Double Sphere Rubber Expansion Joint
1. Product Overview
Double sphere rubber expansion joint, also known as double sphere flexible rubber joint, is a high-performance flexible connection component for piping systems. Compared with single sphere type, its double-sphere structure brings larger compensation range and better flexibility. It can effectively absorb pipeline vibration, reduce noise transmission, and compensate axial, lateral and angular displacement caused by thermal expansion, foundation settlement and assembly deviation. It avoids additional stress acting on pumps, valves and other pipeline equipment, protecting the whole piping system.
2. Main Structure & Material Options
The product consists of rubber body, reinforcing nylon cord layer and steel wire ring.
- Rubber body material:
- ✅ NR (Natural Rubber): For clean water, normal temperature air, good elasticity and cost-effective
- ✅ EPDM: Hot water, seawater, weak acid and alkali, anti-aging, ozone resistance
- ✅ NBR: Oil medium, fuel, oil sewage, excellent oil resistance
- Connection type: Flanged connection (carbon steel / stainless steel flange optional)
- Pressure rating: PN10, PN16
- Working temperature range: -20℃ ~ +120℃ (depends on rubber material)
3. Key Features
- Large compensation capacity: Double sphere design realizes bigger axial, lateral and angular displacement compensation
- Vibration damping & noise isolation: Greatly cut down vibration and noise spread from pumps and compressors
- Tight sealing: Integrated rubber structure, no leakage risk under normal working condition
- No rigid stress transfer: Flexible structure, will not transmit external force to connected equipment
- Weather & ageing resistance: Suitable for indoor and outdoor pipeline installation
- Easy installation and maintenance, no special tools required
4. Application Fields
Widely used in various fluid conveying pipelines:
- HVAC, central air conditioning and cooling water system
- Water supply, drainage and sewage treatment project
- Power plant, pump station, circulating water pipeline
- General chemical pipeline with weak corrosive medium
- Marine seawater pipeline
- Oil transfer pipeline (NBR version)
5. Technical Notes & Installation Tips
- Do not exceed the allowable displacement and working pressure during operation
- Avoid sharp objects scratching the rubber surface during transportation and installation
- Do not use the joint to correct large pipeline misalignment forcibly
- Keep away from open flame, strong solvent and strong oxidizing medium
- Custom sizes, special materials and special pressure grades are available on request
6. Quality Standard
Manufactured following GB/T 12777 standard, can provide MTC, test certificate as required.
