PSS Flange and Bladder System.

Flange & Bladder System

The PSS Flange & Bladder System is available in aluminum, steel and stainless steel.

A large number of installations are manufactured with a multi bolt flange in lieu of a stern tube. Very often these flanges have a standard bolt pattern. In order to facilitate the installation of the PSS Shaft Seals on these type of flanges, PYI manufactures an array of flanges which fit the "standard" bolt patterns and transform the flange into a stern tube ready to accept the PSS Shaft Seal.

These adapters can be ordered as a standard unit or as a inflatable bladder unit. The inflatable bladder option allows the operator to seal the stern tube, while the shaft is not rotating, in order to inspect or clean the seal. Another advantage is that if uncoupling of the shaft is needed, this operation can be done in the water as the shaft can be moved aft with bladder inflated, and no water intrusion will happen. Of course this inflatable bladder can also be used in case of an emergency.

Numerous Materials Available

Available in aluminum, steel or stainless steel.

Multiple Versions

Two units available. A standard unit or a inflatable bladder unit.


  • Blank or pre-drilled flange bolt pattern for your specific application
  • Inflatable bladder unit minimizes downtime by allowing you to uncouple the shaft while in the water

Cross section view of PSS Flange and Bladder System.

Cross Section of Flange & Bladder System

Cross section diagram of the PSS Flange & Bladder System with a PSS mechanical seal.

How It Works!
For PSS Flange Systems with a bladder.

When the rubber bladder is deflated it allows water to flow through.

Once the bladder is inflated it prevents the water from entering into the PSS seal.

How the PSS Flange and Bladder System works.


All PSS mechanical seals have these certifications.

ABS Certification

ABS Certified

Bureau Veritas Certification

Bureau Veritas Certified

RINA Certification

RINA Certified


Materials: Available in aluminum, steel or 316L stainless steel
Size: Can manufacture to any size and application
Operating Temperature: -25°F to +225°F (-31°C to +107°C)


Inflatable bladder.


What Is A PSS Shaft Seal?