PSS 02-120M-700 - Dripless Shaft Seal 120 mm, 7" Stern Tube

PSS 02-120M-700 - Dripless Shaft Seal 120 mm, 7" Stern Tube

The PSS 02-120M-700 is an advanced mechanical face seal designed to provide reliable performance in demanding marine environments. This innovative shaft seal features a unique construction that ensures a tight seal while accommodating the natural movement of the shaft.

The Type B PSS Shaft Seal utilizes 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 bellow using hose clamps, while the back end fits snugly over the stern tube, also secured with hose clamps. The stainless-steel rotor is mounted on the shaft in front of the carbon flange, and its compression of the bellow maintains continuous contact between the rotor and the flange. This pre-load feature allows the PSS to effectively adapt to any fore and aft movement caused by propeller thrust.

The carbon flange is designed with an over-bored configuration to the shaft diameter, enabling it to float around the shaft, which helps to mitigate misalignment and vibration issues. Sealing is enhanced by two O-rings recessed in the collar bore; these O-rings 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

Specifications:
Part #: 02-120M-700
Shaft Diameter (A): 120mm
Stern Tube Diameter (B): 7" to 7-1/8"
Approx. Length (C): 13.742"
Approx. Compression: 1" to 1-1/4"
Rotor Diameter (D): 7.875"
Stern Cuff Length (E): 2.5"