Eaton Series Counterbalance Valve 1SE30F35S2
The 1SE30F35S2 is a threaded cartridge counterbalance valve of Eaton IH series. It features low pilot ratio, small flow rate and cost-effective performance. Applied for load holding, anti-slip protection and hose burst safety safeguard, it is widely used in medium and low pressure construction machinery, forklifts and compact aerial work platforms.
1. Model Code Interpretation
- 1SE: Series code, economical counterbalance valve integrating pilot relief and check valve function
- 30: Flow rating, nominal flow 30 L/min
- F: Adjustment mode, hex socket screw adjustment
- 35: Pressure grade, adjustable range 100-350 bar, factory preset pressure about 210 bar
- S: Seal material, nitrile rubber (NBR)
- 2: Pilot ratio, 2.5:1 low-pressure pilot control
2. Main Technical Parameters
- Mounting style: Threaded cartridge, standard cavity A6610
- Nominal flow: 30 L/min (8 US gpm)
- Maximum load pressure: 270 bar (4000 psi)
- Maximum relief pressure: 350 bar (5000 psi)
- Adjustable pressure scope: 100-350 bar
- Pilot ratio: 2.5:1
- Internal leakage: ≤ 0.3 mL/min at low pressure side
- Operating temperature: -20℃ ~ +90℃
- Standard seal: SK395 NBR; Optional seal: SK395V FKM
- Material: Heat-treated and precision ground steel for spool and sleeve; Aluminum or steel valve body
- Installation torque: 45 Nm
- Weight: Approximately 0.15 kg
- Original part number: 406AA00004A
3. Structure & Working Principle
Three-port design
- Port 1 Load port: Connect to hydraulic cylinder or hydraulic motor
- Port 2 Service port: Connect to working port of directional control valve
- Port 3 Pilot port: External pilot pressure control
Three integrated functions
1. Check valve: Smooth fluid flow from port 2 to port 1 with low pressure drop
2. Relief valve: Overpressure protection when pressure exceeds 350 bar at load port
3. Low-pressure pilot balance control: Low pilot pressure can regulate valve opening during load descending, realizing stable low-speed operation. The valve will lock automatically once pressure drops to prevent load falling caused by pipeline damage.
4. Product Advantages
- Low pilot pressure demand, fast response and energy saving
- Automatic load locking against pressure loss and hose rupture
- Suitable for small and medium-sized hydraulic circuits with 30L/min flow capacity
- Ultra-low internal leakage thanks to precision machining spool
- Omni-directional installation, compact structure saves installation space
5. Typical Application
- Forklifts, loaders and mini excavators
- Aerial work platforms within 10 meters lifting height and lifting platforms
- Balancing control for low-torque winch and slewing hydraulic motors
- Medium and low pressure mobile hydraulic systems requiring low pilot control
6. Common Spare Parts & Equivalent Models
- Seal kit: SK395 (NBR), SK395V (FKM)
- Alternative models: 1SE30F35S5 (5:1 pilot ratio), 1SE30F35S8 (8:1 pilot ratio)
- Original assembly part number: 1SE30F35S2 (406AA00004A)
