JPH0123022Y2 - - Google Patents
Info
- Publication number
- JPH0123022Y2 JPH0123022Y2 JP1981112351U JP11235181U JPH0123022Y2 JP H0123022 Y2 JPH0123022 Y2 JP H0123022Y2 JP 1981112351 U JP1981112351 U JP 1981112351U JP 11235181 U JP11235181 U JP 11235181U JP H0123022 Y2 JPH0123022 Y2 JP H0123022Y2
- Authority
- JP
- Japan
- Prior art keywords
- rubber
- pipe
- joint
- fitting
- joint body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 229920001971 elastomer Polymers 0.000 claims description 53
- 239000005060 rubber Substances 0.000 claims description 53
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 26
- 239000010439 graphite Substances 0.000 claims description 25
- 229910002804 graphite Inorganic materials 0.000 claims description 25
- 150000001875 compounds Chemical class 0.000 claims description 23
- 238000009830 intercalation Methods 0.000 claims description 22
- 230000002687 intercalation Effects 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 13
- 238000004073 vulcanization Methods 0.000 claims description 8
- 229920003051 synthetic elastomer Polymers 0.000 claims description 6
- 239000005061 synthetic rubber Substances 0.000 claims description 6
- 244000043261 Hevea brasiliensis Species 0.000 claims description 5
- 229920003052 natural elastomer Polymers 0.000 claims description 5
- 229920001194 natural rubber Polymers 0.000 claims description 5
- 239000007789 gas Substances 0.000 description 29
- 238000012856 packing Methods 0.000 description 26
- 238000007789 sealing Methods 0.000 description 15
- 238000010438 heat treatment Methods 0.000 description 10
- 238000001816 cooling Methods 0.000 description 9
- 229920001084 poly(chloroprene) Polymers 0.000 description 6
- 239000000945 filler Substances 0.000 description 5
- 238000004898 kneading Methods 0.000 description 5
- 230000035699 permeability Effects 0.000 description 5
- 238000005452 bending Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- 239000006260 foam Substances 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000010455 vermiculite Substances 0.000 description 4
- 235000019354 vermiculite Nutrition 0.000 description 4
- 229910052902 vermiculite Inorganic materials 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 229920000126 latex Polymers 0.000 description 3
- 239000004816 latex Substances 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000010425 asbestos Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 235000019353 potassium silicate Nutrition 0.000 description 2
- 229910052895 riebeckite Inorganic materials 0.000 description 2
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical group [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 2
- 229920000181 Ethylene propylene rubber Polymers 0.000 description 1
