In the real world, things don’t always run smoothly—especially when you’re dealing with machines. Whether it’s a hydraulic pump, a transmission system, or an electric motor, the smallest component often has the biggest say in how long that equipment keeps running without a hitch.
One of those often-overlooked components? The oil seal. And when standard oil seals aren’t enough—either due to pressure spikes, tricky shaft layouts, or combined motion—you’ll likely hear engineers talk about combi oil seals.
Now, a “combi seal” isn’t a new invention. In its simplest form, it’s a seal system built from two or more components. Most classic designs use a combination of a metal ring and oil-resistant rubber. But in tougher conditions, that’s not always enough. That’s where the newer generation of rubber + PTFE (Teflon) combi seals come in.
What's Inside a Combi Oil Seal—and Why That Matters
Let’s get technical for a moment. PTFE (polytetrafluoroethylene) is known for its low friction and high chemical resistance. When paired with oil-resistant rubber, you get a composite seal that holds up under pressure, resists wear, and runs cooler during continuous motion.
The beauty of this kind of setup is how the materials complement each other. Rubber gives you a good tight seal and flexibility, while PTFE handles friction and high-speed motion without sticking or deforming. At DEDE, we’ve optimized this structure so that the rubber part has minimal contact with the shaft—enough to seal, but not enough to generate heat or drag.
This design makes it a great choice for reciprocating or rotating systems that run hard, stop and start frequently, or work in dirty or chemically aggressive environments.
Combi Seals Aren’t for Everything—but They’re Perfect for the Right Jobs
We don’t believe in one-size-fits-all. A combi seal isn’t meant to replace all standard oil seals. But it’s absolutely the right fit for certain applications—especially where regular seals just wear out too quickly.
Here’s where our clients most often use DEDE combi oil seals:
· Hydraulic cylinders, especially in construction or agricultural machinery, where pressure surges and debris are common.
· Electric motors with high-speed shafts that require low startup torque and long service intervals.
· Gearboxes and transmissions, where both internal oil retention and external contamination control are key.
· Robotics and automation, where tiny motions happen fast and frequently.
· Wind power units or steel plants, where temperature and medium compatibility matter just as much as pressure.
· Heavy-duty diesel engines, particularly crankshafts and camshafts, where sealing oil and blocking dirt both matter.
Now, a quick heads-up: in systems where static sealing performance is critical, such as some crane hydraulics or pressure-locked equipment, combi seals (especially sliding-ring types) may underperform compared to traditional lip seals. It’s not a flaw—it’s about matching the right seal to the job.
So What Makes DEDE Different in All This?
At DEDE, we run our own factory—not just assembly, but actual material processing, in-house tooling, testing, and full production. That means we control everything from material quality to tolerances, and more importantly, we respond fast.
Need standard parts? We've got over 10,000 SKU in stock—O-rings, shaft seals, and of course, a wide range of combi oil seals. Urgent delivery? We’ve built our internal supply chain for next-day shipping on most core items.
Have something non-standard or custom? We’ll help you from the ground up—choosing the right material mix, helping with CAD-based seal design, testing prototypes, and scaling up only when it’s proven to work in your real application. Whether it's a new powertrain spec or a modified hydraulic system, our engineers will guide you to a seal that works first time, every time.
Built for Global Markets—Trusted by Serious Brands
Our seals are in machines operating in over 80 countries. That includes everything from offshore energy to food-grade robotics. We’re proud to be:
· A certified High-Tech Enterprise and Specialized “Little Giant” company recognized for technical excellence.
· A provincial-level R&D innovation center, developing sealing systems for next-gen machinery.
· A long-term partner to global OEM, helping them reduce maintenance cycles, prevent leakage failures, and extend system uptime.
· A real manufacturer, not just a trading brand. Our name is on the line, so we build it to last.
We’re also located at the heart of a specialized industrial cluster—so whether it’s materials, tooling, or testing, we’ve built a network that delivers fast and flexibly.
We’re here to help you pick the right solution—whether that’s a standard seal from our shelf or a fully customized combi seal designed around your machine. We know the trade-offs, we’ve seen the failures, and we know what works where.
Need support? Talk to our team. We’ll help you find the balance between friction, pressure, temperature, and long-term performance—because we don’t just sell seals. We help machines keep moving.
