The N4W backup ring is an auxiliary sealing component used in hydraulic systems to protect primary sealing elements (such as O-rings) from extrusion and damage under high pressure conditions . Made from rigid materials like POM (Polyoxymethylene) or Polyamide (PA/Nylon), it provides solid support to O-rings by filling the gap between the seal and groove, preventing deformation when system pressure exceeds 250 bar .
SANPING SEAL – Engineering Machinery High-End Seals – 17 Years Export Expertise
Product Overview
The N4W backup ring is a protective sealing component designed specifically for hydraulic systems. Unlike primary seals that prevent fluid leakage, the backup ring serves a support function – it prevents the soft rubber O-ring from extruding into the gap between metal components under high pressure .
The N4W is typically an open/split ring structure with a circular cross-section, allowing for easy installation in standard groove designs .
How It Works
When hydraulic system pressure increases, the force attempts to push the soft O-ring into the clearance gaps between metal parts. The N4W backup ring, made of hard material, is installed on the low-pressure side of the O-ring to fill this gap . It provides rigid support that prevents excessive deformation and extrusion of the O-ring, thereby avoiding tearing and damage to the primary seal .
The N4W backup ring does not perform a sealing function itself – it is always used in combination with static seals such as O-rings .
Specifications and Parameters
| Parameter |
Detail |
| Product Name |
N4W Backup Ring / Anti-Extrusion Ring |
| Type |
Open/split ring support component |
| Material |
POM (Polyoxymethylene), PA (Polyamide/Nylon) |
| Hardness |
High rigidity, high strength |
| Working Pressure |
Suitable for pressures > 250 bar |
| Temperature Range (POM) |
-40°C to +100°C |
| Application |
Backup ring for O-rings, SPGO Glyd Ring systems |
| Function |
Prevents O-ring extrusion, extends seal system life |
Product Features
1. O-Ring Extrusion Prevention
The N4W backup ring provides solid support that prevents soft O-rings from extruding into metal gaps under high pressure . It is specifically designed for applications with pressures exceeding 250 bar .
2. High Rigidity Material
Made from POM or Polyamide (Nylon) materials known for high strength, high rigidity, good fatigue resistance, and wear resistance . The smooth surface and high hardness effectively resist deformation under high pressure.
3. Temperature Stability
POM material operates within -40°C to +100°C, offering good oil resistance and resistance to peroxides .
4. Cost-Effective Protection
Significantly reduces the risk of O-ring extrusion and damage under high pressure at a relatively low cost, extending the life of the entire sealing system .
5. Wide Application Compatibility
Specifically designed for SPGO Glyd Ring systems and compatible with various O-ring seal configurations in hydraulic cylinders, pumps, and valves .
6. Split Design for Easy Installation
The open ring-shaped structure allows for straightforward installation without special tools .
Need N4W backup rings for your high-pressure hydraulic seals?
Contact SANPING SEAL today with your size requirements. Our team will provide a free quote within 24 hours.
