JP2019132329A - Flange-type pipe joint - Google Patents

Abstract

To provide a flange-type pipe joint which is easy in manufacturing and low in cost since a disc circular gasket hardly contacts directly with an in-pipe fluid owing to a metal inner cylinder body which is arranged inside, and the metal inner cylinder body for prohibiting the deformation of the gasket has a simple cylindrical shape.SOLUTION: Circular recesses 8 are formed in inside end faces of both loose flanges 3, 3, and as a packing material, there are employed a metal inner cylinder body 14 having a dimension substantially equal to that of a pipe, and a disc circular gasket 12 which is smaller than the flange circular recess 8 in an external peripheral diameter, and vulcanization-attached or seized to an external peripheral face of the metal inner cylinder body 14. The gasket is formed into a rectangular shape at its cross section, and its width thickness is slightly wider than a width thickness of the metal inner cylinder body 14.SELECTED DRAWING: Figure 2

Description

  In the present invention, the annular gasket is less likely to come into direct contact with the fluid in the pipe by the inner metal cylinder, and the metal inner cylinder that prevents the gasket from being deformed in the radial direction is a simple cylinder. The present invention relates to a flange type pipe joint that is easy and inexpensive.

  In plumbing work such as water supply and air conditioning, a flange-type coupling method is used to connect metal pipes in a straight line, and this method is superior in terms of mechanical strength of the connecting portion and piping workability. Loose flange type pipe joints are easy to perform piping work because the bolt through-holes of both flanges can be matched during piping by simply turning one flange, and there is no need to forcibly twist the metal pipe. In loose flange type pipe joints, loose flanges with multiple bolt through holes are fitted into metal pipes before the pipe ends are tapped out and the stub ends are welded. The end faces of the parts are butted through sheet packing and O-rings, and bolts are passed through the through holes and tightened with nuts.

  Conventional flange-type pipe joints are made of soft resin or hard rubber with a seat packing or O-ring made of soft resin or hard rubber as disclosed in Japanese Utility Model Laid-Open Nos. 5-8175 and 9-163562. is there. For this reason, when the inside of the pipe becomes high pressure or negative pressure, the tightening force of each bolt must be increased so that the packing or O-ring does not deform plastically. Water leakage occurs, and the loose flange also requires high strength, increasing its overall weight.

  On the other hand, the affiliated company of the present applicant, in utility model registration Nos. 3136954 and 3194436, etc., is an annular elastic gasket as a sealing member arranged between both flanges and a metal made on the outer peripheral side of the elastic gasket. This elastic gasket has a reverse V-shaped lip cross section. Since the pipe joints disclosed in Utility Model Registration Nos. 3136954 and 3194436 compress and seal an elastic gasket that is easily compressively deformed, the tightening force by each bolt only needs to withstand the tube pulling force.

Japanese Utility Model Publication No. 5-8175 JP-A-9-163562 Utility Model Registration No. 3136954 Utility Model Registration No. 3194436 Utility Model Registration No. 3210602

  The flange type pipe joints disclosed in Utility Model Registration Nos. 3136954 and 3194436 need only be able to withstand the pipe pulling force with the tightening force of each bolt. Since the rubber gasket is always in direct contact, deterioration with time of the rubber gasket is likely to progress, and the plasticizer may leak from the gasket into the fluid in the pipe. In the utility model registration No. 3210602, the present applicant uses a metal ring having a U-shaped cross section to be fitted on the inner peripheral side of the annular elastic gasket so that the elastic gasket does not directly contact the fluid in the pipe, By separating from the elastic gasket, the deterioration of the gasket over time is delayed.

  However, in the utility model registration No. 3210602, a metal ring having a U-shaped cross section in which flange portions are formed on both sides in the swiveling process is used. Since this is not possible, it is necessary to increase the outer diameter of the elastic gasket in order to obtain a predetermined sealing pressure. In addition, the metal ring having a U-shaped cross section manufactured by the ribing process is considerably higher in manufacturing cost than a simple cylindrical ring.

