JP2011144870A - Gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket that allows uniform fastening by the easy and sure selection of a right gasket according to a nominal diameter and a class of a flange and previously prevents the occurrence of leakage by simple mounting work. <P>SOLUTION: The gasket is interposed between flanges of a raised face formed with a planar seat protruding from the flange. The gasket has an annular plate shape and includes an annular seal part 11, interposed between the planar seats, on the inner-peripheral side of an outer ring 10 located more internally than bolt holes drilled in the flange. The outer ring 10 is integrally formed with at least four ribs 12 radially protruding to the outer-peripheral edge of the flange, while being circumferentially spaced at intervals so that the ribs are respectively arranged between bolt holes. A spacer 13, having the thickness dimension equivalent to the height dimension of the planar seat, is fixed to each rib 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gasket interposed between flanges for preventing leakage in various pipes connected by a flange joint.

Generally, when various pipes are connected by flange joints using bolts and nuts, a gasket for preventing leakage is interposed between the flange surfaces of the pipes.
FIG. 7 shows a conventional gasket interposed between flanges of a raised face in which a flat seat 3a protruding from the flange 3 is formed. This gasket is a filler material on the inner side of a metal outer ring 1. An annular seal portion 2 made of, for example, is formed, and the outer ring 1 is called a spiral wound gasket in which the outer ring 1 is disposed inside the bolt hole 4 of the flange 3. It is also known that an annular inner ring is further provided on the inner peripheral side of the seal portion 2.

By the way, in the flange joint, although a gasket is interposed, sometimes a leakage trouble occurs. As causes of such a leakage trouble, the following (1) to (6) are mainly considered.
(1) Wrong gasket size at small diameter For example, when a gasket for 3 / 4B flange is incorrectly inserted into 1B flange. In such a case, as shown in FIG. 8, as a result of the outer ring 1 of the gasket being supported between the lower bolts 5 between the flanges 3, the gasket is displaced and leakage occurs.

(2) Incorrect rating For example, a JPI class 150 gasket is incorrectly inserted into a JPI class 300 flange. By the way, in the spiral wound gasket for piping (JPI-7S-41-2005), the outer diameter D of the outer ring 1 of the gasket used for the nominal diameter 1B of class 150 and the nominal diameter 3 / 4B of class 300, 400, 600 The outer diameter D of the outer ring 1 of the gasket used for each is 66.8 mm. Further, in the class 300 or higher, the outer diameter of the outer ring 1 is the same for the nominal diameter 3B or less even if the class is different. For this reason, there is a high possibility that the rating is wrong if only the outer diameter of the outer ring 1 of the gasket is used for judgment.

(3) Flange one-side tightening If multiple flange bolts are not tightened by a uniform force, the surface pressure of the gasket varies, and leakage occurs at places where the tightening is insufficient.
(4) Over tightening of bolts If bolts 5 are over tightened, as shown in FIG. 9, the flange 3 rotates around the outer edge 1a of the outer ring 1 of the gasket (flange rotation). Contact will result in leakage from the location.

(5) Entrapment of foreign matter in gasket seal portion When foreign matter is caught between gasket seal portion 2 and flange 3, the seal is broken and leakage occurs.
(6) Surface Roughness at the Sealed Portion of the Gasket If the unevenness due to corrosion or loss of smoothness due to plastic deformation due to excessive tightening of the bolt 5 occurs in the gasket sealed portion 2, a uniform contact surface pressure is applied to the seal portion 2. It leaks without being obtained.

Of the causes (1) to (6), the causes (1) to (4) can be avoided by means of a gasket or measures at the time of attachment.
For example, with respect to the above causes (1) and (2), it is confirmed that the diameters of the flange 3 and the outer surface of the gasket 3 coincide with each other by visually observing the position of the flange bearing surface and the gasket 3 This can be prevented.

  The above causes (3) and (4) can be prevented by using a torque wrench to tighten the bolt 5 or measuring the gap between the flanges 3 with a gap gauge. is there.

  However, in order to visually check the inner seating surface and the outer peripheral position of the gasket 3 from the narrow gap between the flanges 3, it becomes a work that requires skill using a separate flashlight etc., and for all the flanges, It is not practical to perform the visual check, tightening with a torque wrench, or measuring with a clearance gauge because it requires excessive labor.

  The present invention has been made in view of the above circumstances, and can easily and surely select the correct gasket according to the nominal diameter and class of the flange and tighten it evenly. It is an object of the present invention to provide a gasket that can prevent the above.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a gasket interposed between flanges of a flat face, which is formed in an annular plate shape and is located inside a bolt hole drilled in the flange. The outer ring is provided with an annular seal portion on the inner peripheral side, and at least four ribs projecting to the outer peripheral edge of the flange in the radial direction with the same thickness as the outer ring, respectively, It is formed integrally with a circumferential interval so as to be disposed between the bolt holes.

