Numerous types of seal technology can be used in pumps and other rotating equipment. From simple seals to very complex mechanical seal designs, there are various options to understand and consider for your pump system. One factor that you must review is your processing application. The types of fluids or materials you are moving, flow rates, pressures, temperatures, and other issues should determine which type of seal will provide the best performance and durability.
The three most common types of pump seals are:
- Braided compression packing
- Mechanical seals
- Air seals
Let’s take a look at some general types of fluid applications to help provide more clarity on proper seal selection and implementation.
Ultimately, you need to dig deeper to understand your specific equipment, process materials, and desired performance characteristics to find the ideal sealing solution for your particular application.
Water, clean liquids, and environmentally safe fluids work well with braided compression packing as the fluids are generally less corrosive. Combine the packaging with various lubricants and coatings to match the fluid consistency or abrasiveness, as well as the shaft speed of the application.
Many compression packing applications will require a flush line into the flush port, which helps keep the stuffing box environment cool and clean while minimizing shaft wear and increasing the packing life. If leakage cannot be allowed for environmental reasons or per plant standards, you may want to consider a mechanical seal. Mechanical seals can hold up to higher temperatures and pressures. Therefore, this upgrade may be beneficial—or necessary for more challenging applications. For example, you can install a cost-effective single-seal mechanical seal that is easy to operate and maintain. Or, you can go a step further with a more specialized mechanical seal solution.
Compression packing and single mechanical seals are generally inadequate for environmentally hazardous fluids. Compression packing must allow for some leakage, and single seals enable dangerous vapors to escape. Therefore, a double mechanical seal configuration and an exterior barrier fluid for lubrication are required. These seals help prevent any leaks from occurring. In addition, the seal will have a longer lifespan, especially if you use the proper material and coating based on the corrosiveness or abrasiveness of the process fluid.
Even more robust seals may be required when pumping thick slurries, wastewater, fluids with high solids, and mine tailings. More advanced sealing technology can reduce or eliminate shaft wear, which is crucial in these extreme applications. Some applications may be OK with a single mechanical seal and external flush system—others may benefit significantly from a double-seal configuration or an even more specialized mechanical seal design.
Heavy Mixtures & Dry Powders
Use a mixer or agitator to move or mix powders and heavy slurries. The wrong seal could lead to equipment failure, lost production, and product waste. In addition, a noncontact air seal may be your best sealing solution for these applications. The air sealing process will eliminate particle ingress, and the seal can handle deflection that commonly occurs in these mixing processes.
Understanding your application, your fluids, and your processing needs will go a long way in helping you select the proper equipment. Do not overlook your seal technology. Know the options available and which solution will provide the desired results and durability based on your application. DXP Pacific is here to help with all your pump equipment and seal selection needs. Our team can help you analyze your application and determine the right solutions. Contact us today to learn more.