Type A Dripless Shaft Seal, 1" Shaft

The PYI Inc. 02-100-112 is a standard duty Type A dripless shaft seal engineered to provide a reliable, watertight mechanical face seal for marine vessels. It effectively prevents water intrusion through the stern tube where the propeller shaft exits, offering a significant upgrade from traditional, often dripping, flax packing systems. This seal is ideal for both sail and power boats. The PSS Type A seal operates by creating a sealing surface between a spinning stainless steel rotor, attached to the propeller shaft, and a stationary carbon-graphite stator collar, mounted to the stern tube. The flexible nitrile-PVC bellow presses the rotor against the stator, maintaining constant contact and compensating for shaft movement. This specific model is designed for a 1" propeller shaft diameter and a 1-1/2" to 1-5/8" stern tube diameter, with a total length of 6.975". It operates within temperature limits of 5°F to 225°F (-15°C to 107°C) and pressure limits of 15 PSI (1 BAR), with shaft RPM limits of 10,000 RPM. The carbon-graphite stator is lapped to a 4 HLB tolerance, and the stainless steel rotor is faced to 9 Ra. All shaft seals include a hose barb fitting on the carbon flange. This fitting can be used for venting trapped air on low-speed boats or for a cooling water feed on vessels exceeding 12 knots. For boats operating over 12 knots, a Water Pick-Up Hose Tee Kit, sold separately, is recommended for cooling water supply. On twin engine installations, it is crucial to link the cooling water plumbing between engines to ensure continuous lubrication for both seals if one engine is shut down while the other is at high speed. The product comes with a 3-year limited warranty and is certified by ABS, RINA, and Bureau Veritas.