D41FCB31FC4NE7019 Hydraulic Directional Proportional Valve D1 D3 D31 D41 D91 D31F D81 Series

I. Technical Parameters
1.
Flow parameter
Rated flow: 100 L/min (at 1500 rpm and a working pressure of 16MPa), suitable for proportional regulation requirements of medium and high-pressure medium flow hydraulic systems
2.
Maximum flow rate: 120 L/min (at working pressure of 10MPa), flow control accuracy ±1.5% (at rated flow), flow repeatability accuracy ±0.8%
3.
Work pressure
Continuous working pressure: 21 MPa (210 bar), capable of stably carrying medium and high-pressure cyclic operations for a long time, suitable for scenarios with load fluctuations
4.
Instantaneous peak pressure: 25 MPa (250 bar), single duration ≤10 seconds, suitable for extreme working conditions such as system start-up and shutdown, load impact, etc
5.
Control mode:
Control type: electro-hydraulic proportional flow control, input signal 4-20mA DC current signal, signal resolution 0.01mA
6.
Response characteristics: Step response time ≤50ms (from 10% to 90% of the rated flow), regulation time ≤80ms, no overshoot or overshoot amount ≤5%
7.
Structural form: Slide valve type structure, single-stage proportional control (model “D41FCB” indicates series and structural grade); The valve core is made of high-strength alloy steel (surface nitrided treatment, hardness HV900-1100), and the valve sleeve is a tin bronze-based alloy. “FC4” indicates the flange installation specification, and “NE7019” is an integrated pressure compensation valve + electrical connector with a protection grade (IP65).
8.
Oil requirements
Applicable oil type: L-HM 46 or 68 anti-wear hydraulic oil is recommended. For low-temperature working conditions (below -20℃), L-HV 68 low-temperature anti-wear hydraulic oil should be selected, with a viscosity range of 18-300 mm²/s
9.
Working oil temperature: -20℃ to 80℃. The oil cleanliness should reach ISO 16/13 grade (NAS 7 grade). A 5μm high-pressure filter is installed at the oil inlet, and a 10μm fine filter is added at the oil return port
10.
Installation and adaptation
Installation type: SAE C4 flange installation, connection hole specification M16×2, positioning pin diameter Φ10mm, valve body sealing adopts O-ring (material is fluororubber)
11.
Oil port specifications: Inlet G2.5, outlet G2.5, return G3. Supports bidirectional flow regulation. Overall weight is approximately 18 kg. Can be installed horizontally or vertically in both directions (for vertical installation, make sure the electrical connector is facing down).
twelve
Other parameters: Pressure loss ≤0.8MPa (at rated flow), internal leakage ≤0.3 L/min (at 21MPa), working life ≥1 million cycles, electrical connector protection grade IP65, rated power of proportional electromagnet 15W, ambient temperature -30℃ to 85℃Ii. Working Principle

This valve is an electro-hydraulic proportional flow control valve. Its core components include a proportional electromagnet, valve core, valve sleeve, pressure compensation valve, reset spring and electrical connector. It achieves precise flow regulation through the proportional conversion of electrical signals and hydraulic signals. The pressure compensation structure ensures stable flow when the load changes. The specific process is as follows:
1.
Electrical signal input and force conversion: The control system outputs a 4-20mA DC proportional signal, which is transmitted to the proportional electromagnet through the electrical connector. The electromagnet generates proportional electromagnetic force based on the signal strength, which overcomes the elastic force of the reset spring to push the valve core to make axial displacement along the valve sleeve axis. The signal strength and the displacement of the valve core have a linear proportional relationship
2.
Flow proportional regulation: The displacement of the valve core changes the opening degree (area) of the throttle port on the valve sleeve. After high-pressure oil enters the valve chamber through the oil inlet, the flow through the throttle port is proportional to the area of the throttle port (conforming to the flow formula Q=K×A×√ΔP). By adjusting the input signal strength, continuous proportional control of the flow rate from the minimum (about 5 L/min) to the maximum (120 L/min) can be achieved
3.
Pressure compensation and stability control: The integrated pressure compensation valve detects the pressure difference between the oil inlet and the oil outlet in real time. When the load changes and causes pressure fluctuations at the oil outlet, the compensation valve automatically adjusts the opening of the damping hole in the valve core to maintain a constant pressure difference at both ends of the throttle port. Even if the system pressure varies within the range of 5 to 21MPa, the flow control accuracy can still be maintained within ±1.5%, ensuring the stable movement speed of the actuator
4.
Reset and safety protection: When the input signal is interrupted (≤3mA), the reset spring pushes the valve core back to the initial closed position, cutting off the flow in the main oil circuit. If the system pressure exceeds 25MPa, the unloading structure inside the valve body will automatically open to guide the excess oil back to the oil tank, preventing damage to the valve body

