R900483785 ZDR6DP2-4X/25YM Hydraulic valve Rexroth direct acting pressure reducing valve

FAQ:

Q1: What is the primary function of the Rexroth ZDR6DP2-4X/25YM valve?

A:​ It is a direct-acting pressure reducing valve. Its core function is to reduce and regulate a higher, variable primary (inlet) pressure to a lower, stable, and adjustable secondary (outlet) pressure, regardless of fluctuations in the primary pressure or flow demand (within its rated range). It ensures a constant lower pressure for a specific branch of a hydraulic circuit.

Q2: What does the "25" in the model number signify?

A:​ The "25" indicates the maximum adjustable secondary (outlet) pressure​ for this valve, which is 25 bar. This is the highest pressure that can be set at the outlet (A or A(B) port) of the valve. The primary (P port) inlet pressure must be higher than this setting for the valve to function.

Q3: How does a direct-acting pressure reducing valve work?

A:​ In its typical normally open state, fluid flows freely from the primary (P) to the secondary (A) port. The secondary pressure is fed back (internally or externally) to act on a control piston or spool against an adjustable spring. When the secondary pressure reaches the spring setting, the spool moves to restrict or close the flow from P to A, thereby maintaining the set outlet pressure. It opens again if the outlet pressure drops below the set point.