Pipe connector

1. A pipe connector comprising:

a tubular metal part having a first portion with a first outer diameter and a second portion with second outer diameter which is larger than the first outer diameter, which second portion has a circumferential groove,

a removable stop ring, which, when arranged in the groove, protrudes radially from the tubular metal part, and

a flange part having a central through opening for receiving the tubular metal part, wherein the flange part has a shoulder for abutting against the stop ring when the flange part is arranged around the stop ring,

wherein the pipe connector has a first end face at the first portion and a second end face at the second portion, wherein a length of the pipe connector is defined by a distance between the first end face and the second end face, wherein a longitudinal extension of the pipe connector is along a single central axis; and

wherein each of the outer diameters and of the first portion and the second portion of the tubular metal part are smaller than a diameter of the central through opening of the flange part, wherein the pipe connector further comprises another tubular part comprising a tubular plastic part having a plastic external peripheral surface, wherein a periphery of the tubular plastic part is arranged around a tubular metal surface of the first portion of the tubular metal part.

2. The pipe connector as claimed in claim 1 , wherein the second portion and the tubular metal surface of the first portion forms a one-piece metal unit.

3. The pipe connector as claimed in claim 1 , wherein the tubular plastic part has a length that is shorter than the length of the first portion of the tubular metal part.

4. The pipe connector as claimed in claim 1 , wherein the second portion has an outer diameter d 2 which is larger than an outer diameter d 3 of the tubular plastic part.

5. The pipe connector as claimed in claim 1 , wherein the outer diameter d 2 of the tubular metal part at the groove is at least as large as an outer diameter d 3 of the tubular plastic part.

6. The pipe connector as claimed in claim 1 , wherein the tubular metal part has a greater axial extension than the flange part.

7. The pipe connector as claimed in claim 1 , wherein the inner diameter dl of the tubular metal part is constant.

8. The pipe connector as claimed in claim 1 , wherein the stop ring has a slit.

9. The pipe connector as claimed in claim 1 , wherein the flange part has a radially extending first flange surface extending between the through opening and the outer periphery of the flange part, wherein the first flange surface aligns with an end face of the tubular metal part when the shoulder mates with the stop ring.

10. The pipe connector as claimed in claim 1 , further comprising a removable inner pipe coupling part having an outer diameter smaller than the inner diameter of the tubular metal part, wherein the inner pipe coupling part protrudes from the tubular plastic part when arranged in the tubular metal part.

11. The pipe connector as claimed in claim 10 , wherein the inner pipe coupling part comprises a conductive material.

12. The pipe connector as claimed in claim 1 , further comprising a fixing device for fixing a portion of the tubular plastic part around the first portion of the tubular metal part.

13. The pipe connector as claimed in claim 12 , wherein the fixing device is cylindrical and is arranged to receive the tubular plastic part.

14. The pipe connector as claimed in claim 1 , wherein the first portion comprises a plurality of peripheral protrusions.