R900595835 Z2FS22B8-3X/S Hydraulic valve German Rexroth one-way throttle valve

FAQ: R900595835 Z2FS22B8-3X/S One-Way Throttle Valve

Q1: What is the primary function and key difference of the "B8" variant?

A:​ The primary function is to provide manually adjustable, one-way flow control for hydraulic actuators, with free return flow via an integrated check valve. The key identifier "B8" specifies a particular spool design and flow characteristic curve. This means its flow rate at a given handwheel setting follows a predefined, repeatable relationship with the pressure drop, which may differ from other variants (like "5" or "8" in smaller sizes). It is engineered for predictable performance within a specific operating range.

Q2: What does the "NG22" size mean for installation and performance?

A:​ NG22​ is the nominal size, corresponding to a CETOP 8 / ISO 4401-08 subplate. It indicates a valve designed for high-flow applications. This requires larger port connections (typically 1" UNF) and is physically larger and heavier than NG10 or NG16 valves. Its internal passages are sized to handle flows up to approximately 200 L/min with acceptable pressure losses.

Q3: What is the maximum system pressure rating?

A:​ The valve is rated for a maximum operating pressure of 315 bar.

Q4: How is the valve adjusted and the setting secured?

A:​ Flow is adjusted by turning the handwheel, which moves a precision-ground spindle to vary the orifice size. To prevent the setting from changing due to system vibration or accidental contact, a separate locking nut​ is provided. Once the desired flow is set, this nut must be tightened firmly against the valve housing to lock the spindle in position.

Q5: How are the throttle and check valve functions routed?

A:​ The valve has two main functional paths:

• Throttled Flow (Controlled Speed):​ Fluid is metered when flowing from Port 1 (P, pressure port)​ to Port 2 (A, actuator port). This controls actuator speed.

• Free Return Flow:​ Fluid can flow freely from Port 2 (A)​ back to Port 1 (P)​ by pushing open the internal check valve, allowing fast actuator return.