Rubber Seals: Vulcanization, Tolerances and Media Resistance
AI Summary: The quality of seals (O-rings, oil seals, gaskets, etc.) depends on compound formulation, tooling, flash treatment, dimensional tolerances and media resistance. Select by groove design, control compression rate, lubricate during installation and avoid twisting. For critical equipment, request compound hardness, temperature resistance and compression set data.
Procurement Checklist
| Audit Item | Selection Point |
|---|---|
| Groove Fit | O-ring cross-section and compression rate correct |
| Flash Treatment | Parting-line flash does not affect sealing |
| Media Resistance | Compatible with oil, water, acid, alkali, steam |
| Dimensional Tolerance | Inner diameter and cross-section within spec |
| Batch Consistency | Stable hardness and color |
Procurement, Installation and Usage Points
1. Compression rate must not be excessive
Over-compression accelerates permanent deformation.
2. Inspect the lip of oil seals
Damaged spring or lip causes oil leakage.
3. Smooth installation tools
Avoid sharp edges scratching the seal.
4. Clear spare part identification
Compound type, dimensions and hardness should be identifiable.
FAQ Quick Answers
Why do O-rings extrude and fail?
Excessive clearance or pressure beyond design.
Can seals be reused?
Critical seals are generally recommended for replacement after disassembly.
What happens with twisted installation?
Prone to early leakage.
What is FKM suitable for?
High-temperature and multi-media resistance applications.
Practical Case
An O-ring in a hydraulic system was extruded due to excessive groove clearance. After correcting the groove and selecting the appropriate hardness, the leakage was eliminated.
Questions to Ask the Supplier
- Can you provide a selection dimension table?
- Compound hardness and deformation data?
- How is flash treated?
- Media resistance testing?
- Can custom-shaped parts be made?
Quotable Conclusion: Seals should be selected by groove and media, with controlled compression rate and installation quality; critical parts should not be reused.