JP4260475B2

JP4260475B2 - Refractory double-layer pipe fittings

Info

Publication number: JP4260475B2
Application number: JP2002383440A
Authority: JP
Inventors: 厚荻野; 孝幸小島
Original assignee: フネンアクロス株式会社
Priority date: 2002-12-19
Filing date: 2002-12-19
Publication date: 2009-04-30
Anticipated expiration: 2022-12-19
Also published as: JP2004197926A

Description

【０００１】
【発明の属する技術分野】
本発明は、合成樹脂製の内管の外周を繊維モルタル層で覆った構成の耐火二層管継手に関する。
【０００２】
【従来の技術】
従来より、耐火二層管を接続するために使用される上記のような合成樹脂と繊維モルタルの二層構成を有する継手は公知である。また、このような継手が持つ構造上の不都合、すなわち、内管の外周に形成された繊維モルタル層がその形成後に乾燥硬化する過程で収縮し、その収縮力により繊維モルタル層がひび割れする不都合、内管の内部を熱流体が流れたときに内管に熱膨張が生じ、その熱膨張力により繊維モルタル層がひび割れする不都合、を解決するため、該内管の全周面をシートで被覆したのちその上に繊維モルタル層を形成し、該シートと内管の間に気体あるいは液体を圧入することが提案されている（特開昭５５−１５２９９５号公報）。
【０００３】
【特許文献】
特開昭５５−１５２９９５号（特許請求の範囲、第２図）
【０００４】
【発明が解決しようとする課題】
上記のような気体や液体を圧入するには、特殊な設備が必要で圧入工程が付加されるため製品がコスト高になって好ましくない。また、上記従来のものでは気体等の圧入で内管の全周面に隙間を形成しているが、発明者等の検討によれば、繊維モルタル層の形成後のモルタル養生工程を比較的高い温度の雰囲気中において行えば、内管が膨張した状態で繊維モルタル層が硬化し、養生完了後に常温中に取り出されたときには内管が収縮して繊維モルタル層との間に多少の隙間が形成され、この隙間が後日の内管の膨張をある程度許容して繊維モルタル層の損壊を多少とも防止でき、それゆえ、必ずしも内管の全周面に隙間は必要でないことがわかった。該内管の全周をシートで覆う作業は、比較的難しい作業であり、このような作業を省略できればコスト高になる原因のひとつを解消できる。
【０００５】
さらに、繊維モルタル層の破損した製品は、その出荷時には検査によりチェックして交換できるが、配管工事中あるいは工事後に破損した場合は再工事しなければならず、これは容易でない。配管工事中あるいは工事後の破損の原因を調べてみると、耐火二層管継手とこれに接続される耐火二層管などの管の中心軸が多少ずれていることが主な原因であることが分かった。つまり、接続される管の中心軸が耐火二層管継手の中心軸からずれた状態で耐火二層管継手に無理に挿入されることにより、比較的大きな力が受け口部の内管に作用し、内管が熱膨張などよりも大きく膨出するため引張力に弱い外周の繊維モルタル層が破損してしまうということが分かった。
【０００６】
本発明は、耐火二層管継手の受け口部の繊維モルタル層が配管工事において損壊する不都合を回避するため、該受け口部の内管の周囲に比較的大きな隙間を簡単且つ安価に形成することを目的とするものである。
【０００７】
【課題を解決するための手段】
本発明では、上記目的を達成すべく、配管を挿入するための円筒状の受け口部を２つ以上備えた合成樹脂製の内管の外周を繊維モルタル層で覆った構成の耐火二層管継手に於いて、該受け口部の内管の周面と繊維モルタル層の間に吸水性を有する紙葉を介在させると共に該紙葉の繊維方向を該受け口部の円周方向または軸線方向に設定し、該紙葉の吸水による面方向の伸びを制御して該内管の膨出変形を吸収する隙間を形成した。該隙間は、該紙葉の繊維方向を受け口部の円周方向または軸線方向に設定することで該紙葉の吸水による面方向の伸びを制御することと該紙葉の吸水による厚みの増大とその後の乾燥による紙葉の厚みの減少とにより、制御して形成することができる。
【０００８】
該紙葉の厚さを該受け□部の入り□側よりも奥部側で厚く形成することで、奥部側か広くなった隙間を形成できる。
【０００９】
【発明の実施の形態】