  The present invention has been proposed to improve the above-mentioned problems associated with conventional flange-type pipe joints, and by placing a simple cylindrical metal inner cylinder inside the gasket, the outer surface of the elastic gasket can be improved. An object of the present invention is to provide a flange-type pipe joint that can be reduced in diameter and that is less in direct contact with the fluid in the pipe. Another object of the present invention is to provide a flange-type pipe joint in which the gasket does not deform inward even when the pressure inside the pipe becomes negative.

  In the flange-type pipe joint according to the present invention, the end portions of the small-diameter pipes are processed to be stretched, and a packing material is interposed between the end surfaces of the flange portions of both pipes. This flange-type pipe joint is formed with circular recesses on the inner end faces of both loose flanges, and the packing material is a metal inner cylinder having a dimension substantially equal to that of the pipe, and a smaller diameter than the outer peripheral diameter of the flange circular recess. An annular gasket that is vulcanized or bonded to the outer peripheral surface of the metal inner cylinder is used. This gasket has a rectangular cross section and its width and thickness are slightly larger than the width of the metal inner cylinder, and the pipe-passing fluid is less likely to come into contact with the gasket by the metal inner cylinder after assembling the joint.

  The flange-type pipe joint according to the present invention is formed with a circular recess on the inner end faces of both loose flanges, and as a packing material, a cylindrical metal inner cylinder having a dimension substantially equal to that of a pipe, and larger than the metal inner cylinder. A metal outer cylinder having a diameter and an annular gasket that is vulcanized or bonded to the outer peripheral surface of the metal inner cylinder and the inner peripheral surface of the metal outer cylinder may be used. This gasket has a rectangular cross section and its width and thickness are slightly larger than the width and thickness of the metal inner cylinder and the metal outer cylinder. At this time, the metal outer cylinder may be composed of a single or two narrow rings. By forming an annular gap between the narrow rings, a resin annular ring is formed along the annular gap. It is possible to fit the inner periphery of the plate.

  In the flange-type pipe joint according to the present invention, an annular groove is provided on the outer peripheral surface of the gasket or the metal outer cylinder, and the inner peripheral edge of the annular plate made of resin or thin metal plate is fitted along the annular groove. Alternatively, it is preferable that the annular plate is provided with a plurality of circular holes or semicircular notches for bolts. Further, the inner peripheral edge of the metal inner cylinder projects in the front-rear direction, and the front and rear end surfaces thereof are in intimate contact with the bent portion of the pipe collar portion, thereby further reducing the contact of the pipe passing fluid with the gasket.

  In the flange type pipe joint according to the present invention, by arranging a simple cylindrical metal inner cylinder inside the gasket, the outer diameter of the elastic gasket can be made smaller than before, the cost of the gasket is reduced, and the weight of the joint is reduced. It is effective for. In addition, the metal inner cylinder used in the present invention is a simple cylindrical ring and can be applied by cutting the connection pipe, and the manufacturing cost is lower than that of a metal ring having a U-shaped cross section manufactured by swallowing. It is very cheap.

  In the flange type pipe joint according to the present invention, the gasket is less likely to come into direct contact with the fluid in the pipe due to the metal inner cylinder disposed on the inner side, and leakage of the rubber component of the gasket and deterioration with time due to contact between the fluid passing through the pipe and the gasket is reduced. Can be Since the flange-type pipe joint of the present invention is sealed using a gasket that compresses and deforms, the tightening force by each bolt only needs to withstand the tube pulling force. There is no occurrence of water leakage due to the cylinder.

It is a side view which shows the flange type pipe joint which concerns on this invention. It is a disassembled sectional view which shows the arrangement | positioning state of the flange type pipe joint of FIG. It is a front view which shows the loose flange used by this invention. It is a front view which shows the packing material comprised with the gasket and metal inner cylinder used by this invention. It is a partial cross-sectional view which expands and shows the packing material cut | disconnected along the AA line of FIG. It is a front view which shows the other packing material which attached the annular | circular shaped plate with a hole. It is a partial cross-sectional view which expands and shows the packing material cut | disconnected along the BB line of FIG. It is a front view which shows another packing material comprised with a metal outer cylinder, a gasket, and a metal inner cylinder. Furthermore, it is the same partial cross-sectional view as FIG. 7 which expands and shows another packing material. It is an expanded horizontal sectional view which shows the modification of the metal inner cylinder in packing material. It is an expanded transverse cross section which shows the modification of the metal outer cylinder in packing material.

