A Mechanical Seal is available in a wide range of materials depending on the purpose.
When you pick the correct material for the pump seal, it will give you long-lasting service and prevent unnecessary maintenance and failures.
While choosing the material, one should consider the “environment” the seal is exposed to. If you do not select the right material, then you will pay more in the long run.
The material used for the seal face has to be stable and should be able to conduct heat. Not just that, the material should be chemically resistant, and it should deliver good wear resistance. But certain environments will need the properties to be stronger as compared to others.
In abrasive and harsh environments, the material opted for must be able to withstand the conditions. Thus, it might be expensive. However, you will get the cost back to you over time.
Improper selection and low-quality material grade selection will result in expensive repair or shutdowns, or replacements of mechanical seals.
On the other hand, if the fluid you are pumping is clean fluid, then you will save money for good-quality bearings.
What materials are used for mechanical seals?
Based on your needs and requirements, you can choose any material. You can find the right material for the seal by looking at the properties of the material, e.g., wear, chemical resistance, hardness, and stiffness. You can choose the ideal material for the seal.
Metal Bellow Mechanical Seals and other types of seals bring a variety of advantages.
Initially, seal faces were made from metals like copper, bronze, or hardened steel. However, other exotic materials are used because of their advantages. Examples are ceramics or mechanical carbons.
Carbon / Ceramic
This material comprises of 99.5% aluminum oxide. It offers excellent abrasion resistance because of its hardness. Since carbon is a chemically inert element, it can withstand different chemicals. However, it is not suitable for extreme temperature changes. It may result in cracking or shattering.
Silicone Carbide
When silica and coke are fused together, Silicone Carbide is made. It is similar to ceramic, but it has better lubrication qualities. Also, Silicone Carbide is harder than ceramic. Therefore, it is suitable for harsh environment. Re-lapping, polishing, and refurbishing of this material is possible.
Tungsten Carbide
This is a highly versatile material. Though it is similar to silicone carbide in versatility, it is more suited to high pressure applications. It is because of the high elasticity of Tungsten Carbide.
Like Silicone Carbide, it can also be re-lapped and polished.
GFPTFE
This is highly chemical resistant Materia. To reduce the friction of the sealing faces, glass is added to it. When you have comparatively clean applications, then there is nothing better material than GFPTFE. Moreover, it is a cost-effective alternative.
Conclusion
In short, there is a wide range of materials available as far as mechanical seal material is concerned. However, you need to closely match the seal to your environment and needs. It improves the overall performance of the seal.
Also Read: What Are Metal Bellows Used For?