The PSS Shaft Seal 02-212-400 is a premium marine mechanical face seal designed for vessels with 2-1/2" propeller shafts and 4" stern tubes. As the world's number one selling marine shaft seal, it's installed as standard equipment by leading boat builders and certified by Bureau Veritas, ABS, and RINA.
Key Specifications:
- Shaft Diameter: 2-1/2"
- Stern Tube Diameter: 4"
- Total Length: 9.625" (8.375" compressed)
- Rotor Diameter: 4.2"
- Carbon Cuff Diameter: 3.75"
- Stern Cuff Length: 2"
How It Works:
The PSS creates a watertight seal through contact between a rotating stainless steel rotor and a stationary carbon flange. The carbon flange attaches to the stern tube and is bored larger than the shaft diameter, allowing it to "float" and compensate for misalignment and vibration. Two recessed O-rings in the stainless steel collar seal against the shaft and rotate with it, eliminating wear during operation. The bellows compression maintains constant face contact and compensates for propeller thrust.
Benefits:
- 100% watertight operation eliminates water in the bilge
- No maintenance, adjustment, or repacking required
- Prevents propeller shaft wear
- Compensates for shaft misalignment and vibration
- Easy retrofit installation
Maintenance Requirements:
PYI recommends inspecting the bellows regularly for wear, aging, or chemical deterioration. As preventative maintenance, replace the bellows every six years along with the O-rings and set screws. More frequent inspection may be required in environments with sulfuric acid vapor from non-sealed batteries or ozonators, which accelerate rubber deterioration.
What's Included:
Complete PSS Shaft Seal assembly with stainless steel rotor, carbon flange, bellows, O-rings, set screws, hose clamps, and installation hardware.