- 238000005411 Van der Waals force Methods 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000010451 perlite Substances 0.000 description 1
- 235000019362 perlite Nutrition 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000010058 rubber compounding Methods 0.000 description 1
- 229920002379 silicone rubber Polymers 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L sulfate group Chemical group S(=O)(=O)([O-])[O-] QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 229920006174 synthetic rubber latex Polymers 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Joints With Pressure Members (AREA)
Description
［産業上の利用分野］
本考案は新規な管継手に関するものである。更
に詳述すれば本考案は通常使用時は勿論のこと、
異常な高温下或いは異常な高温と室温とのヒート
サイクルを受けても優れたシール機能を発揮する
管継手に関するものである。
［従来の技術］
高圧ガス配管や高圧油配管では異常加熱、例え
ば配管部周辺に火災が発生したとしても管内を通
過する流体、例えばガスや油を管外へ漏洩させな
いことが重要である。
このため高圧ガス配管や高圧油配管は耐火性が
優れた金属管と金属製管継手により構成されてい
る。しかしながら管継手のシール部には耐火性が
劣るパツキンが使用されている。
第１図は従来の管継手により接続したガス配管
や油配管等の接続部を示したものである。
第１図において１，２は対向配置してある被接
続管であり、これら被接続管１，２は管継手によ
り接続されている。
この管継手は、第１図に示すように、端部内面
にテーパー面を有して被接続管１，２の端部に嵌
合する継手本体７と、その継手本体７の端部に螺
合する締付金具３と、ゴムパツキン４とから成る
ものである。
ゴムパツキン４は縦断面が梯形の環状パツキン
である。このゴムパツキン４は締付金具３と被接
続管１，２及び前記継手本体７とにより形成され
る間隙部に装着される。
この場合、締付金具３は袋ナツトであつて、継
手本体７の両端外周に形成されたねじ部に螺着す
るようになつている。この締付金具３はその内側
にゴムパツキン４をセツトしてから継手本体７の
両端外周に形成されたねじ部に螺着することによ
り、ゴムパツキン４を押圧変形して締付金具３、
被接続管１，２及び継手本体７とにより形成され
た間隙部の各対向面に押圧するように装着し、シ
ール機能を発揮するようになつている。
第１図において５はゴムパツキン４の回転ねじ
れを防止するカラーであり、また、６は被接続管
１，２が長手方向に引張られた際引抜かれるのを
防止するストツパーリングである。
第１図の配管接続部の工事方法は、まず被接続
管１の一端に締付金具３、ストツパリング６、カ
ラー５を順次嵌合させ、次にゴムパツキン４を嵌
合させ、それから管継手本体７の一端側を被接続
管１に嵌合させ、最後に締付金具３をその継手本
体７の一端側に螺合して締付ける。同様に被接続
管２側も同様に接続する。
しかしながら従来の管継手は、異常な温度上昇
と室温までの冷却のヒートサイクルを繰り返すと
シール性を損なう難点がある。即ち、従来のゴム
パツキン４は異状な高温に加熱したときには熱膨
脹してシール性を保持するが、一旦、加熱が止み
温度が低下すると急激に収縮して継手本体７、締
付金具３及び被接続管１，２の各対向面との押圧
力が急激に弱まり、その結果管継手部分から管内
流体のガスや油が漏洩する。そしてこの漏洩した
ガスや油は着火、爆発、延焼拡大等の重大な二次
災害を招く危険があつた。
このためこれらの欠点を改良した管継手の検討
が行なわれている。
その第１は耐熱性を向上したゴムパツキンを用
いた管継手の検討である。
しかし耐熱性ゴムパツキンを用いたとしても管
継手は、異状な高温、例えば管継手周辺に火災が
発生した時に受けるような800℃以上の高温によ
る熱膨脹と、それから室温までの冷却のヒートサ
イクルを与えると、熱膨脹したゴムパツキンが急
激に熱収縮して継手本体７、締付金具３及び被接
続管１，２の各対向面との押圧力が急激に弱まつ
て管継手部分から管内流通物のガスや油の漏洩を
招くことが避けられない。
第２はゴムパツキンより耐熱性が優れたアスベ
ストパツキンや金属パツキン用いた管継手の検討
である。
しかしアスベストパツキンや金属パツキンは本
質的にゴムパツキンのような弾性やシール機能が
乏しく、高圧ガス配管や高圧油配管の管継手用パ
ツキンとして使用したときにはガスや油の漏洩を
完全に抑止できない難点がある。
第３は、締付金具３、被接続管、２及び継手本
体７とにより形成される間隙部に、加熱により発
泡して体積膨張する不燃性充填材（例えば、実公
昭54−6085号）を充填した管継手の検討である。
しかしながらこの不燃性充填材は、水ガラス、
合成ゴムラテツクス、酢酸ビニルエマルジヨン等
に蛭石、真珠岩、黒旺石、あるいは水ガラス硬化
体のような加熱により発泡して体積膨張する無機
粉末を混練して成るパテ状混練物であるため、こ
れらを空隙部に充填、乾燥して得られる充填膜は
水分蒸発時に塗膜欠陥部が発生して緻密性に欠
け、その結果ガスや油の透過性が大きくなり、し
かもこの充填膜は高温加熱により発泡して膨脹す
るため多孔質となり、その結果耐曲げ性、耐衝撃
性、弾性が劣り、高圧ガス配管や高圧油配管の管
継手のパツキンとしては到底実用できないもので
ある。
［考案が解決しようとする課題］
本考案はかかる点に立つて為されたものであつ
て、その目的とするところは、前記した従来技術
の欠点を解消し、通常使用時は勿論のこと、周辺
部が火災発生時のような異常な高温加熱と室温ま
での冷却とのヒートサイクルを受けても優れたシ
ール性を有する管継手を提供することにある。
［課題を解決するための手段］
本考案の要旨とするところは、対向配置してあ