本発明の実施の形態を９０°曲がり管継手に適用した場合について図１および図２に基づき説明すると、符号１は、耐火二層管などの配管２を挿入するための２つの円筒形の受け口部３、３を備えた耐火二層管継手を示す。該耐火二層管継手１は、硬質塩化ビニールなどの合成樹脂からなる内管４と、その外周を覆う耐火性の繊維モルタル層５の二層構成を有し、該繊維モルタル層５は、一般的には、金型内に内管４を設置したのち該金型と内管の間に繊維モルタルを注入することにより形成される。
【００１０】
金型から取り出した耐火二層管継手１は、該繊維モルタル層５を養生し乾燥硬化させたのち製品として提供されるが、前記したような配管工事において受け口部３に無理な力が加わったときに受け口部外周の繊維モルタル層が破損するという不都合を防止するために、本発明では、受け口部３の内管４の周面と繊維モルタル層５の間に、図６に明示したような、無理な力による内管４の変形を許容する比較的大きな隙間７を形成したもので、該隙間７を簡単に形成するため図画用紙や白板紙などの吸水性の良好な紙葉６を受け口部３の内管４と繊維モルタル層５の間に介在させるようにした。
【００１１】
該内管４を金型内に設置するに先立ち、受け口部３の内管４の外周に図画用紙などの紙葉６を取り付けておき、これを金型内に設置して繊維モルタルを注入すると、受け口部３の内管４と繊維モルタル層５との間に紙葉６が介在した構成の半製品が得られる。該紙葉６は、未硬化の繊維モルタル層５からの水分の吸収と乾燥とで伸縮するが、その吸収による伸長量は、発明者等の知見によれば、紙葉６が持つ繊維方向との関係により大きく変化し、繊維方向と直交する方向への伸びは、繊維方向に比べて約８〜１０倍も大きいことが分かった。図画用紙などの紙葉６は製紙工程において繊維方向が形成されるものと思われる。紙葉６の厚さ方向も繊維方向と直交する方向という意味に含まれる。
【００１２】
実測によれば、厚さ０．５５ｍｍの白板紙に吸水させた場合、その繊維方向には０．２％、繊維方向と直交する方向には１．８％、厚さ方向には４９．１％の伸びであった。
【００１３】
吸水して該紙葉６が伸長すると未硬化の繊維モルタル層５を押し上げ、その後の繊維モルタル層５を養生する工程を経て層が乾燥硬化した状態になると該紙葉６も乾燥状態になり、紙葉６が薄くなるため内管４との間に比較的大きな隙間７を形成できる。配管工事により無理な力が内管４に作用したときに発生する該内管４の外方への比較的大きな膨出変形は、この隙間７で吸収され、その結果、外部の繊維モルタル層５の破損を防止できるようになる。この隙間７は、耐火二層管継手の製造工程に伴う紙葉６の伸縮により形成され、特別の装置などを使って形成する必要もないから簡単かつ安価に形成できる。
【００１４】
また、紙葉６は、その繊維方向を見定めたのち、図４に示したように、円筒形の受け□部３の内管４の周囲を取り巻くように設ければよいから、作業が簡単で製造時間を短縮しコストを低減することができる。この場合、紙葉６の伸びの大きさや形成する隙間７の大きさにより、図５に示したように、紙葉６の繊維方向１３を受け口部３の内管４の円周方向Ｓに設定するか、あるいは内管４の軸線方向Ｔに設定するかを決定する。
【００１５】
更に説明すると、該受け口部３の内管４の内部には配管２の先端を受け止める段部９を形成すると共に、その外周面を継手本体８の外周面よりも外方へ膨出させて段差部１０を形成するのが通常であるが、この構成では、該受け口部３に配管２を接続するとき、例えば配管２にズレ１２があってその中心軸Ｌが耐火二層管継手１の中心軸Ｍとが一致しないとき、該配管２を強い力で押し込まなければならず、この押し込み力で該段部９が外方へ押し出され、同時に受け口部３の段差部１０も外方へ押し出され、その力で該段差部１０を覆う繊維モルタル層５が破損することがあった。しかし、受け口部３のみでなく該段差部１０の外周に環状に紙葉６を巻き付けてそこに該隙間７を形成しておくと、配管２を強く圧入して接続しても、内管４の変形が繊維モルタル層５にまで到達せず、繊維モルタル層５が破損する事故を防止でき、その結果、再工事などの煩わしさから解放され、配管作業の能率が向上する。
【００１６】
該段差部１０を紙葉６できれいに覆うために、図５に示すように、紙葉６の一側を波形１１に形成しておき、波形の紙片を段差部１０の表面に接着等により取り付けてもよい。該紙葉６を受け口部３に固定する手段には、例えば粘着テープを使用するなど任意である。また、紙葉６には、紙筒あるいは伸縮性のある紙筒を使用できる。
【００１７】