  The invention according to claim 2 is a gasket interposed between the flanges of the raised face formed with a flat seat projecting from the flange surface, which is formed in an annular plate shape and is formed in the flange. An annular seal portion interposed between the plane seats on the inner peripheral side of the outer ring located inward of the bolt hole, and the outer ring has the same thickness dimension as the outer ring and the flange in the radial direction. At least four ribs protruding to the outer peripheral edge are integrally formed at intervals in the circumferential direction so as to be arranged between the bolt holes, and the height of the flat seat is formed on the rib. A spacer having a corresponding thickness dimension is fixed.

  The invention according to claim 3 is characterized in that the spacer according to claim 2 is made of a softer material than the flange.

  Furthermore, the invention according to claim 4 is the invention according to claim 2 or 3, wherein the spacer is formed by bending a rectangular plate into a U-shape, and the rib is provided between the opposing surfaces. It is fixed to the rib by being inserted and crimped.

  According to the invention described in any one of claims 1 to 5, at least four of which the outer peripheral edge protrudes in the radial direction to the outer peripheral edge of the flange on the outer ring positioned inside the bolt hole formed in the flange. Since the ribs are integrally formed at intervals in the circumferential direction, the gasket is easily inserted by inserting the gasket between the flanges so that the end portions of the ribs coincide with the outer peripheral edge of the flange. And the center of the flange can be matched.

At this time, since the outer diameter of the flange varies depending on the nominal diameter, it is possible to reliably prevent the occurrence of leakage due to the above causes (1) and (2).
In addition, since four or more ribs are inserted to the outer peripheral edge between the bolt holes of the flange, the flange is worried due to one-side tightening, or the flange pivots on the outer edge of the gasket due to over-tightening of the bolt. Can also be prevented, and therefore leakage due to the above causes (3) and (4) can also be prevented.

  Further, in the raised face flange, the plane seat protrudes from the flange surface. For this reason, the clearance gap between the outer peripheral parts of a flange becomes large only the protrusion dimension of the said flat seat surface rather than the clearance gap between flat seat surfaces. Therefore, as for the gasket interposed between the flanges of the raised face, a spacer having a thickness corresponding to the height of the flat seat is fixed to the rib, as in the second aspect of the invention. That's fine.

  As a result, when the bolt is tightened, the spacer serves as a stopper, so that the spacer can be tightened evenly until it comes into contact with the flange surface. In addition, since the spacer serves as a stopper to prevent the flange from being inclined, the seal portion can be brought into surface contact with certainty. Thus, the same effects as those of the first aspect of the invention can be obtained.

  According to the invention described in claim 3, since the spacer is made of a softer material than the flange, the manufacturing tolerance of the height dimension of the raised face of the flange is absorbed by the plastic deformation of the spacer. As a result, the seal portion can be surely brought into surface contact.

  Furthermore, according to the invention described in claim 4, the spacer can be fixed to the rib by a simple method.

It is a disassembled perspective view which shows 1st Embodiment of the gasket which concerns on this invention. It is sectional drawing in the rib of FIG. It is a top view which shows the state which interposed the gasket of FIG. 2 between the flanges. The 2nd Embodiment of this invention is shown, (a) is the partially exploded top view, (b) is a front view of a spacer. It is a front view which shows the said 2nd Embodiment. It is a top view which shows the state which interposed the gasket of FIG. 5 between the flanges. It is a longitudinal cross-sectional view which shows the shape of the gasket interposed between the flanges of a general raised face. It is a top view which shows the state of position shift at the time of inserting the gasket of incorrect size in the conventional flange joint. It is a longitudinal cross-sectional view of the principal part which shows the state of the flange rotation by the bolt tightening too much in the conventional flange joint.

(First embodiment)
Hereinafter, a first embodiment of a gasket according to the present invention will be described based on the drawings. Note that the configuration of the flange in which the gasket of this embodiment is interposed is the same as that shown in FIG.
1 to 3 show a first embodiment of a gasket interposed between flanges of the raised face shown in FIG. 7, and reference numeral 10 in the drawing denotes an outer ring in this gasket.

  The outer ring 10 has an annular plate shape made of carbon steel or the like, and is formed with an outer diameter dimension in which an outer peripheral edge 10 a is positioned inward of the bolt hole 4 drilled in the flange 3. An annular seal portion 11 made of a filler material or the like that contacts the flat seat 3a (see FIG. 7) of the flange 3 is joined and integrated inside the outer ring 10.

  Further, in this gasket, four ribs 12 protruding in the radial direction from the outer peripheral edge 10a of the outer ring 10 are formed. These ribs 12 are integrally formed by stamping simultaneously with the outer ring 10 when the plate-like material such as carbon steel is processed into the outer ring 10, and is formed in the circumferential direction of the outer ring 10. It is formed at equal intervals.

  Here, since the bolt hole 4 in the flange 3 is generally formed at an integer multiple of 4, the ribs 12 are formed so as to be arranged between the bolt holes 4, respectively. The ribs 12 are formed so that the length dimension (outer diameter dimension) from the center of the gasket to the outer peripheral edge 12a is equal to the outer diameter dimension of the flange 3 for interposing the gasket. .

