の継手本体７に溶接（全周溶接Ｗ３）した場合、一方の絶縁パッキン１４ａの圧縮量が他方の絶縁パッキン１４ｂの圧縮量よりも大きくなり、一方の絶縁パッキン１４ａの面圧が他方の絶縁パッキン１４ｂの面圧よりも高くなるため、上記一方の絶縁パッキン１４ａはシールに要する十分大きな面圧を確保することができる。
【００３５】
また、上記全周溶接Ｗ３をした後、引抜方向Ａへの引張力が作用した場合、上記一方の絶縁パッキン１４ａの面圧が増大するため、上記一方の絶縁パッキン１４ａによるシール性がさらに向上する。また、押込方向Ｂへの圧縮力が作用した場合、他方の絶縁パッキン１４ｂの接触面積が大きい分、他方の絶縁パッキン１４ｂの圧縮量が小さくなり（あまり圧縮されない）、このため、一方の絶縁パッキン１４ａの圧縮量はわずかに減少するだけであまり変化せず、一方の絶縁パッキン１４ａの面圧の減少も軽微となり、上記一方の絶縁パッキン１４ａによるシール性の低下はほとんどなく、十分なシール性が確保できる。したがって、鍔部８の端面８ｃ（図４参照）と段付部９の端面９ａ（図３参照）との間が上記一方の絶縁パッキン１４ａによって確実にシールされ、内部の流体が上記両端面８ｃ，９ａ間を通って外部へ漏れ出すのを防止することができる。
【００３６】
また、図２に示すように、上記一方の絶縁パッキン１４ａの外周縁には、このパッキン１４ａと同程度以上の硬度を有する第１の樹脂部材１４ｃが配置され、一方の絶縁パッキン１４ａの内周縁には、このパッキン１４ａと同程度以上の硬度を有する第２の樹脂部材１４ｄが配置されているため、一方の絶縁パッキン１４ａの径方向への変形を防止することができる。また、第１の絶縁樹脂部材１４ｃは、位置決め用突片１４ｃｉが鍔部８の被係合部８ｂ（図４参照）に係合することにより、押込方向Ｂへの位置ずれが防止される。
【００３７】
さらに、図２に示すように、第１の継手本体６の内周面６ａは挿入孔５よりも外側に拡径しているため、上記第１の継手本体６の内周面６ａと鍔部８の外周面８ａとは径方向において一定の段差Ｅが形成される。これにより、万一、配管内の異物が上記内周面６ａに堆積しても、上記段差Ｅの存在によって上記異物が第２の継手本体７の鍔部８にまで達することは防止され、したがって、上記異物を介して第１の継手本体６と第２の継手本体７とが導通するのを防ぐことができる。
【００３８】
尚、第１の絶縁樹脂部材１４ｃの内周面と鍔部８の外周面８ａとの間は内側Ｏ−リング１７によってシールされ、第１の絶縁樹脂部材１４ｃの外周面と挿入孔５の内周面との間は外側Ｏ−リング１９によってシールされる。これにより、上記一方の絶縁パッキン１４ａによるシール機能に、上記両Ｏ−リング１７，１９によるシール機能が加わるため、万一、上記一方の絶縁パッキン１４ａが劣化したり損傷しても、上記両Ｏ−リング１７，１９によってシール性が保持され、これにより、安全性が向上する。
【００３９】
上記第１の実施の形態では、防爆対象の流体として都市ガスが流れる管路に上記絶縁継手構造１を採用しているが、都市ガスに限定されるものではなく、他の流体、例えば石油精製プラント等の管路に上記絶縁継手構造１を採用してもよい。
【００４０】
次に、第２の実施の形態を図１１〜図１３に基づいて説明する。すなわち、第２の実施の形態は、先述した第１の実施の形態における絶縁継手構造１を供えたボール弁３０であり、その構成は以下の通りである。
【００４１】
上記ボール弁３０は二方弁であり、その弁箱３１は弁箱本体３２と継手４とで構成されている。一方の管体２は、弁箱本体３２の一端側に鍛造によって一体に形成されており、配管（図示省略）に対する挿口を成している。
【００４２】
また、上記弁箱本体３２の他端側には、継手４の第１の継手本体６の一端部が全周溶接Ｗ５によって一体に接合されており、第１の継手本体６の挿入孔５には第２の継手本体７の一端部が挿入され、第２の継手本体７には他方の管体３と固定部材１３とがそれぞれ全周溶接Ｗ３，Ｗ４によって一体に接合されている。尚、他方の管体３は配管（図示省略）に対する挿口を成している。また、第１の継手本体６は、第２の継手本体７側から弁箱本体３２側に向けて次第に拡大するテーパー状に形成されている。また、継手４と他方の管体３との接合構造は先述した第１の実施の形態のものと同様である。
【００４３】
上記一方の管体２内の奥端側には、弁箱内空間３３と一方の管体２内とに連通する一方の弁箱ポート３４が形成され、一方の弁箱ポート３４の開口周縁部には円環状の弁箱シート３５が設けられている。また、第２の継手本体７内の奥端側には、弁箱内空間３３と第２の継手本体７内とに連通する他方の弁箱ポート３６が形成されている。尚、他方の弁箱ポート３６には弁箱シートは設けられていない。
【００４４】
弁箱内空間３３には、弁棒３７の軸心廻りに回転する弁体３８が配置されている。この弁体３８は、図１２に示すように全開時において上記両弁箱ポート３４，３６間を連通する弁体流路３９を有し、この弁体流路３９に直交する方向のいずれか片側位置には、図１１に示すように全閉時において上記弁箱シート３５に圧接する円板状の弁体シート４０が設けられている。
以下、上記構成における作用を説明する。
【００４５】
第１の継手本体６を弁箱本体３２に溶接する前に、先ず、両Ｏ−リング１７，１９をそれぞれ溝１６，１８に嵌め込んだ後、第１の継手本体６の一端側から一方の絶縁パッキン１４ａと第１の絶縁樹脂部材１４ｃとを挿入し、上記第１の絶縁樹脂部材１４ｃを挿入孔５の内周面に嵌め込み、上記一方の絶縁パッキン１４ａを第１の絶縁樹脂部材１４ｃ内に嵌め込んで段付部９の端面９ａに当て付ける。
【００４６】
