| Class | Steel-ring flanges | Steel-hub flanges |
| Class B (86psi) | NPS 4-144 (DN100-3600) | – |
| Class D (175-150psi) | NPS 4-144 (DN100-3600) | NPS 4-96 (DN100-2400) |
| Class E (275psi) | NPS 4-144 (DN100-3600) | NPS 4-96 (DN100-2400) |
| Class F (300psi) | NPS 4-48 (DN100-1200) | – |