JP2002323184A - Fixing packing for flange joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To advantageously maintain airtightness of a fixing packing for a flange joint by reducing tightening errors of each bolt, when the fixing packing is pressed between both flange members in a method pipe. SOLUTION: This fixing packing comprises a packing body provided with a center-hole corresponding to internal diameter of the pipe, a hollow part of the packing body for sealing in a filling fluid or air, and a number of internal projections arranged dispersedly on the inside surface of a side wall in the hollow part. When tightening both flange members, compression deformation of the packing body is reduced by the internal projections in the hollow part, and airtightness is maintained by compressing by fluidizing the filling fluid and air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flange joint capable of retaining airtightness by enclosing a flowable object in a packing to reduce a tightening error when crimping between two flange members of a metal pipe. Related to fixed packing.

[0002]

2. Description of the Related Art Stainless steel pipes are often used for large-diameter metal pipes to be piped inside buildings. When piping each metal pipe, the mechanical strength of the pipe joint and the workability of the pipe are required. Use a flange connection method to connect them. Generally, in a flange type pipe fitting, a pipe end is fitted with a wrap joy-shaped flange member, and then the pipe end is worked out or a stub end is welded. The flange member may be fixed to the pipe by welding after slip-on insertion.

[0003] Four or six through holes are provided in the flange member of the metal pipe to be joined at equal intervals in the circumferential direction. Tighten with. Further, a fixed packing made of rubber or asbestos is arranged between the two flange members, and the packing is strongly pressed between the two flange members by tightening a plurality of sets of bolts and nuts penetrating the both flange members. This crimping prevents liquid leakage from between the two flange members.

[0004]

The fixed packing used in the flange-type pipe joining method is generally made of a hard round material made of polytetrafluoroethylene (PTFE) resin around a packing body made of flat round asbestos or rubber. Covered with cover. This type of packing has extremely low elasticity in the axial direction, and when crimping with four or six sets of bolts and nuts, if all sets are not uniformly tightened, the pressure distribution in the packing plane becomes uneven, Liquid leakage will occur from the tightly packed packing.

On the other hand, if the fixed packing is made of soft rubber or polyurethane, it is difficult to keep the entire packing tight by a high pressing force, so that it is difficult to maintain high airtightness at the pipe connecting portion. When a soft rubber or polyurethane packing is bonded in a manner that has inherent bending stress, even if the pipe joint is piped as specified, it will bend after piping, and the pipe joint will not be as strong as pressure resistance and mechanical strength. May be a problem.

The present invention has been proposed in order to improve the above-mentioned problems concerning the packing used in the flange-type pipe connection method, and the packing body is hollow and the filling liquid and air are present. It is an object of the present invention to provide a fixed packing for a joint in which a filling liquid or air appropriately flows inside a packing body when tightened between flange members of a metal pipe, and a pressure distribution on a packing plane is equalized. Another object of the present invention is to fix a joint for preventing deterioration of the packing body and increasing its service life by preventing the liquid flowing in the pipe from directly contacting the packing body when both pipes are connected and used. Is to provide packing. Another object of the present invention is to provide a fixed packing for a joint in which a cylindrical boss of a packing protrusion is fitted into a bolt hole of a flange member when tightening between the two flange members, thereby preventing a displacement between the flange member and the packing. It is to provide.

[0007]

In order to achieve the above object, a fixed packing for a flange joint according to the present invention is arranged between flange members of both metal pipes to be joined, and is tightened by clamping between the two flange members. For packing to be crimped. This packing is used for sealing a stationary part such as a pipe flange, and is called a stationary seal or a stationary seal in Japanese Industrial Standards (JIS).

The fixed packing according to the present invention includes a packing body provided with a center hole corresponding to an inner diameter of a pipe, a hollow portion of the packing body for filling a filling liquid or air, and a distributed arrangement on the inner surface of an opposing side wall in the hollow portion. And a large number of internal projections. It is preferable to fill the hollow portion of the packing body with a filling liquid such as silicon grease, rather than air that may leak from the packing body due to long-term pressure bonding. This packing body is preferably composed of two injection-molded halves, and both halves are U-shaped with a shallow cross-section in the diameter direction, and the two halves are fitted with a tenon ridge and a tenon groove. Alternatively, they are integrated by applying an adhesive or the like. In the hollow portion of the packing main body, each of the internal projections is formed on one or both of the inner surfaces of the hollow portion in a dispersed manner.

