JP6978993B2 - Flange joint fastening method - Google Patents

Description

The present invention relates to a method for fastening a flange joint.

When connecting pipes extending in the horizontal direction, the flange joints face each other and are aligned, and a gasket is inserted between the facing surfaces of the flange joints to fasten the flange joints with bolts.

In this case, if the flange joint is fastened without supporting the gasket, the gasket will be placed on the lower bolt.

Due to the difference between the bolt holes in the flange joint and the diameter of the bolt, the center of the gasket on the bolt usually does not coincide with the center of the flange joint.

Therefore, a jig is inserted between the surfaces of the flange joint, the gasket is supported while adjusting the position of the gasket with respect to the flange joint, and the bolt is tightened in that state to fasten the flange joint (for example, a patent). See Document 1).

Japanese Unexamined Patent Publication No. 7-310874

When the jig is inserted between the surfaces of the flange joint to adjust the position of the gasket as in Patent Document 1, a worker who operates the jig is required separately from the worker who tightens the bolt. In addition, when fastening flange joints with fastening bolts, the gasket is placed on the threaded portion of the fastening bolt, so there is a problem that the threaded portion of the fastening bolt damages the gasket when tightening the fastening bolt. There was a point.

The present invention has been made against the background of the above problems, and an object of the present invention is to obtain a flange joint fastening method for preventing damage to a gasket due to a threaded portion of a fastening bolt when fastening flange joints to each other.

In order to achieve the above object, the present invention is a method for fastening a flange joint of two pipes extending in the horizontal direction, with a first bolt hole provided in the lower half of the flange joint of one pipe. The step of inserting the first reamer pin into the second bolt hole provided in the flange joint of the other pipe at the corresponding position, and the first step provided in the lower half of the flange joint of the one pipe. The process of inserting the second reamer pin into the third bolt hole different from the bolt hole and the fourth bolt hole provided in the flange joint of the other pipe at the corresponding position, and the flange of the one pipe. A step of inserting a gasket between the joint and the flange joint of the other pipe, a step of placing the gasket on the first reamer pin and the second reamer pin, and a step of placing the gasket on the flange joint of the two pipes are provided. Insert the fastening bolts into a plurality of bolt holes other than the first bolt hole, the second bolt hole, the third bolt hole, and the fourth bolt hole, and flange the flange joint of the one pipe. , And the step of temporarily fastening the flange joint of the other pipe, and the flange joint of the one pipe and the flange joint of the other pipe by pulling out the first reamer pin and the second reamer pin and inserting a fastening bolt. possess a step of fastening the flange joint, wherein the diameter of the body portion of the first reamer pin and the second reamer pin, said first bolt holes, said second bolt holes, said third bolt hole , And the inner diameter of the gasket is the same as the inner diameter of the flange joints of the two pipes, and the gasket is in contact with the plurality of bolt holes. be.

According to the method for fastening a flange joint according to the present invention, it is possible to prevent damage to the gasket due to the threaded portion of the fastening bolt.

It is an whole view of the reaper pin which concerns on embodiment of this invention. It is an installation state diagram of the reaper pin and the gasket which concerns on embodiment of this invention. It is a schematic diagram at the time of mounting a conventional gasket. It is a schematic diagram at the time of mounting the gasket which concerns on embodiment of this invention.

FIG. 1 is an overall view of a reamapin according to an embodiment of the present invention. Further, FIG. 2 is an installation state diagram of the reamer pin and the gasket according to the embodiment of the present invention. As shown in FIGS. 1 and 2, the reamer pin 10 is provided at the cylindrical main body portion 1, the conical tapered shape portion 2a provided at one end of the main body portion 1, and the other end of the main body portion 1. It is composed of a head 2b.

The two reamer pins 10 are combined by the connecting member 3.

The main body 1 which is a part of the reamer pin 10 is made of a material softer than the material of the flange joint 5, for example, a resin material. The outer peripheral surface of the main body 1 is processed to be smooth and have no resistance without protrusions or the like.

