JP5931348B2 - Squeeze cut fitting - Google Patents

Description

  The present invention relates to a squeeze cut joint for squeezing off a buried steel pipe such as city gas that is no longer needed and leaving the end of the steel pipe buried in a closed state.

When the supply of gas or the like is no longer required, the buried steel pipe used for supplying city gas is cut at the boundary between the public road and private land to close the tip of the buried steel pipe. In order to shut off the gas while maintaining the supply to other gas supply destinations, a squeeze-off method is widely used to close the buried steel pipe.
After shutting off the gas supply by the squeeze-off method, for example, in Patent Document 1, a cap with a sealing material is fitted to the cut end of the supply pipe cut by the squeeze-off method. It is described to do. According to this, gas leakage from the cutting opening can be completely sealed.

Patent Document 2 discloses a rubber cap that covers a pipe end of a squeezed steel pipe, a main body that covers a closed end side of the rubber cap, a fixture that is locked to a squeezed steel pipe, and a tightening that tightens the main body and the fixture. A steel pipe squeeze closure device is described.
Patent Document 3 discloses a flat rubber cap that covers a squeezed pipe end of a steel pipe, and two squeezed parts of the steel pipe through a rubber cap that covers the closed end and the flat outer surface of the rubber cap. A steel pipe squeeze cap consisting of a split squeeze cover is described. According to this, the steel pipe squeeze cap is prevented from slipping out from the pipe end portion, and the safety against leakage is enhanced.

JP 61-31796 A (4th page, upper left column, FIG. 6) JP 2000-249284 A JP 2000-55286 A

As shown in FIG. 6, the ends of the squeeze-cut steel pipe 50 are widened in the squeeze-off direction at the distal end flattened closed part 51, the undeformed circular pipe part 55, the flattened closed part 51 and the circular pipe part 55 And a semi-deformed portion 53 between them. When the steel pipe 50 is closed by being squeezed off, a crack 59 may sometimes enter in the axial direction from the cut surface 57 along the side surface 52 of the flat closing portion 51. In an aging pipe that has been aged for a long time after being buried, the crack 59 may reach the semi-deformed portion 53. Since the sealing material is applied only to the cut end, the ones described in Patent Documents 1 and 2 cannot prevent leakage from this crack. Since the rubber cap covers up to the squeezed flat deformed portion of the rubber cap, if the crack is slightly long, the rubber cap can prevent leakage, but the crack length is up to the half-deformed portion 53. In the case of several centimeters, the leakage cannot be prevented.
In addition, the dashed-two dotted line in a figure has shown the boundary of the flat obstruction | occlusion part 51, the semi-deformation part 53, and the circular pipe part 55. FIG.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a squeeze-cut joint that can reliably prevent leakage even if an axial crack is generated by a squeeze-off method. .

The gist of the present invention is that a rubber cap having a flat portion covering a squeeze-cut end portion of a steel pipe, a cylindrical portion covering at least a part of an outer surface of the non-deformed circular pipe portion of the steel pipe, and the flat portion A split cover main body for clamping the rubber cap from the wide direction; and a fastening means for fastening the cover main body, wherein the rubber cap has a predetermined length from the end surface of the cylindrical portion toward the flat portion. A slit formed at a predetermined distance from the side surface of the steel pipe that has been squeezed and cut, and a flange that extends along the slit, and the flange is sandwiched and compressed by the cover body. This is a squeeze cut joint.
According to the squeeze cut joint of the present invention, the rubber cap covers the flat closed portion having cracks, the semi-deformed portion, and a part of the outer surface of the undeformed steel pipe, and further splits these portions into two parts. Hold it so that it is wrapped in the cover body. Therefore, since the cover body fixes the rubber cap to the cracked portion so as to compress, leakage from the end portion of the steel pipe in which the axial crack is generated by the squeeze-off method can be surely prevented. Moreover, since the rubber cap has a slit, the cylindrical portion can be expanded, and when the rubber cap is attached to the steel pipe, it is not damaged by the cut surface of the steel pipe end. Further, the rubber cap is formed with a flange portion along the slit, and the flange portion is sandwiched and compressed by the cover body, so that no leakage occurs from the slit.