  Furthermore, a square plate-like spacer 13 having a width dimension substantially equal to that of the rib 12 is provided on both surfaces of each rib 12. Each spacer 13 is made of the same metal as the rib 12 and is fixed to the surface of the rib 12 by spot welding or welding.

(Second Embodiment)
4 to 6 show a second embodiment of the present invention. The same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is simplified.
In this gasket, a hole 12 b is formed in the center of a rib 12 formed integrally with the outer ring 10. A spacer 15 is fixed to the rib 12.

  This spacer 15 is formed by bending a rectangular plate made of a metal such as aluminum or bronze softer than the flange 3 into a U shape so that a gap corresponding to the thickness dimension of the rib 12 is formed between the opposing surfaces S. It is a thing. Then, as shown in FIG. 4A, the spacer 15 is sheathed on the rib 12 from the direction orthogonal to the radial direction, so that the rib 12 is inserted into the space S between the opposing surfaces, and the hole 12b. It is fixed to the rib 12 by crimping in a direction perpendicular to the surface at the position. In addition, the code | symbol 16 in a figure is the annular | circular shaped inner ring joined and integrated by the inner peripheral side of the seal part 11. FIG.

  According to the gaskets of the first and second embodiments configured as described above, the outer ring 10 located inward of the bolt hole 4 drilled in the flange 3 projects in the radial direction to the outer peripheral edge of the flange 3. Since the four ribs 12 are integrally formed at equal intervals in the circumferential direction, the gasket is inserted between the flanges 3, and the outer peripheral edges 12 a of the ribs 12 are connected to the outer peripheral edges of the flanges 3. By matching, the center of the gasket and the flange 3 can be easily aligned.

  At this time, since the outer diameter of the flange 3 varies depending on the nominal diameter, it is possible to reliably prevent leakage due to an incorrect gasket size or an incorrect rating at a small diameter. Moreover, since the four ribs 12 are interposed between the bolt holes 4 of the flange 3 up to the outer peripheral edge, the flange 3 is wrinkled by one-side tightening, or the flange 3 is gasketed by overtightening the bolt 5. It is also possible to prevent the outer edge of the shaft from rotating about the axis.

  Furthermore, since the spacers 13 and 15 having a thickness corresponding to the height of the plane seat 3a of the flange 3 are fixed to the rib 12, the spacers 13 and 15 are stoppers when the bolt 5 is tightened. Will play a role. As a result, by tightening until the spacers 13 and 15 come into contact with the flange surface, uniform tightening can be performed and the inclination of the flange 3 can be prevented. Can also be brought into surface contact.

In addition, according to the gasket shown in the second embodiment, since the spacer 15 is made of a softer material than the flange 3, the manufacturing tolerance of the height dimension of the raised face of the flange can be reduced. Absorbing by deformation, the seal portion 11 can be surely brought into surface contact.
Moreover, since the spacer 15 is fixed by caulking at the position of the hole 12b formed in the rib 12, even if the spacer 15 is made of a different material from the rib 12, it can be fixed by a simple method. Can do.

  In the first and second embodiments, only the case where the four ribs 12 are integrally formed on the outer ring 10 has been shown. However, the present invention is not limited to this, and the bolt in the flange 3 is shown. Depending on the number of holes 4, a plurality of ribs such as 6, 8, 12, 16, etc. may be formed as long as they can be arranged between the bolt holes 4.

  Moreover, although the said 1st and 2nd embodiment demonstrated both embodiment of the gasket interposed between the flanges of a raised face, when applying to the gasket interposed between the flanges of a flat face. Therefore, it is only necessary to omit the spacers 13 and 15, and it is possible to obtain the same effects as those of the first and second embodiments.

  Furthermore, it can be applied to gaskets of various materials such as joint sheet gaskets in addition to vortex gaskets.

3 Flange 3a Flat seat 4 Bolt hole 5 Bolt 10 Outer ring 10a Outer peripheral edge 11 Seal part 13, 15 Spacer

Claims (4)

A gasket interposed between flat face flanges,
It has an annular plate shape and has an annular seal portion on the inner peripheral side of the outer ring located inward of the bolt hole drilled in the flange, and the outer ring has the same thickness as the outer ring. A gasket characterized in that at least four ribs protruding in the direction to the outer peripheral edge of the flange are integrally formed at intervals in the circumferential direction so as to be disposed between the bolt holes. A gasket interposed between the flanges of the raised face formed with a flat seat protruding from the flange surface,
It has an annular plate shape, and has an annular seal portion interposed between the plane seats on the inner peripheral side of the outer ring located inward of the bolt hole drilled in the flange, and the outer ring At least four ribs having the same thickness as the outer ring and projecting radially to the outer peripheral edge of the flange are integrally formed at intervals in the circumferential direction so as to be disposed between the bolt holes, respectively. The gasket is characterized in that a spacer having a thickness corresponding to the height of the flat seat is fixed to the surface of the rib.   The gasket according to claim 2, wherein the spacer is made of a softer material than the flange.   The spacer is formed by bending a rectangular plate into a U shape, and is fixed to the rib by inserting and crimping the rib between opposing surfaces thereof. Item 4. The gasket according to Item 2 or 3.

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