The fixed packing according to the present invention includes a packing body provided with a center hole corresponding to an inner diameter of a pipe, a hollow portion of the packing body that fills a filling liquid or air, and a concentric inner surface of an opposing side wall in the hollow portion. And a row of curved projections arranged in a row. This type of fixed packing is, for example, a spectacle-shaped packing (FIG. 1), a flat round packing (FIG. 8) or a relatively large-diameter full-flange packing or a flange-diameter packing (FIG. 9).

The fixed packing according to the present invention has a center hole corresponding to the inner diameter of the pipe, and is formed and filled when the two half molds are fitted to the packing body composed of two half molds. It has a hollow portion of a packing body for sealing liquid or air, and a ring member provided on the inner peripheral wall of the packing in one of the half molds. In this fixed packing, when the two pipes are connected and used, the liquid flowing in the pipes comes into contact with only the ring member, and does not come into direct contact with the packing body.

Further, the fixed packing according to the present invention includes a packing body provided with a center hole corresponding to an inner diameter of a pipe, a protrusion provided with two or a plurality of bolt holes arranged in a diametric direction or a circumferential direction, and A cylindrical boss formed on the protruding portion and capable of being fitted into the bolt hole of the flange member. When the packing is tightened between the two flange members, the cylindrical boss of the packing protrusion is fitted into the bolt hole of the flange member, thereby preventing a displacement between the flange member and the packing.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fixed packing according to the present invention is flat as shown in FIGS.
As shown in FIG. 3, the gasket has a packing body 8 provided with a center hole 9 corresponding to the inner diameter of the pipe, and a hollow portion 10 of the packing body 8 capable of filling air. The hollow portion 10 having a donut shape has an internal projection 17 on one or both of the inner surfaces of the upper and lower walls.
The compression deformation of the packing body 8 is suppressed by the internal protrusions 17 and 18 when the two flanges 18 are arranged in a distributed manner.

The fixed packing 7 is, as shown in FIG.
By being compressed between the two flange members 3 and 3 and compressing and flowing the filling liquid and air in the hollow portion 10 of the packing body 8, the pressure distribution is equalized with respect to the packing plane and the airtightness is improved. In order to achieve the uniform pressure distribution and the pressure resistance at the same time, it is necessary that the packing 7 can be compressed and deformed even if the material thereof is relatively hard. Therefore, the hollow portion 10 is formed below the compression plane of the packing body 8. At the same time, it is desirable that a large number of internal projections 17 and 18 are provided in the hollow portion to prevent deformation easily, and that even if the entire surface of the hollow portion 10 is in communication, its internal volume is relatively small.

In the present invention, the internal projections 17 and 18
Is a curved shape as shown in FIG. 4 and FIG. 5, a circular or square plane as shown in FIG. 10, and if it is a curved projection row, it is arranged concentrically with the center hole, or a straight line having a certain length or The bent ridges may be arranged in parallel, or these planar projections may be arranged in combination with one another. Each of the inner projections is provided on the opposing wall surface of the hollow portion 10, that is, the half-split type
May be dispersedly arranged in one or both of them, and a fitting mode of the projection and the concave portion (see FIG. 14) may be adopted. The height of the internal projections 17 and 18 is generally equal to the inner dimension of the hollow portion 10, that is, the depth of the annular recesses of the half halves 15 and 16, as shown in FIG.

The material of the fixed packing 7 is polyolefin resin, polyurethane resin, nylon resin, silicone resin, silicone rubber, polyvinyl chloride resin, polyacetal resin (trade name: Duracon), neoprene rubber, PT
PTFE resin and the like, and PTFE resin can be powder-molded, but is not used for complicated molding processing, and is used in combination with other molded products. The fixed packing 7 is made of a relatively hard material, and the thin opposed side wall of the hollow portion may be slightly bulged outward as compared with the thick portion as shown in FIG.

