Mechanical Seals

Styles 73P and 75P

Dual Cartridge Seals
Environmental protection

• Flex-A-Seal is a respected leader in the design and manufacture of dual cartridge seals for critical toxic and fugitive emission applications where single seals are not acceptable. The simple idea of a second layer of protection provides the level of assurance that the world has come to expect.
• The Style 73P / 75P is the latest new and improved version of the proven style 73 / 75 designs. These new seal designs incorporate many high performance features to help extend seal life.
• First a unique integral bidirectional pumping system feature was incorporated.
  • This feature significantly improves the flow of the barrier fluid providing better heat dissipation which allows the seal faces to run cooler.

• The second major improvement was changing the inboard rotary assembly to the Patent #7979986 Plunger-Lock drive.
  • The torque transmission strength is increased five-fold over traditional cup point set screws. Most importantly, it allows for quick/easy assembly and seal-kit replacement.
  • The entire drive mechanism is out of the product.
  • This system eliminates any possibility of sleeve distortion from over-tightened set screws.
  • There are no set screws to “back out”. The spring-loaded mechanism keeps the lug “trapped” in position.
• The Style 73P offers all the advantages of a Stationary Welded Metal Bellows design on the inboard side.
  • Eliminates all dynamic elastomer problems caused by product and temperature incompatibility.
• The Style 75P offers all the advantages of a Stationary Multi Spring Design.
  • All of the springs are isolated from the product.
• The Style 73P / 75P is fully interchangeable. If the product or operating conditions change this dual cartridge seal can be easily converted from a pusher multi spring design to a welded metal bellows design or vice-versa.
• Both dual seal designs are hydraulically balanced and can be operated in a pressurized or non-pressurized state.
• Simple Cartridge Seal design for easy installation.
• Shrouded face designs provides added protection and eliminates troublesome drive pins.
• These designs fit pumps with standard and enlarged bores without modification.
• Metric sizes are available.
• A high performance dual mechanical seal like the Styles 73P / 75P may require a barrier fluid support system that maximizes the seal performance. Flex-A-Seal has a wide range of support system options to handle the simple to the most demanding service conditions.
• A more economical SMD is also available for lighter duty services.

Operating Conditions

Max Temp - 400ºF (204ºC)
Consult Flex-A-Seal for higher temperatures

Max Pressure - 300 PSI (20 bar)

Differential Pressure

• Style 73P: 15-25 PSIG
  *Higher pressure is available consult Flex-A-Seal.
• Style 75P: 300 PSIG

Max Speed - 4500 FPM (22 m/sec)

Note: Maximum Temperature / pressure/ speed indicate operating extremes independently and does not imply the seal will function at these extremes at the same time. Contact Flex-A-Seal if you have any more questions.