In this invention, it is preferable to have an annular protrusion at the end of the cylindrical portion.
According to this configuration, in addition to compressing and sealing the rubber cap in the cracked direction, it is possible to seal the end portion of the cylindrical portion, so that the safety factor can be further increased.

In the above invention, the outer surface of the rubber cap has a convex portion extending in the width direction of the flat portion, a concave groove is formed inside the cover body, and the convex portion and the concave groove are fitted. Is preferred.
According to this structure, positioning with a rubber cap and a cover main body becomes easy, and workability | operativity can be improved.

  According to the squeeze cut joint of the present invention, the rubber cap covers the flat closed portion having cracks, the semi-deformed portion, and a part of the outer surface of the undeformed steel pipe, and further splits these portions into two parts. Hold it so that it is wrapped in the cover body. Therefore, since the cover body is fixed so that the rubber cap is compressed in the cracked portion, leakage from the end portion of the steel pipe in which the axial crack is generated by the squeeze-off method can be surely prevented.

It is the perspective view which showed one Embodiment of the squeeze cut joint of this invention, and decomposed | disassembled for every component. It is a figure which shows a rubber cap, and is the perspective view seen from the cylindrical part side of the rubber cap. It is a perspective view which shows the process of attaching the rubber cap to the steel pipe which carried out the squeeze cut. It is a perspective view which shows the process of attaching one cover main body to the steel pipe which carried out the squeeze cut. It is a perspective view which shows the state which the attachment of the squeeze cut joint completed to the steel pipe which carried out the squeeze cut. It is a perspective view which shows the edge part of the steel pipe which carried out the squeeze cut.

  As shown in FIG. 1, the squeeze cut joint 1 includes a rubber cap 2, two cover bodies 3A and 3B, and fastening means 4A and 4B.

The rubber cap 2 is a rubber seal member having a space for receiving a squeezed steel pipe 50. The rubber cap 2 is a wide flat part 21 that covers a pipe end part (flat closed part) 51 of the steel pipe 50, and an undeformed steel pipe. A cylindrical portion 23 covering the outer surface (circular tube portion) 55 and a slit 25 extending a predetermined length from the end surface of the cylindrical portion 23 toward the flat portion 21 are provided. One slit 25 is preferably provided on each of the upper and lower surfaces, but at least one slit may be provided. Moreover, the length of the slit 25 should just be formed to such an extent that the rubber cap 2 can be easily attached to the steel pipe 50. What is necessary is just to set by the shape of the diameter, the squeeze-cut steel pipe 50, etc., and it may be extended to the part which covers the semi-deformed part 53 of the steel pipe 50.
Further, the slit 25 needs to be separated from the squeeze-cut pipe end side surface 52 of the steel pipe 50 by a predetermined distance. This is to ensure a distance for sealing the portion of the crack 59 on the pipe end side surface 52. Preferably, the steel pipe 50 is formed in the axial direction (that is, the direction perpendicular to the wide direction of the flat portion 21).

  A flange portion 26 is formed along the edge of the slit 25. A convex portion 27 is formed in a direction perpendicular to the slit 25 (that is, the wide direction of the flat portion 21). Further, as shown in FIG. 2, an annular protrusion 28 is provided at the end of the cylindrical portion 23. The material is preferably NBR in consideration of gas permeability.

  The cover main bodies 3A and 3B are symmetrical members that are sandwiched from a right-angle direction of the direction in which the rubber cap 2 is squeezed (that is, the same direction as the wide direction of the flat portion 21). The outer surface of the cap 2 is almost covered. The inner side surface of the cover main body 3A has a shape that substantially conforms to the outer surface shape of the rubber cap 2. The rectangular portion 31 that covers the flat portion 21, the reduced diameter portion 33 that covers the semi-deformed portion 53, and the semicircular arc that covers the cylindrical portion 23. Part 35. Further, a concave groove 36 is formed at a position facing the convex portion 27 of the rubber cap 2.

Flange portions 37 are formed on the outer surfaces of the cover main bodies 3A and 3B, and a through hole 38 is formed in the flange portion 37 of the cover main body 3A, and a female screw 39 is formed in the flange portion 37 of the cover main body 3B. Yes. The material can be formed of black core malleable cast iron, spheroidal graphite cast iron or the like, and the surface is subjected to anticorrosion treatment such as hot dip galvanization, resin coating, or a combination of plating and coating.
The cover main bodies 3A and 3B formed by the casting method have draft angles in the rectangular portion 31, the reduced diameter portion 33, and the semicircular arc portion 35. Specifically, the mating surfaces of the cover main bodies 3A and 3B (the side in contact with the collar portion 26) are large and become smaller as they move away.

