📋 Common Seal Material Comparison
🔴 NBR (Nitrile Butadiene Rubber)
Good for: Petroleum oils, mineral oils, gasoline, water
Temperature range: -40°C to +120°C
Cost: Low-Medium
Applications: General hydraulic systems, cylinders
🟠 FKM (Viton®)
Good for: High temperature, chemicals, petroleum oils
Temperature range: -20°C to +200°C
Cost: High
Applications: High temperature systems, chemical industry
🟢 EPDM
Good for: Water, steam, ketones, brake fluids
Temperature range: -50°C to +150°C
Cost: Medium
Applications: Water-based systems, steam applications
🔵 PU (Polyurethane)
Good for: High pressure, abrasion resistance
Temperature range: -35°C to +100°C
Cost: Medium-High
Applications: Severe duty cylinders, high pressure systems
⚪ PTFE (Teflon®)
Good for: Chemical resistance, low friction, high temperature
Temperature range: -200°C to +260°C
Cost: Very High
Applications: Chemical processing, extreme environments
🟤 VMQ (Silicone)
Good for: Extreme temperature, medical applications
Temperature range: -70°C to +230°C
Cost: High
Applications: Food industry, medical equipment
⚠️ Quick Selection Tip
For most standard hydraulic applications in Southeast Asia: NBR for normal temperature, FKM for high temperature or aggressive chemicals.
🌡️ Temperature Range Comparison
| Material | Minimum Temp | Maximum Temp | Continuous Service | Peak Temperature |
|---|---|---|---|---|
| NBR | -40°C | +120°C | +100°C | +130°C |
| FKM | -20°C | +200°C | +180°C | +220°C |
| EPDM | -50°C | +150°C | +130°C | +170°C |
| PU | -35°C | +100°C | +80°C | +110°C |
| PTFE | -200°C | +260°C | +230°C | +300°C |
| VMQ | -70°C | +230°C | +200°C | +260°C |
🌡️ Tropical Climate Note
In Southeast Asia, where ambient temperatures are high:
- Select materials rated for at least +40°C higher than fluid operating temperature
- Ensure continuous service rating exceeds your normal operating temperature
- Consider FKM or PTFE for systems running hot
🧪 Chemical Compatibility Guide
| Fluid/Material | NBR | FKM | EPDM | PU | PTFE |
|---|---|---|---|---|---|
| Mineral Hydraulic Oil | Excellent | Excellent | Poor | Excellent | Excellent |
| Synthetic Hydraulic Oil | Fair | Excellent | Poor | Fair | Excellent |
| Water/Glycol | Excellent | Excellent | Excellent | Excellent | Excellent |
| Gasoline/Diesel | Excellent | Excellent | Poor | Excellent | Excellent |
| Steam | Poor | Fair | Excellent | Poor | Excellent |
| Ketones (MEK) | Poor | Excellent | Excellent | Poor | Excellent |
| Vegetable Oil | Excellent | Excellent | Poor | Excellent | Excellent |
🔍 Seal Failure Diagnosis
Common Failure Types & Solutions
🔥 Hardening & Cracking
Symptom: Seal becomes brittle, cracks develop
Cause: High temperature, oxidation
Solution: Switch to FKM or PTFE, reduce system temp
💧 Swelling
Symptom: Seal swells, increases in volume
Cause: Chemical incompatibility, wrong material
Solution: Change to compatible material, verify fluid type
🔪 Cutting & Wear
Symptom: Seal material torn, abraded, or cut
Cause: Poor installation, contamination, rough surface
Solution: Improve installation, add filtration, polish surface
🌡️ Extrusion & Nibbling
Symptom: Seal material extrudes through gap
Cause: Pressure too high, clearance too large
Solution: Add back-up rings, reduce clearance, use harder material
📏 Seal Installation Best Practices
- Clean everything: All parts must be spotless before installation
- Use proper tools: Seal pick tools, not screwdrivers or sharp objects
- Lubricate first: Use compatible oil or assembly lube on seals
- Check surfaces: No nicks, scratches, or rough spots on seal seats
- Warm seals in cold climate: Flex seals gently to avoid cracking
- Inspect new seals: No defects from shipping or storage
- Store properly: Cool, dark location, original packaging
🎯 Application-Specific Recommendations
🚜 Construction Machinery
Recommended Materials:
PU Polyurethane for cylinder seals - excellent abrasion resistance
NBR for general seals - good for standard conditions
FKM for high temperature applications
🏭 Industrial Hydraulic Systems
Recommended Materials:
NBR as standard - economical, good all-around
FKM for high temperature systems or special fluids
EPDM for water-based systems
🌊 Marine & Offshore
Recommended Materials:
FKM for saltwater resistance
PTFE for corrosion resistance
NBR for general use
🛍️ Seal Products from Haichen Hydraulic
🔧 Complete Seal Kits
Pre-assembled seal kits for most popular hydraulic cylinders and valves
Available for: Caterpillar, Komatsu, Hitachi, Kobelco, Sany, XCMG, and more
View Seal Kits📦 O-Ring Boxes
Comprehensive O-ring assortment boxes for maintenance shops
Materials: NBR, FKM, EPDM
View O-Rings⚙️ Custom Seals
Custom manufacturing for special applications or obsolete machines
Send us: Drawing or sample for quotation
Request Custom SealNeed Help Selecting the Right Seal?
Contact our technical team with your application details: fluid type, temperature, pressure, and equipment model.
💬 Get Technical Help 📱 WhatsApp Support📋 What to Prepare for Seal Consultation
- Equipment model and serial number
- Hydraulic fluid type in use
- Normal operating temperature
- System operating pressure
- Photos of failed seal (if available)
Last updated: May 2, 2026 | Seal Material Guide by Haichen Hydraulic