OK Ring Hydraulic Seals Manufacturer for Heavy-Duty Piston Applications
Introduction
OK ring hydraulic seals are high-performance piston sealing solutions designed for heavy-duty hydraulic cylinders, especially double-acting piston systems operating under high pressure. As an experienced China OK ring hydraulic seals manufacturer, Xiamen Jinshun Sealing Technology Co., Ltd. supplies durable, easy-to-install OK ring seals trusted by OEMs in construction machinery, mining equipment, and industrial hydraulics.
Our OK rings are engineered to deliver stable sealing, low friction, and long service life, even under shock loads, contamination, and high-pressure conditions up to 50 MPa.
What Are OK Ring Hydraulic Seals?
An OK ring hydraulic seal is a double-acting piston seal made of two functional components:
- A rectangular PTFE or reinforced plastic sliding ring that forms the main sealing surface
- A rectangular elastomer energizer ring (NBR or FKM) that provides elastic preload
This open-structure design allows the seal to compress radially once installed in the bore, closing the step cut and creating drift-free, high-pressure sealing. Unlike some traditional piston seals, OK rings can be installed without special tools, reducing assembly time and installation errors.
Key Advantages of OK Ring Hydraulic Seals
- Excellent wear resistance for long service life
- High resistance to extrusion, even with large radial gaps
- Stable sealing under high pressure (≤ 50 MPa)
- Low starting and running friction, even after long dwell times
- Easy installation without tools, thanks to open structure
- Shock-load and contamination resistant
- Double-lip design helps block dust and debris
Compared with Glyd rings or some PTFE-based seals that require special installation tools, OK ring hydraulic seals are more installer-friendly and less prone to damage during assembly.
Standard Materials & Structure
| Component | Material Options |
|---|---|
| Sliding Ring | Glass-filled Nylon, POM, or Filled PTFE (F-PTFE) |
| Energizer Ring | NBR (standard) or FKM |
| Elastomer Hardness | NBR 75 Shore A |
| Seal Structure | Open-type combination piston seal |
This material combination provides a balance of strength, elasticity, and wear resistance, making OK rings suitable for demanding hydraulic environments.
Technical Performance Data
| Parameter | Value |
|---|---|
| Working Pressure | ≤ 50 MPa |
| Speed | ≤ 1 m/s |
| Temperature Range | -30°C to +110°C (NBR) Up to +200°C (FKM) |
| Media Compatibility | Hydraulic oil, water, emulsions, fire-resistant fluids |
| Sealing Type | Double-acting piston seal |
Typical Applications of OK Ring Hydraulic Seals
OK ring hydraulic seals are widely used in high-load, high-pressure equipment, including:
- Excavators and loaders
- Bulldozers, graders, and scrapers
- Forklifts and dump trucks
- Mining trucks and cranes
- Aerial work platforms
- Agricultural and forestry machinery
- Waste handling and transfer vehicles
These applications demand seals that can handle frequent pressure changes, side loads, and contamination-conditions where OK rings perform reliably.
Why OK Rings Outperform Traditional Piston Seals
- Low friction even after long pressure holding
- High extrusion resistance under large clearances
- No special installation tools required
- Compliant with ISO 7425-1 groove standards
- Resistant to scratching, chipping, and breakage during installation
This makes OK ring hydraulic seals a practical upgrade for OEMs looking to reduce downtime and maintenance costs.
Installation Dimensions (Reference Table)
| Cylinder Bore Ø (DH9) | Groove Ø (dh9) | Groove Width (L+0.2) | Height (H) | O-Ring Section (d2) |
|---|---|---|---|---|
| 6 – 13.9 | D – 3 | 2.5 | 2.3 | 1.9 |
| 14 – 26.9 | D – 4 | 3.2 | 3.0 | 2.4 |
| 27 – 56.9 | D – 6 | 4.7 | 4.4 | 3.1 |
| 57 – 160.9 | D – 10 | 7.5 | 7.0 | 5.7 |
| 161 – 500.9 | D – 15 | 11.0 | 10.5 | 8.4 |
Exact groove dimensions can be customized based on operating pressure and application conditions.
Delivery & Lead Time
OK ring hydraulic seals are fast-moving products in both domestic and international markets.
- In-stock items: shipped within 2–3 days
- Large or customized orders: typically 5–7 days
Stable inventory and in-house production allow us to support urgent OEM schedules.
Why Choose Xiamen Jinshun as Your OK Ring Hydraulic Seals Supplier?
- Over 20 years of sealing manufacturing experience
- In-house mold, rubber, and machining workshops
- Strong R&D and QC teams ensuring batch consistency
- OEM & ODM support for custom OK ring hydraulic seals
- Fast tooling and flexible order quantities
- Trusted by global buyers in construction, mining, and hydraulics
We don't just supply seals-we help OEMs improve hydraulic reliability and reduce maintenance risk.
FAQs – OK Ring Hydraulic Seals
1. Are OK ring hydraulic seals suitable for double-acting pistons?
Yes. OK rings are specifically designed as double-acting piston seals for high-pressure hydraulic cylinders.
2. What pressure can OK ring hydraulic seals handle?
Standard designs support up to 50 MPa, and higher pressures are possible in special configurations.
3. Do OK rings require special installation tools?
No. The open structure design allows easy installation without special tools.
4. Can you customize OK ring hydraulic seals?
Yes. We provide OEM and ODM OK ring hydraulic seals based on drawings, samples, or operating conditions.
5. What is the difference between OK rings and Glyd rings?
OK rings are easier to install, more resistant to damage during assembly, and perform better under shock loads and contamination.
Looking for a reliable OK ring hydraulic seals manufacturer in China?
Send us your cylinder specifications or drawings today. Our engineers will help you select or customize the right OK ring piston seal for your hydraulic system.
👉 Contact Xiamen Jinshun Sealing Technology now for samples, pricing, and ODM support.