Since the fixed packing 7 is usually manufactured by injection molding, it can correspond to an arbitrary shape. If the fixed packing 7 is composed of the half halves 15 and 16 as shown in FIG. 3, it is easy to manufacture and mass production is possible (FIG. 3). 4, FIG. 5). In order to integrate the halves 15 and 16, a tenon-shaped projection 2
2, 24 and tenon grooves 19, 20 and tenon holes may be formed and fitted together, or an adhesive may be applied and fixed to the surface of each thick part (see FIG. 14). Further, it is also possible to integrate them by using ultrasonic welding, high frequency welding, rotary friction welding, induction heating welding, hot plate welding or the like. As shown in FIG. 12, the fixed packing 7 may have an integral shape in which an upper die 72 and a lower die 74 of a donut-shaped plane are connected by an inner peripheral annular portion 75.

The fixed packing is provided on the inner peripheral wall of the packing body or on one half mold 40.
1 (FIGS. 6 and 7) is preferably installed on the inner peripheral wall of the packing. The ring member 41 has a substantially semicircular, U-shaped or rectangular cross section, and may be inserted at the time of injection molding if made of metal, or may be fitted after molding if made of PTFE resin or the like. If the ring member 41 is made of metal, it is desirable to perform an appropriate electrical insulation treatment such as resin coating. When the ring member 41 is installed on the inner peripheral wall of the packing body, when the packing is used between both pipes,
The liquid such as high-temperature water flowing through the pipe contacts only the ring member and does not directly contact the resin packing body. Since the resin does not come into direct contact with high-temperature water or the like, deterioration is small, and the service life of the packing is prolonged. Instead of this ring member, a cover made of PTFE resin or the like may be attached.

As shown in FIGS. 4 to 7, this fixed packing has bolt holes 32 in the projections 31 and 31 and forms a cylindrical boss 33 in the projection, and the cylindrical boss has a flange. It is preferable to have an outer diameter that can be fitted into the bolt hole 36 of the member 35. In the protrusions 31, 31, the bolt holes 32 have a smaller diameter than the bolt holes 13 (FIG. 1), or the bolt holes 36 of the flange member 35 have a larger diameter than the bolt holes of the flange member 3 (FIG. 2). It is. Tubular boss 33
Are bolt holes 36 of the flange member 35 at the time of assembling the joint.
And the gap between the fixed packing and the flange member 35 can be prevented. As a result, the pipe 37 and the flange member 35
Even if there is some deviation, the deviation between the flange member and the packing 30 is not added, and the possibility that a part of the packing 30 projects into the inner peripheral surface of the pipe 37 is eliminated.

[0019]

Next, the present invention will be described based on examples, but the present invention is not limited to the examples. The joint 1 to which the fixed packing 7 (FIG. 1) according to the present invention is applied has a stainless steel metal pipe 2, 2 as illustrated in FIG.
And flange members 3 and 3 in the form of wrap joys used for the connection of the members. The flange members are made of steel. For example, the metal pipe 2 has a diameter of 6.5 cm and a length of 5.5 m, and the center hole of the wrap joy-shaped flange member 3 is about 6.6 cm. The flange member 3 is fitted to the end of the pipe 2, and then the end of the pipe 2 is formed by a known boring machine to form a brim 5, and then the other end of the pipe is also formed. Process similarly.

The eyeglass-shaped fixed packing 7 is made of, for example, a polyurethane resin or a polyethylene resin. As shown in FIG. 2, a circular packing body 8 has an outer diameter substantially equal to the flange 5 of the pipe 2. It has a center hole 9 corresponding to the inner diameter of the pipe 2 and a hollow part 10 having a donut-shaped plane in which a filling liquid such as silicon grease can be filled.
In the fixed packing 7, the outer peripheral edge 1 of the circular packing body 8
1 and a flat protrusion 12, 1 extending diametrically outward.
2 and the size and position of the bolt hole 13 of the protrusion are
It corresponds to that of the bolt hole 14 of the flange member 3.

