JPS5940627Y2 - flange type pipe fitting - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a flange-type pipe joint in which a flange is provided at the end of the pipe.

When connecting a pipe whose inner surface is lined or coated with a resin such as vinyl chloride to a flange, one of the methods for fixing the flange to the end of the pipe that does not involve welding or screws is shown in Figure 1. There was something.

In the method shown in FIG. 1, the seal 1 is attached to the outer peripheral surface 3. Hollow tapered packing contact surface inside flange 4 5. End face of mating flange 6 7° End face of pipe 2 8. and lock ring 9
It is compressed from almost the entire circumference by tightening the hexagonal bolt 10.

With this packing shape, it is difficult to absorb the thermal expansion of the pipe when hot water, etc. flows into the pipe, and since the packing is fully compressed, the compression surface pressure becomes too high, which tends to cause compression permanent strain in the packing, which shortens the life of the seal. Because they were short and could not maintain airtightness even under high fluid pressures, their usable range was extremely limited.

This invention not only protects the end of the tube from corrosion, but also maintains an appropriate surface pressure on the packing when the flange is connected to a plane perpendicular to the tube axis, and has a long seal life that absorbs elongation due to thermal expansion of the tube. We provide a wide range of flange type pipe fittings.

The gist of the present invention is to provide a trumpet-shaped packing abutting surface with an inner diameter that gradually increases toward the end on the inner circumference of a flange having an inner diameter that is approximately the same as the outer diameter of the pipe to be connected. The ring fitted to the outer circumference of the pipe is stored deep inside the contact surface,
a ring-shaped hollow portion surrounded by the packing contact surface, the outer peripheral surface of the tube, and the end surface perpendicular to the tube axis of the mating flange;
The inner peripheral surface is provided with a concentric lip that contacts the outer circumference of the tube and faces toward the tube end, and the vertical end surface of the mating flange also has a concentric lip that contacts the end surface and faces toward the tube axis, and further between the two lips. The flange type pipe joint is characterized in that it is equipped with a packing provided with a concentric collar that protrudes toward the end surface of the mating flange and curves toward the pipe end surface on its inner peripheral side.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 6.

In FIG. 2, reference numeral 4 denotes a flange, which has an inner diameter portion 11 that has approximately the same dimensions as the outer diameter of the steel pipe 2, that is, can be fitted into the steel pipe 2.

The inner periphery of the flange 4 is provided with a trumpet-shaped packing contact surface 5 whose inner diameter gradually increases toward the end.

An annular lock ring 9 having a triangular cross section is housed at the back of the seal contact surface 5.

A ring-shaped packing 1' having a special cross-sectional shape is then fitted onto the inner peripheral portion of the packing contacting surface 5.

As shown in the figure, the ring-shaped packing 1' has a substantially trapezoidal cross section, and has a concentric lip 12 on its inner circumferential surface in contact with the tube 2, and a concentric lip 12 on its inner circumferential surface in contact with the end surface 7 of the mating flange 6. A lip 13 is provided.

Also, it is provided on the inner periphery of the end face on the mating flange 6 side.

Also, one of the ribs protrudes from between the lips 12 and 13 toward the end surface 7 perpendicular to the tube axis of the mating flange 6.
The inner diameter of the tube 4 is approximately the same as the inner diameter of the tube 2, and its cross section is such that the tip 15 of the collar 13 is curved toward the tube end surface 8.

Next, the shape and function of the gasket 1' will be explained based on FIG. 3.

For assembly, the cross-sectional shape of the front packing 1' is shown by the solid line, the inner diameter of the lip 12 is smaller than the outer diameter of the tube 2, and the tip of the lip 12 is oriented in the direction of the collar 14.

Further, the tip of the lip 13 is provided to protrude toward the mating flange 6, and the tip is oriented in the inner diameter direction.

Note that the tip 15 of the collar 14 provided on the inner peripheral side is curved toward the tube end surface 8.

