| Symbol | Description | Capacity | Cavity | Model |
|---|
| |
 | Normally closed, balanced poppet, logic element - vent-to-open | 15 gpm60 L/min. | T-21A | DKDR |
| |
 | Normally closed, balanced poppet, logic element with integral T-8A control cavity - vent-to-open | 15 gpm60 L/min. | T-21A | DKDR8 |
| |
| Normally closed, balanced poppet, logic element - vent-to-open | 30 gpm120 L/min. | T-22A | DKFR |
| |
| Normally closed, balanced poppet, logic element with integral T-8A control cavity - vent-to-open | 30 gpm120 L/min. | T-22A | DKFR8 |
| |
| Normally closed, balanced poppet, logic element - vent-to-open | 60 gpm240 L/min. | T-23A | DKHR |
| |