As illustrated in FIG. 3, the fixed packing 7
Is composed of two half molds 15 and 16 having similar shapes with respect to the packing body 8. Donut-shaped half-split type 15,
Reference numeral 16 has a U-shaped annular recess having a shallow diametrical cross section that forms the internal projections 17 and 18, and the hollow portion 10 is formed by both annular recesses. Referring to FIGS. 4 and 5, one half mold 15 having a protrusion has a circular tenon groove 19 having a diameter larger than the outer diameter of the annular recess and a circular tenon having a diameter smaller than the inner diameter of the annular recess. A groove 20 is provided. On the other hand, the other half mold 16 has a circular tenon 22 that can fit into the tenon 19 at the annular outer extension 21 and a circular tenon 24 that can fit into the tenon 20 at the annular inner extension 23. To form

Internal projections 17 and 18 are respectively arranged on the inner surfaces of the annular recesses of the half molds 15 and 16, and the height of each projection is equal to the interval between the opposing side surfaces, that is, the inner size of the hollow portion 10. It is determined as follows. As exemplified in FIGS. 4 and 5,
The internal projections 17 and 18 are composed of a row of curved projections divided into a predetermined length.
In the half mold 16, two curved projection rows are arranged concentrically, and the circular projections of the curved projection rows are all different, so that when the half molds 15 and 16 are fitted, the internal projections 17 and 18 are hollow. Distributively arranged on the inner surface of the opposing side wall of the part 10, and a narrow annular space is formed between each row of projections.

When the fixed packing 7 is used, a filling liquid such as silicon grease is put into the annular recesses of the two half molds 15 and 16 at the time of use, and the tenon-shaped projections 22 and 24 of the half mold 15 are joined to the half molds 15 and 16. Half-split type 1 fit into tenon grooves 19 and 20
By integrating 5 and 16, the hollow portion 10 in which the filling liquid is sealed is formed. The metal pipe 2 may be transported to the piping site and stored after completion of the fining process at the factory. At the piping site, pipes 2, 2
The ends of (FIG. 1) are brought close to each other, the flange members 3 and 3 are positioned, the fixed packing 7 is interposed between the end faces of the flanges 5 of both pipes 2, and the bolt-nut 2 is passed through the bolt hole 13.
At 6, the two flange members 3, 3 are connected. When this joining operation is completed, the pipe 2 is attached to a wall surface or the like with a fixing bracket (not shown) such as a U bolt.

When each set of bolts and nuts 26 is strongly tightened, the packing 7 is strongly pressed by the end face of the flange 5 of the pipes 2, 2, and the packing is slightly compressed and deformed in the axial direction. Even if the amount of rotation of the nut in each set of bolts and nuts 26 is different and the pressing force on the packing 7 is slightly different, the filling liquid is partially and strongly compressed in the hollow portion 10 of the packing 7 at this time. By properly flowing through the annular space formed between the internal projections of the hollow portion, the packing 7 is compressed almost uniformly with respect to its plane, thereby maintaining airtightness.
Even if the fixed packing 7 is continuously compressed between the pipes 2 and 2 for a long time after the piping, the hollow portion 10 does not slack due to the presence of the filling liquid, and always maintains a constant compressive stress.

In a test experiment, a flat round packing was manufactured, and the packing was sandwiched between flange members of a metal pipe and tightened with each set of bolts and nuts. The packing was found to be airtight. On the other hand, in the case of the conventional rubber packing, even if the planar shape is the same, when tightening the bolts and nuts of each group, if the pressing force is increased, leakage always occurs from almost the same place.

The fixed packing 30 (FIG. 6) constituted by the half halves 15 and 16 shown in FIGS. 4 and 5 is slightly different from the packing 7 in FIG.
Bolt holes 32 are formed in the protruding portions 31, and a cylindrical boss 33 is formed in the protruding portion. The cylindrical boss has an outer diameter capable of being fitted into the bolt hole 36 of the flange member 35 (see FIG. 6). For this reason, the bolt hole 32 has a smaller diameter than the bolt hole 13 (FIG. 1).

