Rexroth MK Series Throttle Valve | MK6G MK10G MK15G MK20G | One-way Throttle Valve

The MK Series one-way throttle valves from Chengyuan Hydraulic are high-quality line-mounted components fully compatible with Rexroth Series 1.X standards. This valve provides precise flow regulation in one direction while allowing free flow in the opposite direction. For core models like MK6G1.2B/2 and MK10G, we utilize high-frequency induction-hardened needles and corrosion-resistant blued surfaces. Every valve undergoes 100% cracking pressure and flow linearity testing before delivery to ensure smooth adjustment under 31.5 MPa high-pressure conditions, guaranteeing 100% original-place interchangeability.

Technical Specifications:

• Series Model: MK Series (One-way Throttle Valve)

• Nominal Sizes: 6, 8, 10, 15, 20, 25, 30 (NG6 to NG30)

• Design Series: Series 1.X (e.g., 1.2B)

• Max Operating Pressure: 31.5 MPa (315 bar)

• Cracking Pressure (Reverse Free Flow): 0.05 MPa (0.5 bar)

• Operating Medium: Mineral oil (HL, HLP) to DIN 51524

• Fluid Temperature Range: -30°C to +80°C

• Connection Type: G-threaded inline connection (ISO 228)

• Sealing Material: Standard NBR / Optional FKM (Viton)

Key Technical Advantages:

• Highly Linear Throttling Characteristics: The MK series needle valve features a computer-optimized taper, ensuring that the flow rate changes linearly with the knob’s rotation angle. Even at micro-flow stages, it maintains stable output, preventing actuators from “crawling.”

• Integrated Large-Bore Check Valve: The free-flow direction utilizes a high-flow area poppet design, significantly reducing pressure drop during reverse cycling. This is critical for actuators requiring rapid return strokes, such as hydraulic cylinders.

• Double-Locking Mechanism: The adjustment knob is equipped with a clear scale indicator and a lateral locking screw. Once the target flow is set, the locking mechanism prevents the adjustment bolt from shifting due to severe system vibration or pressure spikes.

• All-Steel High-Pressure Body: Unlike standard aluminum valves, Chengyuan’s MK series is machined from high-strength alloy steel. This construction withstands pulsed pressures of 315 bar without fatigue damage, ensuring an industrial-grade service life.

Application Areas:

• Speed Control Circuits: Regulating the extension or retraction speed of hydraulic cylinders (meter-in/meter-out).

• Synchronization Circuits: Fine-tuning flow rates between multiple actuators for simple synchronization.

• Pressure Damping: Used as a signal buffer or delay in gauge lines or logic control circuits.

Expert Maintenance Tips:

• Avoid Forcing the Knob: When adjusting to the minimum flow (closed position), stop immediately upon feeling resistance. Forcing the knob beyond this point can damage the precision-ground throttling cone.

• Verify Installation Orientation: The valve body is clearly marked with arrows for A→B (throttling direction) and B→A (free flow). Always double-check the circuit logic before installation to prevent malfunctions.

• Contamination Control: Because the throttle orifice can be extremely small, impurities in the oil can cause clogging and flow fluctuations. It is recommended to maintain system return filtration at 10μm or better.