Further, the diameter of the cylindrical main body 1 is the same as the diameter of the bolt hole 7a, the bolt hole 7c (see FIG. 3), the bolt hole 7b, and the bolt hole 7d (see FIG. 2) provided in the flange joint 5. Is. It was stated that the diameter of the main body 1 is the same as the diameter of the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d, but it does not have to be exactly the same. For example, the main body 1 The diameter of the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d may be smaller by about 0 mm to 0.5 mm.

The conical tapered portion 2a, which is a part of the reamer pin 10, is formed so that the diameter decreases toward one end, and the reamer pin 10 is provided with a bolt hole 7a, a bolt hole 7b, and a bolt hole 7c of the flange joint 5. And when it is inserted into the bolt hole 7d, it serves as a guide function to facilitate the insertion work. Further, the conical tapered portion 2a serves to align the flange joints 5 with each other when the reamer pin 10 is inserted into the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d.

The diameter of the head 2b, which is a part of the reamer pin 10, is larger than the diameter of the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d. Therefore, when the reamer pin 10 is inserted into the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d, the head 2b is caught in the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d. It prevents the reamer pin 10 from penetrating through the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d and falling off.

Further, the head portion 2b has a strength and a function that can be used for striking when the reamer pin 10 is inserted into the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d.

As shown in FIG. 2, flange joints 5 are provided at the ends of the two pipes 4 extending in the horizontal direction. Although it was stated that the two pipes extend in the horizontal direction, they do not have to be strictly horizontal and include the concept of substantially horizontal. For example, the inclination angle with respect to the horizontal is 45 ° or less.

The flange joint 5 is made of, for example, a raised face (RF) type. The flange joint 5 has a plurality of bolt holes 7, bolt holes 7a, bolt holes 7b, bolt holes 7c, and bolt holes 7d equidistantly from the center of the flange joint 5. The bolt hole 7, the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d have the same diameter. The bolt hole 7a and the bolt hole 7c are provided in the same flange joint 5, and are divided into left and right with the center of the flange joint 5 interposed therebetween. Similarly, the bolt hole 7b and the bolt hole 7d are provided in the same flange joint 5, and are divided into left and right with the center of the flange joint 5 interposed therebetween.

The bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d are provided in the lower half portion of the flange joint 5. The bolt holes 7a, bolt holes 7b, bolt holes 7c, and bolt holes 7d are the "first bolt hole", "second bolt hole", "third bolt hole", and "third bolt hole" in the present invention, respectively. Corresponds to "four bolt holes".

The inner diameter of the gasket 8 is the same as the inner diameter of the flange joint 5 of the two pipes 4, and the gasket 8 is externally connected to a plurality of bolt holes 7, bolt holes 7a, bolt holes 7b, bolt holes 7c, and bolt holes 7d. do.

On the surface of the flange joint 5, for example, a flange sheet surface 6 for installing a gasket 8 which is a spiral gasket is provided.

FIG. 3 is a schematic view when a conventional gasket is attached. Further, FIG. 4 is a schematic view of the gasket according to the embodiment of the present invention. Here, the conventional flange joint fastening method and the flange joint fastening method according to the embodiment of the present invention will be described with reference to FIGS. 2 to 4.

[Conventional flange joint fastening method]
As shown in FIGS. 2 and 3, conventionally, when fastening the flange joints 5 of two pipes 4 extending in the horizontal direction to each other, the flange joints 5 are aligned with each other on the flange sheet surface 6. The fastening bolts 9 are inserted into the bolt holes 7a, the bolt holes 7b, the bolt holes 7c and the bolt holes 7d, and the positions of the flange joints 5 are temporarily fixed to each other.

Next, the gasket 8 is mounted inside the temporarily fixed flange joints 5. At this time, it was necessary to place the gasket 8 on the threads of the fastening bolt 9 in order to prevent the gasket from falling off. Therefore, when the fastening bolt 9 is retightened, the thread of the fastening bolt 9 and the gasket 8 may come into contact with each other, and the gasket 8 may be damaged.

