PSS 02-120M-858 - Dripless Shaft Seal 120 mm, 8 5/8" Stern Tube

PSS 02-120M-858 - Dripless Shaft Seal 120 mm, 8 5/8" Stern Tube

The PSS 02-120M-858 Dripless Shaft Seal is designed for optimal performance in marine applications. This innovative mechanical face seal utilizes a unique construction to ensure a reliable and leak-free operation.

The Type B PSS Shaft Seal features a sealing surface formed between a rotating stainless-steel rotor and a stationary carbon flange. The carbon flange is securely attached to the front of the bellow with hose clamps, while the back of the bellow fits over the stern tube and is also secured with clamps. The stainless-steel rotor is mounted on the shaft in front of the carbon flange, compressing the bellow before being fastened with set-screws. This pre-load ensures constant contact between the flat faces of the rotor and flange, accommodating any forward and backward movement caused by propeller thrust.

Designed for flexibility, the carbon flange can "float" around the shaft, addressing misalignment and vibration issues. The rotor’s sealing mechanism includes two O-rings recessed into the collar bore, which rotate with the shaft and rotor, minimizing wear over time.

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 Tolerance: Lapped to 4 HLB (0.000044" tolerance)
• 316SS / Nitronic 50 Finish: Faced to 9-12 Ra
• Bellows Material: Mandrel formed silicone / fabric

Part Details:

• Part #: 02-120M-858
• Shaft Dia. (A): 120mm
• Stern Tube Dia. (B): 8-5/8" to 8-3/4"
• Approx. Length (C): 13.742"
• Approx. Compression: 1" to 1-1/4"
• Rotor Diameter (D): 7.875"
• Stern Cuff Length (E): 2.5"