紙葉６は、図画用紙や白板紙のように比較的吸水性のよい紙質のものでよいが、水分を吸収して厚みが増大する和紙やパルプなどの天然植物繊維、木綿や麻などの天然植物繊維の編み物や織物を使用することも可能である。
【００１８】
本発明の具体的実施例は次の通りである。図３に示したものにおいて、継手本体８の呼び径が１００ｍｍ、受け口部３の内径と外径が夫々１１４ｍｍと１２４ｍｍで、硬質塩化ビニールの内管４の肉厚が５ｍｍであった。受け口部３の軸線方向長さは５０ｍｍである。この受け口部３の周面に、厚さ０．５５ｍｍ、幅５５ｍｍの白板紙の紙葉６を切れ目が生じないように環状に連続した状態で巻きつけ、要所をセロファンテープで係止した。これを金型に収め、周面に厚さ約１１ｍｍの繊維モルタル層５を形成した。繊維モルタルの組成は、普通ポルトランドセメント６４％、骨材２１％、無機質繊維１０％、有機質繊維５％で、これを含水率２８％になるように混練した。この白板紙の紙葉６は、繊維方向に０．２％、繊維方向と直交する方向には１．８％、厚さ方向に換算すると４９．１％の伸びを生じるもので、繊維方向１３は受け口部３の内管４の円周方向になるようにセットした。
【００１９】
金型からこれを取り出し、繊維モルタル層５の養生を行ったが、白板紙の紙葉６は繊維モルタル層５の形成直後から該層に含まれる水分を吸収し始め、円周方向に伸びるとともにその厚みが最大０．８２ｍｍになり、その後、繊維モルタル層５の養生が完了して乾燥したときにはほぼ元の厚さに戻った。受け口部３の周囲には０．３９ｍｍの隙間７が形成され、繊維モルタル層５の硬化の過程における破損はなかった。そして、この継手１に配管２を接続し、その内部に６０℃の熱湯を流して内管４を膨張させたが、繊維モルタル層５の破損は生じなかった。また、配管２を接合する際、耐火二層管継手１の中心軸との間に２度のズレを生じさせて受け口部３内に強く限度まで押し込んだが、段差部１０に対応する部分の繊維モルタル層５に破損を生じなかった。
【００２０】
０．３９ｍｍ以上の隙間７を形成する場合には、該紙葉６の繊維方向１３を受け口部３の内管４の軸線方向Ｔにセットして繊維モルタル層５の成形を行なえばよい。
【００２１】
該紙葉６が吸水するとその繊維は解舒状態になり、その繊維が繊維モルタル層５内へ混入した状態で繊維モルタル層５が乾燥硬化するため、紙葉６は繊維モルタル層５に付着し、その結果、隙間７は内管４と紙葉６の間に形成される。また、該紙葉６の厚さを受け口部３の入り口側よりも奥部側で厚く形成しておくことで、隙間７の奥部を広く形成することができ、比較的大きな内管４の変形を吸収して繊維モルタル層５の破損を防止できる。
【００２２】
なお、以上の実施例の説明では受け口部３が２つの例を説明したが、３つ以上の受け口部を有する耐火二層管継手にも本発明は適用可能である。
【００２３】
【発明の効果】
以上のように、本発明では、耐火二層管継手の受け口部の内管の周面と繊維モルタル層の間に吸水性を有する紙葉を介在させると共に該紙葉の繊維方向を受け口部の内管の円周方向または軸線方向に設定し、該紙葉の吸水による紙面方向の伸びを制御して該内管の膨出変形を吸収する隙間を形成したので、特別の装置を使用せずに受け口部の内管の周囲のみに紙葉の吸水と乾燥で比較的大きな隙間を簡単確実に形成でき、その隙間を紙葉の繊維方向の設定で自在に変更できる効果があり、配管の無理な圧入により内管が膨出変形しても繊維モルタル層の破損が防止され、配管工事を迅速に行なえる効果がある。また、該紙葉の厚さを上記受け□部の入り口側よりも奥部側で厚く形成することで、隙間の奥部を広く形成することができ、内管が大きく膨出しても繊維モルタル層の破損を防止できる。
【図面の簡単な説明】
【図１】本発明の実施の形態を示す側面図
【図２】図１の２−２線に沿った断面図
【図３】内管の要部の拡大截断側面図
【図４】紙葉の巻き付け状態を示す外観図
【図５】紙葉の形状の一例を示す斜視図
【図６】図２の要部の拡大図
【符号の説明】
１耐火二層管継手、２配管、３受け口部、４内管、５繊維モルタル層、６紙葉、７隙間、８継手本体、９段部、１０段差部、１３繊維方向、[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fireproof two-layer pipe joint having a configuration in which an outer periphery of a synthetic resin inner pipe is covered with a fiber mortar layer.