Further, since the diameter of the screw portion of the fastening bolt 9 is smaller than the diameter of the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d, the gasket 8 rattles by the clearance. Therefore, the center of the gasket 8 does not match the mounting core of the flange sheet surface 6, and manual adjustment and position holding work of the gasket 8 are required for adjusting the position of the gasket 8.

Further, if the center of the gasket 8 and the mounting core of the flange sheet surface 6 do not match, a part of the gasket 8 is exposed in the pipe 4. For this reason, the gasket 8 is partially missing due to exposure to the fluid flowing in the pipe 4, and the missing gasket 8 causes a malfunction or failure of a machine or device on the downstream side. There was a risk of causing such things.

[Method for fastening a flange joint according to an embodiment of the present invention]
Next, the method of fastening the flange joint according to the embodiment of the present invention will be described in order according to the following steps with reference to FIGS. 2 and 4.

(Step S1)
The reamer pin 10 is inserted into the bolt hole 7a provided in the lower half of the flange joint 5 of one pipe 4 and the bolt hole 7b provided in the flange joint 5 of the other pipe 4 at the corresponding position.

(Step S2)
The reamer pin 10 is provided in the bolt hole 7c provided in the lower half of the flange joint 5 of one pipe 4 and different from the bolt hole 7a, and in the bolt hole 7d provided in the flange joint 5 of the other pipe 4 at the corresponding position. insert.

(Step S3)
A gasket 8 is inserted between the flange joint 5 of one pipe 4 and the flange joint 5 of the other pipe 4.

(Step S4)
The gasket 8 is placed on the two reamer pins 10.

(Step S5)
Fastening bolts 9 are inserted into a plurality of bolt holes 7 other than the bolt holes 7a, bolt holes 7b, bolt holes 7c, and bolt holes 7d provided in the flange joints 5 of the two pipes 4, and the flanges of one of the pipes 4 are flanged. Temporarily fasten the joint 5 and the flange joint 5 of the other pipe 4.

(Step S6)
The two reamer pins 10 are pulled out, the fastening bolts 9 are inserted, and the flange joint 5 of one pipe 4 and the flange joint 5 of the other pipe 4 are fastened.

[Effect of embodiment]
From the above, according to the present embodiment, there is a method of fastening the flange joint 5 of the two pipes 4 extending in the horizontal direction, and the bolt provided in the lower half of the flange joint 5 of one of the pipes 4. The process of inserting the first reamer pin 10 into the bolt hole 7b provided in the hole 7a and the flange joint of the other pipe at the corresponding position, and the bolt provided in the lower half of the flange joint 5 of one pipe 4 The step of inserting the second reamer pin 10 into the bolt hole 7c different from the hole 7a and the bolt hole 7d provided in the flange joint 5 of the other pipe 4 at the corresponding position, and the flange joint 5 of one pipe 4. And the step of inserting the gasket 8 between the flange joint 5 of the other pipe 4, the step of placing the gasket 8 on the first reamer pin 10 and the second reamer pin 10, and the flange joint 5 of the two pipes 4. Insert the fastening bolts 9 into a plurality of bolt holes 7 other than the bolt holes 7a, bolt holes 7b, bolt holes 7c, and bolt holes 7d provided in the pipe 4, and the flange joint 5 of one pipe 4 and the other pipe 4 In the process of temporarily fastening the flange joint 5, the first reamer pin 10 and the second reamer pin 10 are removed, and the fastening bolt 9 is inserted to connect the flange joint 5 of one pipe 4 and the flange joint 5 of the other pipe 4. It shall have a process of fastening.

By doing so, since the surface of the reamer pin 10 is smooth and has no resistance, even if the gasket 8 is brought into contact with the reamer pin 10, damage or the like does not occur due to the tightening of the fastening bolt 9.

Further, the diameter of the main body 1 of the first reamer pin 10 and the second reamer pin 10 is configured to have the same diameter as the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d.

