- CN
| Parameter | Specification | Testing Standard |
|---|---|---|
| Operating Pressure Range | 5-25 MPa (725-3,626 PSI) | ISO 10766 |
| Temperature Range | -30°C to +100°C (-22°F to +212°F) | ASTM D2000 |
| Bore Diameter (D20-21A-6 Specific) | 70mm (±0.015mm) | ISO 286-2 |
| Rod Diameter (D20-21A-6 Specific) | 40mm (-0/+0.010mm) | ISO 286-2 |
| Seal Material Hardness | 80-90 Shore A (component specific) | ASTM D2240 |
| Pressure Cycle Rating | 200,000 cycles at 20 MPa | ISO 10767-1 |
| Friction Coefficient | 0.14-0.22 (optimized for small dozer operation) | ASTM D1894 modified |
| Contaminant Exclusion | >95% efficiency for >15µm particles | ISO 4548-12 |
| Drift Rate | ≤3 mm/minute at 20 MPa | Proprietary test method |
| Abrasion Resistance | ≤70 mm³ loss (Taber, CS-17 wheel) | ASTM D4060 |
| Thermal Conductivity | 0.25-0.32 W/m·K | ASTM E1225 |
| Service Life | 3,000-4,500 hours in typical small dozer service | Field validation data |
| Response Time | <0.4 seconds for full cylinder movement | Field validation data |
| Component | COGENG Part Number | Material | Dimensions | Special Features | Quantity |
|---|---|---|---|---|---|
| D20 Piston Seal | CG-DPS-05420-01 | HNBR with reinforcement | ID: 70mm (D20 specific) | Compact design, optimized for small bore | 2 |
| D20 Rod Seal | CG-DRS-05420-01 | Polyurethane (EU) | ID: 40mm (D20 specific) | Low friction, moderate pressure rating | 2 |
| Compact Wiper | CG-CWP-05420-01 | Dual-density PU | Wiper specific | Double-lip design for small dozer conditions | 1 |
| D20 Wear Bands | CG-DWB-05420-01 | Bronze-PTFE composite | Width: 12mm | Reduced width for compact cylinder | 2 |
| Backup Rings | CG-BKR-05420-01 | Glass-filled PTFE | Groove specific | Standard anti-extrusion protection | 4 |
| Component | Function | Material | D20-21A-6 Specification |
|---|---|---|---|
| Compact Load Compensator | Adjusts seal pressure under load | Microcellular PU | 85 ± 3 Shore A |
| Small Cylinder Guide | Maintains alignment in compact space | Oil-impregnated bronze | 0.10-0.18mm oil capacity |
| Moderate Impact Cushion | Protects during light impact loads | Energy-absorbing TPU | 0.2 second activation |
| Compact Linkage Seal | Pivot point protection for small dozer | HNBR with fabric backing | D20 specific linkage geometry |
| Component Type | Material Specification | Quantity | D20-21A-6 Application |
|---|---|---|---|
| Static O-Rings | FKM (Grade 70) | 6 | Hydraulic connections |
| Port Seals | HNBR with anti-extrusion | 4 | High-pressure ports |
| Gland Gasket | Fiber-reinforced composite | 1 | Gland interface sealing |
| Thread Sealant | PTFE paste | 1 kit | Fitting installation |
| Retaining Clips | Spring steel | 2 | Component retention |
| Komatsu Model | Serial Number Range | Manufacture Years | Kit Compatibility |
|---|---|---|---|
| D20-21A-6 | 210001-215000 | 2018-2022 | Full compatibility |
| D20-21A-6 | 215001-220000 | 2022-Present | Verify production updates |
| D20-21A-5 | Earlier models | 2015-2018 | NOT COMPATIBLE |
| D20-21 | Earlier models | 2012-2015 | NOT COMPATIBLE |
| Cylinder Type | Location | Function | D20-21A-6 Specific Features |
|---|---|---|---|
| Blade Lift Cylinder | Frame to blade | Blade elevation | Compact design for small dozer |
| Blade Tilt Cylinder | Different application | Blade tilt | Separate kit may be required |
| Optional Attachments | Various | Attachment control | Verify specific requirements |
| Production Period | Key Changes | Kit Adaptation Required |
|---|---|---|
| Early D20-21A-6 | Standard compact mechanism | Standard kit 707-98-05420 |
| Mid-Production | Enhanced linkage design | Kit includes updated seals |
| Current Production | Updated hydraulic system | Verify hose connection compatibility |
| Attachment | Kit Compatibility | Additional Requirements |
|---|---|---|
| Standard Blade | Full compatibility | Standard installation |
| Angle Blade | Verify compatibility | May require different cylinder |
| Ripper | Not applicable | Separate ripper system |
| Snow Blower | Not applicable | Different hydraulic requirements |
⚠️ COMPACT DOZER SPECIFIC REQUIREMENTS:
ONLY for D20-21A-6 cylinders - not for larger dozers
REQUIRED: Follow Komatsu D20-21A-6 service manual exactly
MANDATORY: Use proper support for small dozer blade
CRITICAL: Verify calibration after installation
⚠️ PERFORMANCE-SENSITIVE FACTORS:
Linkage condition affects seal performance
Hose routing must accommodate compact space
Control valve adjustment may be required
Hydraulic system bleeding critical for performance
⚠️ SAFETY CONSIDERATIONS:
Blade can fall if not properly supported
Hydraulic pressure can be retained in system
Machine stability important during service
Compact space requires careful work practices
