Flange connection having a weld ring gasket

1. A flange connection comprising:

(a) first and second flanges; and

(b) a weld ring gasket arranged between the first and second flanges and comprising a first weld ring half arranged on top of a second weld ring half;

wherein the first weld ring half comprises a first base section and a first lip arranged on the first base section and the second weld ring half comprises a second base section and a second lip arranged on top of the second base section;

wherein the first base section is welded to the first flange by way of a first fillet weld and the second base section is welded to the second flange by way of a second fillet;

wherein the first and second lips form a torus-shaped connection section having a hollow interior, and the first and second weld ring halves are welded to each other at the torus-shaped connection section by way of a caulking seam; and

wherein the torus-shaped connection section lies radially inside the first and second weld ring halves,

wherein each of the first and second base sections has a respective first contact surface that lie against each other;

wherein at least one of the first contact surfaces has a setback that extends in a vertical direction; and

wherein a ring gap that is open radially outward is formed between the first and second weld ring halves.

2. The flange connection according to claim 1 , wherein at least one of the first and second weld ring halves has a notch extending in a circumferential direction, on a second contact surface that lies opposite the first contact surface of the at least one of the first and second weld ring halves.

3. The flange connection according to claim 1 , wherein at least one of the first and second weld ring halves comprises an austenitic chromium-nickel steel or a nickel-based material.

4. The flange connection according to claim 1 ,

wherein the first base section is formed separately from the first lip, wherein the first base section and the first lip are connected with one another by way of a first cladding; or

wherein the second base section is formed separately from the second lip, wherein the second base section and the second lip are connected with one another by way of a second cladding.

5. The flange connection according to claim 4 , wherein at least one of the first and second base sections comprises a non-alloy or low-alloy ferritic carbon steel, and at least one of the first and second lips comprises austenitic chromium-nickel steel or a nickel-based material.

6. The flange connection according to claim 1 , further comprising a hood that sheathes the torus-shaped connection section.

7. The flange connection according to claim 6 , wherein the hood comprises a chromium-nickel steel.

8. The flange connection according to claim 1 , wherein at least one radial channel extends from outside the flange connection to the hollow interior of the torus-shaped connection section.

9. A weld ring seal for the flange connection according to claim 1 ,

wherein the first contact surfaces lie against each other, and at least one of the first contact surfaces has a setback that extends in a vertical direction; and

wherein a ring gap that is open radially outward is formed between the first and second weld ring halves, and at least one of the first and second weld ring halves has a notch extending in a circumferential direction, on a second contact surface that lies opposite the first contact surface of the at least one of the first and second weld ring halves.

10. A weld ring half for forming the weld ring seal according to claim 9 .

11. A method for forming the flange connection according to claim 1 , comprising:

(a) connecting the first and second lips with each other by way of the caulking seam to form a torus-shaped connection section;

(b) arranging the weld ring gasket between first and second flanges and bracing the weld ring gasket against the first and second flanges; and

(c) welding the first weld ring half to the first flange on a first sealing surface by way of the first fillet weld and welding the second weld ring half to the second flange on a second sealing surface by way of the second fillet weld.

12. The method according to claim 11 , further comprising inspecting the caulking seam on the torus-shaped connection section with regard to quality of the caulking seam before placing the caulking seam between the first and second flanges.

13. The method according to claim 11 , further comprising heat-treating the caulking seam on the torus-shaped connection section before placing the weld ring gasket between the first and second flanges.

14. The method according to claim 11 , further comprising preheating the first and second weld ring halves before at least one of:

welding the first and second weld ring halves to one another; and

welding the first and second weld ring halves to the first and second flanges, respectively.