  The present invention will be described with reference to the drawings. In the flange-type pipe joint 1 shown in FIG. 1, the metal pipes 2 and 2 are mainly stainless steel pipes, and the same or different alloy steel pipes, cast iron pipes, cast steel pipes, carbon steel pipes or resin-coated pipes. It may be a steel pipe or a metal pipe with a different inner diameter. The pair of loose flanges 3 and 3 are preferably made of cast iron, cast steel, alloy steel or carbon steel from the viewpoint of cost, and stainless steel can also be used. In the case of cast iron or cast steel, galvanizing or plastic coating May be applied.

  The loose flange 3 is a donut-shaped plane as illustrated in FIG. 3, and usually has a plurality of circular or irregular mounting holes 5 at equal intervals in the circumferential direction. The contour of the flange 3 is recessed except for the portion 6 where the plurality of mounting holes 5 are present to reduce the size and weight, and 3 to 6 mounting holes are arranged at equal intervals in the circumferential direction. The inner surface of the loose flange 3 is provided with a circular recess 8 concentrically with the inner diameter, that is, the through hole 7, and the peripheral wall of the recess does not contact the peripheral wall of the mounting hole 5. The loose flange 3 may have a smaller diameter than the conventional packing material 16 (FIG. 4), so that its planar shape is considerably smaller and thinner than the conventional product shown by the chain line in FIG. And it becomes lighter. The loose flange 3 may be formed as a donut shape as shown in the figure or two halves.

  As shown in FIG. 2, in the loose flange 3, the diameter of the through hole 7 may be substantially equal to the outer diameter of the metal pipe 2 to be connected or may have some margin. The diameter of the circular recess 8 is determined so as to be approximately equal to or slightly larger than the outer diameter of the flange 10 at the end of the pipe and the outer diameter of the gasket 12. Further, the depth of the circular recess 8 is determined so as to be approximately equal to or smaller than the added value of the thickness of the flange portion 10 at the end of the pipe and the half of the thickness of the metal inner cylinder 14 (FIG. 2). FIG. 10).

  The annular gasket 12 (FIG. 4) constitutes a packing material 16 together with the annular metal inner cylinder 14. As shown in FIG. 2 and FIG. 5, the gasket 12 has a rectangular or chamfered cross-section and is almost square. When the gasket 12 is integrated with the metal inner cylinder 14 by injection molding or the like, the inner periphery of the gasket 12 is generally used. The surface becomes flat. The gasket 12 is made of rubber or plastic with high elasticity, and for example, ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), polypropylene, polyester, polyamide, polyacetal resin or the like is used.

  The metal inner cylinder 14 (FIG. 4) has a simple cylindrical shape as shown in FIGS. 2 and 5, and is fitted into the inner peripheral surface of the gasket 12 to be integrated. The metal inner cylinder 14 is made of stainless steel, cast steel, carbon steel, or the like, and in the case of cast steel or carbon steel, anticorrosion processing such as galvanization or resin coating may be performed. The metal inner cylinder 14 has a thickness of about 0.7 to 3.0 mm and generally has the same inner diameter and outer diameter as the metal pipe 2. For example, the metal pipe 2 is cut into a short cylinder and used as it is. May be. In order to integrate the metal inner cylinder 14 with the gasket 12, when the metal inner cylinder 14 is fitted to the inner periphery of the gasket and vulcanized or bonded, a strong bonding interface is obtained. There is no peeling.

  The width thickness of the gasket 12 is slightly thicker than that of the metal inner cylinder 14 as shown in FIG. 5 when not compressed, and is almost the same as that of the metal inner cylinder 14 after the joint is assembled (the chain line in FIG. 5). reference). When the loose flanges 3 and 3 are tightened, the thickness of the gasket 12 is usually compressed to 85 to 95%, and the surfaces of the gasket 12 and the metal inner cylindrical body 14 are almost flush with each other. Further, the compression thickness of the gasket 12 is usually slightly larger than the added depth of the circular recesses 8 and 8 of the loose flanges 3 and 3 when the thickness of the pipe collar portions 10 and 10 is added. When tightened, a minute gap is formed between the end faces of both flanges as shown in FIG. 1, and a cover (not shown) may be further covered to conceal this gap.