  The fastening means 4A and 4B are composed of, for example, hexagon socket head bolts, and are tightened to the female screw 39 by passing the hexagon socket head bolts through the through holes 38. The fastening means 4B on the lower side in construction may connect the cover main bodies 3A and 3B with a hinge structure in order to facilitate construction.

  The flange portion 37 is provided on the rectangular portion 31 covering the pipe end portion 51 of the squeeze-cut steel pipe 50 which is likely to be cracked and the semicircular arc portion 35 covering the circular pipe portion 55 in order to ensure a stable sealing property. Yes.

When attaching the squeeze cut joint 1 to the steel pipe 50, first, the rubber cap 2 is covered from the pipe end portion 51 of the steel pipe 50 as shown in FIG. 3. At this time, since the rubber cap 2 has the slit 25, the cylindrical portion 23 can be expanded, and when the rubber cap 2 is attached to the steel pipe 50, the rubber cap 2 is damaged by the cut surface 57 of the pipe end portion 51. There is nothing.
When the flange portion 26 and the convex portion 27 of the rubber cap 2 are positioned close to each other, the tip of the slit 25 is thickened. Therefore, when the rubber cap 2 is mounted by expanding the circular tube portion 23, the slit is provided. It is possible to prevent a crack from occurring from the tip of 25.

  Next, as shown in FIG. 4, the cover main bodies 3 </ b> A and 3 </ b> B are covered and the rubber cap 2 is sandwiched so that the concave grooves 36 of the cover main bodies 3 </ b> A and 3 </ b> B fit into the convex portions 27 of the rubber cap 2. Since the concave groove is fitted to the convex portion 27, the positions of the rubber cap 2 and the cover main bodies 3A and 3B are not shifted.

Then, as shown in FIG. 5, the hexagon socket head cap screws 4 </ b> A and 4 </ b> B are passed through the through-hole 38 and fastened to the female screw 39. In this way, the rubber cap 2 is compression-fixed at the cracked portions with the cover main bodies 3A and 3B, so that leakage of the end portion of the steel pipe in which the axial crack is generated by the squeeze-off method can be reliably prevented. it can. Furthermore, since the annular protrusion 28 is provided at the end of the cylindrical portion 23, the steel pipe 50 can be sealed (double sealed) at this portion, and safety can be further increased. Further, a flange portion 26 is formed along the slit 25, and the flange portion 26 is compressed by being sandwiched between the cover main bodies 3A and 3B, so that no leakage occurs from the slit 25.
Since the rectangular portion 31, the reduced diameter portion 33 and the semicircular arc portion 35 have draft angles, when tightened by the fastening means 4A and 4B, a force is applied to the side that closes the crack, and leakage can be reliably prevented. .

1: Squeeze cut joint,
2: rubber cap, 21: flat part, 23: cylindrical part, 25: slit, 26: brim part, 27: convex part, 28: annular projection,
3A, 3B: cover main body, 31: rectangular portion, 33: reduced diameter portion, 35: semicircular arc portion, 36: concave groove, 37: flange portion, 38: through hole, 39: female screw,
4A, 4B: Fastening means 50: Steel pipe, 51: Pipe end, 52: Side face, 53: Semi-deformed part, 55: Circular pipe part, 57: Cut surface, 59: Crack

Claims (1)

A rubber cap having a flat portion covering a squeeze-cut end portion of the steel pipe, and a cylindrical portion covering at least a part of an outer surface of the circular pipe portion which is not deformed, and the rubber cap from the wide direction of the flat portion. A cover body that is divided into two parts, and fastening means for fastening the cover body,
The rubber cap is
A slit that extends from the end surface of the cylindrical portion to a predetermined length toward the flat portion, and is formed a predetermined distance away from the squeeze-cut tube end side surface of the steel pipe;
Having a brim portion along the slit,
The squeeze cut joint characterized in that the collar portion is sandwiched and compressed by the cover body .

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