Quad-Ring

Quad Ring(X-Ring) is normally used for dynamic sealing applications (rotary or linear movement).
Table of content
- Quad Ring Material Selection
- Quad-Ring Size Calculation
- Working Temperature Range
- Chemical Resistance
- Quad-Ring Lubrication
- Quad-Ring Color
- Typical Applications
Quad Ring Material Selection

Working Temperature Range
Temperature range : –50°C to 200°C, depanding on the rubber material used.
Chemical Resistance
Chemical Resistance of EPDM Rubber | |||||
Chemical Type | Examples | Concentration | Temperature Limit | Resistance Rating | Notes |
Inorganic Acids | |||||
Sulfuric Acid (H₂SO₄) | Dilute | ≤70% | ≤60°C | Good | Avoid >70% concentration or >80°C (swelling/degradation). |
Hydrochloric Acid (HCl) | Dilute | ≤30% | ≤60°C | Good | >30% or >80°C causes corrosion. |
Nitric Acid (HNO₃) | Dilute | ≤10% | ≤50°C | Moderate | >10% or >50°C leads to rapid oxidation. |
Phosphoric Acid (H₃PO₄) | All | Any | ≤100°C | Excellent | Full concentration range tolerated. |
Organic Acids | Acetic Acid, Citric Acid | <30% | ≤80°C | Good | High concentrations (>30%) or >80°C may cause swelling. |
Alkaline Media | |||||
Sodium Hydroxide (NaOH) | ≤50% | ≤100°C | Excellent | >50%: Limit to ≤80°C. | |
Potassium Hydroxide (KOH) | ≤50% | ≤100°C | Excellent | Slight hardening at >120°C. | |
Ammonia (NH₃·H₂O) | Any | ≤80°C | Excellent | Suitable for full concentration range. | |
Oxidizing Agents | |||||
Hydrogen Peroxide (H₂O₂) | ≤30% | ≤60°C | Moderate | >30% concentration or >60°C accelerates aging. | |
Ozone (O₃) | All | Any | Excellent | Exceptional ozone resistance (ideal for outdoor use). | |
Sodium Hypochlorite (NaClO) | ≤15% | ≤25°C | Moderate | >15% concentration or high temperatures cause cracking. |
Quad-RING Size Calculation
The selection of X-rings primarily depends on compression ratio because it directly impacts the sealing performance, durability.
Formula for Compression Ratio
The compression ratio (C) of an O-ring is calculated using the following equation:
C=(CS−Gd)/CS × 100%
Where:
CS = Cross-sectional diameter of the O-ring (mm or inches)
Gd = Groove depth (mm or inches)
Acceptable Compression Ratio Guidelines
Application Type | Recommended Compression Ratio | |
---|---|---|
Static Seals | 15% – 25% | |
Dynamic Seals | 10% – 15% | |
High-Pressure Seals | 20% – 25% |
Quad-Ring Size Standard
Standard System | Typical ID Range | Common CS (mm) |
AS568 | 1.02 mm ~ 1000 mm | 1.78, 2.62, 3.53 |
ISO 3601 | 1 mm ~ 1000 mm | 1.5, 2.4, 3.0 |
JIS B2401 | 6 mm ~ 600 mm | 1.9, 2.4, 3.1 |
Quad-Ring Lubrication
Surface coatings are applied to O-rings to enhance their performance in demanding applications. The primary purposes include:
Friction Reduction: Minimize assembly force.
Chemical Resistance: Protects against aggressive media (acids, solvents, fuels).
Coating Materials
Coating Material | Key Properties | Color |
---|---|---|
PTFE (Polytetrafluoroethylene) | – Ultra-low friction (μ ≈ 0.05–0.1) – Chemical inertness – Temp range: -60°C to +260°C | Light white |
Lubricate FP(PFPE based lubricating fluid) | – Low friction – Prevent the O-rings from twisting – Compatible with cleanness requirements – NO impact on the mechanical properties of the rubber | Transparent |
Molybdenum Disulfide (MoS₂) | – Low friction – Anti-galling | Dark grey |
Quad-Ring Color
Black is normally used. Please contact with us if different color is needed.
Typical Applications
- Automotive – Valves
- Industrial Pumps and Motors
- Hydraulic Systems
Thanks to contact us to discuss your requirements regarding Quad-RINGs. We are ready to assist you with fast, reliable support.