Mechanical Seal Style SB1

Single Stationary Welded Metal Bellows Cartridge with Circulation Gland

Mechanical Seal Style SB1


  • Part of Flex-A-Seal’s integrated/platform single cartridge seal design;
  • Patented (Patent Number US 7,979,986) Plunger-Lock drive;
  • Easy cartridge installation;
  • Sleeve is isolated from product;
  • Stationary bellows design – maximizes face alignment;
  • Hydraulically balanced design;
  • Even face loading;
  • No dynamic elastomers;
  • Only two static O-rings – cost savings are substantial when perfluorelastomer are required;
  • Flush position maximizes face cooling;
  • Shrouded rotary seal ring for maximum face protection and reliable start-up;
  • Uniform 360° transfer of torque to the primary rotating face;
  • No pins to break or hang up;
  • Fits ANSI standard and big bore pumps;
  • Faces, metallurgies and elastomers are easily upgradeable;
  • Faces designed for optimum heat dissipation;
  • Metric sizes are available.

SB3 with Circulation, Vent & Drain Gland

  • All the benefits of the SB1 design plus vent and drain gland with throttle bushing
  • Pipe connections are made to different sizes to assure that correct piping plans are employed
  • Cost-effective “upgrade”


Operating Conditions

Max Temp:400°F (204°C)
Max Pressure:300 PSI (20 bar)
Max Speed:6000 FPM (30 m/sec)

Note: Max Temperature / pressure / speed indicate operating extremes independently and do not imply the seal will function at these extremes at the same time. Contact Flex-A-Seal if in doubt.


For more information on the SB1


Depending on your specific needs and application, Flex-A-Seal can help you identify the ideal products. Contact us to tell us about your needs and request a quote.