Danfoss 39055 Self-Levelling Valves
The Danfoss 39055-FAZ is a line-mounted, flow-dividing dual self-level valve that automatically adjusts a machine’s bucket or attachment position in response to movement of the boom cylinder, maintaining a constant bucket attitude through the boom’s range of travel. It is specifically designed for skid steer loaders, agricultural tractor loaders and small wheel loaders.
The valve connects into open centre, closed centre and load sensing systems, and can be used with parallel or series circuit control valves. With a parallel circuit valve, the system can self-level or operate the boom and bucket independently; with a series circuit valve, the boom spool must be upstream of the bucket spool for correct levelling operation. Danfoss also produces control valves with precise metering to enhance dual self-level valve operation and offers boom and bucket design assistance to help optimise attachment levelling.
A cast iron body with cored internal passages houses precision ground, induction-hardened spools for low internal leakage and long service life. An externally adjustable flow divider allows the proportion of flow directed to the bucket cylinder to be tuned to the application, and an optional solenoid bypass valve allows the operator to deactivate self-level raise or lower independently, without affecting bucket cylinder movement.
The valve’s inline design suits both new machine builds and aftermarket add-on applications, with fewer hydraulic connections required than other methods of dual self-level control.
Key Specifications
| Specification | Detail |
| Technology | Line-mounted, flow-dividing dual self-level valve |
| Assembly order number | 39055-FAZ |
| Body | Cast iron, cored internal passages |
| Spools | Precision ground and induction hardened |
| Circuit compatibility | Open centre, closed centre, and load sensing systems; parallel or series circuit control valves |
| Inlet flow rate | 76 l/min (20 US gpm) |
| Rated pressure | 240 bar (3,500 psi) |
| Maximum pressure | 275 bar (4,000 psi) |
| Work ports | 6, SAE O-ring, 7/8-14 UNF-2B |
| Flow divider setting, raise | Port E 60%, Port D 40% |
| Flow divider setting, lower | Port F 30%, Port B 70% |
| Pressure drop, port C to D | 14 bar (200 psi) at 30 l/min (8 US gpm), adjustment orifice “R” closed |
| Pressure drop, port A to B | 14 bar (200 psi) at 57 l/min (15 US gpm), adjustment orifice “L” closed |
| Relief valve setting, port C | 52 bar (750 psi) maximum at 38 l/min (10 US gpm) |
| Relief valve setting, port A | None (plugged) |
Port Functions
| Port | Function |
| A | Boom cylinder head end – boom raise |
| B | Control valve – boom raise |
| C | Boom cylinder rod end – boom lower |
| D | Control valve – boom lower |
| E | Bucket cylinder head end / control valve – bucket dump |
| F | Bucket cylinder rod end / control valve – bucket curl |
Production Options
- Flow divider setting for application customisation
- Relief valve setting
- Solenoid bypass valving, to deactivate self-level raise or lower independently
Typical Applications
- Skid steer loaders
- Agricultural tractor loaders
- Small wheel loaders
Downloads
The following manuals are available from Danfoss for service and maintenance reference:
Contact Us for further technical details and configuration options.