  In the flange-type pipe joint 1, the loose flange 3 is usually fitted to the metal pipes 2 and 2, and then the ends of the pipes are tapped out. For example, at the piping site or a pipe processing factory, the flange portion is formed by forming the flange portion 10 at a right angle outwardly in the diametrical direction by a publicly-known flange-rolling machine, and then the other end portion of the pipe is similarly protruding. Process. Thereafter, the packing material 16 is interposed between the end faces of the flange portion 10 of the metal pipe 2, and then both flanges 3 and 3 are coupled and tightened with a plurality of sets of bolts 18 and nuts 20.

  In the flange-type pipe joint 1, when the loose flanges 3 and 3 are tightened with the bolts 18 and the nuts 20, the gasket 12 is appropriately compressed, and the front and rear end surfaces of the metal inner cylinder 14 are not deformed. It is in close contact with the end face of the pipe collar 10. As a result, the metal inner cylindrical body 14 comes into direct contact with the passing fluid of the metal pipes 2 and 2, and the gasket 12 made of rubber or the like hardly comes into contact with the passing fluid. The rubber plasticizer can be prevented from leaking from the gasket into the passing fluid. On the other hand, even when the pressure inside the pipe is negative, since the metal inner cylinder 14 is disposed on the inner peripheral side of the gasket, it is possible to prevent inward deformation of the gasket 12 and water leakage due to the deformation of the gasket 12. There is no accident.

  In the packing material 22 shown in FIG. 6, an annular plate 24 is attached to the outer peripheral surface of the gasket 12, and a plurality of bolt circular holes 26 are provided at equal intervals in the circumferential direction. The annular plate 24 is made of a donut-shaped thin metal plate, a resin sheet, or the like. The outer diameter is made smaller than usual for weight reduction, and the outer diameter is further reduced to make the bolt hole into a semicircular notch shape. May be. The flange 3 (FIG. 3) can also have the same appearance as that of FIG. 6 to reduce the weight so as to match the annular plate 24.

  As shown in FIG. 7, the annular plate 24 is fixed by fitting an inner peripheral edge into an annular groove 28 provided on the outer periphery of the gasket. Since the packing material 22 includes the annular plate 24, when the bolt 18 is temporarily fixed to the circular hole 26, the packing material 22 is not displaced when the loose flanges 3 and 3 are tightened. Even if it is horizontal, the packing material 22 can be easily positioned. Since the annular plate 24 is only used to hold the packing material 22 until the loose flanges 3 and 3 are tightened, the strength is not particularly required.

  The packing material 30 illustrated in FIG. 8 includes a cylindrical metal inner cylinder 14, an annular gasket 34, and a metal outer cylinder 32 having a larger diameter than the metal inner cylinder 14. Like the gasket 16 shown in FIG. 5, the gasket 34 has a substantially rectangular cross section, and its width and thickness are slightly larger than the width and thickness of the metal inner cylinder 14 and the metal outer cylinder 32. Vulcanization adhesion or baking is performed on the outer peripheral surface of the cylindrical body 14 and the inner peripheral surface of the metal outer cylindrical body 32.

  The metal outer cylinder 32 may be made of the same or similar material as the metal inner cylinder 14 and has the same width and thickness as the metal inner cylinder. The metal outer cylinder 32 may be a simple cylinder. After the joint is assembled, the front and rear end surfaces of the metal outer cylinder 32 and the metal inner cylinder 14 are in close contact with the pipe collar, and the pipe passing fluid is used as the metal inner cylinder 14. Makes almost no contact with the gasket. When the joint is assembled, the metal outer cylinder 32 effectively prevents the gasket 34 from expanding outward, so that the gasket can be tightened at a higher pressure, and the pressure resistance of the flange-type pipe joint is further increased.