る被接続管の端部に嵌合する端部内面にテーパー
面を有する継手本体と、該継手本体の端部に螺合
する締付金具と、該締付金具と前記被接続管及び
前記継手本体とにより形成される間隙部に、無発
泡状態で熱脹する黒鉛層間化合物を配合した天然
ゴム組成物または合成ゴム組成物を加硫金型にて
JIS−Ｋ−6301で定めるシヨアーＡ硬度が60〜80
となるように環状体に成形、プレス加硫して成る
ゴムパツキンを各対向面に押圧するように装着さ
れるとから成る管継手にある。
本考案において、無発泡状態で熱膨脹する黒鉛
層間化合物とは、次のようなものである。
即ち、黒鉛は六員環重合体層が層状に重なり合
つた炭素の六方晶系結晶体であるが、その各層間
の結合力はフアン・デル・ワールス力による物理
吸着で結合しているため、その結合力が非常に弱
いものである。このため黒鉛の各層間には種々な
化学物質が結合することができる。例えば、黒鉛
に硫酸を反応させることにより、層間に硫酸根が
結合した黒鉛層間化合物が得られる。
この種の無発泡状態で熱膨脹する黒鉛層間化合
物は180℃以上の温度に加熱すると六員環重合面
の層と層との間が伸長し、無発泡状態で体積が数
十倍から数百倍に膨張する性質がある。黒鉛層間
化合物を800〜1000℃に加熱したとき、その見掛
けの体積は100〜150倍に膨脹する。
従来、この種の無発泡状態で熱膨脹する黒鉛層
間化合物は電気絶縁性が乏しく、カーボンブラツ
クのようなゴムの補強効果も殆どなく、しかも熱
膨張性があるため電気安全上及び寸法精度上の点
から管継手のゴムパツキン用配合材としては全く
見向きもされなかつた。
本考案者等は苛酷なヒートサイクルを受けても
優れたシール性を保持することができる管継手に
ついて鋭意検討した結果、以外にもこの黒鉛層間
化合物を配合したゴムパツキンを装着した管継手
が優れたヒートサイクル性を有することを見出
し、本考案に至つたものである。
本考案の管継手のゴムパツキンに用いられる生
ゴムは、天然ゴムまたは合成ゴムのいずれでもよ
い。合成ゴムとしてはクロロプレンゴム、エチレ
ンプロピレンゴム、シリコンゴム等である。
本考案の管継手のゴムパツキンに用いられるゴ
ム組成物は天然ゴム或いは合成ゴム等の生ゴムに
加硫剤、充填剤等と共に黒鉛層間化合物をロール
混練することにより得られる。
本考案の管継手のゴムパツキンは、この得られ
たゴム組成物を予めセツトしてある環状の金型内
に入れ、それから所定温度と圧力の条件でプレス
加硫することにより得られる。プレス加硫して得
られるゴムパツキンは緻密なゴム膜となり、優れ
た低透過性を発揮することができる。
本考案において、管継手のゴムパツキンの硬度
をJIS−Ｋ−6301で定めるシヨアーＡ硬度で60〜
80としたのは、シヨアーＡ硬度が60以下のゴムパ
ツキンでは圧縮永久歪が大きすぎてシール面圧を
高めることが困難であり、また、逆に80以上では
硬すぎてシール性が乏しく、ガスや油の漏洩を完
全に抑止できないためである。
［作用］
本考案の管継手は、管継手の継手本体、締付金
具及び被接続管とにより形成される間隙部に装着
するゴムパツキンとして、無発泡状態で熱膨脹す
る黒鉛層間化合物を配合して成る天然ゴム組成物
または合成ゴム組成物を環状体に成形、プレス加
硫して得られるゴムパツキンを用いることによ
り、通常使用時にはこのゴムパツキンが本来有す
る低ガス透過性、優れたゴム弾性、耐曲げ性、耐
衝撃性等により優れたシール機能を発揮し、更に
180℃以上の高温時には配合してある黒鉛層間化
合物が分子的に伸長して無発泡状態で熱膨脹し、
その結果このゴムパツキンが本来有する低ガス透
過性、優れたゴム弾性、耐曲げ性、耐衝撃性等を
何等損なわずに継手本体、締付金具及び被接続管
各対向面を強力に押圧してシール性を確保し、そ
して更にその異常な高温加熱が止んで冷却されて
も分子的に膨脹したものであるから異常な収縮が
起らず、その結果ゴムパツキンは本来のシール性
を保持して管内のガスや油の漏洩を効果的に抑止
できることにある。
［実施例］
次に本考案の管継手の一実施例を図面により説
明する。
第２図は本考案の管継手の一実施例を示した一
部断面説明図である。
第２図の番号において１〜７は第１図と同じで
ある。第２図において８は本考案の管継手に装着
されている黒鉛層間化合物を配合したクロロプレ
ンゴム組成物を縦断面がほぼ梯形でしかも環状に
成形、プレス加硫して成るゴムパツキンである。
第２図において、９はゴムパツキン８に配合さ
れている黒鉛層間化合物をわかり易く図示したも
のであつて、実際には黒鉛層間化合物は微粒子で
のあるから他のゴム配合剤と同様にゴム中に均一
に分散している。
次に、従来例のパツキンを装着した管継手と、
比較例のパツキンを装着した管継手と、第２図の
本考案の管継手とについてガス漏洩試験結果を行
つた。
従来例１は黒鉛層間化合物を配合していない従
来のゴムパツキンを装着した管継手である。
従来例２はスチレンブタジエンゴムラテツクス
に蛭石を混練して成る混練充填物を、管継手の締
付金具３、被接続管、２及び継手本体７とにより
形成される間隙部に、充填、乾燥したものであ
る。
比較例１〜３は、黒鉛層間化合物を配合したク
ロロプレンゴム組成物を縦断面がほぼ梯形でしか
も環状に成形、プレス加硫して加硫後のJIS−Ｋ
−6301で定めるシヨアーＡ硬度が50，55，85のゴ
ムパツキンをそれぞれ装着した管継手である。
実施例１〜３は、黒鉛層間化合物を配合したク
ロロプレンゴム組成物を縦断面がほぼ梯形でしか
も環状に成形、プレス加硫して加硫後のJIS−Ｋ
−6301で定めるシヨアーＡ硬度が60，70，80のゴ
ムパツキンをそれぞれ装着した管継手である。
なお、ガス漏洩試験は、２本の接続管を管継手
により接続した配管接続部内に圧力45Kg／cm2の炭
酸ガスを入れ、その接続管の端部をシールし、熱
履歴無しのまま室温で48時間経過後の圧力、及び
800℃２分加熱・室温冷却48時間経過後の圧力を
測定したものである。
次表はこれらの試験結果を示したものである。
[Industrial Application Field] The present invention relates to a new pipe joint. To be more specific, the present invention can be used not only during normal use, but also during normal use.
