SFM & MVI Series Hydraulic Valves | SFM2 SFM3 MVI1200S MVI800S | Flow Control & Directional Valves

The SFM Series (SFM2, SFM3) and MVI Series (MVI400, MVI600, MVI1200) hydraulic valves by Chengyuan Hydraulic are high-performance solutions for complex flow control and multi-spool directional requirements. The SFM multifunctional valves (e.g., SFM2AAKN) integrate pressure compensation and flow regulation within a single body. In contrast, the MVI series (e.g., MVI1200S) is a robust manual/mechanical multi-spool valve range celebrated for its exceptional inching performance and resistance to high-pressure shocks. Every Chengyuan valve offers 100% original-place interchangeability and undergoes 100% simulated condition testing to guarantee superior precision and zero-leakage performance under extreme digging, lifting, or traveling conditions.

Technical Specifications :

• Core Models: SFM2, SFM3, MVI400S2-V, MVI600S, MVI800S, MVI1200S

• Max Operating Pressure: $25\text{ MPa}$ to $35\text{ MPa (up to 5075 psi)}$

• Rated Flow Range: $40\text{ L/min}$ (MVI400) up to $120\text{ L/min}$ (MVI1200)

• Spool Functions: O-type, Y-type, M-type, A-type available

• Control Methods: Manual, Mechanical, Proportional Pilot

• Material: High-strength Compacted Graphite Iron (CGI) or Ductile Iron for maximum rigidity

• Temperature Range: $-20\text{°C}$ to $+80\text{°C}$

• Mounting: Threaded ports or subplate mounting options

Key Technical Advantages:

• Excellent Inching Performance: Spools in the MVI series (such as MVI800S) are designed with precision metering notches. This provides superior inching characteristics, allowing operators to achieve millimeter-level positioning of heavy execution mechanisms with tactile feedback.

• Highly Integrated Multifunctional Logic: SFM2/3 series combine relief, check, throttle, and pressure compensation functions in a compact unit. This integrated design reduces the number of plumbing connections, minimizes leak points, and significantly saves installation space.

• Robust Shock Resistance: Valve bodies are manufactured from materials with high thermal and mechanical strength, followed by secondary tempering. This ensures that the spool remains free-moving even under sudden hydraulic surges (e.g., excavators hitting hard rock), preventing “sticking” caused by housing distortion.

• Ultra-Low Internal Leakage: Spools and bores are precision-matched with clearances controlled at the micron level. This ensures that internal leakage remains far below industry standards even at high temperatures and pressures, maintaining the holding stability of actuators.

Application Areas:

• Mobile Machinery: Travel and attachment control for excavators, bulldozers, and harvesters.

• Material Handling: Flow distribution for crane winches and telehandler boom systems.

• Industrial Equipment: Power logic control for scrap shears and large garbage compactors.

Expert Maintenance Tips:

• Linkage Lubrication: For manually operated MVI valves, ensure all external mechanical linkages are well-lubricated. Friction in the linkage can interfere with the operator’s feedback from the hydraulic resistance.

• Seal Inspection: In high-cycle applications, inspect the static seals at the end caps every $2000$ working hours to prevent external leakage due to aging seals.

• Pressure Verification: SFM valves feature integrated relief valves. Always verify the cracking pressure via a test port after installation to ensure it stays within the actuator’s rating. Never adjust the setting screw without monitoring a gauge.