PSS 02-50M-212 - Dripless Shaft Seal 50 mm, 2 1/2" Stern Tube

PSS 02-50M-212 - Dripless Shaft Seal 50 mm, 2 1/2" Stern Tube

The PSS 02-50M-212 Dripless Shaft Seal is engineered for optimal performance in marine applications. This innovative shaft seal utilizes a mechanical face seal design to effectively prevent leaks and ensure reliable operation.

The Type A PSS Shaft Seal features a sealing surface formed between the smooth, flat surfaces of the rotating stainless-steel rotor and the stationary carbon flange. The carbon flange is securely attached to the front of the bellows using hose clamps, while the back end of the bellows fits snugly over the stern tube and is also secured in place. Positioned in front of the carbon flange, the stainless-steel rotor is tightly fitted onto the shaft. This assembly compresses the bellows before the rotor is fastened to the shaft with set screws, creating a pre-load that maintains consistent contact between the rotor and the flange surfaces. This design allows the PSS seal to accommodate the variable movement caused by propeller thrust.

Moreover, the carbon flange is designed to be over-bored to the shaft diameter, enabling it to “float” and thus effectively compensate for misalignment and vibrations. The stainless-steel rotor is sealed to the shaft using two O-rings that are recessed into the collar's bore. These O-rings rotate along with the shaft and rotor, ensuring minimal wear during operation.

Temperature Limits: 5°F to 225°F (-15°C to 107°C)
Pressure Limits: 15 PSI (1 BAR)
Shaft RPM Limits: 10,000 RPM
Carbon Graphite: Lapped to 4 HLB (0.000044" tolerance)
316SS / Nitronic 50: Faced to 9-12 Ra
Bellows Material: Molded Nitrile - PVC

Specifications:
Part #: 02-50M-212
Shaft Diameter (A): 50mm
Stern Tube Diameter (B): 4" to 4-1/8"
Approx. Length (C): 9.03"
Approx. Compression: 1"
Rotor Diameter (D): 3.75"
Stern Cuff Length (E): 2"