The present invention relates to a pipe joint that exhibits an excellent sealing function even when subjected to heat cycles between abnormally high temperatures or between abnormally high temperatures and room temperature. [Prior Art] In high-pressure gas piping and high-pressure oil piping, even if abnormal heating occurs, such as a fire in the vicinity of the piping, it is important to prevent the fluid passing through the pipe, such as gas or oil, from leaking out of the pipe. For this reason, high-pressure gas piping and high-pressure oil piping are constructed of metal pipes and metal pipe joints that have excellent fire resistance. However, the seal portion of the pipe joint uses packing that has poor fire resistance. FIG. 1 shows the connection parts of gas piping, oil piping, etc. connected by conventional pipe joints. In FIG. 1, reference numerals 1 and 2 are connected pipes arranged opposite each other, and these connected pipes 1 and 2 are connected by a pipe joint. As shown in FIG. 1, this pipe joint includes a joint main body 7 which has a tapered surface on the inner surface of the end and fits into the ends of the connected pipes 1 and 2, and a joint main body 7 that is threaded into the end of the joint main body 7. It consists of a fitting fitting 3 and a rubber packing 4. The rubber packing 4 is an annular packing having a trapezoidal longitudinal section. This rubber packing 4 is installed in the gap formed by the fastening fitting 3, the connected pipes 1 and 2, and the joint body 7. In this case, the fastening fitting 3 is a cap nut and is adapted to be screwed into threaded portions formed on the outer periphery of both ends of the joint body 7. This tightening fitting 3 is made by setting a rubber packing 4 inside thereof and then screwing it into the threaded portions formed on the outer periphery of both ends of the joint body 7, so that the rubber packing 4 is pressed and deformed.
It is mounted so as to be pressed against each opposing surface of the gap formed by the connected pipes 1 and 2 and the joint body 7, and exhibits a sealing function. In FIG. 1, 5 is a collar that prevents rotational twisting of the rubber packing 4, and 6 is a stopper ring that prevents the connected pipes 1, 2 from being pulled out when they are pulled in the longitudinal direction. The method for constructing the pipe connection shown in FIG. 1 is to first fit the clamping fitting 3, stopper ring 6, and collar 5 to one end of the pipe 1 to be connected, then fit the rubber seal 4, and then fit the pipe joint body 7. One end of the fitting is fitted into the pipe to be connected 1, and finally the fastening fitting 3 is screwed onto the one end of the joint body 7 and tightened. Similarly, the connected pipe 2 side is also connected in the same manner. However, conventional pipe joints have the disadvantage that sealing performance is lost when heat cycles of abnormal temperature rise and cooling to room temperature are repeated. That is, when the conventional rubber seal 4 is heated to an abnormally high temperature, it thermally expands and maintains its sealing properties, but once the heating stops and the temperature drops, it rapidly contracts and damages the joint body 7, the fastening fitting 3, and the connected pipe. The pressing force with the opposing surfaces 1 and 2 suddenly weakens, and as a result, gas and oil in the pipe fluid leak from the pipe joint. This leaked gas and oil posed the risk of causing serious secondary disasters such as ignition, explosion, and fire spread. For this reason, studies are being conducted on pipe joints that improve these drawbacks. The first is the study of pipe joints using rubber gaskets with improved heat resistance. However, even if heat-resistant rubber gaskets are used, pipe fittings are subject to a heat cycle of thermal expansion due to abnormally high temperatures (e.g., 800°C or higher, such as those experienced when a fire breaks out around a pipe fitting), and then cooling to room temperature. The heat-expanded rubber packing rapidly shrinks, and the pressing force with the opposing surfaces of the joint body 7, fastening fitting 3, and connected pipes 1, 2 rapidly weakens, causing gases and other fluids flowing in the pipe to escape from the pipe joint. This will inevitably lead to oil leakage. The second is a study of pipe fittings using asbestos packing or metal packing, which have better heat resistance than rubber packing. However, asbestos gaskets and metal gaskets inherently lack the elasticity and sealing properties of rubber gaskets, and when used as gas and oil gas piping joint gaskets, they have the disadvantage of not being able to completely prevent gas or oil leakage. . Third, a noncombustible filler (for example, Utility Model Publication No. 54-6085) that foams and expands in volume when heated is placed in the gap formed by the fastening fitting 3, the connected pipe 2, and the joint body 7. This is a study of filled pipe joints. However, this non-combustible filler is water glass,
