JPS59170592A - Corrosionproof pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corrosion-resistant pipe joint suitable for connecting a lined pipe whose inner peripheral surface is entirely coated with a synthetic resin layer.

Conventionally, as this type of corrosion-resistant pipe joint, one having a structure shown in a vertical cross-sectional view in FIG. 3 is known. This pipe joint consists of a corrosion-resistant pipe joint A' whose inner circumferential surface is coated with a fully synthetic resin layer 2' of a metal pipe joint 3', and a lining pipe B whose inner circumferential surface of a metal pipe 3' is coated with a fully synthetic resin layer G'. ' were screwed together and a flanged core C' was inserted into the end of the lining pipe B', but the corrosion prevention effect was not sufficient.

That is, since the synthetic resin layer 2' of the corrosion-resistant pipe joint A' and the collar of the core C' do not come into close contact with each other, there is a problem in that the fluid inside the pipe enters from this part, causing corrosion of the metal part.

The present invention addresses the shortcomings of such conventional corrosion resistant pipe fittings.

Hereinafter, the present invention will be explained in detail with reference to all the drawings.

FIG. 1 is a vertical cross section showing one embodiment of the present invention; FIG.
is a lining pipe connected to the corrosion-resistant pipe joint A.

Corrosion-resistant pipe fitting A is a metal pipe fitting with a female thread at the end, whose inner circumferential surface is entirely covered with a synthetic resin layer of a predetermined thickness except for the female thread, and which extends from the synthetic resin layer. The exposed cylindrical part is completely formed, and a gap of a predetermined width is created between the cylindrical part 2 and the screw 77 surface, and there are four slots in the deep part of the gap.
2, and the four parts 2-! A sealing material ji is filled over part of the gap.

This gap is determined according to the wall thickness of the lining pipe B, and is formed to have a gap width that is approximately the same as the wall thickness of the lining pipe B, or is formed to be slightly smaller. and,
In the deep part of this gap, there is a through hole communicating with the inner surface of the cylindrical part, 2/, or the outer surface of the metal pipe joint, if necessary.
Set up an appropriate number.

Note that this through hole j/ is for draining excess sealant when the lining pipe Bi is screwed and joined to the corrosion-resistant pipe joint A as described later, so instead of the through hole j/, As shown in FIG. 2, a continuous discharge groove O/ may be provided on the outer circumferential surface of the cylindrical portion 2/ from the back side toward the opening side.

Further, the outer circumferential surface of the cylindrical portion 27 is formed with a 3-tapered surface, and the outer circumferential surface is provided with four consecutive stripes or convex stripes in the circumferential direction as necessary. . On the other hand, the inner circumferential surface of the cylindrical part is formed on the inner circumferential surface of the synthetic resin layer and the road surface, and the tip thereof is internally eroded and expanded smoothly.

As a specific example of this, the inner surface of the tip end of the cylindrical portion 27 may be expanded into a trumpet shape with a continuous arc surface, or may be expanded into a tapered surface.

It should be noted that the cylindrical part 2/ does not need to have the entire thread of the thread.
It is only necessary to have the entire length such that a gap is formed between the thread 77 and the surface.

The entire structure has 37.

Hereinafter, the corrosion-resistant pipe joint A of the present invention and the double-lining pipe B-(i7
To explain the procedure for screwing and joining, wrap Teflon tape, etc. around the thread 3 of Ushizu lining pipe B, and then tape a silicone resin tape to the extent that it spans the 4th part of the corrosion-resistant pipe joint A and part of the gap. , two-component curing sealant such as urethane resin! Fill completely.

And sealant! is pressed against the end face of the lining pipe B, and a part of the sealing material J infiltrates between the synthetic resin layer and the cylindrical part 2/, and the excess sealing material that cannot be filled in the VC is deep in the gap. Through hole j/
Alternatively, it is discharged to the outside through the discharge groove slI. As a result, the lining pipe B is firmly screwed to the corrosion-resistant pipe joint A, the end face of the lining pipe B is brought into close contact with the sealing material, and the synthetic resin layer and the cylindrical part λ/ are tightly connected through the sealing material. Closely bonded.

In addition, the solution-form butyl rubber sealing material was injected and filled to the extent that it covered the recess 2.2 and part of the gap of the J-i corrosion-resistant pipe joint A, and the butyl rubber hardened and exhibited its full elasticity. The lining pipe B may be screwed into the joint A in this state.

Furthermore, the lining pipe 131c may be screwed into the joint A after filling the butyl rubber or the like having full elasticity in advance so as to straddle the part.

The embodiment shown in FIGS. 1 and 2 is not limited to bow joints, but can be applied to various metal pipe joints such as T joints, socket joints, and end camp joints. On the other hand, the synthetic resin layer that covers the inner peripheral surface of the metal pipe joint may be made of vinyl chloride resin, polyethylene resin, etc. A cylindrical part with a gap of a predetermined width is fully extended between the threaded surface of the joint, a gap recess is formed in the deep part of the gap, and a seal is formed between the gap and a part of the gap. When joining a lining pipe to this corrosion-resistant pipe joint, simply provide a screw on the outer circumferential surface of the end of the lining pipe and screw it into place, making it easy and reliable without requiring any skill. Can be joined. Moreover, the joint between the corrosion-resistant pipe fitting and the lining pipe is covered by the cylindrical part, and the lining pipe can be screwed together when the end face of the lining pipe is in close contact with the sealing material and the sealant is in an uncured state. For example, a sealing material infiltrates between the synthetic resin layer and the cylindrical part, and the sealing material 4tw provides a tight connection between the synthetic resin layer and the cylindrical part, so that the fluid in the pipe does not enter from this part and cause the entire metal part to corrode. The corrosion-preventing effect of this sealant can be improved even more by providing four convex stripes on the outer circumferential surface of the cylindrical portion to improve its watertight properties.

Furthermore, by forming the inner circumferential surface of this cylindrical part and the synthetic resin layer of the corrosion-resistant pipe joint so that it is similar to the road surface, and continuously and smoothly expanding on the inner surface of the tip of the cylindrical part. , the fluid inside the pipe can pass smoothly, and the inconvenience of sedimentation of dirt, filth, etc. does not occur.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing one embodiment of a corrosion-resistant pipe joint of the present invention, Fig. 1 is a partial longitudinal cross-sectional view of another embodiment of the present invention, and Fig. 3 is a longitudinal cross-sectional view of a conventional pipe joint. . A: Corrosion-resistant pipe fitting B: Lining pipe／・・・Metal pipe fitting／／／・・・・・・
Screw λ...Synthetic resin layer 22...Sink recess 3...Metal tube 3/...
...Screwing...Synthetic resin layer j...
・Sealing material temperature 1 Figure 2 Figure 3

Claims (1)

[Claims] The inner circumferential surface of the metal pipe joint (1) having a female thread (//) at the end is entirely covered with a synthetic resin layer of a predetermined thickness except for the female thread (/).
2), a gap of a predetermined width is provided between the cylindrical part (y) extending from the synthetic resin layer (2) and the female screw (/), and four undercuts ( = 22) A corrosion-resistant pipe joint formed by completely forming the recess (22) and filling a part of the gap with a sealing material (C-f).