Iii. Product Features and Advantages

1.
High proportional control accuracy: The 4-20mA signal has a strict linear relationship with the flow rate, with a flow control accuracy of ±1.5% and a repeatability accuracy of ±0.8%. It can achieve stepless adjustment of the movement speed of the actuator, replacing the traditional “multi-stage throttle valve + relief valve” combination scheme, reducing the speed regulation error by 80%, and is suitable for precision operation scenarios
2.
Excellent pressure compensation stability: The integrated pressure compensation valve can maintain a stable flow rate within the pressure range of 5-21 mpa. When the load changes (such as when the load increases during the lifting of the excavator bucket), the speed fluctuation of the actuator is ≤2%, which improves stability by 60% compared to the non-compensation proportional valve and avoids a decrease in operation accuracy
3.
Strong anti-pollution and reliability
The valve core is made of nitrided alloy steel, and the valve sleeve is a tin bronze-based alloy. The fit clearance is controlled within 0.005-0.01mm. Under ISO 16/13 grade polluted environments (such as construction machinery dust and industrial oil stains), the working life can reach 1 million cycles, which is 40% longer than that of ordinary proportional valves
4.
The electrical connector with IP65 protection grade can adapt to outdoor rain and dust environments. The proportional electromagnet adopts a sealed structure, which is moisture-proof and oil-proof, reducing the failure and shutdown rate by 50%
5.
Compact structure and good integration: It integrates proportional control, pressure compensation and unloading protection into one unit. The overall volume is reduced by 35% compared with the split solution, and there is no need to install additional compensation valves and unloading valves. The standardized SAE C4 flange installation can directly replace the ordinary throttle valve of the same specification, reducing the modification cost by 60%
6.
Strong wide working condition adaptability: It can operate normally without preheating in a low-temperature environment of -20℃, and the flow accuracy does not decline in a high-temperature working condition of 80℃. Supports horizontal/vertical installation, suitable for different layouts such as construction machinery chassis and industrial equipment hydraulic stations, and compatible with various hydraulic oils including mineral oil and synthetic ester

Iv. Usage Functions and Purposes

1. Usage function

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As a core component for flow ratio control in medium and high-pressure hydraulic systems, it can achieve stepless flow regulation ranging from 5 to 120 L/min, driving hydraulic cylinders and motors to precisely control the movement speed (such as the lifting speed of excavator buckets and the opening and closing speed of injection molding machines).
•
Pressure compensation function: Automatically maintain stable flow when the load changes, suitable for scenarios where “multiple actuating elements act simultaneously” (such as the combined action of lifting and flipping of a loader), ensuring that the speeds of each action do not interfere with each other and enhancing the coordination of the operation
•
Bidirectional flow regulation: Through the symmetrical structure design of the valve core, it can achieve bidirectional flow ratio control of oil inlet and return, which is suitable for scenarios requiring bidirectional power (such as the forward/backward speed adjustment of hydraulic trolleys), without the need for additional directional control valves
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Integrated safety protection: Automatically cut off the flow when the signal is interrupted and automatically unload when the pressure exceeds the limit, preventing the actuator from losing control or the valve body from being damaged, and enhancing the system safety
2. Uses

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Construction machinery: Control of the boom/boom/bucket movement speed of 15-25-ton crawler excavators, adjustment of the lifting/flipping speed of 20-ton wheel loaders, and proportional control of the lifting/tilting speed of 8-ton hydraulic forklifts
•
Industrial equipment: Regulation of mold opening and closing, ejection and feeding speeds for 800-1500-ton injection molding machines, hierarchical control of pressing speeds for large hydraulic presses, and precise control of the extension and rotation speeds of hydraulic robotic arms in automated production lines
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Special machinery: Steering speed regulation of ship hydraulic steering gears, cutting/conveying speed control of large agricultural machinery (such as sugarcane harvesters), and proportional regulation of advancement speed for small underground tunnel boring machines in mines

V. Applicable Machines and Scenarios

1. Applicable machines

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Construction machinery: 15-25 ton crawler excavators, 20 ton wheel loaders, 8 ton hydraulic forklifts
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Industrial equipment: 800-1500-ton injection molding machines, large hydraulic presses, and hydraulic robotic arms for automated production lines
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Special machinery: Marine hydraulic steering gears, large sugarcane harvesters, small underground tunnel boring machines for mines
2. Applicable scenarios

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Precision speed control scenarios: Precise speed regulation for opening and closing molds of injection molding machines (speed error ≤1mm/s), assembly operations of hydraulic mechanical arms (positioning accuracy ≤0.5mm), and improvement of operation quality by relying on ±1.5% flow accuracy
•
Load fluctuation scenarios: Excavators excavate materials of different hardness, and presses press workpieces of different thicknesses. The pressure compensation function ensures stable speed and prevents a decline in operation efficiency
•
Harsh environmental scenarios: underground rock powder environment in mines, outdoor infrastructure dust environment, high salt spray environment in ports. Strong anti-pollution performance and IP65 protection can extend the maintenance cycle to over 2,000 hours
•
Integrated modification scenarios: Speed control upgrade of old equipment (such as changing multi-stage throttle valves to proportional valves), compact hydraulic system design of new equipment, and integrated structure reduces installation space and modification costs