次に、図１３に示すように、第２の継手本体７を第１の継手本体６の一端側から挿入孔５に挿入する。この際、鍔部８が一方の絶縁パッキン１４ａを介して段付部９に当接することにより、第２の継手本体７の引抜方向Ａへの移動が規制され、上記挿入孔５に第２の継手本体７の一端部が挿入される。その後、他方の絶縁パッキン１４ｂと第２の絶縁樹脂部材１４ｄとを第２の継手本体７に外嵌し、上記第２の絶縁樹脂部材１４ｄを段付部９の内周面９ｃと第２の継手本体７の外周面との間に挿入し、上記他方の絶縁パッキン１４ｂを段付部９の端面９ｂに当て付けて第２の絶縁樹脂部材１４ｄに外嵌する。
【００４７】
そして、固定部材１３を第２の継手本体７の他端側から第２の継手本体７に外嵌して第１の継手本体６側に押し付けるとともに、上記第２の継手本体７に引抜方向Ａ（図１１参照）への引張力Ｆを加えて引張り、第２の継手本体７を引抜方向Ａへ伸ばした状態で、固定部材１３を第２の継手本体７の外周面に溶接（全周溶接Ｗ３）する。次に、上記引張力Ｆを除くことによって、第２の継手本体７が押込方向Ｂ（図１１参照）へ縮もうとするため、固定部材１３と鍔部８とがそれぞれ段付部９に強い押圧力で押圧され、隙間が生じることはない。
【００４８】
その後、他方の管体３を第２の継手本体７の他端に全周溶接Ｗ４によって一体に接合する。さらに、図１１に示すように、第１の継手本体６の一端側を全周溶接Ｗ２によって弁箱本体３２に一体に接合する。これにより、継手４を介して他方の管体３が弁箱３１に接続される。
【００４９】
また、ボール弁３０内に都市ガス等の可燃性の流体が流れる場合であっても、上記弁箱３１と他方の管体３との間が絶縁されるため、防爆および防食効果が得られる。
【００５０】
また、従来（図１５，図１６参照）のようにボルト５７，ナット５８で両フランジ５３，５６同士を接合する形式の絶縁継手構造６２を備えたボール弁６７に比べて、上記ボール弁３０の方が外力に対する接合強度が増大し、耐震性が向上する。
【００５１】
また、図１２に示すように、弁棒３７を介して弁体３８を全開位置まで回転した場合、両弁箱ポート３４，３６間が弁体流路３９によって連通し、一方の管体２内から流れ込んだ流体は、一方の弁箱ポート３４と弁体流路３９と他方の弁箱ポート３６とを通って、他方の管体３内へ流出する。
【００５２】
また、図１１に示すように、弁棒３７を介して弁体３８を全閉位置まで回転した場合、弁体シート４０が弁箱シート３５に圧接することにより、一方の弁箱ポート３４側が弁体シート４０で閉塞されるため、一方の管体２内の流体は、上記弁体シート４０で遮断され、他方の管体３へ流れることを阻止される。
【００５３】
上記第２の実施の形態では、一方の管体２側を流体入口とし、他方の管体３を流体出口としているが、流体出入口を反対にしてもよい。
上記第２の実施の形態では、防爆対象の流体として都市ガスが流れる管路に上記ボール弁３０を設けているが、都市ガスに限定されるものではなく、他の流体、例えば石油精製プラント等の管路に上記ボール弁３０を設けてもよい。
【００５４】
上記第２の実施の形態では、ボール弁３０を二方弁としているが、三方弁や他の形式の弁であってもよい。
【００５５】
【発明の効果】
以上のように本第１発明では、継手を介して一方の管体と他方の管体とを接続した際、第１の継手本体と第２の継手本体との間および第１の継手本体と固定部材との間は絶縁材で絶縁される。また、ボルト，ナットで両フランジ同士を接合する従来形式の絶縁継手構造に比べて、外力に対する接合強度が増大し、耐震性が向上する。
【００５６】
また、本第２発明では、一方の絶縁パッキンはシールに要する十分大きな面圧を確保することができ、鍔部の引抜方向側の端面と段付部の押込方向側の端面との間が上記一方の絶縁パッキンによって確実にシールされ、内部の流体が上記鍔部の引抜方向側の端面と段付部の押込方向側の端面との間を通って外部へ漏れ出すのを確実に防止することができる。
【００５７】
さらに、本第３発明では、ボルト，ナットで両フランジ同士を接合する従来形式の絶縁継手構造を備えた弁に比べて、外力に対する接合強度が増大し、耐震性が向上する。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態における絶縁継手構造の断面図である。
【図２】同、絶縁継手構造の一部拡大断面図である。
【図３】同、絶縁継手構造の第１の継手本体の一部拡大断面図である。
【図４】同、絶縁継手構造の第２の継手本体の一部拡大断面図である。
【図５】同、絶縁継手構造の固定部材の一部拡大断面図である。
【図６】同、絶縁継手構造の絶縁材を構成している構成部材の断面図である。
【図７】同、絶縁継手構造を用いて管体を接続する手順を示す断面図であり、第１の継手本体に絶縁材を装着する行程を示す。
【図８】同、絶縁継手構造を用いて管体を接続する手順を示す断面図であり、第１の継手本体に第２の継手本体を装着する行程を示す。
【図９】同、絶縁継手構造を用いて管体を接続する手順を示す断面図であり、継手に固定部材を装着する行程を示す。
【図１０】同、絶縁継手構造を用いて管体を接続する手順を示す断面図であり、継手に管体を溶接する行程を示す。
【図１１】本発明の第２の実施の形態における絶縁継手構造を備えた弁の断面図であり、全閉状態を示す。
【図１２】同、絶縁継手構造を備えた弁の断面図であり、全開状態を示す。
【図１３】同、絶縁継手構造を備えた弁の絶縁継手構造部分の拡大断面図である。
【図１４】従来の絶縁継手構造の断面図である。
【図１５】従来の絶縁継手構造を備えた弁の断面図である。
【図１６】同、絶縁継手構造を備えた弁の絶縁継手構造部分の拡大断面図である。
【符号の説明】
１ 絶縁継手構造
２ 一方の管体
３ 他方の管体
４ 継手
５ 挿入孔
６ 第１の継手本体
７ 第２の継手本体
８ 鍔部
８ａ 鍔部の外周面
８ｃ 鍔部の引抜方向側の端面
９ 段付部
９ａ 段付部の押込方向側の端面
９ｂ 段付部の引抜方向側の端面
９ｃ 段付部の内周面
１３ 固定部材
