PSS Type A Shaft Seal

PSS Type A Seals

For 3/4" to 3-3/4" Shafts
(20mm to 95mm)

PSS Type B Shaft Seal

PSS Type B Seals

For 4" to 6" Shafts
(100mm to 150mm)

PSS Rudder Post Seal

PSS Rudder Post Seals

For 1-1/4" to 6" Shafts
(32mm to 150mm)

PSS Maintenance Kit

PSS Maintenance Kits

For 3/4" to 3-3/4" Shafts
(20mm to 95mm)

PSS Flange and Bladder System

Flange & Bladder System

For 2-1/2" to 6" Shafts
(63.5mm to 150mm)

PSS T-Kits

PSS Accessories

T-Kits & O-Ring Kits

PSS Shaft Seals

The PSS Shaft Seal is the #1 selling marine mechanical seal worldwide and is installed as standard equipment by many of the worlds most reputable boat builders and boat yards. The PSS Shaft Seal is also recognized as the premiere retrofit (aftermarket) seal on the world market. Boat builders and boat yards recognize the advantages and value of installing the PSS as it eliminates the maintenance, constant adjustment and cost associated with traditional packing type glands. Aside from these benefits, the PSS Shaft Seal helps to eliminate water in the bilge (100% water tight) and wear to the propeller shaft. The PSS Shaft Seal can be easily retrofitted and is available for shafts ranging from 3/4” to 6” (20mm to 150mm).

How Does It Work

The PSS Shaft Seal is a mechanical face seal that is created between the flat surfaces of the rotating stainless steel rotor and the stationary carbon flange. The stationary carbon flange is attached to the vessels stern tube with hose clamps and the carbon flange is attached to the front side of the bellows with hose clamps. The stainless steel rotor is fit on the shaft in front of the carbon flange. The stainless steel rotor is used to compress the bellows before the collar is secured to the shaft with set-screws. This compression (pre-load) maintains contact between the faces and allows the PSS to compensate for the thrust from the propeller. The carbon flange is bored larger than the shaft diameter allowing it to "float" around the shaft and thus compensate for most misalignment and vibration problems. The stainless steel collar is sealed to the shaft by two o-rings that are recessed into the bore of the collar. These o-rings rotate with the shaft and stainless steel rotor and do not experience wear during operation.

How a PSS Seal works

PSS Shaft Seal Components

Click or hover over the components to see more information!

stainless steel rotor
carbon stator
rubber bellow


The PSS Shaft Seal has been thoroughly tested and approved by these certifications.

ABS Certification


What Is A PSS Shaft Seal Video