Because it is a putty-like kneaded product made by kneading synthetic rubber latex, vinyl acetate emulsion, etc. with an inorganic powder that foams and expands in volume when heated, such as vermiculite, perlite, kurostone, or hardened water glass. The filled film obtained by filling voids with these materials and drying them lacks density due to the occurrence of film defects during water evaporation.As a result, gas and oil permeability increases, and this filled film is heated at high temperatures. Because it foams and expands, it becomes porous, resulting in poor bending resistance, impact resistance, and elasticity, making it completely unpractical as a pipe fitting seal for high-pressure gas piping or high-pressure oil piping. [Problems to be Solved by the Invention] The present invention has been made based on the above points, and its purpose is to eliminate the drawbacks of the prior art described above, and to solve the problem in normal use. An object of the present invention is to provide a pipe joint that has excellent sealing properties even when the peripheral part is subjected to a heat cycle of heating to an abnormally high temperature and cooling to room temperature, such as when a fire occurs. [Means for Solving the Problems] The gist of the present invention is to provide a joint body having a tapered surface on the inner surface of the end portion that fits into the ends of the connected pipes disposed oppositely, and an end portion of the joint body. a natural rubber composition containing a graphite intercalation compound that expands under heat in a non-foamed state in a gap formed by the clamping fixture, the connected pipe, and the joint body; Synthetic rubber composition in vulcanization mold
Shore A hardness specified by JIS-K-6301 is 60 to 80
There is a pipe joint consisting of a rubber gasket formed by molding into an annular body and press-vulcanizing it so as to be attached to each opposing surface so as to press it. In the present invention, the graphite intercalation compound that thermally expands in a non-foamed state is as follows. In other words, graphite is a hexagonal crystal of carbon made up of layers of six-membered ring polymers, and the bonding force between the layers is physical adsorption due to the Van der Waals force. Its binding force is very weak. Therefore, various chemical substances can be bonded between each layer of graphite. For example, by reacting graphite with sulfuric acid, a graphite intercalation compound in which sulfate groups are bonded between the layers can be obtained. When this type of graphite intercalation compound, which thermally expands in an unfoamed state, is heated to a temperature of 180°C or higher, the space between the layers on the six-membered ring polymerization surface expands, and the volume increases by several tens to hundreds of times in an unfoamed state. has the property of expanding. When a graphite intercalation compound is heated to 800-1000°C, its apparent volume expands 100-150 times. Conventionally, this type of graphite intercalation compound, which thermally expands in an unfoamed state, has poor electrical insulation properties and has almost no reinforcing effect on rubber such as carbon black, and is thermally expandable, making it difficult to maintain electrical safety and dimensional accuracy. Therefore, it was not considered as a compound material for rubber seals of pipe joints. The inventors of the present invention conducted extensive studies on pipe fittings that can maintain excellent sealing performance even when subjected to severe heat cycles, and found that pipe fittings equipped with rubber seals containing this graphite intercalation compound were superior. It was discovered that it has heat cycle properties, leading to the present invention. The raw rubber used for the rubber gasket of the pipe joint of the present invention may be either natural rubber or synthetic rubber. Examples of synthetic rubber include chloroprene rubber, ethylene propylene rubber, and silicone rubber. The rubber composition used for the rubber packing of the pipe joint of the present invention is obtained by roll-kneading a graphite intercalation compound with raw rubber such as natural rubber or synthetic rubber together with a vulcanizing agent, a filler, and the like. The rubber packing of the pipe joint of the present invention is obtained by placing the obtained rubber composition into a previously set annular mold and then press-vulcanizing it under predetermined temperature and pressure conditions. The rubber packing obtained by press vulcanization becomes a dense rubber film and can exhibit excellent low permeability. In this invention, the hardness of the rubber gasket of the pipe joint is 60 to 60 on the Shore A hardness specified by JIS-K-6301.
The reason why it is set to 80 is because rubber seals with a Shore A hardness of 60 or less have too large a compression set, making it difficult to increase the sealing surface pressure.Conversely, if the Shore A hardness is 80 or more, they are too hard and have poor sealing performance, making it difficult to handle gas or gas. This is because oil leakage cannot be completely prevented. [Function] The pipe joint of the present invention is composed of a graphite intercalation compound that thermally expands in a non-foamed state and is used as a rubber seal to be installed in the gap formed by the joint body of the pipe joint, the fastening fitting, and the connected pipe. By using a rubber packing obtained by molding a natural rubber composition or a synthetic rubber composition into an annular body and press vulcanizing it, during normal use, this rubber packing inherently has low gas permeability, excellent rubber elasticity, bending resistance, Demonstrates excellent sealing function due to impact resistance, etc., and
At high temperatures of 180℃ or higher, the blended graphite intercalation compound expands molecularly and thermally expands without foaming.