[0002]
[Prior art]
Conventionally, a joint having a two-layer structure of a synthetic resin and a fiber mortar as described above used for connecting a fireproof two-layer pipe is known. In addition, the structural inconvenience of such a joint, that is, the fiber mortar layer formed on the outer periphery of the inner tube shrinks in the process of drying and hardening after the formation, and the fiber mortar layer is cracked by the contraction force, In order to solve the inconvenience that thermal expansion occurs in the inner pipe when a thermal fluid flows inside the inner pipe and the fiber mortar layer cracks due to the thermal expansion force, the entire circumference of the inner pipe is covered with a sheet. After that, it has been proposed to form a fiber mortar layer thereon and press-fit a gas or liquid between the sheet and the inner tube (Japanese Patent Laid-Open No. 55-152959).
[0003]
[Patent Literature]
JP-A-55-152959 (Claims, Fig. 2)
[0004]
[Problems to be solved by the invention]
In order to press-in the gas or liquid as described above, special equipment is required and a press-in process is added, which is not preferable because the product becomes expensive. Further, in the above conventional one, a gap is formed in the entire peripheral surface of the inner tube by press-fitting gas or the like, but according to the study by the inventors, the mortar curing process after forming the fiber mortar layer is relatively high. If done in a temperature atmosphere, the fiber mortar layer hardens with the inner tube expanded, and when it is taken out to room temperature after curing is complete, the inner tube shrinks to form a slight gap with the fiber mortar layer. Thus, it has been found that this gap allows some expansion of the inner tube at a later date to prevent the fiber mortar layer from being damaged to some extent, and therefore it is not always necessary to provide a gap on the entire peripheral surface of the inner tube. The operation of covering the entire circumference of the inner tube with a sheet is a relatively difficult operation, and if such an operation can be omitted, one of the causes of the cost increase can be eliminated.
[0005]
Further, a product having a damaged fiber mortar layer can be checked and replaced by inspection at the time of shipment. However, if the product is damaged during or after piping work, it must be reworked, which is not easy. When examining the cause of damage during or after piping work, the main cause is that the center axis of the fireproof double-layer pipe joint and the pipe of the fireproof double-layer pipe connected to this are slightly shifted. I understood. In other words, a relatively large force acts on the inner pipe of the receiving portion by being forcibly inserted into the fireproof two-layer pipe joint with the center axis of the pipe to be connected shifted from the center axis of the fireproof two-layer pipe joint. It has been found that the outer fiber mortar layer, which is weak against tensile force, is damaged because the inner tube swells larger than thermal expansion.
[0006]
In order to avoid the inconvenience that the fiber mortar layer of the receiving part of the fireproof two-layer pipe joint is damaged in the piping work, the present invention is to form a relatively large gap around the inner pipe of the receiving part easily and inexpensively. It is the purpose.
[0007]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, a fireproof two-layer pipe joint having a structure in which the outer periphery of a synthetic resin inner pipe provided with two or more cylindrical receptacles for inserting pipes is covered with a fiber mortar layer. in setting the fiber direction of Rutotomoni the paper leaf in the circumferential direction or the axial direction of the socket portion is interposed paper having a water absorption between the circumferential surface of the inner tube of the socket portion and the fiber mortar layer and was form form the gap to absorb the bulging deformation of the inner tube by controlling the elongation in the surface direction due to water absorption of the paper leaves. The clearance has an increase in thickness due to water absorption of it and the paper leaf to control the elongation water by the surface direction of the paper leaves by setting the fiber direction of the paper leaf in the circumferential direction or the axial direction of the socket portion It can be formed in a controlled manner by reducing the thickness of the paper sheet by subsequent drying.
