Graco 105278 Packing O-Ring – Durable Seal for High-Pressure Pump Systems
The Graco 105278 Packing O-Ring is a genuine, precision-molded sealing component designed to maintain pressure integrity in professional-grade airless sprayers and pump systems. Built from high-quality elastomer materials, it ensures long-lasting protection against fluid leakage and performance loss under heavy-duty operation.
Compatible Machines
- Graco King Airless Sprayers
- Graco Merkur ES Packages
- Graco President and Senator Pumps
- Graco High Pressure Filter Assemblies
Key Features
- Material: High-grade Nitrile or Viton® elastomer for chemical resistance
- Function: Provides a tight, reliable seal in high-pressure systems
- Design: Precisely machined profile for balanced load distribution
- Maintains optimal sealing even with temperature or pressure fluctuations
- Extends service life of packing assemblies and pump components
Technical Specifications
| Property | Specification |
| Part Number | 105278 |
| Material | Nitrile / Viton® (depending on model) |
| Pressure Rating | Up to 3000 psi (210 bar) |
| Temperature Range | -20°C to 150°C |
| Function | Seals fluid passages in packing and piston assemblies |
| Application | Airless Spray Pumps, Filters, and Pressure Systems |
Performance Advantages
- Prevents fluid leakage and air intrusion under load
- Improves pump pressure consistency and atomization quality
- Reduces seal wear and system vibration
- Compatible with both solvent-based and waterborne materials
Installation & Maintenance
- Clean sealing surfaces before installation to ensure proper fit
- Lightly lubricate with compatible grease for smoother assembly
- Inspect the O-ring regularly for cracks, flattening, or chemical degradation
- Replace as part of regular pump maintenance for consistent performance
Frequently Asked Questions
It creates a secure seal in the packing area of high-pressure pumps, preventing leakage and ensuring consistent spray pressure.
Replacement intervals vary by use, but it’s recommended to inspect the O-ring every 500 hours of operation or during each maintenance cycle.
It fits most high-pressure Graco systems, including King, Merkur, and President pumps. Always confirm your model’s parts list before ordering.
Conclusion
The Graco 105278 Packing O-Ring is a small but vital part of high-pressure pump assemblies. Its durable elastomer design ensures strong sealing performance, extending the lifespan of your sprayer and maintaining consistent operation in even the most demanding coating environments.