１３ａ 固定部材の押込方向側の端面
１４ 絶縁材
１４ａ 一方の絶縁パッキン
１４ｂ 他方の絶縁パッキン
１４ｃ 第１の絶縁樹脂部材
１４ｄ 第２の絶縁樹脂部材
３０ ボール弁
３１ 弁箱
３８ 弁体
Ａ 引抜方向
Ｂ 押込方向
Ｄａ，Ｄｂ 径方向の幅[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an insulated joint structure for connecting one tube to another via a joint, and a valve provided with the insulated joint structure.
[0002]
[Prior art]
Conventionally, as an insulating joint structure, for example, as shown in FIG. 14, one flange 53 having a plurality of screw holes 52 is integrally formed at one end of one tubular body 51, and the other tubular body 54 has one end 53. In some parts, the other flange 56 having a plurality of bolt holes 55 is integrally formed, and both flanges 53 and 56 are joined together by a plurality of bolts 57 and nuts 58.
[0003]
Each of the bolts 57 is inserted into the bolt hole 55 and screwed into the screw hole 52. An insulating sheet 59 having electrical insulation and sealing properties is interposed between the flanges 53 and 56, and a cylindrical insulating sleeve 60 is inserted into the inner peripheral surface of each of the bolt holes 55. An insulating washer 61 is interposed between the nut 58 and the other flange 56.
[0004]
According to this, when one pipe body 51 and the other pipe body 54 are joined using the bolt 57 and the nut 58, the two flanges 53, 56 are insulated by the insulating sheet 59, and the bolt 57 and the other flange 56 are insulated. Are insulated by an insulating sleeve 60, and between the nut 58 and the other flange 56 are insulated by an insulating washer 61.
[0005]
In addition, as a valve provided with the above-described insulating joint structure 62, as shown in FIGS. 15 and 16, for example, a valve body 66 having a ball valve 65 built therein is composed of one main body 66a and the other main body 66b. One flange 53 is formed integrally with one main body 66a, the other flange 56 is formed integrally with the other main body 66b, and these two flanges 53, 56 are connected to a plurality of bolts 57, Some are joined by a nut 58 (for example, see Patent Document 1).
[0006]
[Patent Document 1]
Japanese Utility Model Publication No. 62-149677
[0007]
[Problems to be solved by the invention]
However, in the above-described conventional type, for example, when piping buried underground is joined using the insulating joint structure 62 shown in FIG. 14, both flanges 53 and 56 are joined together by bolts 57 and nuts 58. Therefore, there is a problem that the joint strength is weak against external force and the earthquake resistance is poor.
