Compressor Seals: The Espey™ WKA250ND

Espey chamber seals have a modular design which means the seals can be composed using standard parts to meet individual application requirements. Espey chamber seals work with a very small operation gap between shaft and seal ring – leading to very low leakage – and are designed for dry-running and compensate radial and axial shaft deflections. Another advantage is that no sealing components which could generate additional shaft vibrations are actually fitted on the shaft. The seal rings are axially spring-loaded to prevent swinging up at pressure-less machine operation.

Espey chamber seals are applied in several turbo machines: integral gear, screw and chiller compressors, steam turbines, and shut-off valves for power plants. The main industries in which it is implemented are oil and gas, refining, chemical and petrochemical industry, power plants, and plants for iron and steel production. A further industry field with several references and successes is carbon dioxide capture and storage (CCS). So, what might a success story look like? Check out this WKA 802 HD mechanical seal for a multi-stage integral-gear compressor:

Espey Application Story

Espey™ WKA 802 HD as sealing for a multi-stage integral-gear compressor in a fertilizer production facility.

Client’s Issue

Urea is the worldwide leader in nitrogen fertilizer production. Urea is produced via high pressure synthesis from liquid ammonia and a gas-water mixture with 88.7 % carbon dioxide under high pressure and elevated temperatures in a synthesis tower. Thereby synthetic ammonia carbamate is produced, which is finally obtained as white granules under supply of acid and heat. The high pressure processes are generated by multi-stage radial integrally geared compressors. The seal has to work as leakage protection of the highly-compressed CO2.

The Espey Solution

turbo compressorEspey developed the compact chamber seal Espey™ WKA 802 HD with barrier gas and leakage port and up to 8 seal rings for this radial integrally geared compressor (which was designed by MAN Diesel & Turbo SE). The operation pressure of 140 bar (2031 PSI), the temperature of 225 °C (437 °F) and revolutions up to 40,000 min-1 were the main design parameters. Each of the 8 stages was equipped with an individual Espey ™ WKA 802 HD with different installation lengths, seal, and outer diameters. The one-piece seal rings with titanium bandage were designed axially spring-loaded to avoid vibrations during start and spin-out phase.

The Espey Result

The seal solution has been highly reliable and routinely operates maintenance-free, helping to maximize production.

About the Shaft Seal Espey™ WKA250ND – 1100HP

picture of WKA250NDFeatures
  • Chamber seal (modular design), optional with housing and lidVery small operation gap – low leakage
  • Dry running
  • Compensation of radial and axial shaft deflections
  • No sealing components mounted on the shaft and hence no additional shaft vibrations
  • Seal rings running contact-free – sliding faces and machine consume no additional power
  • One-piece seal ring with titanium bandage
  • Both side balanced seal ring inside chamber for short-term back pressure operation
  • Seal ring axially spring-loaded – no swinging up at pressure-less machine operation
Advantages
  • High reliability
  • Maintainability
  • Maintenance-free
Recommended Applications
  • Gases
  • Fumes and exhaust, solids containing, flammable
    (ATEX), acid containing and toxic gases
  • (Solids containing) steams/liquid mist
  • Oil mist/penetrating oil
  • Water
  • Oil and gas industry
  • Refining technology
  • Chemical and petrochemical industry
  • Pulp and paper industry
  • Metal production and processing
  • Power plant technology
  • Integral-gear compressors (one or multi-stage)
  • Screw and chiller compressors

For more information about mechanical seals, contact Gallagher Fluid Seals today. Gallagher is a preferred distributor for EagleBurgmann mechanical seals.

The original case study and materials for Espey WKA 802 HD can be found on EagleBurgmann’s website.