As a result, the joint body, fastening fittings, and the opposing surfaces of the connected pipes are strongly pressed and sealed without impairing the low gas permeability, excellent rubber elasticity, bending resistance, impact resistance, etc. inherent to this rubber packing. Furthermore, even when the abnormally high temperature heating stops and the pipe is cooled, the rubber gasket retains its original sealing properties and does not contract abnormally because it has expanded molecularly. The reason is that it can effectively prevent gas and oil leaks. [Example] Next, an example of the pipe joint of the present invention will be described with reference to the drawings. FIG. 2 is a partially sectional explanatory view showing an embodiment of the pipe joint of the present invention. In the numbers 1 to 7 in FIG. 2 are the same as in FIG. In FIG. 2, reference numeral 8 denotes a rubber packing which is attached to the pipe joint of the present invention and is made by molding a chloroprene rubber composition containing a graphite intercalation compound into a ring shape having a substantially trapezoidal longitudinal section and press vulcanization. In Fig. 2, numeral 9 is an easy-to-understand diagram of the graphite intercalation compound compounded in the rubber packing 8, and since the graphite intercalation compound is actually fine particles, it is uniformly distributed throughout the rubber like other rubber compounding agents. are distributed in Next, a pipe fitting equipped with a conventional packing,
Gas leakage test results were conducted on a pipe joint equipped with a packing according to a comparative example and a pipe joint according to the present invention shown in FIG. Conventional Example 1 is a pipe joint equipped with a conventional rubber seal that does not contain a graphite intercalation compound. In conventional example 2, a kneaded filler made by kneading vermiculite into styrene-butadiene rubber latex is filled into the gap formed by the clamping fitting 3 of the pipe joint, the connected pipe 2, and the joint body 7. It is dry. In Comparative Examples 1 to 3, a chloroprene rubber composition blended with a graphite intercalation compound was molded into a substantially trapezoidal longitudinal section and annular, press vulcanized, and JIS-K after vulcanization.
These are pipe fittings equipped with rubber gaskets with Shore A hardness of 50, 55, and 85 as specified by -6301. In Examples 1 to 3, a chloroprene rubber composition blended with a graphite intercalation compound was molded into a substantially trapezoidal longitudinal section and annular, press vulcanized, and JIS-K after vulcanization.
These are pipe fittings equipped with rubber gaskets with Shore A hardness of 60, 70, and 80 as specified by -6301. In addition, in the gas leak test, carbon dioxide gas at a pressure of 45 kg/cm 2 is introduced into the pipe joint where two connecting pipes are connected by a pipe joint, the ends of the connecting pipes are sealed, and the pipes are left at room temperature without any thermal history. Pressure after 48 hours, and
The pressure was measured after heating at 800°C for 2 minutes and cooling to room temperature for 48 hours. The following table shows the results of these tests.
【表】
表からわかるように、黒鉛層間化合物を配合し
ていない従来例１のゴムパツキンを装着した管継
手の熱履歴無し品の圧力は全く低下しないが、
800℃２分加熱処理してから室温に冷却した後の
圧力は13Kg／cm2と急激に低下した。これは加熱時
には熱膨脹するためガス漏洩を抑止できるが、加
熱を止めればゴムパツキンが急激に熱収縮して継
手本体、締付金具及び被接続管とのギヤツプが大
きくなり、その結果ガス漏洩量が大きくなるため
である。
スチレンブタジエンゴムラテツクスに蛭石を混
練して成る混練充填物を充填して成る従来例２の
管継手の熱履歴無し品はの圧力は26Kg／cm2と低
く、その上800℃２分加熱処理してから室温に冷
却した後の圧力は８Kg／cm2と急激に低下した。こ
れはこの従来例２の管継手に用いたパツキンが水
分散体であるスチレンブタジエンゴムラテツクス
に蛭石を混練して成る混練充填物を充填、乾燥し
たものであるから、乾燥時の水分蒸発により緻密
性に欠け、その結果ガス透過量が大きく、しかも
800℃２分加熱処理してから室温に冷却した後に
は無数の発泡膨脹により緻密度が更に低下し、そ
の結果ガス透過性がより大きくなると共に曲げ特
性、耐衝撃特性及び弾性が低下してパツキンと継
手本体７、締付金具３及び被接続管１，２との押
圧力も低下してガス漏洩量が大きくなるためであ
る。
黒鉛層間化合物を配合したクロロプレンゴム組
成物を縦断面がほぼ梯形でしかも環状に成形、プ
レス加硫して加硫後のJIS−Ｋ−6301で定めるシ
ヨアーＡ硬度が50，55のゴムパツキンをそれぞれ
装着した比較例１，２の管継手の熱履歴無し品の
圧力は36，39Kg／cm2と低く、その上800℃２分加
熱処理してから室温に冷却した後の圧力は35，38
Kg／cm2と低下した。これは硬度が小さ過ぎるゴム
パツキンのため圧縮永久歪が大きくなり、その結
果シール面圧を高めることが困難でガス漏洩が起
こるためである。
黒鉛層間化合物を配合したクロロプレンゴム組
成物を縦断面がほぼ梯形でしかも環状に成形、プ
レス加硫して加硫後のJIS−Ｋ−6301で定めるシ
ヨアーＡ硬度が85のゴムパツキンをそれぞれ装着
した比較例３の管継手は、熱履歴無し品の圧力は
37Kg／cm2と低く、その上800℃２分加熱処理して
から室温に冷却した後の圧力は36Kg／cm2に低下し
た。これは硬すぎるゴムパツキンを装着したため
シール性が乏しく、ガス漏洩を抑止できないため
である。
これに対して実施例１〜３のゴムパツキンを装