[0008]
The thickness of the paper than enters □ side of receiving only □ Parts by thick in the back side, can be formed a gap widened or innermost side.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The case where the embodiment of the present invention is applied to a 90 ° bent pipe joint will be described with reference to FIGS. 1 and 2. Reference numeral 1 denotes two cylindrical receptacles for inserting a pipe 2 such as a refractory double-layer pipe. The fireproof two-layer pipe joint provided with the parts 3 and 3 is shown. The fireproof two-layer pipe joint 1 has a two-layer structure of an inner tube 4 made of a synthetic resin such as hard vinyl chloride and a fireproof fiber mortar layer 5 covering the outer periphery thereof. Specifically, it is formed by injecting fiber mortar between the mold and the inner tube after the inner tube 4 is installed in the mold.
[0010]
The fire-resistant double-layer pipe joint 1 taken out from the mold is provided as a product after curing and drying and curing the fiber mortar layer 5, but an excessive force is applied to the receiving port 3 in the piping work as described above. In order to prevent the inconvenience that the fiber mortar layer on the outer periphery of the receiving port sometimes breaks, in the present invention, between the peripheral surface of the inner tube 4 of the receiving port 3 and the fiber mortar layer 5 as clearly shown in FIG. A relatively large gap 7 that allows deformation of the inner tube 4 due to excessive force is formed. In order to form the gap 7 simply, a paper sheet 6 having good water absorption, such as drawing paper or white paperboard, is received. It was made to intervene between the inner tube 4 of the part 3 and the fiber mortar layer 5.
[0011]
Prior to installing the inner tube 4 in the mold, a paper sheet 6 such as drawing paper is attached to the outer periphery of the inner tube 4 of the receiving port 3, and this is installed in the mold to inject fiber mortar. A semi-finished product having a configuration in which the paper sheet 6 is interposed between the inner tube 4 of the receiving port 3 and the fiber mortar layer 5 is obtained. The paper sheet 6 expands and contracts due to the absorption and drying of moisture from the uncured fiber mortar layer 5, and the amount of elongation due to the absorption is determined by the fiber direction of the paper sheet 6 according to the knowledge of the inventors. It was found that the elongation in the direction perpendicular to the fiber direction was about 8 to 10 times larger than that in the fiber direction. It is considered that the fiber direction of the paper sheet 6 such as drawing paper is formed in the paper making process. The thickness direction of the paper sheet 6 is also included in the meaning of the direction orthogonal to the fiber direction.
[0012]
According to actual measurement, when water is absorbed by white paperboard having a thickness of 0.55 mm, the fiber direction is 0.2%, the direction orthogonal to the fiber direction is 1.8%, and the thickness direction is 49.1. % Growth.
[0013]
When the paper sheet 6 absorbs water and expands, the uncured fiber mortar layer 5 is pushed up, and when the layer is dried and hardened through a process of curing the subsequent fiber mortar layer 5, the paper sheet 6 is also in a dry state. Since the paper sheet 6 becomes thin, a relatively large gap 7 can be formed with the inner tube 4. A relatively large bulging deformation to the outside of the inner pipe 4 that occurs when an unreasonable force is applied to the inner pipe 4 due to the piping work is absorbed by the gap 7, and as a result, the external fiber mortar layer 5 Can be prevented from being damaged. The gap 7 is formed by the expansion and contraction of the paper sheet 6 accompanying the manufacturing process of the fireproof two-layer pipe joint, and can be formed easily and inexpensively because it does not need to be formed using a special device or the like.
[0014]
Further, after determining the fiber direction, the paper sheet 6 may be provided so as to surround the inner tube 4 of the cylindrical receiving square 3 as shown in FIG. Manufacturing time can be shortened and costs can be reduced. In this case, the fiber direction 13 of the paper sheet 6 is set in the circumferential direction S of the inner tube 4 of the receiving port 3 as shown in FIG. 5 depending on the size of the extension of the paper sheet 6 and the size of the gap 7 to be formed. Whether to set in the axial direction T of the inner tube 4 is determined.
