Thin wall pipe and manufacturing process

Abstract

A thin wall pipe for fluid transfer including a body having a thin wall, a first end configured to be connected with another pipe or tube or element for fluid transfer, wherein the first end of the pipe includes a hem which is at least double folded so that the pipe end has a triple thickness.

Claims

1. Thin wall pipe for fluid transfer comprising: a body having a thin wall, a first end configured to be connected with another pipe or tube or element for fluid transfer, wherein the first end of the pipe comprises a hem which is at least double folded so that the pipe end has a triple thickness wherein the double folding of the end hem consists in a first folded part oriented inward the pipe and in a second folded part on the first folded part and oriented outward the pipe, and wherein the first folded part and the second folded part are distant from the thin wall of the pipe, forming an angle () with the thin wall.

2. Thin wall pipe according to claim 1, wherein the cross-section of the end is globally trapezoidal or flared compared to the body of the pipe.

3. Thin wall pipe according to claim 1, the first folded part and the second folded part are in contact with each other.

4. Thin wall pipe according to claim 1, the second folded part can be trimmed or dulled by a forming tool.

5. Thin wall pipe according to claim 1, the pipe comprises a circumferential recess shaped to house a seal ring.

6. Manufacturing process of a thin wall pipe according to claim 1, wherein the process comprises the following steps: forming with internal pressure an expanded pipe equipped with a circumferential recess intended to house a seal ring; cutting residual pipe length except for some length needed for holding during cutting; and forcing the pipe end in to the pipe and at the same time folding up twice the hem of the pipe end in order to obtain three layers of thickness.

7. Manufacturing process according to claim 6, wherein the forming step is realized by a forming tool and by hydroforming.

8. Manufacturing process according to claim 6, wherein the forcing step is realized by a punching operation.

9. Thin wall pipe according to claim 5, wherein the seal ring is an O-ring.

Description

(1) The invention will be better-understood thanks to the detailed specification hereinafter, which describes several embodiments of the invention as examples and based on the following figures:

(2) FIG. 1 is a cross-sectional view of the thin wall pipe according to the invention,

(3) FIG. 2 is a detail according to the box A in FIG. 1 and illustrating the folded end of the pipe according to the invention,

(4) FIG. 3 is a side view of the thin wall pipe according to the invention,

(5) FIG. 4 is a perspective view of the thin wall pipe according to the invention,

(6) FIG. 5 is a cross-sectional view of the thin wall pipe according to the invention connected to another element for fluid transfer.

(7) According to the invention, and as illustrated in FIGS. 1, 3 to 5 the thin wall pipe 1 comprises a body 2 having a thin wall 2a and a first end 4 configured to be connected with another pipe or tube or element for fluid transfer 100 as illustrated in FIG. 5.

(8) As illustrated in FIG. 1 and with more details in FIG. 2, the first end 4 of the pipe 1 comprises a hem 5, which is at least double folded so that the pipe end 4 has a triple thickness. More particularly, the double folding consists in a first folded part 5a oriented inward the pipe 1 and in a second folded part 5b on the first folded part 5a and oriented outward the pipe 1.

(9) As seen in FIG. 2, the first folded part 5a and the second folded part 5b are in contact with each other. Moreover, the first folded part 5a and the second folded part 5b are distant from the thin wall 2a of the pipe 1, forming an angle with the thin wall 2a.

(10) In a variant not represented, when angle is in the vicinity of 0 , the first folded part 5a and the second folded part 5b are in contact with the thin wall 2a of the pipe 1.

(11) As it can be seen in FIG. 1, the cross-section of the end is globally trapezoidal or flared compared to the body 2 of the pipe 1.

(12) As illustrated in FIGS. 1, 3, and 4, the pipe 1 comprises a circumferential recess 3 arranged upstream the pipe end 4 on the body 2 of the pipe 1 and shaped to house a seal ring 101, for example an O-ring.

(13) The thin wall pipe 1 illustrated in this example is formed by a hydroforming process and the second folded part 5b can be trimmed or dulled by a forming tool.

(14) The pipe is made of metal, like steel, copper or aluminium, and alloys based on these materials, like, for example, stainless steel.

(15) Obviously, the invention is not limited to the embodiments described and represented with the annexed figures. Modifications remain possible, in particular from the point of view of the constitution of each element or by substitution of technical equivalents, without leaving for all that the scope of the invention.