When the packing 1' is assembled by tightening the hexagonal bolt 10 as shown in Fig. 2, its cross-sectional shape is such that the lip 12, 13 and the tip 15 of the collar 14 meet the outer circumference of the pipe, as shown by the dotted line in Fig. 3. It deforms so as to come into close contact with the surface, the mating flange surface, and the tube end surface 8.

For this reason, the seal will not be completely compressed when assembled, so a long seal life can be expected.

In addition, because of this shape, even if the tube expands in the axial direction due to fluid such as hot water, the elastic deformation of the curved collar 14 will absorb the expansion of the tube while protecting the tube end surface from corrosion. .

Therefore, external force due to the elongation of the tube is not applied to other connecting parts or fixed parts, and excessive surface pressure is prevented from being applied to the packing 1'.

Further, when the pressure of the fluid is high, self-sealing by the lips 12, 13 works to maintain complete airtightness.

FIG. 4 is a sketch of the lock ring 9, in which a cut 16 is provided at one location on the ring.

FIG. 5 shows another embodiment of the present invention, in which the seal 1'' is provided with a collar 17 on the outer periphery of the end to prevent the lip 12 from being deformed more than necessary by tightening the hexagonal bolt 10. This has a positive effect on seal life.

FIG. 6 shows another embodiment according to the present invention, in which two pipes are connected, using two flanges 4, two packings 1'' and two lock rings 9, as shown in the figure. This figure shows a state in which the end surfaces of the tubes are brought into contact with each other and the hexagonal bolts 10 are tightened to connect them, and it is also possible to connect the flange type pipe joints of the present invention in such a way that they face each other.

As explained above, according to the present invention, it is possible to absorb the elongation due to thermal expansion of the pipe while maintaining the limiting corrosion effect at the end of the connecting pipe. The present invention provides a flange type pipe joint that maintains appropriate surface pressure of the packing, has a long seal life, and can be used over a wide range of fluid temperatures and pressures.

In the above embodiment, the packing contact surface provided on the inner periphery of the flange is a linear tapered surface with the longitudinal section 5 crossed, but the invention is not limited to this, and the longitudinal section may be curved or stepped. You can also use it as

Further, the cross-sectional shape of the annular lock ring 9 may have a shape other than the example shown as long as it can prevent the flange from coming out of the steel pipe.

Furthermore, it goes without saying that the flange type pipe joint of the present invention can be applied not only to resin-inner-coated steel pipes, but also to a wide range of general piping connections.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the main parts of a conventional flange type pipe joint.
Fig. 2 is a vertical sectional view of the main part showing an embodiment of the invention, Fig. 3 is a longitudinal sectional view showing the packing according to the invention, Fig. 4 is a sketch showing the shape of the lock ring, and Figs. 5 and 6. 2A and 2B are vertical cross-sectional views of main parts showing embodiments of the present invention, respectively. 1'l'': Packing, 2: Steel pipe, 4: Flange, 9: Lock ring, 10: Hex bolt.

Claims (1)

[Scope of Claim for Utility Model Registration] A trumpet-shaped packing contact surface whose inner diameter gradually increases toward the end is provided on the inner circumference of the flange, which has an inner diameter that is approximately the same as the outer diameter of the pipe to be connected, A ring fitted to the outer periphery of the pipe is housed in a deep part of the packing abutting surface, and a ring-shaped hollow part is surrounded by the packing abutting surface, the outer circumferential surface of the tube, and an end face of the mating flange perpendicular to the tube axis. The inner peripheral surface is provided with a concentric lip that contacts the outer circumference of the tube and faces toward the tube end, and the vertical end surface of the mating flange also has a concentric lip that contacts the end surface and faces toward the tube axis, and further, both lips A flange type, characterized in that the flange type is equipped with a packing provided with a concentric collar that protrudes from between the gaps toward the end surface of the mating flange and whose inner peripheral side is curved toward the pipe end surface.