Six. Similar models

1. Models of the same series

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D41FCB25FC4NE7019: Electro-hydraulic proportional flow control valve, rated flow 80 L/min (1500 rpm), continuous pressure 21MPa, suitable for medium and small flow scenarios such as 12-15 ton excavators and 600-800 ton injection molding machines. The installation dimensions are the same as those of model 31
•
D41FCB35FC4NE7019: Electro-hydraulic proportional flow control valve, rated flow rate 120 L/min (1500 rpm), continuous pressure 21MPa, suitable for high-flow scenarios such as 25-30 ton excavators and 1500-2000 ton injection molding machines
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D41FCB31FC4NE7019-P: Consistent with the parameters of model 31, the “P” marking is equipped with pressure feedback function, making it suitable for closed-loop control scenarios with high requirements for pressure monitoring
2. Similar alternative models

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4WRAE10W30-2X: Electro-hydraulic proportional flow valve, rated flow rate 100 L/min, continuous pressure 21MPa, adopts direct-acting proportional control, response time ≤40ms, suitable for scenarios with high response speed requirements
•
DBETE-6X/100G24: Proportional pressure-flow compound valve, rated flow rate 100 L/min, continuous pressure 21MPa, integrates pressure and flow proportional control, suitable for systems that require coordinated pressure and flow regulation
•
EPFR-100: Electromagnetic proportional flow valve, rated flow rate 100 L/min, continuous pressure 21MPa, more compact structure (weight approximately 12 kg), suitable for scenarios with limited installation space

Vii. Precautions for Use

1.
Core norms for Oil and Fluid Management
Strictly use L-HM 46/68 or L-HV 68 anti-wear hydraulic oil. Do not mix different brands, grades of oil or oil containing impurities to avoid valve core jamming and proportional electromagnet wear. Before changing the oil, the valve chamber and the inlet and return oil pipelines should be thoroughly flushed with new oil (the flushing oil volume should be no less than 1.5 times the system volume)
2.
The cleanliness of the 5μm filter at the oil inlet should be checked every 300 hours, and the 10μm filter at the oil return port should be replaced every 600 hours. Hydraulic oil should be replaced every 1500 to 2000 hours. When changing the oil, the sediment at the bottom of the oil tank should be cleaned (a sediment thickness of ≤1mm is normal), and the moisture content of the oil should be ≤0.15%
3.
Installation accuracy control
Flange face sealing installation is adopted. The flatness error of the flange contact surface is ≤0.02mm. The installation bolts are evenly tightened (torque 250-300 N·m) to avoid valve body deformation causing valve core jamming. The electrical connector should be installed facing down to prevent rainwater and oil stains from seeping in
4.
The diameter of the inlet and return oil pipelines shall not be less than Φ50mm, the number of pipeline elbows shall not exceed 2, and throttling elements shall not be installed within a range of 1m from the valve body to reduce pressure loss. When installed vertically, the valve body should be pre-filled with hydraulic oil to prevent cavitation during startup
5.
Debugging and operation monitoring
Before the initial commissioning, the valve cavity should be flushed with low-pressure oil (5MPa) to expel air. Connect the 4-20mA signal source, gradually adjust from the minimum signal (4mA) to the maximum (20mA), record the flow variation curve, and ensure that the linearity error is ≤1.5%. For low-temperature start-up (below -15℃), the oil should be preheated to above 10℃ first
6.
Core parameters for monitoring during operation: Oil temperature 30-75℃ (if the temperature exceeds 80℃, the machine needs to be shut down to check the cooling system), working pressure ≤21MPa, flow fluctuation ≤2%. If “speed regulation failure” occurs, “signal normal but flow rate unchanged”, or the leakage exceeds 0.5L /min, the machine must be stopped immediately to check for valve core jamming, filter blockage or proportional electromagnet failure
7.
Maintenance and upkeep nodes
Check the contact condition of the electrical connector every 800 hours. If it is loose or oxidized, it needs to be ground. Disassemble and inspect the wear of the valve core and valve sleeve every 1500 hours. When the fit clearance exceeds 0.015mm, the valve core assembly needs to be replaced
8.
Calibrate the linearity of the proportional control every 2000 hours. Adjust the stroke of the proportional electromagnet through a dedicated test bench to ensure that 4mA corresponds to the minimum flow rate and 20mA corresponds to the maximum flow rate, with the linear error controlled within ±1.5%
9.
Security and storage requirements
Before maintenance or repair, the hydraulic power source and control power supply must be cut off. Open the pressure relief valve to reduce the pressure to 0MPa. Disassembly can only be carried out when the oil temperature drops below 40℃. When disassembling, make sure to mark the installation direction of the valve core to avoid reverse reinstallation causing malfunctions
10.
When the machine is out of service for a long time (more than 3 months), the oil in the valve should be drained and anti-rust oil injected. The oil port and the interface of the electrical connector should be sealed. It should be stored in a dry and well-ventilated environment (humidity ≤65%), avoiding direct sunlight or proximity to high-temperature heat sources