  In the packing material 30 shown in FIG. 8, it is also possible to attach the thin annular plate 24 shown in FIG. In FIG. 9, the metal outer cylinder 32 is composed of two narrow rings 36 and 36 arranged in parallel, and a narrow annular gap 38 is formed between both cylinders. The annular plate 24 may be fixed by fitting the inner peripheral edge into the gap 38. In FIG. 10, the annular groove 42 may be provided on the outer periphery of the metal outer cylinder 40, and the inner peripheral edge of the annular plate 24 may be fitted into the annular groove and fixed.

  In FIG. 11, the inner peripheral edge of the metal inner cylinder 42 protrudes in the front-rear direction, and the inner peripheral edge is wider than the outer peripheral edge. If possible, it is preferable that the front and rear end surfaces 44 are not simple inclined surfaces, but the cross section is cut into a curved shape so as to be in close contact with the bent portion 46 of the pipe collar 10. As a result, when the joint is assembled, the front and rear end faces 44 of the metal inner cylindrical body 42 can be brought closer to the pipe collar portion 10, and the pipe passing fluid is further reduced from coming into contact with the gasket. In order to cut the front and rear end surfaces 44 into a curved shape, the curvature radius of the bent portion needs to be large to some extent.

  Since the inner peripheral edge of the metal inner cylindrical body 42 protrudes in the front-rear direction, the packing material 48 can be accurately positioned simply by fitting the packing material to the pipe collar portion 10. For this reason, even if the positioning annular plate 24 is omitted, if an adhesive is applied to one end face of the gasket 34, it can be easily temporarily fixed with the adhesive when fitted to the pipe collar 10. Further, since the pipe 2 is usually a ferritic stainless steel pipe and is attached to the magnet, when the metal outer cylinder 40 is magnetized or the gasket 34 is made of a rubber magnet, the packing material 48 is temporarily fixed only by being fitted to the pipe collar 10. Can be positioned easily.

  In the packing material 50 shown in FIG. 11, the inner peripheral edge of the metal inner cylinder 42 protrudes in the front-rear direction, and the lateral width of the metal outer cylinder 52 is substantially equal to the outer dimension between the pipe collars 10 and 10 when the joint is tightened. The inner diameter of the outer metal cylinder is determined to be substantially equal to the outer diameter of the pipe collar 10. At this time, if the front and rear inner peripheral surfaces of the metal outer cylindrical body 52 or the outer peripheral surface of the collar portion 10 is cut slightly in a taper shape in the axial direction, the packing material 50 is pushed into the collar portion 10 strongly or lightly. By simply driving in, the packing material can be fitted into the pipe collar portion 10 and temporarily fixed, and the positioning annular plate 24 and the adhesive can be omitted. Further, the packing material 50 can be temporarily fixed only by caulking the metal outer cylinder 52 and the flange portion 10.

  Next, the present invention will be described based on examples, but the present invention is not limited to the examples. In the flange-type pipe joint 1 shown in FIG. 1, the loose flanges 3 and 3 made of cast steel are substantially donut-shaped planes having a central through hole 7 as shown in FIG. 3, and the diameter of the through hole is 50.4 mm. is there. The loose flange 3 is provided with three bolt mounting holes 5 at equal intervals in the circumferential direction outside the circular recess 8 having a diameter of 62.9 mm.

  The metal pipes 2 and 2 have a nominal diameter of 40A, an inner diameter of 46.2 mm, an outer diameter of 48.6 mm, and a wall thickness of 1.2 mm. The metal pipes 2 and 2 are the same ferritic stainless steel stainless steel pipes. A loose flange 3 is fitted to the metal pipe 2 before the end of the pipe is pulled out. The outer diameter of the collar part 10 is 61.9 mm.

  With respect to the loose flange 3, the diameter of the central through hole 7 is slightly larger than the outer diameter of the metal pipe 2 to be connected. The diameter of the circular recess 8 is 62.9 mm, which is approximately 0.5 mm larger in radius than the outer diameter of the flange 10 at the end of the pipe. The depth of the circular recess 8 is about 4 mm, which is slightly smaller than the sum of the thickness 1.2 mm of the flange 10 at the end of the pipe and the half of the thickness of the gasket 12.

