Compact raised face flange

1. A raised face flange system comprising:

a first, raised face flange having:

a bolting face defining one or more openings for one or more bolts, respectively; and

a pair of raised faces including a first raised face disposed in a first plane and a second raised face to form a seal in a nuclear reactor module, the second raised face disposed in a second plane that is different than the first plane;

a second, flat-faced flange; and

a bolt extending through the first flange and the second flange in series,

wherein the bolting face is disposed between the raised faces in a third plane that is different than the first and second planes;

wherein the bolting face and the raised faces face in one direction; and

wherein a distance between an area of the second raised face and the third plane is greater than a distance between an area of the first raised face and the third plane to distribute contact force with the second flange over the area of the second raised face to maintain the seal.

2. The raised face flange system of claim 1 , wherein the first and second planes are non-intersecting.

3. The raised face flange system of claim 1 , wherein the first and second planes are intersecting.

4. The raised face flange system of claim 1 , wherein the first raised face includes one or more features to mount a gasket thereon or therein.

5. The raised face flange system of claim 4 , further comprising the gasket, and wherein the gasket comprises one or more ring gaskets, and wherein the one or more features comprise one or more grooves to receive the one or more ring gaskets, respectively.

6. The raised face flange system of claim 1 , wherein a surface of the first raised face has a linear slope, the linear sloped surface having a first section and a second section, the first section being farther from the third plane than is the second section, and wherein the first section is farther from a nearest one of the one or more bolt openings than is the second section.

7. The raised face flange system of claim 1 , wherein the seal comprises a seal of a reactor vessel of the nuclear reactor module.

8. The raised face flange system of claim 1 , wherein the seal comprises a seal of a containment vessel of the nuclear reactor module.

9. The raised face flange system of claim 1 , wherein each of the first and second raised faces form at least one corresponding continuous ring shape.

10. The raised face flange system of claim 1 , wherein a difference between the distances is selected based on a deformability of a sidewall of a pressure device on which the raised face flange is mounted.

11. A vessel of a nuclear reactor module, the vessel comprising:

a vessel flange joint to couple a first cylindrical sidewall of the vessel to a second sidewall of the vessel;

the vessel flange joint including an upper flange coupled to a lower flange using at least one bolt extending through the upper flange and the lower flange in series, wherein at least one of the upper flange or the lower flange is a flat-faced flange, and wherein the other of the upper flange or the lower flange includes:

a bolting face having one or more openings for the at least one bolt, respectively;

a pair of raised faces positioned on opposite sides of the bolting face, and including a first raised face in a first plane and a second raised face in a second plane, the raised faces positioned to make contact with a mating surface of the other of the upper flange or the lower flange, the raised faces and the bolting face facing in one direction; and

wherein a distance between an area of the second raised face and a third plane corresponding to the bolting face is greater than a distance between an area of the first raised face and the third plane to distribute a contact force with the mating surface.

12. The vessel of claim 11 , wherein the second sidewall comprises a second cylindrical sidewall.

13. The vessel of claim 11 , wherein the vessel contains a reactor coolant.

14. The vessel of claim 11 , wherein the vessel contains a reactor pressure vessel or a containment vessel for a reactor pressure vessel.

15. The vessel of claim 14 , wherein the vessel flange joint comprises a first vessel flange joint, and wherein the reactor pressure vessel comprises a second vessel flange joint.

16. A raised face flange assembly, comprising:

an upper flange;

a lower flange; and

at least one bolt coupling the upper flange and the lower flange:

wherein at least one of the upper flange or the lower flange is a flat-faced flange, and the other of the upper flange or the lower flange comprises:

a bolting face having at least one opening for the at least one bolt;

a pair of raised faces positioned on opposite sides of the bolting face, and including a first raised face in a first plane and a second raised face in a second plane, the raised faces positioned to make contact with a mating surface of the other of the upper flange or the lower flange;

wherein the bolting face and the raised faces face in one direction; and

wherein a distance between an area of the second raised face and a third plane corresponding to the bolting face is greater than a distance between an area of the first raised face and the third plane to distribute a contact force with the mating surface.

17. The raised face flange assembly of claim 16 , further comprising one or more gaskets located in one or more grooves formed in the first raised face.

18. The raised face flange assembly of claim 16 , wherein the upper flange is formed on an edge of a first cylindrical sidewall of a vessel having a cylindrical body, and the lower flange is formed on an edge of a second, different cylindrical sidewall of the vessel.

19. The raised face flange assembly of claim 18 , wherein the vessel comprises a containment vessel or a nuclear reactor vessel.

20. The raised face flange assembly of claim 16 , wherein a difference between the distances is in the range of 20-40 mils.