At the piping site, the ends of the two pipes 37 are brought close to each other, the two flange members 35 are positioned, the fixed packing 30 is interposed between the end faces of the flanges of the two pipes 37, and the bolts passed through the bolt holes 32. The two flange members 35 are connected by a nut (not shown). When tightening between the two flange members 35, the cylindrical boss 33 of the packing protrusion 31 is fitted into the bolt hole 36 of the flange member 35, thereby preventing the flange member 35 from being displaced from the packing 30. As a result, even if there is some deviation between the pipe 37 and the flange member 35, the deviation between the flange member and the packing 30 is not added, and the packing 3 is inserted into the inner peripheral surface of the pipe 37.
The possibility that a part of 0 protrudes is eliminated.

The fixed packing 38 shown in FIG. 7 has a ring member 4 having a substantially semicircular cross section in one half mold 40.
1 is installed on the inner peripheral wall of the packing. If the ring member 41 is made of metal, it may be inserted at the time of injection molding.
If it is made of FE, it may be fitted after molding. If the ring member 41 is made of metal, the ring member 41 is subjected to an electrical insulation treatment by resin coating or the like. In the other half mold 42, it is necessary that the inner peripheral end 43 does not extend to the inner peripheral wall of the packing.

As shown in FIG. 6, the fixed packing 38 constituted by the half-split type 40.42 is interposed between the end faces of the flanges of the two pipes 37, and is connected to the two flange members by bolts and nuts passed through the holes 32 and 36. 35. Fixed packing 38
Then, when both pipes 37 are connected and used, the liquid such as high-temperature water flowing through the pipes comes into contact only with the ring member 41 and does not come into direct contact with the packing body. Therefore, even if the resin of the packing body does not come into direct contact with the high-temperature water or the like in the high-pressure environment after piping in a high-pressure environment for a long time, the resin does not directly contact the high-temperature water and the like, so that the deterioration is small and the ring member 41 increases the durability of the packing 38. .

FIG. 8 shows a flat round fixed packing 44 having an outer diameter substantially equal to the flange 5 (FIG. 2) of the pipe 2 and corresponding to the inner diameter of the pipe 2 as shown in FIG. It has a packing main body provided with a center hole 9 and a hollow portion 45 of the packing main body capable of filling air, and is constituted by two half-molds having substantially the same shape. On the other hand, the fixed packing 46 shown in FIG. 9 is a full-flange packing, and the annular protrusion 4 extending outward from the outer peripheral edge of the circular packing body.
Seven. The fixed packing 46 includes a packing body having a center hole corresponding to the inner diameter of the pipe, four or six bolt holes 48 formed at equal intervals in the circumferential direction at the protrusion 47, and a packing capable of sealing air. Hollow part 4 of main body
9 is provided. The size and position of each bolt hole 48 correspond to those of each bolt hole of the flange member 3.

The fixed packing 5 in the form of glasses shown in FIG.
0 is the same appearance as the packing 7 shown in FIG. As shown in FIG. 11, the fixed packing 50 has a substantially identical shape.
It is composed of half halves 51 and 52. Each half mold 51,
52 has a U-shaped shallow cross section in the diameter direction, and has an inner peripheral thick portion 54 and an outer peripheral thick portion 56 having a rectangular cross section. In both halves, a mortise 58 is formed on the surface of one thick portion 54, 56, and a tenon 60 is formed on the surface of the other thick portion 54, 56.

On the inner surface of the opposing side wall 62 of each of the half halves 54 and 56, projections 64 each having a circular horizontal cross section are dispersedly formed, and the projections have an elongated conical shape with a round head. The height of each projection 64 is determined so as to be substantially equal to the interval between the opposing side walls 62, 62, that is, the inner dimension of the hollow portion. The protrusions 64 on one side wall 62 are located between the protrusions 64 on the other side wall 62 and are densely arranged so that the space of the hollow portion 66 is reduced. In the fixed packing 50, the two half molds 51 and 52 are overlapped during use, and the mortice 58 of one half is fitted into the mortise 60 of the other half and integrated to form the hollow portion 66. The packing body has a center hole 68 corresponding to the pipe inner diameter.

