Diamond coated face seals
About diamond coated face seals
- Virtually no wear
- Extended pressure and speed (PV values)
- Very high resistance against dry running and lack of lubrication
- Can be used in sever abrasive environments
- Increased time between service
Since 1998(i) CVD diamond coatings have been tested and evaluated for mechanical face seals. The results are stuning with very good performance in tough situations like dry running, lack of lubrication and abrasive media. The diamond coating also enables extended PV values and energy savings for the mechanical seals. In addition the service interval can be extended substantially.
Today the mechanical seal failure contributes to a large part of the pump failures and service cost. The majority of the failures are due to dry running/lack of lubrication for the seal. Depending on the application, a diamond coating can result in a very short ROI and also be enabling in some severe applications. With constant improvement/development since the first published results i) of the technology, we know have the third generation of diamond coatings which is a reliable and show a very high performing solution for mechanical seals. Today we have many hundred successful installation in the world. The installation range from completely dry running to extremely severe applications with PV values of 70 MPa m/s in abrasive sub-sea installations. We also have installed seal rings that have been running for over 10 years in the pulp industry.
For many applications the reduced friction gives considerable energy savings for the user. Diamond coatings for face seals are a good choice in many applications but typically gives the best value in
- Oil, gas and multiphase applications
- Slurry applications – abrasive wear resistance
- Pharmaceutical industry – dry running
- Chemical industry – chemical inertness
- Hot water applications
- High PV values
Our unique technology which rotate the seal rings during diamond growth gives flat seal surfaces regardless of thickness. We can deposit diamond to very thick layers and still there are no demands for extra processing (lapping). We also have improved the adhesion to very high levels. Not only enough for normals use but also for extremely high loads.
i) Surface and coatings technology volume 105, Issues 1–2, 5 June 1998, Pages 169–174
Typical results from some of our Diamond coatings. Comparable tests give significant differenses and the same good results are shown in real field applications.
FAQ
Find answers to frequently asked questions. Save time and get the information you need.
We only coat silicon carbide ceramic sealing rings. We strongly recommend using sintered material as reaction sintered materials may contain residues that interfere with the diamond coating process.
A simple rule of thumb is 2000 times what typical lab tests give. In reality, a diamond-coated surface will normally never wear out during the lifetime of the seal.
It varies depending on installation and sealing. In good cases, a water-lubricated seal can have a friction reduction of 50%, which can save a lot of energy during its lifetime. If the seal has an oil lubrication that separates the surfaces, the frictional losses occur in the viscous resistance of the oil and the friction remains the same. The typical friction reduction is high under severe conditions such as start/stop and dry running. This is important to keep the temperature down, save the sealing surfaces and the secondary seals (o-rings), which significantly increases the service interval.
Depending on which performance is required, it is possible to both make very tight seals and give them significantly higher PV numbers. For example. by creating fine surface structures with a laser (number of µm), it is possible to create surfaces with even lower friction and higher PV numbers by controlling the medium between the surfaces.