[0008]
Similarly, when the valve 67 buried underground is provided with the above-described insulating joint structure 62 as shown in FIGS. 15 and 16, the flanges 53 and 56 are similarly connected to each other by bolts 57 and nuts 58. However, there is a problem that the joining strength is weak against external force and the earthquake resistance is inferior.
[0009]
An object of the present invention is to provide an insulated joint structure capable of increasing the joint strength with respect to an external force and improving seismic resistance, and a valve provided with the insulated joint structure.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is an insulating joint structure for connecting one pipe body and the other pipe body via a joint, wherein the joint has an annular first shape having an insertion hole. A joint main body and a cylindrical second joint main body whose one end is inserted into the insertion hole, and the second joint main body protrudes outward over the entire circumference on the outer peripheral surface of the one end. A step having a flange portion, wherein the first joint body has an inner diameter smaller than the outer diameter of the flange portion and is located in front of the insertion hole to regulate movement of the flange portion in the pull-out direction; An annular fixing part is formed integrally over the entire circumference, one of the tubes is welded to the first joint main body, and is arranged to face the stepped part from the side opposite to the flange part. The member is externally fitted to the second joint body, and the fixed member and the other tube are welded to the second joint body, Between the fitting body and between the first fitting body and the second joint body and the fixing member, in which an insulating material is provided over the entire circumference.
[0011]
According to this, one end of the second joint body is inserted into the insertion hole of the first joint body, and a fixing member is externally fitted from the other end side of the second joint body. Weld to the body. Accordingly, the stepped portion is opposed to the flange in the pulling-out direction, so that the movement of the second joint body in the pulling-out direction is restricted by the stepped portion and the flange. In addition, since the stepped portion faces the fixing member in the pushing direction, the movement of the second joint body in the pushing direction is restricted by the stepped portion and the fixing member. Thereby, the second joint body is fixed to the first joint body, and the space between the first joint body and the second joint body and the space between the first joint body and the fixed member are insulated by the insulating material. You.
[0012]
Also, one tube is welded to the first joint body, the other tube and the fixing member are welded and integrally attached to the second joint body, and the stepped portion is formed of the first joint body. Since it is formed integrally with the joint body, the joint strength against external force is increased and the earthquake resistance is improved as compared with the conventional insulated joint structure in which both flanges are joined together with bolts and nuts.
[0013]
Also, in the second invention, the insulating material may include one insulating packing loaded between an end surface of the facing flange portion on the pulling direction side and an end surface of the stepped portion on the pushing direction side, and the opposing step. The other insulating packing loaded between the end surface of the attachment portion on the pulling direction side and the end surface of the fixing member on the pushing direction, and the other insulating packing loaded between the outer peripheral surface of the flange portion and the inner peripheral surface of the insertion hole. A first insulating resin member and a second insulating resin member loaded between the outer peripheral surface of the second joint main body and the inner peripheral surface of the stepped portion. The width is formed smaller than the radial width of the other insulating packing.
[0014]
According to this, since the contact area of one insulating packing is smaller than the contact area of the other insulating packing, the amount of compression of one insulating packing is larger than the amount of compression of the other insulating packing, and the amount of compression of one insulating packing is The surface pressure becomes higher than the surface pressure of the other insulating packing. Thereby, the one insulating packing can secure a sufficiently large surface pressure required for sealing, and therefore, the gap between the end surface of the flange portion on the pulling-out direction side and the end surface of the stepped portion on the pushing direction side is the one-sided one. It is reliably sealed by the insulating packing, and it is possible to reliably prevent the internal fluid from leaking to the outside through the space between the end surface of the flange portion on the pulling direction side and the end surface of the stepped portion on the pushing direction side. .
[0015]
Further, the third invention is a valve provided with the insulating joint structure of the first invention or the second invention, wherein the first joint body forms a part of a valve box, and one valve is connected to the valve box. The body is provided integrally, and the other tube is welded to the other end of the second joint body, and by opening the valve body in the valve box, fluid flows between the one body and the other body. It flows through.
[0016]
According to this, since the other pipe is connected to the valve box via a joint, the joint strength against external force is lower than that of a valve having a conventional type insulated joint structure in which both flanges are joined by bolts and nuts. It increases and the earthquake resistance improves.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, reference numeral 1 denotes an insulating joint structure for connecting one tube 2 and the other tube 3 via a joint 4.
[0018]
As shown in FIGS. 1 to 5, the joint 4 has an annular first joint body 6 having an insertion hole 5 and a cylindrical second joint body having one end inserted into the insertion hole 5. 7. As shown in FIG. 3, the insertion hole 5 is formed at the other end of the first joint body 6, and the diameter of the one end of the first joint body 6 is increased outside the insertion hole 5. An inner peripheral surface 6a is formed. Further, as shown in FIG. 4, the second joint body 7 has a flange 8 protruding outward over the entire circumference on the outer peripheral surface at one end. Note that an engaged portion 8b which is recessed inward in the radial direction is formed on the outer peripheral surface 8a of the flange portion 8.
[0019]
As shown in FIGS. 1 and 3, the first joint body 6 is provided with a stepped portion 9 which is located in front of the insertion hole 5 and regulates the movement of the flange 8 in the pulling-out direction A. Are formed integrally. The inner diameter Di of the stepped portion 9 is formed smaller than the outer diameter Do of the flange 8 and slightly larger than the outer diameter D of the second joint body 7.
