Pipe connection for conducting a fluid that is under pressure

Abstract

A pipe connection for conducting a fluid that is under pressure is provided, having two tubular connection parts for a conical clamping connection, which are screwed together by a union nut while one is inserted in the other, wherein each connection part has a conical sealing surface that contacts the other in a sealing manner and wherein an annular groove is provided in one of the sealing surfaces. In order to enable the pipe connection also to conduct a fluid having cycling or varying temperature, the inner of the two connection parts has thermal insulation on the inside of the pipe at least in the axial segment of the sealing surface of the connection part, wherein the thermal insulation tube has a cam or a collar on the outer surface, which engages in a recess, which is axially bounded by the two connection parts.

Claims

1. A pipe connection for conducting a fluid that is under pressure, comprising two pipes which are screwed together by means of a union nut, being plugged one into the other in a cone clamping connection, wherein each pipe has a conical sealing face which respectively bears against the other of the two sealing faces, wherein an inner one of the pipes has, at least in an axial section of a sealing face, a thermal barrier pipe inside the inner one of the pipes with an interspace between the thermal barrier pipe and the inner one of the pipes along the axial section, wherein the thermal barrier pipe has, on a lateral surface, a protuberance or a collar which engages in a recess which is delimited axially by the two pipes.

2. The pipe connection as claimed in claim 1, wherein at least one end of the thermal barrier pipe is formed as a close sliding fit.

3. The pipe connection as claimed in claim 2, wherein both ends are formed as close sliding fits.

4. The pipe connection as claimed in claim 1, wherein the union nut is prevented from coming loose.

5. The pipe connection as claimed in claim 4, wherein the union nut is locked.

6. The pipe connection as claimed in claim 1, further comprising a graphite-containing seal arranged in an annular groove in one of the two sealing faces.

7. A method of using a pipe connection as claimed in claim 1, comprising conducting a fluid with a varying temperature or whose temperature deviates, at least briefly, from the temperature of the pipe connection by more than 100 K.

8. A pipe connection comprising: two pipe sections joined by a cone clamping connection to define a passage for a fluid; a first of the pipe sections comprising an outward-oriented conical sealing face and a second of the pipe sections comprising an inward-oriented conical sealing face, the respective sealing faces urged against each other along an axial section of the passage forming the cone clamping connection; and a thermal barrier effective to slow a transfer of heat disposed between the passage and the first of the pipe sections along the axial section of the passage; wherein the thermal barrier comprises a thermal barrier pipe; and further comprising an interspace between the thermal barrier pipe and the first of the pipe sections along the axial section of the passage.

9. The pipe connection of claim 8, further comprising a collar on an outer surface of the thermal barrier pipe which is axially fixed between the two pipe sections.

10. The pipe connection of claim 8, further comprising a close sliding fit formed at opposed axial ends of the thermal barrier pipe to limit ingress of the fluid into the interspace.

11. The pipe connection of claim 8, further comprising an annular groove formed in at least one of the conical sealing faces.

12. The pipe connection of claim 11, further comprising a sealing element disposed in the annular groove.

13. The pipe connection of claim 12, wherein the sealing element comprises graphite.

14. A pipe connection comprising: two pipe connection pieces joined by a cone clamping arrangement to define a passage for a fluid; a first of the pipe connection pieces comprising an outward-oriented conical sealing face and a second of the pipe connection pieces comprising an inward-oriented conical sealing face, the respective sealing faces urged against each other along an axial section of the passage by the cone clamping arrangement; a thermal barrier pipe disposed within the passage and separated from the first of the pipe connection pieces by an interspace along the axial section of the passage; and a radial widening of the thermal barrier pipe formed proximate at least one end of the thermal barrier pipe effective to establish a contact between the thermal barrier pipe and the first of the pipe connection pieces.

15. The pipe connection of claim 14, further comprising a collar on a surface of the thermal barrier pipe which is axially delimited between the two pipe connection pieces.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a longitudinal section through a pipe connection including a thermal barrier pipe for conducting a fluid that is under pressure.

(2) FIG. 2 shows a longitudinal section through a pipe connection including a thermal barrier for conducting a fluid that is under pressure.

DETAILED DESCRIPTION OF INVENTION

(3) FIG. 1 shows, in longitudinal section, a pipe connection 10 for conducting a fluid that is under pressure. In that context, the pipe connection 10 comprises two connection pieces 12, 14 which are connected for a cone clamping connection 16. To that end, the first connection piece 12 has a cone 18 with an outward-oriented conical sealing face 20. The second connection piece 14 has, at an inclination which corresponds to the sealing face 20, an also conical sealing face 22, as part of a cone 24. The cone 24 forms the outer cone and the cone 18 forms the inner cone of the cone clamping connection.

(4) In the sealing face 20 there is provided an endless circumferential annular groove 26 for receiving graphite as sealant. The two connection pieces 12, 14 are connected to one another with the aid of a union nut 28. Specifically, to that end, the union nut 28 is screwed onto the second connection piece 14, wherein the union nut 28 presses a conical shaft collar 29, a rearward part of the cone 18 of the first connection piece 12, in the direction of the second connection piece 14. The two connection pieces 12, 14 are tubular, such that in their interiors the fluid, for example a hydraulic oil but also a gaseous or liquid fuel, can be conveyed from one pipe section 11 into a second pipe section 13.

(5) A thermal barrier pipe 30 is arranged inside the pipe connection 10. The thermal barrier pipe 30 is arranged at least in that axial section of the pipe connection 10 at which the inner connection piece in this case the connection piece 12bears by means of its sealing face 20 against the other sealing face 22. However, according to the exemplary embodiment, the thermal barrier pipe is elongated axially in both directions, wherein the ends 32, 34 of the thermal barrier pipe 30, where possible, bear in a sealing manner against the inner faces of the pipe sections 11, 13, so as to avoid ingress of the fluid into an interspace 36 between the thermal barrier pipe 30 and the inner faces of the pipe sections 11, 13. In this case, that end 32 of the thermal barrier pipe 30 which is assigned to the connection piece 12 takes the form of a close sliding fit. In addition, a collar 38 is provided on the outer lateral surface of the thermal barrier pipe 30, which is axially fixed 40 between the two connection pieces 12, 14. A locknut 39 prevents the union nut 28 from coming loose.

(6) Instead of a thermal barrier pipe 30, there is of course also the possibility of applying a thermal barrier coating 42, as illustrated in FIG. 2, to those inner faces of the pipe connection 10 which according to the prior art were hitherto in direct contact with the fluid to be conducted, in order to slow the transfer of heat between the pipe material or the cone material and the fluid, when the temperature of the fluid changes.

(7) In summary, the invention indicates a pipe connection 10 for conducting a fluid that is under pressure, comprising two tubular connection pieces 12, 14 which are screwed together by means of a union nut 28, being plugged one into the other for a cone clamping connection 16, wherein each connection piece 12, 14 has a conical sealing face 20, 22 which bears in a sealing manner against the other, and wherein an annular groove 26 is provided in one of the sealing faces 20, 22. In order to provide a sealed pipe connection 10 even for conducting a fluid with changing or varying temperature, it is proposed that a graphite band, which additionally seals the connection 10, is provided in the annular groove 26 and advantageously completely fills the annular groove 26, and that the inner of the two connection pieces 12 has, at least in the axial section of its sealing face 20, a thermal barrier inside the pipe, advantageously in the form of a thermal barrier pipe 30.