Pro Shaft Seal

Shaft Retention Collar (SRC)

The Shaft Retention Collar is designed to help retain the propeller or rudder shaft in your vessel in the event of catastrophic failure of the coupling or if the shaft comes free from the coupling. The double split design provides the maximum axial holding power with quick and efficient assembly with the shaft installed. Design fully engages the shaft without marring. Easily installed where major disassembly would otherwise be required. Greater axial holding power than set screw or one-piece clamping collars. Effective on hard and soft shafts.

Rotor

The PSS stainless steel rotor is slid down the shaft and is secured to the shaft with set screws at 90° for maximum holding power. Precision tolerances are maintained by computer controlled lathes. The faces have a number 9 micro finish and are perpendicular to the bore to prevent run-out as the collar rotates. The carbon graphite stator will polish the face of the rotor during the first few minutes of operation. The stainless steel rotor should not need to be replaced under normal operating conditions. The stainless steel rotor used on the PSS Type A Shaft Seal is made from 316L stainless steel.

Carbon Stator

The high density, resin impregnated carbon/graphite stator is a composite that is first mixed, molded and then formed under pressure. The blanks are then baked, machined and lapped. The face of our carbon is finished to a flatness of 4 helium light bands (measured .000044" of variation over entire lapped surface). The grade of carbon used in the PSS has an operating temperature over 500° Fahrenheit (+260° Celsius), and cannot melt if the seal runs dry, unlike a rubber lip seal or plastic face seal. The high density of the carbon greatly increases the longevity and wear resistance. Several commercial vessels have recorded over 40,000 (over 4-1/2 years of continuous operation) engine hours on the same, original components. The carbon should not need to be replaced under normal operating conditions.

Bellows

The bellows on the PSS Pro Seal is constructed out of high temp silicone laminated with either 4 or 5 plies of polyester fabric (aramid in larger sizes) and covered with a layer of fluorosilicone. In addition, both ends of the bellows are sealed so no water can get in the polyester/Aramid fabric. The 4 or 5 fabric inlay provides excellent strength to abrasion and resistance to pressure without loading the silicone. On the larger models, the strength is greatly increased by using stainless steel hoops laid into the convolutions of the bellows.

Hose Barb

For high-speed vessels (planning hulls or vessels powering over 12 knots), it is required that a positive water supply be plumbed to the PSS Shaft Seal for lubricating and cooling the seal faces. There are many water supply sources; review the PSS Shaft Seal Installation Instructions for more information and note all plumbing must follow the standards and practices of proper boat plumbing. In most cases, a slow-speed boat with no bearing in the shaft log does not require positive water feed and can be "vented." Ideally, the vent line will be run at least 2-3 feet above the waterline and as close to the centerline as possible to ensure the vent hose is never below the water line, even if the boat heels. Again, review the PSS Shaft Seal Installation Instructions for more details on venting the seal.