[0020]
Further, one end of the first joint body 6 is integrally joined to one end of the first joint body 6 by a full-circumferential welding W1 via different diameter short tubes 11 (reducers and the like) having different diameters at both ends. I have. In addition, the said different diameter short pipe 11 is integrally joined to the 1st joint main body 6 by the whole circumference welding W2.
[0021]
Further, an annular fixing member 13 that is arranged to face the stepped portion 9 from the side opposite to the flange 8 (outer side) is externally fitted to the second joint body 7. Note that the other end of the fixing member 13 is integrally joined to the outer peripheral surface of the second joint body 7 by full circumference welding W3. Further, the other pipe 3 is integrally joined to the other end of the second joint main body 7 by a full circumference weld W4.
[0022]
Further, the insulating material 14 insulates between the first joint body 6 and the second joint body 7 and between the first joint body 6 and the fixing member 13. That is, as shown in FIGS. 2 and 6, the insulating material 14 is loaded between the end face 8 c of the facing flange portion 8 on the pullout direction A side and the end face 9 a of the stepped portion 9 on the push direction B side. One of the ring-shaped insulating packings 14a, and the other of the ring-shaped insulating packings loaded between the facing end surface 9b of the stepped portion 9 on the drawing direction A side and the end surface 13a of the fixing member 13 on the pushing direction B side. An insulating packing 14b, a cylindrical first insulating resin member 14c to be loaded between the outer peripheral surface 8a of the flange portion 8 and the inner peripheral surface of the insertion hole 5, and a step between the outer peripheral surface of the second joint body 7 and the step. It is composed of a cylindrical second insulating resin member 14d loaded between the inner peripheral surface 9c of the attaching portion 9 and the inner peripheral surface 9c.
[0023]
The material of the insulating packings 14a and 14b is, for example, ethylene tetrafluoride (PTFE). Each of the insulating resin members 14c and 14d is also made of an insulating resin having a hardness equal to or higher than that of the insulating packings 14a and 14b.
[0024]
The inner diameters of the two insulating packings 14a and 14b are the same, and the outer diameter of one of the insulating packings 14a is smaller than the outer diameter of the other insulating packing 14b. Is smaller than the radial width Db of the other insulating packing 14b.
[0025]
The first insulating resin member 14c has a positioning projection 14ci that engages with the engaged portion 8b (see FIG. 4) of the flange 8 to prevent displacement in the pushing direction B. I have. As shown in FIG. 2, the positioning projection 14ci is located on the outer peripheral side of one insulating packing 14a, and the second insulating resin member 14d is located on the inner peripheral side of both insulating packings 14a and 14b. are doing.
[0026]
A groove 16 formed over the entire outer circumference 8a of the flange 8 has an inner O-ring for sealing between the inner circumference of the first insulating resin member 14c and the outer circumference 8a of the flange 8. 17 (an example of a sealing member) is fitted. Further, an outer O-ring 19 for sealing between the outer peripheral surface of the first insulating resin member 14c and the inner peripheral surface of the insertion hole 5 is provided in the groove 18 formed over the entire inner peripheral surface of the insertion hole 5. (An example of a seal member) is fitted.
[0027]
Hereinafter, the operation of the above configuration will be described.
First, as shown in FIGS. 7 and 8, after both O-rings 17 and 19 are fitted in the grooves 16 and 18, respectively, one insulating packing 14 a and the first insulating packing 14 a are inserted from one end of the first joint body 6. The insulating resin member 14c is inserted, the first insulating resin member 14c is fitted into the inner peripheral surface of the insertion hole 5, and the one insulating packing 14a is fitted into the first insulating resin member 14c to form a stepped portion. 9 to the end face 9a.
[0028]
Next, as shown by a virtual line in FIG. 8, the second joint body 7 is inserted into the insertion hole 5 from one end side of the first joint body 6. At this time, as shown in FIG. 9, the movement of the second joint body 7 in the withdrawing direction A is regulated by the flange portion 8 abutting on the stepped portion 9 via one of the insulating packings 14a. One end of the second joint body 7 is inserted into the insertion hole 5. Thereafter, the other insulating packing 14b and the second insulating resin member 14d are externally fitted to the second joint body 7, and the second insulating resin member 14d is connected to the inner peripheral surface 9c of the stepped portion 9 and the second insulating resin member 14d. It is inserted between the outer peripheral surface of the joint main body 7 and the other insulating packing 14b is applied to the end surface 9b of the stepped portion 9 to fit outside the second insulating resin member 14d.
[0029]
Then, as shown in FIG. 10, the fixing member 13 is externally fitted to the second joint body 7 from the other end side of the second joint body 7 and pressed against the first joint body 6, and the second joint body 6 is pressed. The fixing member 13 is welded to the outer peripheral surface of the second joint body 7 while the second joint body 7 is extended in the pull-out direction A by applying a tensile force F in the pull-out direction A to the joint body 7 to pull the joint member 7 (total). Girth welding W3) is performed. Next, since the second joint body 7 tries to shrink in the pushing direction B by removing the tensile force F, the fixing member 13 and the flange 8 are each pressed against the stepped portion 9 with a strong pressing force. There is no gap.
