PSS 02-140M-634 - Dripless Shaft Seal 140 mm, 6 3/4" Stern Tube

PSS 02-140M-634 - Dripless Shaft Seal 140 mm, 6 3/4" Stern Tube

The PSS 02-140M-634 is a high-performance dripless shaft seal designed for marine applications. This product ensures a reliable seal under varying conditions, preventing water from entering the stern tube while allowing for movement and flexibility.

The Type B PSS Shaft Seal operates as 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 side of the bellows with hose clamps, while the back end fits over the stern tube, also secured by hose clamps. The stainless-steel rotor mounts on the shaft in front of the carbon flange, compressing the bellows before it is fastened to the shaft with set screws. This pre-load ensures constant contact between the rotor and the flange, which compensates for any fore and aft movement caused by propeller thrust. The carbon flange is designed to be over-bored to the shaft diameter, allowing it to "float" and thus effectively address misalignment and vibration issues. The rotor is sealed to the shaft using two O-rings recessed into the collar's bore. These O-rings rotate with the shaft and rotor, ensuring minimal 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 Tolerance: Lapped to 4 HLB (0.000044" tolerance)
• 316SS / Nitronic 50 Finish: Faced to 9-12 Ra
• Bellows Material: Mandrel formed silicone / fabric

Part Specifications:

• Part #: 02-140M-634
• Shaft Diameter (A): 140 mm
• Stern Tube Diameter (B): 6-3/4" to 6-7/8"
• Approx. Length (C): 13.742"
• Approx. Compression: 1" to 1-1/4"
• Rotor Diameter (D): 7.875"
• Stern Cuff Length (E): 2.5"