Bellows Single Cartridge Seal

The  BQFD™ (Bellows Quench Flush Drain) range of single cartridge mechanical seals uses many of the same modular parts as a BSIV™ but has the added features of Quench and Drain, making it usable in more diverse applications. 

With 50% more bellows than the industry standard (12 instead of 8) there is less stress on each convolution in the bellows stack which helps increase seal life. AESSEAL® standard bellows material, Alloy 276, has superior mechanical and corrosion resistance properties than other industry standard bellows materials such as 300 series Stainless Steel or Alloy 20. The hydraulically balanced bellows unit is available in a variety of different material options with either elastomer or graphite packing sealing rings.


  • Cartridge design for reliable installation
  • Hydraulically balanced seal face loading, which maximizes seal life and allows for vacuum service capability
  • The BQFD™ range has quench flush and drain ports with optional restriction brush (BQFD-R)
  • BQFD™ sizes available from 1.000" to 5.000" (24mm - 125mm)