[0030]
Thereafter, as shown by the imaginary line in FIG. 10, the other pipe 3 is integrally joined to the other end of the second joint body 7 by full circumference welding W4 (see FIG. 1). Further, the short pipe 11 of different diameter is integrally joined to one end of the first joint body 6 by full circumference welding W2 (see FIG. 1), and the full circumference welding W1 (see FIG. 1) is connected to the short pipe 11 of different diameter. Joints one of the tubes 2 integrally. Thereby, as shown in FIG. 1, one pipe 2 and the other pipe 3 are connected via the joint 4.
[0031]
According to the insulating joint structure 1 as described above, since the stepped portion 9 is opposed to the flange portion 8 in the pulling-out direction A, the movement of the second joint body 7 in the pulling-out direction A is limited to the stepped portion 9. And the flange 8. In addition, since the stepped portion 9 is opposed to the fixing member 13 in the pushing direction B, the movement of the second joint body 7 in the pushing direction B is regulated by the stepped portion 9 and the fixing member 13. . Thereby, the second joint body 7 is fixed to the first joint body 6.
[0032]
At this time, as shown in FIG. 2, the end face 8c of the opposed flange portion 8 and the end face 9a of the stepped portion 9 are insulated by one insulating packing 14a, and the end face 9b of the opposed stepped portion 9 is formed. And the end surface 13a of the fixing member 13 are insulated by the other insulating packing 14b, and the outer peripheral surface 8a of the flange 8 and the inner peripheral surface of the insertion hole 5 are insulated by the first insulating resin member 14c. The outer peripheral surface of the second joint body 7 and the inner peripheral surface 9c of the stepped portion 9 are insulated by the second insulating resin member 14d. Thereby, for example, even when a flammable fluid such as city gas flows in the two pipes 2 and 3, the insulation between the one pipe 2 and the other pipe 3 is provided. Explosion-proof and anti-corrosion effects are obtained.
[0033]
Also, one tube 2 is welded to the first joint body 6 via a short pipe 11 of a different diameter, and the other tube 3 and the fixing member 13 are welded to the second joint body 7 to be integrated. The flanges 53 and 56 are joined together by bolts 57 and nuts 58 as in the related art (see FIG. 14) because they are attached and the stepped portion 9 is formed integrally with the first joint body 6. Compared to the type of insulated joint structure 62, the joint strength against external force is increased, and the earthquake resistance is improved.
[0034]
Further, as shown in FIG. 6, a radial width Da of one insulating packing 14a is formed smaller than a radial width Db of the other insulating packing 14b, and therefore, as shown in FIG. The contact area of the insulating packing 14a is smaller than the contact area of the other insulating packing 14b. Accordingly, when the fixing member 13 is welded to the second joint main body 7 in the state where the fixing member 13 is pushed in the pushing direction B as described above (all-round welding W3), the compression amount of one of the insulating packings 14a is reduced to the other insulating packing 14b. And the surface pressure of one insulating packing 14a is higher than the surface pressure of the other insulating packing 14b. Therefore, the one insulating packing 14a can secure a sufficiently large surface pressure required for sealing. it can.
[0035]
In addition, when a tensile force is applied in the pull-out direction A after performing the entire circumference welding W3, the surface pressure of the one insulating packing 14a increases, so that the sealing performance of the one insulating packing 14a is further improved. . Further, when a compressive force is applied in the pushing direction B, the amount of compression of the other insulating packing 14b is reduced (less compressed) due to the large contact area of the other insulating packing 14b. The amount of compression of the insulating packing 14a does not change much, only slightly decreases, and the surface pressure of the one insulating packing 14a is also slightly reduced. Can be secured. Therefore, the space between the end face 8c of the flange portion 8 (see FIG. 4) and the end face 9a of the stepped portion 9 (see FIG. 3) is securely sealed by the one insulating packing 14a, and the internal fluid is removed. , 9a can be prevented from leaking to the outside.
[0036]
As shown in FIG. 2, a first resin member 14c having a hardness equal to or greater than that of the packing 14a is disposed on an outer peripheral edge of the one insulating packing 14a. Since the second resin member 14d having the same or higher hardness as that of the packing 14a is disposed on the first packing, it is possible to prevent the one insulating packing 14a from being deformed in the radial direction. The first insulating resin member 14c is prevented from being displaced in the pushing direction B by the positioning projection 14ci engaging with the engaged portion 8b (see FIG. 4) of the flange portion 8.
[0037]
Further, as shown in FIG. 2, the inner peripheral surface 6 a of the first joint main body 6 is enlarged outside the insertion hole 5, so that the inner peripheral surface 6 a of the first joint main body 6 and the flange portion are formed. A constant step E is formed in the radial direction with respect to the outer peripheral surface 8a. Accordingly, even if foreign matter in the pipe is deposited on the inner peripheral surface 6a, the foreign matter is prevented from reaching the flange 8 of the second joint body 7 due to the presence of the step E. In addition, conduction between the first joint body 6 and the second joint body 7 via the foreign matter can be prevented.
