Danfoss D1 Series User Manual

NPNN (Pressure Compensated Control)
D1P 130/145/193/260+NPNN
Pressure Compensated Control (P) Principle
The P control design maintains a constant pressure in the hydraulic circuit as flow varies. The P control
modulates pump flow accordingly to maintain system pressure at the P setting as the P adjusting screw
and spring defines.
Pressure Compensated Control (P) Operation
When system pressure, acting on the non-spring end of the P spool, overcomes the force of the P spring,
the spool shifts porting system pressure to the servo piston and the swashplate angle decreases. When
system pressure drops below the P setting, the P spring shifts the spool in the opposite direction
connecting the servo piston to pump case and the swashplate angle increases. The swashplate is
maintained at whatever angle is required to keep system pressure at the P setting.
P characteristic
0
0
Q max
Flow
Pressure
It is recommended that a relief valve be installed in the pump outlet for additional system protection.
Service Manual
D1 High Power Open Circuit Pumps Size 65/130/145/193/260
Operation
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Danfoss | July 2019 L1527453 | AX00000292en-CN0201 | 9

Danfoss D1 Series Specifications

General

Brand	Danfoss
Model	D1 Series
Category	Water Pump
Language	English