The Danfoss PAH 4 (code 180B0022) is an axial piston high-pressure pump for tap water and other low-lubricity fluids. It is oil-free and water-lubricated — the pumped water itself lubricates the bearings, so there is no oil circuit and no path for oil to contaminate the process. The housing is AISI 304 stainless steel.
Documentation & Drawings
Technical Specifications
| Identification | |
| Code number | 180B0022 |
| Pump size | PAH 4 |
| Series | PAH 2 – 12.5 |
| Type | Axial piston, oil-free, water-lubricated |
| Version | Standard |
| Housing material | AISI 304 stainless steel |
| ATEX version | 180B6122 |
| Displacement & Flow | |
| Geometric displacement | 4 cm³/rev (0.24 in³/rev) |
| Flow at 1000 rpm, max. pressure | 3.2 l/min |
| Flow at 1500 rpm, max. pressure | 5.2 l/min |
| Flow at 1200 rpm, max. pressure | 1.0 gpm |
| Flow at 1800 rpm, max. pressure | 1.7 gpm |
| Pressure | |
| Max. outlet pressure | 140 barg (2030 psig) |
| Min. outlet pressure | 10 barg (145 psig) |
| Inlet pressure, continuous | 0-4 barg (0-58 psig) |
| Speed | |
| Min. speed, continuous | 700 rpm |
| Max. speed | 1800 rpm |
| Operating Conditions | |
| Media temperature | 2-50 °C (36-122 °F) |
| Ambient temperature | 0-50 °C (32-122 °F) |
| Sound pressure level LPA at 1 m | 76 dB(A) |
| Mechanical | |
| Weight (dry) | 4.4 kg (9.7 lb) |
| Torque at max. specification | 10.9 Nm (8.0 lbf-ft) |
| Typical Motor | |
| Motor size at 1500 rpm, max. pressure | 1.7 kW |
| Motor size at 1800 rpm, max. pressure | 2.7 HP |
| Identification | |
| Manufacturer | Danfoss High Pressure Pumps |
| Data sheet reference | Danfoss AI073186502976en-001902, §4.1 |
Video
How an axial piston pump works — the same working principle as the PAH range
Video courtesy of Danfoss High Pressure Pumps.
Why an Axial Piston Pump for Tap Water
Flow from a positive-displacement axial piston pump is set by displacement and shaft speed rather than by system pressure, so output holds steady as back-pressure rises — unlike a centrifugal pump, whose output falls away as head increases.
- Oil-free — lubricated by the pumped water, so no oil changes and no contamination path into the process.
- No high-pressure mechanical seal — a common wear point on other pump types is simply absent.
- AISI 304 housing, suited to tap water and other clean low-lubricity fluids.
- Field serviceable — Danfoss supplies purpose-designed service kits and tools, which we stock.
Typical duties include high-pressure water mist and fog systems, humidification, dust suppression, industrial cleaning, hydrostatic testing and water hydraulics.
Frequently Asked Questions
What flow will the PAH 4 give me?
Does it come with a motor?
Can it run on water other than tap water?
What inlet pressure does it need?
Is there an ATEX version?
How is it serviced?
Specifications reproduced from Danfoss data sheet AI073186502976en-001902 (2023.03), §4.1. PAH® is a registered trademark of Danfoss A/S. Danfoss reserves the right to alter specifications without notice; confirm critical values against the current data sheet before purchase.
