PSS 02-400-634 - Dripless Shaft Seal 4", 6 3/4" Stern Tube

PSS 02-400-634 - Dripless Shaft Seal 4", 6 3/4" Stern Tube

The PSS 02-400-634 Dripless Shaft Seal is designed to provide an effective sealing solution for stern tubes, ensuring optimal performance in various marine applications. This mechanical face seal features a robust construction that allows it to handle the dynamic conditions of propulsion systems.

The Type B PSS Shaft Seal employs a mechanical face seal where the sealing surface is formed between the flat surfaces of a rotating stainless-steel rotor and a stationary carbon flange. The carbon flange is securely attached to the front of the bellows using hose clamps, while the bellows itself fits over the stern tube, also secured with hose clamps. The stainless-steel rotor is mounted on the shaft in front of the carbon flange, compressing the bellows before being fastened to the shaft with set screws. This compression maintains consistent contact between the rotor and the flange, enabling the seal to adjust for any fore and aft movements caused by propeller thrust.

Moreover, the carbon flange is over-bored to the shaft diameter, allowing it to "float" and compensate for misalignment and vibration issues. The stainless-steel rotor is sealed to the shaft with two O-rings that are recessed into the collar's bore, which rotate with the shaft and rotor, ensuring minimal wear during operation.

Temperature Limits: -13°F to 425°F (-25°C to 220°C)
Pressure Limits: 50 PSI (3.5 BAR)
Shaft RPM Limits: 7,000 RPM
Carbon Graphite: Lapped to 4 HLB (0.000044" tolerance)
316SS / Nitronic 50: Faced to 9-12 Ra
Bellows Material: Mandrel formed silicone / fabric

Part #: 02-400-634
Shaft Diameter (A): 4"
Stern Tube Diameter (B): 6-3/4" to 6-7/8"
Approx. Length (C): 13.189"
Approx. Compression: 1" to 1-1/4"
Rotor Diameter (D): 7"
Stern Cuff Length (E): 2.5"