| Seal type |
| A |
Pusher seal/Rotary multi coil spring type/O-ring packing |
| B |
Non-pusher seal/Rotary bellows (Hastelloy C) type/O-ring packing |
| C |
Non-pusher seal/Stationary bellows (Inconel 718) type/Grafoil packing |
| Seal arrangement |
| 1 |
Single seal |
| 2 |
Dual seal/Unpressurized buffer lower than product |
| 3 |
Dual seal/Pressurized barrier higher than product |