PSS 02-434-734 - Dripless Shaft Seal 4 3/4", 7 3/4" Stern Tube

PSS 02-434-734 - Dripless Shaft Seal 4 3/4", 7 3/4" Stern Tube

The PSS 02-434-734 Dripless Shaft Seal is a high-performance mechanical face seal designed for marine applications. This innovative product ensures a reliable seal between the stainless-steel rotor and the carbon flange, providing exceptional protection against water ingress in stern tube environments.

The Type B PSS Shaft Seal features a unique design where the sealing surface is established between the flat surfaces of a rotating stainless-steel rotor and a stationary carbon flange. The carbon flange is securely attached to the bellows, which is clamped in place at both ends—one end over the stern tube and the other to the carbon flange. This setup allows the stainless-steel rotor, mounted on the shaft, to compress the bellows, ensuring continuous contact between the rotor and flange surfaces. This pre-loading mechanism accommodates the fore and aft movement caused by propeller thrust, maintaining an effective seal even under varying conditions.

Additionally, the carbon flange is designed with an over-bored shaft diameter, enabling it to "float" around the shaft. This feature compensates for misalignment and vibration, enhancing overall performance. The stainless-steel rotor is sealed to the shaft using two O-rings, which are recessed in the collar's bore and rotate with the shaft, preventing wear during operation.

Specifications:

• 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

Product Details:

• Part #: 02-434-734
• Shaft Diameter (A): 4-3/4"
• Stern Tube Diameter (B): 7-3/4" to 7-7/8"
• Approx. Length (C): 13.671"
• Approx. Compression: 1" to 1-1/4"
• Rotor Diameter (D): 7.875"
• Stern Cuff Length (E): 2.5"