A mechanical seal is a critical component in pumps that prevents leaks.
Selecting the right seal ensures optimal pump performance and longevity.
This article will guide you through the process of choosing the appropriate mechanical seal for your specific pump application.
Identifying the Pumped Fluid Properties
- Higher Viscosity Fluids: Seals for higher viscosity fluids need larger clearances to prevent overheating and excessive wear due to increased friction.
- Corrosive Fluids: Seals exposed to corrosive fluids require materials that are chemically resistant to prevent degradation.
- Abrasive Fluids: Seals in contact with abrasive fluids containing solid particles need hard faces and durable materials to minimize wear.
Pressure
Mechanical seals are rated for specific pressure ranges. Exceeding the seal’s pressure rating can lead to leaks, damage, and even catastrophic failure.
Temperature
The seal materials must be compatible with the temperature range of the pumped fluid to prevent degradation and failure. Mechanical seals are available with different material combinations suitable for various temperature ranges.
For high-temperature applications, materials like graphite, silicon carbide, or tungsten carbide are often used for their thermal stability and resistance to wear. In extreme temperature conditions, specialized seals such as cooled seals or heated seals may be required.
Environmental Regulations
Environmental regulations are rules designed to protect the environment from harmful activities. These regulations can impact the selection of mechanical seals for pumps. Seals must be chosen to comply with regulations on emissions, leakage, and materials.
For example, in the US, the Clean Air Act regulates air pollutants from industrial equipment. Mechanical seals should be designed to minimize emissions of volatile organic compounds (VOCs). Similarly, the Clean Water Act sets limits on pollutants discharged into water bodies. Seals should prevent leakage of hazardous fluids that could contaminate water. Some regulations restrict the use of certain materials in seals, like asbestos.
Shaft Size
The seal must fit the shaft diameter precisely to prevent leakage.
Equipment Type
Different pumps have varying requirements for seal design and materials. Common pump types include centrifugal, positive displacement, and rotary pumps.
For example, centrifugal pumps typically require seals that can handle high rotational speeds and moderate pressures. Positive displacement pumps may need seals designed for high pressures and viscous fluids. Specialty pumps, such as submersible or sanitary pumps, have additional requirements like corrosion resistance or cleanability.
In conclusion
Selecting the right mechanical seal is critical for optimal pump performance and reliability. Consider the operating conditions, materials, and seal arrangement when making your choice.
Need help finding the best seal for your application? Contact our experts today for personalized assistance in selecting the ideal mechanical seal.
