In hydraulic cylinder engineering, reciprocating seals are among the most critical components, directly influencing service life, efficiency, and leakage control. Two of the most widely adopted sealing solutions are Stepseals and Glyd Rings. While they share certain design similarities—both being composite seals consisting of a PTFE-based slide ring combined with an elastomeric O-ring for pre-compression—their functional differences make them suitable for distinct applications.
This article provides a professional overview of their operating principles, design characteristics, material selection, and application scenarios, assisting engineers and procurement professionals in choosing the optimal sealing solution.
1. Functional Directionality
- Stepseal (Unidirectional):
Engineered to withstand fluid pressure from one side only. Commonly specified for piston rods where pressure consistently acts in a single direction. - Glyd Ring (Bidirectional):
Designed for alternating pressure loads. A single Glyd Ring can effectively seal in both directions, eliminating the need for two opposing seals.
📌 General design rule: Stepseals for rods; Glyd Rings for pistons.
2. Structural Design and Installation
| Seal Type | Geometric Profile | Installation Position | Functional Role |
|---|---|---|---|
| Stepseal | Stepped cross-section | Piston rod (shaft) | One-way dynamic sealing |
| Glyd Ring | Rectangular cross-section | Piston (bore) | Bi-directional dynamic sealing |
Both designs rely on a PTFE (polytetrafluoroethylene) glide ring for low-friction sealing, supported by an O-ring pre-load element that maintains consistent radial pressure and compensates for wear or deformation.
3. Operating Parameters
Both sealing types are validated for demanding operating environments:
- Pressure capability: up to 40 MPa
- Reciprocating velocity: 4–5 m/s (depending on lubrication conditions)
- Temperature range: −25°C to +200°C (influenced by elastomer selection)
- Medium compatibility: Broad, including hydraulic oils, environmentally acceptable fluids, and certain water-based media
4. Material Engineering Considerations
The material configuration is decisive for service life and performance reliability:
- PTFE Glide Ring Compounds
- Standard: Virgin PTFE
- Wear resistance enhancement: Bronze powder, carbon fiber, MoS₂, graphene
- Cold flow reduction: Glass fiber, PPS fillers
- Corrosion resistance: Modified PTFE, ETFE, PEEK
- Elastomer O-Ring Selection
- NBR (Nitrile Rubber): Cost-effective choice for conventional mineral oils
- FKM (Fluorocarbon Rubber): High thermal resistance and chemical compatibility
- HNBR, EPDM, FVMQ: Suited for low-temperature service, synthetic fluids, or water-based media
The optimal material pairing is always application-specific, considering factors such as working pressure, thermal load, fluid medium, reciprocating speed, and overall life-cycle cost.
5. Industrial Applications
Stepseals and Glyd Rings are applied across nearly all segments of fluid power engineering:
| Application Area | Typical Installation | Preferred Seal Type |
|---|---|---|
| Mobile hydraulics (excavators, loaders) | Piston rod | Stepseal |
| Heavy press machinery | Cylinder bore | Glyd Ring |
| Plastic injection molding machines | Piston | Glyd Ring |
| Marine/offshore hydraulics | Rod and bore | Combination use |
| Industrial hydraulic presses | Rod sealing | Stepseal |
Statistical analysis indicates that over 90% of reciprocating cylinder sealing systems incorporate either Stepseals or Glyd Rings due to their proven balance of durability, efficiency, and ease of installation.
6. Conclusion
- Stepseal: Optimized for unidirectional rod sealing
- Glyd Ring: Engineered for bi-directional piston sealing
- Both: Composite PTFE + elastomer seals with strong resistance to pressure, wear, and temperature variation
By correctly specifying geometry and material, engineers can ensure leak-free performance, reduced friction losses, and extended cylinder operating life.
For OEMs and end-users seeking custom-engineered sealing solutions, precise matching of application parameters with seal design is essential.
Our Expertise in Hydraulic Sealing Solutions
As a leading hydraulic cylinder and component manufacturer in China, we not only specialize in the production of cylinders but also provide a comprehensive range of hydraulic-related products and sealing solutions. Our product portfolio includes:
- Custom hydraulic cylinders (tie-rod, welded, mill-duty, telescopic, and more)
- Hydraulic components such as honed tubes, piston rods, cylinder barrels, and end caps
- Professional sealing elements including Stepseals, Glyd Rings, O-rings, wipers, and buffer seals
With advanced manufacturing facilities, strict quality control, and a dedicated engineering team, we ensure that every product meets international performance and durability standards. Whether you require standard replacements or custom-engineered sealing solutions, we can supply products tailored to your application requirements.
Our mission is to help clients worldwide achieve:
- Leak-free hydraulic performance
- Extended equipment service life
- Reduced downtime and maintenance costs
By choosing us as your partner, you gain not only a supplier but also a technical advisor for optimizing hydraulic cylinder performance.
JW Hydraulic
JW Hydraulic
JW Hydraulic