The Parker air preparation unit is a modular filter, regulator and lubricator that filters, regulates and lubricates compressed air. It comes in four series, P31, P32, P33 and P3Y, with body widths of 40, 60, 73 and 90 mm.
| Series | P31 Mini / P32 Compact / P33 Standard / P3Y Large |
| Body Width | 40 / 60 / 73 / 90 mm |
| Port Size | 1/4" (P31) / 1/4" to 1/2" (P32) / 1/2" to 3/4" (P33) / 3/4" to 1" (P3Y) |
| Filter Flow | 25 scfm (P31) to 170 scfm (P3Y) |
| Maximum Supply Pressure | 10 bar (plastic bowl) / 17 bar (metal bowl) (P31 filter) |
| Filtration | 5 µm (P31 filter standard) |