The Nachi SS-G03-A4-FR-E115-E22 is an industrial-grade, direct-operated solenoid directional control valve built for high-performance fluid distribution in heavy machinery. Built onto the standardized ISO 4401-05 mounting pattern (equivalent to NFPA D05, CETOP 5, and NG10 sizes), this valve is a global benchmark for both premium OEM builds and high-reliability factory maintenance, repair, and operations (MRO).
This model utilizes Nachi’s renowned wet armature “Super Solenoid” technology. Because the mechanical armature moves within a pressure-sealed tube filled with hydraulic oil, the shifting impact is naturally cushioned. This eliminates the persistent oil weeping typical of dry-pin designs, lowers airborne machine noise, and guarantees continuous-duty operational reliability across millions of high-frequency cycles.
Core Technical Features & Advantages
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Streamlined Internal Casting: Computational fluid dynamics (CFD) optimized internal pathways ensure exceptionally laminar fluid movement, reducing pressure drop ($\Delta p$) and keeping system heat to a minimum.
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High Backpressure Allowance: Advanced pressure-equalizing design elements allow the valve to tolerate high backpressure levels at the tank line (Port T) without causing spool stiction or uncommanded shifts.
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Heavy-Duty Junction Box Structure: The E22 engineering revision features a rugged central terminal junction box that provides excellent IP dust and moisture protection for demanding plant floors.
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Overheat-Resistant Coils: High-grade electrical insulation inside the E115 coil pack ensures stable performance even during prolonged holding cycles or voltage fluctuations.
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Hardened Spool Geometries: Precision-machined, hardened alloy steel spool maintains ultra-tight internal tolerances, effectively controlling cross-port leakage over an extended service lifespan.
Primary Applications
The Nachi SS-G03 size 5 series is an essential component across highly automated, high-pressure industrial processing sectors:
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Heavy-duty CNC machine tools, machining centers, and automated clamping fixtures
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Plastic processing, rubber extrusion plants, and injection molding machinery
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Metal stamping, forming, drawing presses, and industrial shearing machinery
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Large-scale industrial Hydraulic Power Units (HPUs) and automated test stands
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Automated material handling conveyor loops, sorting gates, and lifting platforms
Technical Specifications Table
| Parameter | Value / Specification |
| Brand Name | Nachi Fujikoshi |
| Model Code | SS-G03-A4-FR-E115-E22 |
| Mounting Interface | ISO 4401-05 / Cetop 5 / NFPA D05 / NG10 |
| Actuation Type | Solenoid Operated (Direct Shifting Spool) |
| Solenoid Technology | Wet Armature Type (Fluid Filled) |
| Spool Layout | 2-Position, Single Solenoid |
| Spool Type | A4 Type |
| Electrical Rating | 115V AC (50/60 Hz) / E115 Code |
| Maximum Operating Pressure | Ports P, A, B: Up to 35 MPa (5,076 psi) / Port T: Up to 16 MPa (2,320 psi) |
| Maximum Flow Capacity | Up to 100-160 L/min (Depending on spool configuration & circuit pressure) |
| Wiring Connection | Central Terminal Box (E22 Design Series) |
| Sealing System | High-Grade NBR (Buna-N) Standard / Optional Viton |
