PSS 02-50M-400 - Dripless Shaft Seal 50 mm, 4" Stern Tube

PSS 02-50M-400 - Dripless Shaft Seal 50 mm, 4" Stern Tube

The PSS 02-50M-400 Dripless Shaft Seal is designed for reliable performance in marine environments. This mechanical face seal features a unique design that ensures a leak-free operation, making it an essential component for any stern tube system.

The Type A PSS Shaft Seal employs a mechanical face seal mechanism, where the sealing surface is formed between a rotating stainless-steel rotor and a stationary carbon flange. The carbon flange is securely mounted to the bellows, which is clamped at both ends: one end around the stern tube and the other securing the carbon flange. The stainless-steel rotor is attached to the shaft, compressing the bellows and maintaining constant contact with the carbon flange. This pre-load allows the seal to adjust for the shifting movements caused by propeller thrust, ensuring durability and efficiency.

The carbon flange is designed to float around the shaft, accommodating misalignment and vibrations, while the stainless-steel rotor is sealed to the shaft by two O-rings that rotate with it, preventing wear. The PSS 02-50M-400 operates effectively within a temperature range of 5°F to 225°F (-15°C to 107°C) and can handle pressures up to 15 PSI (1 BAR) with shaft RPM limits reaching 10,000 RPM.

Specifications include a shaft diameter of 50 mm, a stern tube diameter of 4" to 4-1/8", and an approximate length of 9.405". The rotor diameter is 3.75", with a stern cuff length of 2". The carbon graphite is finely lapped to 4 HLB, ensuring minimal tolerance, while the materials used include 316SS and Nitronic 50, faced to 9-12 Ra. The bellows are made from molded nitrile and PVC, ensuring flexibility and resilience.