  Regarding the packing material 16, the metal inner cylinder 14 is made of a ferritic stainless steel similar to the metal pipe 2, and has a simple cylindrical shape having a width thickness of 6 mm, an inner diameter of 46.2 mm, and an outer diameter of 48.6 mm. The gasket 12 is formed by injection molding and baked on the outer peripheral surface of the metal inner cylinder 14. The gasket 12 is made of a highly elastic EPDM having a thickness of about 7 mm, an inner diameter of 46.2 mm, and an outer diameter of 61.9 mm in order to obtain a desired tightening force, and its cross section is a chamfered rectangle as shown in FIG. The shape is close to a square.

  Both metal pipes 2, 2 are disposed to face each other with a packing material 16 having a metal inner cylinder 14 and a gasket 12 interposed therebetween, and then end faces of the loose flanges 3, 3 are abutted. At this time, the flange portions 10 and 10 and the gasket 12 are accommodated in the circular recesses 8 and 8 of the loose flanges 3, and after the loose flanges 3 and 3 are aligned, the three knurled bolts 18 are attached to the nuts 20. Tighten with to assemble.

  In the flange-type pipe joint 1, the gasket 12 is compressed by the loose flanges 3, 3, and both end surfaces of the metal inner cylinder 14 are in close contact with the side surfaces of the flange portions 10, 10. As long as it can withstand the extubation force. Three bolts 18 are sufficient, and even if the area of the contact surface of the flange portion 10 of the metal pipe 2 in the gasket 12 is substantially the same as the conventional one, the flange 3 having the three bolt mounting holes 5 is The outer diameter is smaller than that of the conventional loose flange, and referring to the one-dot chain line in FIG.

In the flange type pipe joint, the loose flange made of cast steel is a substantially donut-shaped plane having a central through hole as shown in FIG. 3, and the diameter of the through hole is 62.7 mm. In the loose flange, three bolt mounting holes are provided at equal intervals in the circumferential direction outside the circular recess 8 having a diameter of 74.8 mm. The metal pipe has a nominal diameter of 50A, an inner diameter of 58.1 mm, an outer diameter of 60.5 mm, and a wall thickness of 1.2 mm. The loose flange 3 is fitted to the metal pipe before the end of the pipe is pulled out. The outer diameter of the collar part 10 is 73.8 mm.

  In this loose flange, the diameter of the central through hole is slightly larger than the outer diameter of the metal pipe 2 to be connected, and the diameter of the circular recess 8 is 74.8 mm, which is larger than the outer diameter of the flange at the end of the pipe. . Further, the depth of the circular recess 8 is about 5 mm.

  Regarding the packing material 30 (FIG. 8), the metal inner cylinder 14 and the metal outer cylinder 32 are made of ferritic stainless steel similar to a metal pipe, and both have a thickness of 6 mm and a thickness of 1.2 mm. The inner cylinder 14 has a simple cylindrical shape with an inner diameter of 58.1 mm and the metal outer cylinder 32 has an outer diameter of 73.8 mm. The gasket 34 is formed by injection molding and is baked onto the outer peripheral surface of the metal inner cylinder 14 and the inner peripheral surface of the metal outer cylinder 32. The gasket 34 is made of a highly elastic EPDM having a thickness of about 7 mm in order to obtain a desired tightening force.

  In this flange-type pipe joint, even if the gasket 34 is compressed by the loose flanges 3, 3, the metal inner cylinder 14 and the metal outer cylinder 32 do not deform in the radial direction, but the metal inner cylinder 14 and the metal outer cylinder 32. The both end faces of the flanges are in close contact with the side faces of the collar portions 10, 10 (see FIG. 10). For this reason, this flange type pipe joint has a higher pressure resistance than the flange type pipe joint 1 of the first embodiment. This flange-type pipe joint is mainly used in places where the pipe connection is vertical.