By doing so, since the clearance between the main body 1 of the reamer pin 10 and the bolt hole 7a, the bolt hole 7b, the bolt hole 7c, and the bolt hole 7d is as close to 0 mm as possible, the gasket 8 is flanged to the flange joint 5. Even when mounted between each other, there is no rattling that occurs when the fastening bolt 9 is used as in the past, and the mounting position of the gasket 8 is the same as the core of the flange sheet surface 6, and the gasket 8 is manually mounted. Position adjustment work and position holding work of the gasket 8 become unnecessary.

Further, the inner diameter of the gasket 8 is the same as the inner diameter of the flange joint 5 of the two pipes 4, and the gasket 8 has a plurality of bolt holes 7, bolt holes 7a, bolt holes 7b, bolt holes 7c, and bolt holes. It is configured to be in contact with 7d.

By doing so, the center of the gasket 8 and the mounting core of the flange sheet surface 6 are aligned with each other, so that a part of the gasket 8 is not exposed in the pipe 4. For this reason, a part of the gasket 8 is missing due to the fluid flowing in the pipe 4, and the missing gasket 8 causes a malfunction or failure of the machine or device on the downstream side. There is no fear.

Further, in order to improve the surface pressure generated in the gasket 8 as much as possible and prevent leakage of the fluid flowing in the pipe 4, the flange joints 5 of the two pipes 4 are configured to be of the raised face type.

Further, the gasket 8 is configured to be a spiral type gasket.

The spiral gasket is a high-performance semi-metallic gasket reasonably designed for high temperature and high pressure. Therefore, it is possible to obtain pipes 4 and flange joints 5 that can be widely applied to process lines and heat medium oil lines of petroleum refining or petroleum chemical industry as well as steam systems of thermal power plants, nuclear power plants, and steam turbine ships. ..

Further, the surfaces of the first reamer pin 10 and the second reamer pin 10 are configured to be smooth.

By doing so, since the surface of the reamer pin 10 is smooth and has no resistance, damage or the like does not occur even if the gasket 8 is brought into contact with the reamer pin 10.

If the bolt holes 7a to 7d into which the reamer pin 10 is inserted are provided on the lower half side of the flange joint 5, a plurality of bolt holes 7 may be appropriately selected.

1 Main body, 2a Tapered shape, 2b Head, 3 Connecting member, 4 Piping, 5 Flange joint, 6 Flange seat surface, 7 Bolt hole, 7a-7d Bolt hole, 8 Gasket, 9 Fastening bolt, 10 Reamer pin

Claims (4)

It is a method of fastening flange joints of two pipes extending in the horizontal direction.
The process of inserting the first reamer pin into the first bolt hole provided in the lower half of the flange joint of one pipe and the second bolt hole provided in the flange joint of the other pipe at the corresponding position. When,
A third bolt hole provided in the lower half of the flange joint of the one pipe and different from the first bolt hole, and a fourth bolt provided in the flange joint of the other pipe at a corresponding position. The process of inserting the second reamer pin into the hole and
The process of inserting a gasket between the flange joint of one of the pipes and the flange joint of the other pipe.
The step of mounting the gasket on the first reamer pin and the second reamer pin, and
Fastening bolts are attached to a plurality of bolt holes other than the first bolt hole, the second bolt hole, the third bolt hole, and the fourth bolt hole provided in the flange joints of the two pipes. The process of inserting and temporarily fastening the flange joint of the one pipe and the flange joint of the other pipe.
It has a step of pulling out the first reamer pin and the second reamer pin, inserting a fastening bolt, and fastening the flange joint of the one pipe and the flange joint of the other pipe.
The diameter of the first reamer pin and the main body portion of the second reamer pin is the same as the diameter of the first bolt hole, the second bolt hole, the third bolt hole, and the fourth bolt hole. can be,
The inner diameter of the gasket is the same as the inner diameter of the flange joint of the two pipes, and the gasket is in contact with the plurality of bolt holes.
How to fasten a flange joint. The flange joints of the two pipes are of the raised face type.
The method for fastening a flange joint according to claim 1. The gasket is a spiral gasket.
The method for fastening a flange joint according to any one of claims 1 and 2. The surfaces of the first reamer pin and the second reamer pin are smooth.
The method for fastening a flange joint according to any one of claims 1 to 3.

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