着した管継手の熱履歴無し品は、そのゴム弾性に
より優れたシール機能を発揮し、しかも800℃２
分加熱処理して室温に冷却した後には配合してあ
る黒鉛層間化合物が無発泡状態で膨脹したままの
状態を維持し、その結果継手本体、締付金具及び
被接続管の各対向面を強力に押圧して管継手部分
から管内流通物のガスの漏洩を完全に抑止した。
［考案の効果］
本考案の管継手は、通常の使用時、異常な高温
下或いは異常な高温加熱と室温までの冷却のヒー
トサイクルを受けても優れたシール機能を有する
ものであり、高度な火災防止性が要求される高圧
ガス配管や高圧油配管等の管継手として工業上有
用である。[Table] As can be seen from the table, the pressure of the pipe fitting with no thermal history and equipped with the rubber seal of Conventional Example 1, which does not contain graphite intercalation compound, does not decrease at all.
After heat treatment at 800°C for 2 minutes and cooling to room temperature, the pressure rapidly decreased to 13Kg/cm 2 . This thermally expands when heated, which can prevent gas leakage, but when heating is stopped, the rubber seal rapidly shrinks due to heat, creating a larger gap between the fitting body, clamping fittings, and connected pipes, resulting in a larger amount of gas leakage. To become. The pipe joint of Conventional Example 2, which is filled with a kneaded filler made by kneading vermiculite into styrene-butadiene rubber latex, has no heat history, and the pressure is as low as 26 Kg/ cm2 , and it is heated at 800°C for 2 minutes. After the treatment and cooling to room temperature, the pressure suddenly decreased to 8 Kg/cm 2 . This is because the packing used in the pipe fitting of Conventional Example 2 was filled with a kneaded filling made by kneading vermiculite into styrene-butadiene rubber latex, which is an aqueous dispersion, and dried. As a result, the amount of gas permeation is large, and
After heat treatment at 800°C for 2 minutes and cooling to room temperature, the density further decreases due to numerous foam expansions, resulting in greater gas permeability and lower bending properties, impact resistance properties, and elasticity, resulting in poor packing quality. This is because the pressing force between the joint body 7, the fastening fitting 3, and the connected pipes 1 and 2 also decreases, and the amount of gas leakage increases. A chloroprene rubber composition blended with a graphite intercalation compound is molded into a ring shape with a longitudinal section almost trapezoidal, press vulcanized, and after vulcanization, rubber pads with Shore A hardness specified by JIS-K-6301 of 50 and 55 are attached respectively. The pressure of the pipe fittings of Comparative Examples 1 and 2 with no thermal history was as low as 36,39Kg/cm2, and the pressure after being heat treated at 800℃ for 2 minutes and then cooled to room temperature was 35,38Kg/cm2.
It decreased to Kg/ cm2 . This is because the hardness of the rubber packing is too low, resulting in large compression set, and as a result, it is difficult to increase the sealing surface pressure and gas leakage occurs. A comparison in which a chloroprene rubber composition containing a graphite intercalation compound was molded into a ring shape with a longitudinal cross section almost trapezoidal, press vulcanized, and a rubber gasket with a shore A hardness of 85 as defined by JIS-K-6301 was attached after vulcanization. For the pipe fitting in Example 3, the pressure of the product with no thermal history is
The pressure was as low as 37 Kg/cm 2 , and furthermore, the pressure after heating at 800° C. for 2 minutes and cooling to room temperature decreased to 36 Kg/cm 2 . This is because the rubber gaskets that are too hard have poor sealing properties and cannot prevent gas leakage. On the other hand, the pipe joints equipped with the rubber seals of Examples 1 to 3 with no heat history exhibited excellent sealing function due to their rubber elasticity, and moreover,
After being heated for several minutes and cooled to room temperature, the blended graphite intercalation compound maintains its expanded state without foaming, and as a result, the opposing surfaces of the fitting body, fastening fittings, and connected pipes are strengthened. This completely prevents gas from leaking from the pipe fittings. [Effects of the invention] The pipe joint of the invention has an excellent sealing function even under abnormal high temperatures or heat cycles of abnormally high temperature heating and cooling to room temperature during normal use. It is industrially useful as a pipe joint for high-pressure gas piping, high-pressure oil piping, etc. that requires fire prevention properties.