FIG. 12 shows a second modification of the hollow portion structure of the packing body. The packing 70 is not two half-split types, but an upper die 72 and a lower die 74 of a donut-shaped plane are formed by an inner annular portion 75. It is an integral shape connected by. In the packing 70, the upper mold 72 and the lower mold 74 are substantially the same shape, and a tenon-like projection 77 is formed on one surface of an outer peripheral thick portion 76 having a rectangular cross section, and a mortise 78 is formed on the other surface. Inner circumference annular part 7
5 is a normal thick portion 54 (FIG. 11) for easy deformation.
Thinner than the wall thickness.

The fixed packing 70 is made of a relatively soft synthetic resin, and is manufactured by, for example, injection molding. The packing 70 may be formed in an open state, as shown by the one-dot chain line in FIG. 12, so that the upper mold 72 and the lower mold 74 can always accurately match at the time of use, and the liquid may enter the hollow portion 80. There is no.

FIG. 13 shows a third modification of the hollow structure of the packing main body. The packing 82 is composed of two half molds 83, 83 having substantially the same shape. In the half mold 83, a tenon projection 86 is formed on the surface of one inner peripheral thick part 84, and a mortise 88 is formed on the surface of the other inner peripheral thick part 84. The thin opposing side wall 90 of each half mold 83 has a thick portion 8
It swells slightly outward compared to 4,85.

The fixed packing 82 can be formed from a relatively hard material. In the packing 82, even if the thick portions 84 and 85 do not deform when the bolts and nuts are tightened, only the opposing side wall 90 is pressed and deformed, and the air is compressed in the hollow portion 91 and flows appropriately. The packing 8
The two planes are pressed almost evenly to maintain airtightness.

FIG. 14 shows a fourth modification of the hollow structure of the packing main body.
A large number of protrusions 106 and concave portions 108 are respectively formed on the inner side surfaces of the opposing side walls 104 of the base members 02 and 102 in a distributed manner. Each protrusion 106 has a conical or pyramid shape with a round head,
The recess 108 fits with the projection 106. The height of each protrusion 106 and recess 108 is determined so as to be substantially equal to the inner size of the packing. The protrusion may be formed on only one of the inner surfaces of the opposing side wall 104, and the concave portion 108 to be fitted with each protrusion may be formed on only the other of the inner surface of the opposing side wall 104.

In the fixed packing 100, the half molds 102, 102 are provided with an adhesive 11 on each thick part surface.
0 is applied and integrated. Instead of applying the adhesive 110, it may be integrated using ultrasonic welding, high frequency welding, rotary friction welding, or the like.

[0039]

The fixed packing according to the present invention is sandwiched and pressed between the two flange members, and when tightened between the two flange members, the filling liquid or the like is compressed and flows in the hollow portion of the packing body so that the packing is flat on the packing plane. Almost equalize the pressure distribution. In the fixed packing of the present invention, by filling a flowable filling liquid or the like in the hollow portion, a tightening error when crimping between the two flange members of the metal pipe is relaxed to improve airtightness, and the presence of the filling liquid The airtightness can be maintained for a long time without the hollow portion becoming flat. The fixed packing facilitates piping work and almost eliminates water leak accidents.

[0040] The fixed packing of the present invention, even if it is made of a relatively hard material, has a pressure in the packing plane even if all sets are tightened somewhat unevenly when crimped with four or six sets of bolts and nuts. The distribution is not uneven, and liquid leakage does not occur from a weakly tightened packing portion. The packing of the present invention does not need to be made of soft rubber or polyurethane, and does not cause any problem regarding the pressure resistance of the packing.

In the fixing packing of the present invention, when a cylindrical boss is formed near the bolt hole of the projecting portion, and the cylindrical boss fits into the bolt hole of the flange member at the time of assembling the joint,
As a result, it is possible to prevent a part of the packing from projecting into the inner peripheral surface of the pipe. In addition, when a ring member is installed on the inner peripheral wall of the fixed packing, liquid such as high-temperature water flowing through the connection pipe contacts only the ring member in a high-pressure environment and does not directly contact the packing body. Since it does not come into direct contact with high-temperature water, deterioration is small and the service life of the packing is prolonged.

