R900481621 Z2FS6-2-4X/1Q Rexroth one-way throttle valve

Frequently Asked Questions (FAQ) for One-Way Throttle Valve Z2FS 6-2-4X/1Q (Order Code: R900481621)

Q1: What is the primary function of this valve?

A:​ It is a manually adjustable one-way throttle valve. It restricts hydraulic flow in one direction to control actuator speed (e.g., cylinder extension or retraction), while allowing free, unrestricted flow in the opposite direction.

Q2: How does a one-way throttle valve work?

A:​ The valve contains a check valve and an adjustable throttle (orifice) in parallel. In the restricting direction, fluid must pass through the adjustable throttle, creating a controlled restriction. In the free-flow direction, the check valve opens, allowing fluid to bypass the throttle with minimal resistance.

Q3: What does the model code "Z2FS 6-2-4X/1Q" signify?

A:

• Z2FS 6:​ Series and nominal size (NG6).

• 2:​ Number of ports (2-way, ports A and B).

• 4X:​ Specifies a linear flow characteristic​ (flow is approximately proportional to the adjustment).

• 1Q:​ Designates the specific variant/manual adjustment type with locknut.

Q4: What is the difference between a throttle valve and a flow control valve?

A:​ A standard throttle valve​ (like this one) creates a fixed orifice. The flow through it varies significantly with changes in system pressure. A pressure-compensated flow control valve​ maintains a nearly constant flow rate regardless of pressure changes upstream or downstream, offering more precise speed control. This valve is not pressure-compensated.

Q5: How is the flow rate adjusted?

A:​ Flow is adjusted manually​ by turning the valve's screw. Turning the screw in (clockwise) reduces the orifice size, decreasing flow and slowing the actuator. Turning it out (counter-clockwise) increases flow. A locknut secures the setting against vibration.