  In the flange-type pipe joint according to the second embodiment, as shown in FIG. 10, an annular groove 42 is provided on the outer periphery of the metal outer cylinder 40, and the inner peripheral edge of the annular plate 24 (see FIG. 6) is fitted into the annular groove 42. Secure with. Since the packing material 48 includes the annular plate 24, when the bolt 18 is temporarily fixed to the circular hole 26, the packing material 48 is not displaced when the loose flanges 3 and 3 are tightened. It can be positioned easily even when it is horizontal.

  In the packing material shown in FIG. 10, the metal outer cylinder 40 has a simple cylindrical shape, and the annular groove 42 may not be provided on the outer periphery thereof. On the other hand, the inner peripheral edge of the metal inner cylinder 42 protrudes in the front-rear direction, and the inner peripheral edge is cut with a lathe so that the inner peripheral edge is wider than the outer peripheral edge and the cross-section is curved. When the joint is assembled, this packing allows the front and rear end surfaces 44 of the inner metal cylinder 42 to be in intimate contact with the pipe collar portion 10, and the pipe passing fluid is further reduced from coming into contact with the gasket.

  Since the inner peripheral edge of the metal inner cylindrical body 42 projects in the front-rear direction, the packing material can be accurately positioned simply by fitting the packing material to the pipe collar portion 10. For this reason, if an adhesive is applied to one end face of the gasket 34, even if the positioning annular plate 24 is omitted, the gasket 34 can be easily temporarily fixed with the adhesive when fitted to the pipe collar 10. Therefore, the packing material 48 can be temporarily fixed alone without passing the bolts 18, and the packing material is not displaced when the loose flanges 3 and 3 are tightened. Regardless, it can be connected easily and accurately.

DESCRIPTION OF SYMBOLS 1 Flange type pipe joint 2,2 Metal pipe 3 Loose flange 5 Bolt mounting hole 8 Circular dent 10 Brim part 12 Gasket 14 Metal inner cylinder 16 Packing material 32 Metal outer cylinder

Claims (5)

  A pipe joint that pipes the end of the pipe, interposes a packing material between the end faces of both pipes, and then tightens both loose flanges with bolts. As the packing material, an inner cylindrical body having a size substantially equal to that of the pipe, and an annular shape that is smaller than the outer peripheral diameter of the flange circular recess and is vulcanized or bonded to the outer peripheral surface of the inner metal cylinder. The gasket has a rectangular cross section and its width and thickness are slightly larger than the width of the metal inner cylinder. After the fitting is assembled, the pipe-passing fluid is brought into contact with the gasket by the metal inner cylinder. Flanged pipe fittings that rarely do.   A pipe joint that pipes the end of the pipe, interposes a packing material between the end faces of both pipes, and then tightens both loose flanges with bolts. As the packing material, a cylindrical metal inner cylinder having substantially the same dimensions as the pipe, a metal outer cylinder having a larger diameter than the metal inner cylinder, an outer peripheral surface of the metal inner cylinder, and a metal outer An annular gasket that is vulcanized or bonded to the inner peripheral surface of the cylindrical body is used, and the gasket has a rectangular cross section, and its width and thickness are larger than the width and thickness of the metal inner cylinder and the metal outer cylinder. Flange-type pipe joint that is slightly larger and the pipe-passing fluid is less likely to come into contact with the gasket by the metal inner cylinder after the joint is assembled.   The metal outer cylinder is composed of a single or two narrow rings, and an annular gap is formed between both narrow rings so that the inner periphery of the resin annular plate is fitted along the annular gap. The pipe joint according to claim 2, wherein the annular plate is provided with a plurality of circular holes or semicircular notches for bolts.   An annular groove is provided on the outer peripheral surface of the gasket or metal outer cylinder, and an inner peripheral edge of a resin or thin metal plate annular plate is fitted along the annular groove, and a plurality of bolts are attached to the annular plate. The pipe joint according to claim 1 or 2, wherein a circular hole or a semicircular cutout is provided.   The pipe inner fluid further reduces contact with the gasket by causing the inner peripheral edge of the metal inner cylindrical body to protrude in the front-rear direction and its front and rear end faces in intimate contact with the bent portion of the pipe collar. The described pipe joint.

Images