[Brief description of the drawings]

FIG. 1 is a plan view showing a spectacle-shaped packing which is a fixed packing according to the present invention.

FIG. 2 is a sectional view showing a flange joint to which the fixed packing shown in FIG. 1 is attached.

FIG. 3 is a partially enlarged sectional view of the fixed packing shown in FIG.

FIG. 4 is a cross-sectional view showing one of the half-split molds constituting the fixed packing.

FIG. 5 is a sectional view showing the other half of the half-split type.

6 is a sectional view showing a fixed packing similar to the packing constituted by the half-split type shown in FIGS. 4 and 5, together with a part of a joint.

FIG. 7 is a sectional view similar to FIG. 2, showing a modification of the fixed packing.

FIG. 8 is a plan view showing a flat round fixed packing.

FIG. 9 is a plan view showing a full flange packing.

FIG. 10 is a plan view similar to FIG. 1 showing a modification of the fixed packing.

FIG. 11 is a partially enlarged sectional view of a main part in FIG. 10;

FIG. 12 is a partially enlarged sectional view showing a second modification of the packing body.

FIG. 13 is a partially enlarged sectional view showing a third modification of the packing body.

FIG. 14 is a partially enlarged sectional view showing a fourth modification of the packing body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint 2 Metal pipe 3, 3 Flange member 5 Pipe collar 7 Fixed packing 8 Packing main body 9 Center hole 10 Hollow part 15, 16 Half-split type 17, 18 Internal projection

Claims (5)

[Claims] 1. A packing which is disposed between flanges of two metal pipes to be joined and which is press-fitted by tightening between two flange members, wherein a packing body provided with a center hole corresponding to an inner diameter of the pipe; It has a hollow portion of the packing body for enclosing air, and a large number of internal projections dispersedly arranged on the inner surface of the opposing side wall in the hollow portion, and when tightening between the two flange members, compressive deformation of the packing body is hollow. A fixed packing for a flange joint, which is suppressed by the internal projections of the part and compresses and flows the filling liquid or air in the hollow part to maintain airtightness. 2. A packing which is arranged between the flanges of both metal pipes to be joined and which is press-fitted by tightening between two flange members, wherein a packing body having a center hole corresponding to the inner diameter of the pipe is provided. It has a hollow portion of the packing body that seals air, and a curved projection row that is arranged concentrically on the inner surface of the opposing side wall in the hollow portion, and when the flange member is tightened, compressive deformation of the packing body is reduced. A fixed packing for a flange joint, which is suppressed by the curved projection rows in the hollow portion and keeps airtight by filling and flowing the filling liquid or air in the annular space between the curved projection rows in the hollow portion. 3. The packing body is composed of two injection-molded halves, each of which has a U-shaped shallow cross section in the diameter direction having an inner projection. The packing according to claim 1 or 2, wherein the packing is integrated by fitting with a tenon groove or applying an adhesive. 4. A packing which is disposed between the flange portions of both metal pipes to be joined and which is press-fitted by tightening between both flange members, wherein a center hole corresponding to the inner diameter of the pipe is provided and two half-split molds are provided. A packing body, a hollow portion of the packing body that is formed when two half molds are fitted to fill the filling liquid or air, and a ring member installed on the inner wall of the packing in one half mold. A fixed packing for a flange joint, wherein when the pipes are connected and used, the liquid flowing through the pipes contacts the ring member and does not directly contact the packing. 5. A packing which is disposed between the flanges of both metal pipes to be joined and which is press-fitted by tightening between both flange members, wherein the packing body has a center hole corresponding to the inner diameter of the pipe. A protrusion provided with two or a plurality of circumferentially arranged bolt holes, and a cylindrical boss formed in the protrusion and capable of being fitted into the bolt hole of the flange member;
When tightening between the two flange members, the cylindrical boss of the packing protrusion is inserted into the bolt hole of the flange member, thereby preventing a deviation between the flange member and the packing and securing airtightness for the flange joint. .