PSS Type A Shaft Seal 2.500"

PSS Type A High Speed Shaft Seal 2.500"

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.

Product Dimensions

• Shaft Diameter: 2-1/2"
• Standard Stern Tube O.D. 3-1/4" to 4-1/8"
• Oversized Stern Tube O.D.  4-1/4" to 5-1/8"
• Compressed Length: 8-1/2"

How it works

• 1) Two nitrile O-rings seal the stainless-steel rotor to the shaft and will not experience wear.
• 2) A primary set screw and a backup set screw (2 sets) are used to secure the stainless-steel rotor to the shaft.
• 3) A seal is created between the two flat surfaces of the carbon stator and the stainless-steel rotor.
• 4) Water is fed into the PSS Shaft Seal for cooling/lubricating the seal faces on high-speed vessels.
• 5) The stationary carbon stator is attached to the nitrile bellows, which is attached to the stern tube (shaft log)