JPS5827185Y2 - Pipe end of internally coated steel pipe with flanges - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an end portion of an inner-coated steel pipe with seven flange.

Conventionally, in order to prevent corrosion at the end of a flanged internally coated steel pipe, for example, as disclosed in Japanese Patent Publication No. 39-18894, metallic 7.
After attaching the lunge and peeling off the synthetic resin lining layer slightly inward from the end of the lining pipe, a flange is provided at one end in the pipe end, and a flange is provided at one end, which is approximately the same as the synthetic resin lining layer of the lining pipe. Insert the straight pipe part of a short synthetic resin pipe with the same wall thickness to line the inward exposed part of the metal tube with the straight pipe part, and glue or glue the end of the straight pipe part and the end of the synthetic resin lining layer. Alternatively, as in Japanese Patent Publication No. 3919126, a metal flange is attached to the end of a lining pipe lined with synthetic resin on the inner surface of the metal pipe, and a thermoplastic synthetic resin short pipe is placed inside the lining pipe. In some cases, the straight pipe part is inserted so as to slightly protrude from the end of the lining pipe, and the straight pipe part is flanged back along the surface of the metal flange attached to the end of the lining pipe.

However, when a conventional type such as Toribo is connected with 7 langes and used for water passage that changes in temperature, the inner coating layer expands and contracts with respect to the steel pipe due to temperature changes, and the brim is fixed. Stress is concentrated at the bent part that connects the collar and the short pipe,
In the past, there was a drawback that this bent portion was damaged and could not provide sufficient corrosion protection.

The present invention was developed with the aim of solving the above-mentioned conventional drawbacks, and its gist is that a C flange is provided at the outer end of an internally coated steel pipe, and from the side of the end inward. A flanged short tube is crowned so that a void is formed on the side of the end surface of the inner coating layer over the circumferential surface, and a groove is provided along the outer circumferential surface of the flanged short tube. It exists at the tube end of a 7-flange inner-coated steel pipe in which an annular backing is installed between the groove and the inner circumferential surface of the inner-coated steel pipe.

Hereinafter, the present invention will be explained with reference to embodiments.

Reference numeral 1 denotes an internally coated steel pipe, and an internally coated layer 12 made of a hard polyvinyl chloride resin pipe or the like is provided on the inner surface of the steel pipe 11, leaving a portion slightly inward from the opening at the end.

A flange 2 is provided outside the end of the inner-coated steel pipe 1 by welding.

3 is a short tube with a flange, and a flange 32 is provided at one end of the short tube 31.

The short pipe 31 has a large diameter portion 321 at one end provided with the collar 32 and a small diameter portion 322 at the other end, and the outer diameter and the axial length of the outer peripheral surface of the large diameter portion 321 are as follows. The inner diameter of the internally coated steel pipe 1 is approximately the same as the inner diameter of the steel pipe 11 and the length of the exposed portion of the inner peripheral surface of the steel pipe 11, and a groove 323 is provided on the outer peripheral surface of the small diameter portion 322 along the circumferential direction. ing.

The flange is formed so that a void 5 is formed on the side of the end surface of the inner surface coating layer 12 from the side surface of the end of the inner surface coated steel pipe 1 or the side surface of the seven flange 2 to the inner peripheral surface of the inner surface coating layer 12 of the inner surface coated steel pipe 1. A short tube 3 is covered.

In this case, the flange 32 of the flanged short pipe 3 is brought into contact with the side surface of the end of the internally coated steel pipe 1 or the side of the flange 2 using an adhesive if necessary, and the large diameter part of the short pipe 32 is The outer circumferential surface of the short tube 321 is brought into contact with the inner circumferential surface of the inner-coated steel pipe 1, which has no inner-coating layer, using an adhesive if necessary.
The outer circumferential surface of the small diameter portion 322 is in contact with the inner coating layer 12 of the inner-coated steel tube 1, and the annular backing 4 is installed between the groove 323 of the short tube 32 and the inner coating layer 12 of the inner-coated steel tube 1. (See Figure 1).

It should be noted that, without being limited to the examples mentioned above, as shown in Fig. 2,
A flange 2' is screwed to the outside of the end of the inner coated steel pipe 1', which has an inner coating layer 12' on the inner surface of the steel pipe 11'. A flanged short pipe 3' is capped so that a gap 5' is formed on the side of the end face of the inner surface coating layer 12' from the side surface of the flange 2' to the inner peripheral surface of the inner surface coating layer 12'. A groove 32 provided along the circumferential direction on the outer peripheral surface of the short pipe 32' of the short pipe 3'.
3' and the inner coating layer 12'.
' may be attached.

The end of the flanged internally coated steel pipe of the present invention is crowned with a flanged short pipe such that a gap is formed on the side of the end surface of the internally coated layer at the end of the internally coated steel pipe where the flange is provided. A groove is provided along the circumferential direction on the outer circumferential surface of the flanged short tube, and an annular backing is installed between the groove and the inner circumferential surface of the internally coated steel tube, so that other flanges When used in connection with a flanged, inner-coated steel pipe, even if the temperature of the water flowing through it repeats and the inner coating layer expands and contracts relative to the steel pipe, the inner coating layer will remain inside the flanged short pipe. By moving the flanged short tube, there is no excessive force applied to the bent part that connects the collar of the flanged short tube and the short tube, so the flanged short tube is not damaged, and the flanged short tube is protected against the expansion and contraction of the inner surface coating layer. An annular backing installed in a groove provided on the short tube slides against the inner circumferential surface of the inner coating layer, sealing between the inner coating layer and the flanged short tube, and sealing the tube end. It is possible to plan corrosion prevention.

[Brief explanation of drawings]

1 and 2 are partially sectional views showing an embodiment of the present invention, respectively. 1.1'...Inner coated steel pipe, 2,2'...
...Flange, 3,3' ...Short pipe with flange,
4,4'...Backing, 11, IV
......Steel pipe, 12, 12'...Inner coating layer, 5,5'...Void portion.

Claims (1)

[Scope of utility model registration request] Seven flanges are provided outside the end of the internally coated steel pipe, and a flanged short pipe is crowned so that a gap is formed on the side of the end surface of the internally coated layer from the side surface of the end to the inner peripheral surface. , a flanged inner surface coating in which a concave groove is provided along the circumferential direction on the outer circumferential surface of the short flanged short tube, and an annular backing is attached between the concave groove and the inner circumferential surface of the inner surface coated steel tube. Pipe end of steel pipe.