[0038]
The space between the inner peripheral surface of the first insulating resin member 14c and the outer peripheral surface 8a of the flange portion 8 is sealed by the inner O-ring 17, and the outer peripheral surface of the first insulating resin member 14c and the inside of the insertion hole 5 are formed. The outer surface is sealed by an outer O-ring 19. As a result, the sealing function of the two O-rings 17 and 19 is added to the sealing function of the one insulating packing 14a. Therefore, even if the one insulating packing 14a is deteriorated or damaged, The sealing performance is maintained by the rings 17, 19, whereby the safety is improved.
[0039]
In the first embodiment, the insulated joint structure 1 is employed in a pipe through which city gas flows as the explosion-proof fluid. However, the present invention is not limited to city gas, and other fluids such as petroleum refining are used. The above-mentioned insulating joint structure 1 may be adopted in a pipeline of a plant or the like.
[0040]
Next, a second embodiment will be described with reference to FIGS. That is, the second embodiment is a ball valve 30 provided with the insulating joint structure 1 according to the first embodiment described above, and has the following configuration.
[0041]
The ball valve 30 is a two-way valve, and its valve box 31 is composed of a valve box body 32 and a joint 4. One of the pipes 2 is integrally formed on one end side of the valve box main body 32 by forging, and forms an opening for piping (not shown).
[0042]
Further, one end of the first joint body 6 of the joint 4 is integrally joined to the other end side of the valve box body 32 by the entire circumference welding W5, and is inserted into the insertion hole 5 of the first joint body 6. One end of the second joint body 7 is inserted, and the other tubular body 3 and the fixing member 13 are integrally joined to the second joint body 7 by full-circumferential weldings W3 and W4, respectively. The other pipe 3 forms an opening for a pipe (not shown). The first joint body 6 is formed in a tapered shape that gradually expands from the second joint body 7 side to the valve box body 32 side. The joint structure between the joint 4 and the other tubular body 3 is the same as that of the first embodiment described above.
[0043]
On the far end side inside the one pipe body 2, one valve box port 34 communicating with the space 33 inside the valve box and the inside of the one pipe body 2 is formed. Is provided with an annular valve box sheet 35. Further, on the far end side in the second joint body 7, the other valve box port 36 communicating with the space 33 in the valve box and the inside of the second joint body 7 is formed. Note that the other valve box port 36 is not provided with a valve box sheet.
[0044]
A valve body 38 that rotates about the axis of a valve rod 37 is disposed in the valve box space 33. As shown in FIG. 12, the valve body 38 has a valve body flow path 39 communicating between the two valve box ports 34 and 36 when fully opened, and one side in a direction orthogonal to the valve body flow path 39 is provided. As shown in FIG. 11, a disc-shaped valve body sheet 40 is provided at the position, which is pressed against the valve box sheet 35 when fully closed.
Hereinafter, the operation of the above configuration will be described.
[0045]
Before welding the first joint body 6 to the valve box body 32, first, the O-rings 17 and 19 are fitted into the grooves 16 and 18, respectively. The insulating packing 14a and the first insulating resin member 14c are inserted, the first insulating resin member 14c is fitted into the inner peripheral surface of the insertion hole 5, and the one insulating packing 14a is inserted into the first insulating resin member 14c. And applied to the end face 9 a of the stepped portion 9.
[0046]
Next, as shown in FIG. 13, the second joint body 7 is inserted into the insertion hole 5 from one end side of the first joint body 6. At this time, the movement of the second joint body 7 in the withdrawal direction A is regulated by the flange 8 contacting the stepped portion 9 via the one insulating packing 14a. One end of the joint body 7 is inserted. Thereafter, the other insulating packing 14b and the second insulating resin member 14d are externally fitted to the second joint body 7, and the second insulating resin member 14d is connected to the inner peripheral surface 9c of the stepped portion 9 and the second insulating resin member 14d. It is inserted between the outer peripheral surface of the joint main body 7 and the other insulating packing 14b is applied to the end surface 9b of the stepped portion 9 to fit outside the second insulating resin member 14d.
[0047]
Then, the fixing member 13 is externally fitted to the second joint body 7 from the other end side of the second joint body 7 and pressed against the first joint body 6, and the second joint body 7 is pulled out in the pulling direction A. (See FIG. 11), the fixing member 13 is welded to the outer peripheral surface of the second joint body 7 in a state where the second joint body 7 is stretched in the pull-out direction A by applying a tensile force F to the second joint body 7 (all-around welding). W3). Next, since the second joint main body 7 tends to contract in the pushing direction B (see FIG. 11) by removing the tensile force F, the fixing member 13 and the flange 8 are each strong against the stepped portion 9. It is pressed by the pressing force, and no gap is generated.
[0048]
After that, the other pipe 3 is integrally joined to the other end of the second joint body 7 by full circumference welding W4. Further, as shown in FIG. 11, one end side of the first joint main body 6 is integrally joined to the valve box main body 32 by full circumference welding W2. Thereby, the other pipe 3 is connected to the valve box 31 via the joint 4.
[0049]
Further, even when a flammable fluid such as city gas flows in the ball valve 30, the valve box 31 and the other pipe 3 are insulated, so that explosion-proof and anti-corrosion effects can be obtained.
