What factors should be considered when choosing the sealing type for a Vertical Turbine Pump?

When choosing a vertical turbine pump, in addition to considering the material, flushing scheme and motor configuration, there is another important factor to consider, that is, the sealing form of the shaft seal. This article will introduce you to the factors that need to be considered when choosing the shaft seal form of a vertical turbine pump. I believe this will help you choose a more suitable vertical turbine pump equipment.

• Common pump shaft seal types include packing seal, mechanical seal, carbide seal, etc. The packing seal has a simple structure, but a large leakage rate and power loss, and is suitable for conveying general media such as water; the mechanical seal has a good sealing effect, a very small leakage rate, and a long service life, but it is expensive and is suitable for conveying petroleum and chemical media.
• Special media considerations: For high-viscosity media, spring-enclosed mechanical seals may not be applicable because they are easily corroded and blocked by impurities in the medium. For equipment that conveys highly corrosive, high-viscosity, and easily crystallized media, spring-external mechanical seals can be considered.

1. Chemical properties of the medium: If the medium is highly corrosive, a sealing material with excellent corrosion resistance, such as polytetrafluoroethylene or Hastelloy, should be selected. For corrosive media, easily corrosive metal materials should be avoided.
2. Particle content of the medium: If the medium contains a large amount of solid particles, it will cause abrasive wear of the sealing surface and shorten the service life of the sealing component. At this time, a wear-resistant sealing material should be selected, or non-contact sealing technology, such as a magnetic drive pump, should be considered.
3. Medium viscosity: For media with higher viscosity, the sealing friction surface requires good lubrication conditions to prevent seal failure due to overheating.
4. Temperature and pressure of the medium: Under high temperature conditions, the physical properties of the sealing material, such as elasticity, strength and wear resistance, will decrease. Therefore, for high-temperature media, the sealing material needs to have good thermal stability, and an auxiliary cooling system may be required to keep the temperature of the sealing surface within a safe range. Under high pressure, the seal must have sufficient strength and rigidity to withstand the impact of the medium pressure on the sealing surface and prevent medium leakage.
5. Medium flow rate: Medium with high flow rate will increase the wear of the sealing surface and aggravate the heating of the sealing surface. Therefore, materials with good wear resistance should be used, and an effective cooling system should be considered to maintain the temperature of the sealing surface.

Taking the above factors into consideration, when selecting the shaft seal type of the vertical turbine pump, it is necessary to determine the most suitable shaft seal material and type according to the specific characteristics of the medium, such as chemical properties, particle content, viscosity, temperature, pressure, flow rate, etc., to ensure the sealing performance and reliability of the pump.