[0015]
More specifically, a step portion 9 for receiving the tip of the pipe 2 is formed inside the inner pipe 4 of the receiving port portion 3 and its outer peripheral surface is bulged outwardly from the outer peripheral surface of the joint body 8 to form a step. In this configuration, when the pipe 2 is connected to the receiving port 3, for example, there is a displacement 12 in the pipe 2, and the central axis L is the center of the refractory double-layer pipe joint 1. When the axis M does not match, the pipe 2 must be pushed in with a strong force, and the step 9 is pushed outward by this pushing force, and at the same time the step 10 of the receiving port 3 is pushed outward. The fiber mortar layer 5 covering the step portion 10 may be damaged by the force. However, if the paper sheet 6 is wrapped around the outer periphery of the stepped portion 10 as well as the receiving portion 3 and the gap 7 is formed there, the inner tube 4 can be connected even if the pipe 2 is strongly pressed and connected. This deformation does not reach the fiber mortar layer 5 and can prevent the fiber mortar layer 5 from being damaged. As a result, it is freed from troublesome work such as re-construction, and the efficiency of the piping work is improved.
[0016]
In order to cleanly cover the stepped portion 10 with the paper sheet 6, as shown in FIG. 5, one side of the paper sheet 6 is formed in a corrugated shape 11, and a corrugated paper piece is attached to the surface of the stepped portion 10 by adhesion or the like. May be. The means for fixing the paper sheet 6 to the receiving port 3 is optional, for example, using an adhesive tape. Further, as the paper sheet 6, a paper tube or an elastic paper tube can be used.
[0017]
The paper sheet 6 may be of paper quality with relatively good water absorption, such as drawing paper or white paperboard, but natural plant fibers such as Japanese paper and pulp that absorb moisture and increase in thickness, natural materials such as cotton and linen, etc. It is also possible to use knitted or woven vegetable fibers.
[0018]
Specific examples of the present invention are as follows. 3, the nominal diameter of the joint body 8 was 100 mm, the inner diameter and the outer diameter of the receiving port 3 were 114 mm and 124 mm, respectively, and the wall thickness of the hard vinyl chloride inner tube 4 was 5 mm. The axial length of the receiving port 3 is 50 mm. A paper sheet 6 of white paperboard having a thickness of 0.55 mm and a width of 55 mm was wound around the peripheral surface of the receiving port 3 in an annularly continuous state so as not to be cut, and important points were locked with cellophane tape. This was placed in a mold, and a fiber mortar layer 5 having a thickness of about 11 mm was formed on the peripheral surface. The composition of the fiber mortar was ordinary Portland cement 64%, aggregate 21%, inorganic fiber 10%, and organic fiber 5%, which were kneaded so as to have a moisture content of 28%. This white paperboard 6 has an elongation of 0.2% in the fiber direction, 1.8% in the direction orthogonal to the fiber direction, and 49.1% in the thickness direction. Was set so as to be in the circumferential direction of the inner tube 4 of the receiving port 3.
[0019]
This was taken out from the mold and the fiber mortar layer 5 was cured, but the paperboard 6 of white paperboard started to absorb moisture contained in the layer immediately after the formation of the fiber mortar layer 5 and extended in the circumferential direction. The thickness became 0.82 mm at the maximum, and after that, when the curing of the fiber mortar layer 5 was completed and dried, the thickness returned almost to the original thickness. A gap 9 of 0.39 mm was formed around the receiving port 3 and there was no breakage in the process of curing the fiber mortar layer 5. Then, the pipe 2 was connected to the joint 1, and hot water at 60 ° C. was allowed to flow therein to expand the inner pipe 4. However, the fiber mortar layer 5 was not damaged. In addition, when joining the pipe 2, a deviation of 2 degrees is caused between the center axis of the fireproof double-layer pipe joint 1 and pushed into the receiving port 3 to the limit, but the portion of the fiber corresponding to the stepped portion 10 The mortar layer 5 was not damaged.
[0020]
When the gap 7 of 0.39 mm or more is formed, the fiber mortar layer 5 may be formed by setting the fiber direction 13 of the paper sheet 6 in the axial direction T of the inner tube 4 of the opening 3.
[0021]
When the paper sheet 6 absorbs water, the fibers are unwound, and the fiber mortar layer 5 is dried and cured while the fibers are mixed into the fiber mortar layer 5, so that the paper sheet 6 adheres to the fiber mortar layer 5. As a result, the gap 7 is formed between the inner tube 4 and the paper sheet 6. Further, by forming the thickness of the paper sheet 6 so that it is thicker on the back side than the entrance side of the mouth part 3, the back part of the gap 7 can be formed wider, and the relatively large inner tube 4 The deformation can be absorbed to prevent the fiber mortar layer 5 from being damaged.