[0050]
In addition, as compared with a conventional ball valve 67 having an insulating joint structure 62 of a type in which both flanges 53 and 56 are joined by bolts 57 and nuts 58 (see FIGS. 15 and 16), In this case, the joint strength against external force is increased, and the earthquake resistance is improved.
[0051]
As shown in FIG. 12, when the valve body 38 is rotated to the fully open position via the valve rod 37, the valve body ports 34 and 36 communicate with each other through the valve body flow path 39, and the inside of one pipe 2 The fluid that flows in from one of the pipes passes through one valve box port 34, the valve body channel 39, and the other valve box port 36, and flows out into the other pipe 3.
[0052]
As shown in FIG. 11, when the valve body 38 is rotated to the fully closed position via the valve rod 37, the valve body sheet 40 comes into pressure contact with the valve box sheet 35, so that one valve box port 34 side has a valve. Since the fluid is closed by the body sheet 40, the fluid in one tube 2 is blocked by the valve body sheet 40 and is prevented from flowing to the other tube 3.
[0053]
In the second embodiment, one of the tubes 2 is used as a fluid inlet and the other tube 3 is used as a fluid outlet. However, the fluid ports may be reversed.
In the second embodiment, the ball valve 30 is provided in a pipe through which city gas flows as a fluid to be explosion-proof. However, the present invention is not limited to city gas, and other fluids, such as a petroleum refining plant, etc. The above-mentioned ball valve 30 may be provided in the pipeline.
[0054]
In the second embodiment, the ball valve 30 is a two-way valve, but may be a three-way valve or another type of valve.
[0055]
【The invention's effect】
As described above, according to the first aspect of the present invention, when one pipe and the other pipe are connected via a joint, the first pipe is connected to the second pipe and the first pipe and the second pipe. It is insulated from the fixing member by an insulating material. Also, compared with the conventional type insulated joint structure in which both flanges are joined to each other with bolts and nuts, the joint strength against external force is increased, and the earthquake resistance is improved.
[0056]
In the second invention, one of the insulating packings can secure a sufficiently large surface pressure required for sealing, and the gap between the end face of the flange in the pulling-out direction and the end face of the stepped portion in the pushing direction is as described above. It is reliably sealed by one of the insulating packings, and reliably prevents the internal fluid from leaking to the outside through the space between the end face of the flange in the pulling-out direction and the end face of the stepped portion in the pushing direction. Can be.
[0057]
Furthermore, in the third aspect of the invention, compared to a valve having a conventional type insulated joint structure in which both flanges are joined together by bolts and nuts, the joint strength against external force is increased, and the earthquake resistance is improved.
[Brief description of the drawings]
FIG. 1 is a sectional view of an insulating joint structure according to a first embodiment of the present invention.
FIG. 2 is a partially enlarged sectional view of the same insulating joint structure.
FIG. 3 is a partially enlarged cross-sectional view of a first joint body having the insulating joint structure.
FIG. 4 is a partially enlarged cross-sectional view of a second joint body having the insulating joint structure.
FIG. 5 is a partially enlarged cross-sectional view of the fixing member having the insulating joint structure.
FIG. 6 is a cross-sectional view of a component constituting the insulating material of the insulating joint structure.
FIG. 7 is a cross-sectional view showing a procedure for connecting the pipes using the insulating joint structure, showing a process of attaching an insulating material to the first joint main body.
FIG. 8 is a cross-sectional view showing a procedure for connecting the pipes using the insulated joint structure, showing a process of attaching a second joint body to the first joint body.
FIG. 9 is a cross-sectional view showing a procedure for connecting a pipe using the insulating joint structure, showing a process of attaching a fixing member to the joint.
FIG. 10 is a cross-sectional view showing a procedure for connecting the pipe using the insulating joint structure, showing a process of welding the pipe to the joint.
FIG. 11 is a cross-sectional view of a valve having an insulating joint structure according to a second embodiment of the present invention, showing a fully closed state.
FIG. 12 is a cross-sectional view of the valve having the insulating joint structure, showing a fully opened state.
FIG. 13 is an enlarged sectional view of an insulating joint structure portion of the valve having the insulating joint structure.
FIG. 14 is a sectional view of a conventional insulating joint structure.
FIG. 15 is a sectional view of a valve having a conventional insulating joint structure.
FIG. 16 is an enlarged sectional view of an insulating joint structure portion of the valve having the insulating joint structure.
[Explanation of symbols]
1 Insulation joint structure
2 One tube
3 The other tube
4 Fitting
5 insertion hole
6. First joint body
7. Second joint body
8 Tsubabe
8a Outer peripheral surface of flange
8c End face of flange in pull-out direction
9 Stepped part
9a End face of stepped part on pushing direction side
9b End face of stepped part on pull-out direction side
9c Inner peripheral surface of stepped part
13 Fixing member
13a End surface of fixing member in pushing direction side
14 Insulation
14a One insulating packing
14b The other insulating packing
14c first insulating resin member
14d second insulating resin member
30 ball valve
31 Valve box
38 valve body
A Pulling direction
B Push direction
Da, Db Radial width
