Skip to main content
FlowserveFlowserveNuclear Primary Pump Seals - N-Seals

Nuclear Primary Pump Seals - N-Seals

BRAND: Flowserve

The result of years of research, thousands of hours of rigorous testing and decades of primary pump application experience, the Flowserve N-Seal primary pump seal represents the nuclear industry’s most advanced mechanical seal technology. With each of three stages capable of sustaining 100% system pressure, the N-Seal has successfully provided proven service life and fail-safe redundancy in Flowserve Byron Jackson® primary coolant pumps for years.


  • Power

industry sectors

  • Nuclear

ASME Section III, Class I

Operating Parameters
  • Discharge pressures to 170 bar (2500 psi)
  • Temperatures to 300°C (580°F)
  • Speeds to 1800 rpm
Design Range

Size Range: 6" to 9.62" shaft size

Features & Benefits
  • Unique cartridge construction simplifies installation, enables more accurate seal setting, and keeps associated costs low.
  • Triple redundant seal design mirrors existing seal system parameters.
  • Each of the three stages can handle 100% of the system pressure.
  • Hydrodynamic seal face technology outperforms hydrostatic designs with dramatically improved reliability and running periods.
  • Three different seal face lift designs are available to ensure non-contacting faces over a broad operating range.
  • Pressure is automatically redistributed to the remaining two stages in the event of a stage failure, allowing the plant to complete the fuel cycle. Interchangeability of stage components enables spare parts inventories and carrying costs to be reduced.
  • Large axial travel capability maximizes operating life; sealing integrity maintained through all plant transient scenarios.

Nuclear Seal


Our global expertise and local service centers ensure that you stay up and running. Learn more about our services.

Learn More