第１図は従来のゴムパツキンを用いて管継手の
一部断面説明図、第２図は本考案の管継手の一実
施例品の一部断面説明図である。
１，２……被接続管、３……締付金具、４，８
……ゴムパツキン、５……カラー、６……ストツ
パリング、７……継手本体、９……黒鉛層間化合
物。
FIG. 1 is a partial cross-sectional view of a pipe joint using a conventional rubber seal, and FIG. 2 is a partial cross-sectional view of an embodiment of the pipe joint of the present invention. 1, 2... Connected pipe, 3... Tightening fitting, 4, 8
... Rubber packing, 5 ... Collar, 6 ... Stopper ring, 7 ... Joint body, 9 ... Graphite intercalation compound.
Claims (1)
する端部内面にテーパー面を有する継手本体７
と、該継手本体７の端部に螺合する締付金具３
と、該締付金具３と前記被接続管１，２及び前記
継手本体７とにより形成される間隙部の各対向面
に押圧するように装着されるゴムパツキンとから
成る管継手において、前記ゴムパツキンは無発泡
状態で熱脹する黒鉛層間化合物を配合した天然ゴ
ム組成物または合成ゴム組成物を加硫金型にて
JIS−Ｋ−6301で定めるシヨアーＡ硬度が60〜80
となるように環状体に成形、プレス加硫して成る
ことを特徴とする管継手。 A joint body 7 having a tapered surface on the inner surface of the end that fits into the ends of the connected pipes 1 and 2 arranged oppositely.
and a tightening fitting 3 that is screwed onto the end of the joint body 7.
and a rubber gasket that is mounted so as to press against each opposing surface of the gap formed by the clamping fitting 3, the connected pipes 1, 2, and the joint body 7, the rubber gasket is A natural rubber composition or a synthetic rubber composition containing a graphite intercalation compound that expands under heat in an unfoamed state is molded into a vulcanization mold.
Shore A hardness specified by JIS-K-6301 is 60 to 80
A pipe joint characterized by being formed into an annular body and press vulcanized so as to have the following properties.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11235181U JPS5818179U (en) | 1981-07-29 | 1981-07-29 | pipe fittings |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11235181U JPS5818179U (en) | 1981-07-29 | 1981-07-29 | pipe fittings |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5818179U JPS5818179U (en) | 1983-02-04 |
| JPH0123022Y2 true JPH0123022Y2 (en) | 1989-07-13 |
Family
ID=29906681
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11235181U Granted JPS5818179U (en) | 1981-07-29 | 1981-07-29 | pipe fittings |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5818179U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007056536A (en) * | 2005-08-24 | 2007-03-08 | Kubota Corp | Drain piping structure, drain collecting pipe, and fire-resistant auxiliary member for drain pipe |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS546085U (en) * | 1977-06-16 | 1979-01-16 |
-
1981
- 1981-07-29 JP JP11235181U patent/JPS5818179U/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS546085U (en) * | 1977-06-16 | 1979-01-16 |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007056536A (en) * | 2005-08-24 | 2007-03-08 | Kubota Corp | Drain piping structure, drain collecting pipe, and fire-resistant auxiliary member for drain pipe |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5818179U (en) | 1983-02-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US1800085A (en) | Pipe coupling | |
| US4900629A (en) | High compressibility gasket material | |
| CA2753752C (en) | Sealing arrangements | |
| KR20070092649A (en) | Process for producing sheet-shaped gasket | |
| JP2005314653A (en) | Fluoroelastomer gasket composition | |
| JP2010509549A (en) | Low stress molded gasket and manufacturing method thereof | |
| CA2396659A1 (en) | Gaskets | |
| JPH0123022Y2 (en) | ||
| JP3094788B2 (en) | Gasket material and its manufacturing method | |
| JP5731036B2 (en) | Spiral gasket and method for manufacturing the same | |
| JP2005290359A (en) | Silicone gasket composition | |
| JP2006028398A (en) | Sheet gasket and method for producing the same | |
| US20070190307A1 (en) | Foamed fluoroelastic gasket material | |
| JP4474637B2 (en) | Pipe line blocking member | |
| JPH10140138A (en) | Joint sheet | |
| JP2594175B2 (en) | Spiral wound gasket | |
| JPH0235175B2 (en) | ||
| KR102469916B1 (en) | Compound composition for sealing luid pipes | |
| KR20200142926A (en) | Gasket improved sealability and preparing method thereof | |
| CN220727448U (en) | Leakage-proof PP air pipe elbow | |
| KR102352074B1 (en) | Gasket for flange | |
| JPS5824686A (en) | Rubber packing and pipe joint using said packing | |
| US20170113426A1 (en) | System and method for repairing leaks in in-service utility pipelines | |
| JPH04341661A (en) | Spiral-wound gasket | |
| JPH0342298Y2 (en) |