[0022]
In the above description of the embodiment, two examples of the receiving port 3 have been described. However, the present invention is also applicable to a fireproof two-layer pipe joint having three or more receiving ports.
[0023]
【The invention's effect】
As described above, in the present invention, the receptacle unit fiber direction Rutotomoni the paper leaves the paper having water absorption is interposed between the circumferential surface and fiber mortar layer of the inner tube of the socket portion of the refractory bilayer fittings The inner tube was set in the circumferential direction or the axial direction, and the gap in the paper surface due to water absorption of the paper sheet was controlled to absorb the bulging deformation of the inner tube. Therefore, it is possible to easily and reliably form a relatively large gap around the inner pipe of the receiving port by water absorption and drying of the paper sheet, and this gap can be freely changed by setting the fiber direction of the paper sheet . Even if the inner pipe swells and deforms by forced press-fitting, the fiber mortar layer is prevented from being damaged, and the piping work can be performed quickly. Further, by forming the paper sheet thicker on the back side than on the inlet side of the receiving □ part, the back part of the gap can be formed wider, and even if the inner tube swells greatly, the fiber mortar Layer damage can be prevented.
[Brief description of the drawings]
1 is a side view showing an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1. FIG. 3 is an enlarged cut side view of the main part of the inner tube. FIG. 5 is a perspective view showing an example of the shape of a paper sheet. FIG. 6 is an enlarged view of the main part of FIG.
1 fireproof double-layer pipe joint, 2 piping, 3 receiving section, 4 inner pipe, 5 fiber mortar layer, 6 paper sheet, 7 gap, 8 joint body, 9 step section, 10 step section, 13 fiber direction,

Claims

配管を挿入するための円筒状の受け口部を２つ以上備えた合成樹脂製の内管の外周を繊維モルタル層で覆った構成の耐火二層管継手に於いて、該受け口部の内管の周面と繊維モルタル層の間に吸水性を有する紙葉を介在させると共に該紙葉の繊維方向を該受け口部の円周方向または軸線方向に設定し、該紙葉の吸水による面方向の伸びを制御して該内管の膨出変形を吸収する隙間を形成したことを特徴とする耐火二層管継手。In a fireproof two-layer pipe joint in which the outer periphery of a synthetic resin inner pipe having two or more cylindrical receptacles for inserting pipes is covered with a fiber mortar layer, the inner pipe of the receptacle the fiber direction of Rutotomoni the paper leaf is interposed paper having a water absorption between the circumferential surface and fiber mortar layer set in the circumferential direction or the axial direction of the socket portion, in a plane direction due to water absorption of the paper leaves refractory bilayer fitting, characterized in that it forms a form a gap by controlling the elongation to absorb bulging deformation of the inner tube.

上記紙葉の厚さを上記受け口部の入り口側よりも奥部側で厚く形成したことを特徴とする請求項１に記載の耐火二層管継手。 The fireproof two-layer pipe joint according to claim 1, wherein the thickness of the paper sheet is formed thicker on the back side than the entrance side of the receiving port .

配管を挿入するための円筒状の受け口部を２つ以上備えた合成樹脂製の内管の外周を繊維モルタル層で覆い、該受け口部の内管と繊維モルタル層の間に吸水性を有する紙葉を介在させた構成の耐火二層管継手において、該内管の膨出変形を吸収する隙間を、該紙葉の繊維方向を該受け口部の円周方向または軸線方向に設定することにより該紙葉の吸水による面方向の伸びを制御して形成したことを特徴とする耐火二層管継手の製造方法。A paper having a fiber mortar layer covering the outer periphery of a synthetic resin inner pipe having two or more cylindrical receptacles for inserting pipes, and having water absorption between the inner pipe of the receptacle and the fiber mortar layer In a fireproof two-layer pipe joint having a configuration in which a leaf is interposed, the gap that absorbs the bulging deformation of the inner pipe is set by setting the fiber direction of the paper sheet to the circumferential direction or the axial direction of the receptacle. A method for producing a refractory double-layer pipe joint, characterized in that it is formed by controlling elongation in the surface direction due to water absorption of a paper sheet.